FORCED-CIRCULATION AIR-COOLING AND AIR …ahrinet.org/App_Content/ahri/files/Certification/OM...

Certification Program for

FORCED-CIRCULATION AIR-COOLING AND AIR-HEATING COILS

OPERATIONAL MANUAL

APRIL 1981

ADDENDUM

Administered by

AIR-CONDITIONING AND REFRIGERATION INSTITUTE

4100 North Fairfax Dr. Suite 200 Arlington VA 22203

FOREWORD

This addendum to Operational Manual, OM-410, contains copies of forms needed for

participation in the ARI Certification Program for Forced-Circulation Air-Cooling and

Air-Heating Coils.

Participants can obtain a supply of these forms by sending a request to:

Director of Engineering

Air-Conditioning and Refrigeration Institute

4100 NORTH FAIRFAX DRIVE, SUITE 200 Χ ARLINGTON, VIRGINIA 22203

TABLE OF CONTENTS

FORM TITLE

CHC-C2B...................................................................Acceptance of Certification

CHC-C2 .....................................................................Request for Approval of Laboratory

410-1 ..........................................................................Calculation Procedure to Determine Fin Efficiencies and Metal Thermal Resistances

410-2 ..........................................................................Calculation of Air-Side Resistances from Steam and Water Coil Tests

410-3 ..........................................................................Calculation of Tube-Side Pressure Drops from Steam and Water Tests

410-4 ..........................................................................Calculation of Refrigerant-Side Thermal Resistances from Volatile Refrigerant Coils Tests

410-5 ..........................................................................Suggested Form for Rating Calculation Procedure for Sensible Heat Air Coils

410-6 ..........................................................................Suggested Form for Rating Calculation Procedure for Cooling and Dehumidifying Coils

410-7 ..........................................................................Calculation of Heat Transfer Coefficient and Friction Factor for Ethylene Glycol Coils

410-8 ..........................................................................Suggested Form for Rating Calculation Procedure for Sensible Heat Air Coils with Ethylene Glycol Solutions

410-9 ..........................................................................Suggested Form for Rating Calculation Procedure for Cooling and Dehumidifying Coils with Ethylene Glycol Solutions

CHC-CF1 ...................................................................Production Coil Line Certification

HCC-2&3-M..............................................................Report of Manufacturer's Shipments

EX-2-Q.......................................................................Report of Total Export Shipments

ACCEPTANCE OF CERTIFICATION

ARI CERTIFICATION PROGRAM FOR FORCED-CIRCULATION AIR-COOLING AND AIR-HEATING COILS

PARTICIPANT ________________________________________________________ DATE ___________________ Data submitted with respect to coil lines listed below have been accepted and these coils lines are hereby released for certification. Data relating to these coil lines as agreed upon by the ARI Air-Heating and Air-Cooling Coils Sub Section of Air-Conditioning Heat Transfer Products Section will be published in the next issue or supplement of the Directory of Certified Applied Air-Conditioning Products and will continue in succeeding issues until the coil line is withdrawn from manufacture, or until the data is withdrawn for any reason as set forth in the License Agreement. You are authorized to apply the Certification Symbol to coils of these coil line, and to display the Certification Symbol on specification sheets or other literature pertaining to the listed coil lines, as specified in the License Agreement. Issue Coil Fluid (s) Catalog Date Type Used Number (or Code) Trade of Brand Names (s): ________________________________________________

SIGNED____________________________ Engineer

For ARI Use Only: Submitted: ________________ Prepared by: ______________ Typed by: ________________ Proofed by: _______________ Listed: ___________________ By: ______________________

REQUEST FOR APPROVAL OF LABORATORY TO TEST

FORCED-CIRCULATION AIR-COOLING AND AIR-HEATING COILS


We, the undersigned, hereby request the Air-Conditioning and Refrigeration Institute to approve our laboratory, located at for the purpose of testing Forced-Circulation Air-Cooling and Air-Heating Coils to qualify for ARI Certification. We certify that all testing will be done according to the testing codes and certified Rating Programs approved by ARI. Accompanying this request is the following information: ________________________________________________________________________________________

Company By ___________________________________________ By_______________________________________ Officer Chief Engineer or Laboratory Director ______________________________________________ Date _____________________________________ Title ______________________________________________ Date

Form CHC-C2 The above requirement for a laboratory has been met by the requesting company in regard to instruments, equipment and laboratory. This laboratory is hereby given general approval to conduct precertification check tests.


By _____________________________________________ Director of Engineering

Date ____________________________________________

This laboratory has satisfactorily met the requirements of the precertification check test and is hereby approved for testing and rating air-cooled and air-heating coils in accordance with ARI Standard 410-81, subject to withdrawal if the quality of the laboratory is not maintained.


By _________________________________________________ Director of Engineering

Date ________________________________________________

Form CHC-C2

CALCULATION PROCEDURE TO DETERMINE FIN EFFICIENCIES AND METAL THERMAL RESISTANCES


COMPANY ___________________________________________________ DATE _____________________________

ITEM NO.

GENERAL DESCRIPTION AND CALCULATION PROCEDURE

(Encircled items refer to preceding item numbers)

DIMENSIONS NUMERICAL VALUE

1 Fin Type and Thickness Profile --

2 As - Secondary Surface Area (See Par. 3.9.3, ARI

sq ft [m2]

Standard 410)

3 Ap - Primary Surface Area (See Par. 3.9.3, ARI Standard 410)

sq ft [m2]

4 Ao - Total External Coil Surface

Area = ( ν2ο + ν3ο )

sq ft [m2]

5 Di - Tube Inside Diameter in. [mm]

6 Nt - Total Number of Tubes in Coil --

7 Lt - Fin Tube Length in. [mm]

8

Ai - Total Internal Coil Surface

Area = 84.45

765 ⟩⟨⟩⟨⟩⟨ ⎥⎦

⎤⎢⎣

⎡ ⟩⟨⟩⟨⟩⟨=

344,318765

A i

sq ft [m2]

9 B - Surface Ratio = ν4ο / ν8ο --

10 Df - Spiral Fin Outside Diameter in. [mm]

*11 Lf - Fin Length Perpendicular to Direction of Tubes in. [mm]

*12 Ld - Fin Depth in Direction of Air Flow in. [mm]

⟩⟨⟩⟨⟩⟨

6x12x11

π

π⟩⟨⟩⟨ 12x11

*For non-circular shaped fins only Sheet 1 of 5 Form 410-1

ITEM NO.




13 xe - Outside Radius of Equivalent Annular Area of Non- Circular Fin or of Annular or Spiral Fin

xe = - for con- tinuous

in.

[mm]

plate fin

xe = for in- dividu- ally finned tube xe = ν10ο / 2 - for spiral fin

14 Do - Tube Outside Diameter in. [mm]

15 Yf - Fin Thickness for Fin of Uniform Thickness

in. [mm]

16 xo - Fin Root Radius

xo = ν14ο + ν15ο - for plate 2 type fins with collars not touching adjacent fins

xD = ν14ο + 2 ν15ο - for plate 2 type fins

with collars touching adjacent fins

xo = ν14ο - for plate type 2 fins without collars and spiral fins

in.

[mm]

Form 410-1

ITEM NO.




17 w - Height of Equivalent or of Actual Annual Fin

w = ν13ο - ν16ο

in. [mm]

18 xe/xo - Radius Ratio of Equivalent Annular Fin

= ν13ο / ν16ο

--

19 kf – Fin Material Thermal Conductivity (See Table 2, ARI Standard 410)

Btu per (hr) (sq ft) (F) / (ft) [W≅mm/m2≅ΕC]

20 kt – Tube Material Thermal Conductivity (See Table 2, ARI Standard 410)

Btu per (hr) (sq ft) (F) / (ft) [W≅mm/m2≅ΕC]

21 Yr - Fin Thickness at Root of Spiral Fins

in. [mm]

22

R1D - for Dry Surface Coils

RaW ⎥⎦⎤

⎢⎣⎡

"moc - for Wet Surface Coils

Note: Arbitrarily assume various values, covering application ratings

(hr) (F) (sq ft) per Btu

[m2≅ΕC/W]

23

fa - Air-Side Film Heat Transfer Coefficient

Where: faD = 1/ ν22ο - for Dry Surface Coils

faW = 1/RaW ⎥⎥⎦

⎤

⎢⎢⎣

⎡

pc"m

for Wet Surface Coils

Btu per (hr) (sq ft) (F)

[W/m2 ≅ ΕC]

24

Fin Efficiency Parameter

for plate-type fins

for spiral fins

--

ITEM NO.




25 ∅Ø - Mean Fin Efficiency (See Figs. 10 and 11)

--

⟩⟨⟩⟨⟩⟨

⟩⟨=15x19x6

2317⎥⎥⎦

⎤

⎢⎢⎣

⎡

⟩⟨⟩⟨⟩⟨

⟩⟨=15x19

23x217

⎥⎥⎦

⎤

⎢⎢⎡

⟨2

⎣ ⟩⟨⟩⟨⟩⟨

⟩=21x19

23x17⟩⟨⟩⟨

⟩⟨⟩⟨=

21x19x62317

26 η 0 - Total Surface Effectiveness

= ( ν25ο x ν2ο ) + ν3ο

ν4ο

--

27

Rf – Thermal Resistance of Fin Based on Total Surface Effectiveness

= ⎥⎦

⎤⎢⎣

⎡⟩⟨⎥

⎦

⎤⎢⎣

⎡⟩⟨

⟩⟨−231

26261

(hr) (sq ft) (F) per Btu

[m2 ≅ ΕC/W]

28

Rt – Thermal Resistance of Tube

⎥⎦

⎤⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨⟩⟨

⟩⟨⟩⟨⟩⟨

=⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨⟩⟨

⟩⟨⟩⟨⟩⟨

=5

14Ln202

595

14Ln202459


[m2 ≅ ΕC/W]

29 RmD - Total Metal Resistance of Fin and Tube

= ν27ο + ν28ο


[m2 ≅ ΕC/W]

30

RaD + RmD - Combined Air Film Plus Metal Thermal Resistance for Dry Surface Coils = ν22ο + ν29ο


[m2 ≅ ΕC/W]

31 Plot (RaD + RmD) vs RaD ( ν30ο) vs

ν22ο ) on rectilinear coordinates, as shown in Fig. 1

-- -- -- -- --

32 Plot RaD vs fa ( ν29ο vs ν23ο) on on rectilinear coordinates, as shown in Fig. 2

-- -- -- -- --

SIGNED ______________________________________________ TITLE ____________________________________ NOTE: Alternate Method to Determine Mean Fin Efficiency by Fin Segmentation

A more accurate, but more involved, method of calculating ∅ and Rf for non-circular shaped fins is described as Method (2), pages 313-315 in Reference A9 of ARI Standard 410. The mean values of ∅, as determined by this alternate method, will be somewhat lower than those calculated by the simpler, equivalent annular area method given in the above procedure.

For non-circular fin designs of large size, in combination with thin, low thermal conductivity fin material, this alternate method is recommended. The difference in ∅, as calculated by the two methods, also becomes greater as the fin becomes more oblong. If this alternate method is used, it is recommended that the fin efficiency, ∅, for each of the individual fin sectors be based on data by K. A. Gardner (Reference A8 of ARI Standard 410), rather than that given in Reference A9.

Where this alternate method is used, please include all necessary information and calculations and attach them to this form.

CALCULATION OF AIR-SIDE RESISTANCES FROM STEAM AND WATER COIL TESTS


COMPANY ____________________________________________________________________ DATE _______________________________

COIL LINE __________________________________ COIL TYPE ______________________

COIL SURFACE ________________________________________________________________ SOLUTION PROCEDURE STEPS FOR SPECIFIC COIL APPLICATION

GENERAL PROCEDURE WATER COILS

STEAM COILS

DR

Y

SU

RFA

CE

FU

LLY

- W

ETTE

D

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.

ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

1 1 1 1

AO - Total External Coil Surface (See Form 410-1)

sq ft [m2]

2 2 2 2 Di - Tube Inside Diameter (See Form 410-1)

in. [mm]

3 3 3 3 B - Surface Ratio (See Form 410-1)

--

- 4 4 4 Nc - Number of Tube Circuits in Coil

--

- 5 5

CO

IL P

HY

SIC

AL

DA

TA

5

Aix - Total Cross-Sectional Fluid Flow Area Inside Tubes = 0.00545 (ν2ο) 2 x ν4ο [Aix] = 7.85 x 10 –7 (ν2ο) 2 x ν4ο]

sq ft [m2]

4 6 6 6 Nr - Coil Depth in Rows --

-- 6a 6a

6a Ls - Straight Tube Length Per Tube Pass in. [mm]

Sheet 1 of 12 Form 410-

SOLUTION PROCEDURE

STEPS FOR SPECIFIC COIL APPLICATION

GENERAL PROCEDURE NUMERICAL VALUES

WATER COILS TEST RUN NUMBER

STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

5 7 7 7 pS - Average Absolute Static Pressure at Test Coil

IN. Hg abs [Kpa abs]

- 8 8 8 tl - Entering Air Dry-Bulb Temperature F [ΕC]

- 9 9 9 'lt - Entering Air Wet-Bulb Temperature F [ΕC]

- - 10 10 hl - Entering Air Enthalpy Btu per lb dry air

[KJ/Kg]

6 9 - 11 t2 - Leaving Air Dry-Bulb Temperature F [ΕC]

- - 11 12 h2 - Leaving Air Enthalpy Btu per lb dry air

[KJ/Kg]

- 10 12 13 twl - Entering Water Temperature F [ΕC]

- 11 13 14 tw2 - Leaving Water Temperature F [ΕC]

- 12 14 15 ww - Rate of Water Flow lb per hr [g/s]

7 - - 16 tvm - Mean Saturated Steam Temperature in Coil Circuit

F [ΕC]

8 13 - 17 qs - Average Sensible Heat Capacity Btuh [W]

- - 15 18 qr - Average Total Heat Capacity Btuh [W]

9 14 16 19 va - Standard Air Face Velocity ft per min [m/s]

- 15 17 20 twm - Mean Water Temperature Inside Tubes = 0.5 (ν13ο) + (ν14ο)

F [ΕC]

10 16 - 21 )Pst - Isothermal Dry Surface Air-Side Friction at Standard Conditions

in. water [Pa]

- - 18

LAB

OR

ATO

RY

TES

T O

BSE

RV

ATI

ON

AN

D C

ALC

ULA

TIO

NS

OB

TAIN

ED F

RO

M

ASH

RA

E ST

AN

DA

RD

33-

78, F

OR

MS

33TD

-1, -

2, -3

22 )Psw - Wet Surface Air-Side Friction at Standard Conditions

in. water [Pa]

Sheet 2 of 12 Form 410-2

SOLUTION PROCEDURE STEPS FOR SPECIFIC COIL APPLICATION



STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

- 17 19 23 qS/qt - Sensible Heat Ratio = ν17ο / ν18ο If << 0.95, coil surface is all wet or partially dry.

If ≥≧ 0.95, coil surface is fully dry.

--

- 18 20 24 Vw - Average Standard Water Velocity

Inside = ν15ο Tubes 224,500 x ν5ο

ft per sec

[m/s]

11 19 -

CA

LCU

LATI

ON

S D

ETER

MIN

E H

EAT

TRA

NSF

ER

CO

EFFI

CIE

NTS

FO

R U

SE IN

APP

LIC

ATI

ON

RA

TIN

GS

25 )tm - Logarithmic Mean Temperature Differ- ence between Air and Heating or Cooling Fluid

⎥⎦

⎤⎢⎣

⎡⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨=

1116816In

811 - For Steam Coils

⎥⎦

⎤⎢⎣

⎡⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨=

1311148In

)1311()148(

For Thermal Counterflow Water Coils If other than thermal counterflow, determine logarithm mean temperature difference from Flgs. 13, 14 or 15.

F

[ΕC]

Form 410-2

⎥⎦

⎤⎢⎣

⎡⟩⟨

⟩⟨=

5x000,000,115v w




STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

12 20 - 26 R - Overall Thermal Resistance Between Air and Heating or Cooling Fluid = ν1ο x ν25ο ν17ο


[m2 ≅ ΕC/W]

13 - - 27 Plot R vs Va on logarithmic coordinates as shown in Fig. 3. This curve is used in obtaining steam coil application ratings.

-- -- -- -- --

- 21 21 28


[W/m2 ≅ ΕC]

* 22 22

CA

LCU

LATI

ON

S TO

DET

ERM

INE

HEA

T TR

AN

SFER

C

OEF

FIC

IEN

TS F

OR

USE

IN A

PPLI

CA

TIO

N R

ATI

NG

S

29 Tube-Side Film Thermal Resistance

Rv = ν3ο /2000 - For Steam [Rv = 3 /11364]

Rw = ν3ο/28n - For Cold and Hot Water


[m2 ≅ ΕC/W]

* These items apply when steam coil tests are used to determine RaD for hot water ratings.

Form 410-2

SOLUTION PROCEDURE




STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

-- 21a 21a 28a Cpw – Specific Heat of Water – at ν20ο Btu/lb Α ΕF [KJ/kg Α ΕC]

-- 21b 21b 28b kw – Thermal Conductivity of Water – at ν20ο Btu

? Α ft Α ΕF [w/m Α ΕC]

-- -- -- --

-- 21c 21c 28c Φw – Absolute Viscosity of Water – at ν20ο

lb/? Α ft [mPa Α s]

-- 21d 21d 28d ttw – Average Tube Wall Temperature (Assumed) For chilled water coils, initially assume ttw is 5ΕF to 10ΕF greater than ν20ο

ΕF [ΕC]

-- 21e 21e 28e Φtw – Absolute Viscosity of Water – at ν28dο lb/? – ft [mPa Αs]

-- 21f 21f 28f Gw – Mass Velocity of Water = ν15ο/ν5ο lb/? – ft2

[g/s Α m2]

-- 21g 21g 28g Raw – Reynolds Number for Water = ν2ο x ν28fο 12 x ν28cο

--

-- 21h 21h 28h Ls/D: = Ratio of Tube Length to Diameter = ν6aο ν2ο

--

-- 21i 21i

CA

LCU

LATI

ON

S TO

DET

ERM

INE

HEA

T TR

AN

SFER

C

OEF

FIC

IEN

TS F

OR

USE

IN A

PPLI

CA

TIO

N R

ATI

NG

S

28i Jw - Colburn Heat Transfer Factor for Water from Fig. 17 using ν28gο and ν28hο 9or calculate from equation ? on Fig. 17)

--

SOLUTION PROCEDURE




STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

-- 21j 21j 28j Prw – Prandtl Number for Water = ν28aο x ν28cο ν28bο

--

-- 21k 21k 28k Prw2/3 = ν28jο 2/3 --

-- 21l 21l 28l (:tw/:w) Α14 – Viscosity Ratio = (ν28eο/ν28cο) Α14 --

-- 21m 21m 28m Stw = Stanton Number for Water = ν28jο ν28kο x ν28lο

--

-- 21n 21n 28n fw = Film Heat Transfer Coefficient for Water = ν28mο x ν28aο x ν28fο

Btu/? Α ft2 Α ΕF [w/m2 Α ΕC]

-- 23a -- 30a ttw ⟨ Average Tube Wall Temperature (calculated) For chilled Water Coils = ν20ο + ν25ο ν29ο ν29ο + ν30ο ν30aο must equal ν28dο within ∀ 10ΕF [∀5.6C], if not assume a new value for ν28dο and repeat calculations thru ν30aο

ΕF [ΕC]

-- -- 28a

CA

LCU

LATI

ON

S TO

DET

ERM

INE

HEA

T TR

AN

SFER

C

OEF

FIC

IEN

TS F

OR

USE

IN A

PPLI

CA

TIO

N R

ATI

NG

S

37a ttw Average Tube Wall Temperature (calculated) For chilled Water Coils = ν20ο + ν29ο (ν37ο - ν20ο) ν29ο + ν34ο ν37aο must equal ν28dο within ∀ 10ΕF [∀5.6C], if not assume a new value for ν28dο and repeat calculations thru ν30aο

ΕF [ΕC]

Form 410-2


GENERAL PROCEDURE

TO SOLVE FOR ROWS DEEP

(Nr)

TO SOLVE FOR CAPACITY

(qs)

STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.

ITEM DESCRIPTION (Encircled items refer to preceding item numbers)

DIMENSIONS NUMERICAL

VALUES

-- 23a -- 23a

30a Cpw – Specific Heat of Water at ν28ο Btu/lb Α ΕF [KJ/kg Α ΕC]

-- 23b -- 23b 30b kw -- Thermal Conductivity of Water at ν28ο Btu h Α ft Α ΕF [w/m Α ΕC]

-- 23c -- 23c 30c Φw – Absolute Viscosity of Water at ν28ο lb/h Α ft [mPa Α s]

-- 23d -- 23d 30d ttw – Average Tube Wall Temperature (assumed) - For chilled water coils, initially assume ttw is 5ΕF to 10ΕF greater than ν28ο - For hot water coils, initially assume ttw is 10ΕF to 20ΕF less than ν28ο

ΕF [ΕC]

-- 23e -- 23e 30e Φtw = Absolute Viscosity of Water – at ν30dο lb/h Α ft [mPa Αs]

-- 23f -- 23f 30f Gw – Mass Velosity of Water = ν29ο/ν11ο lb/h – ft2

[g/s Α m2]

-- 23g -- 23g 30g Raw – Reynolds Number for Water = ν10ο x ν30fο 12 x ν30cο

--

23h -- 23h 30h Ls/D: = Ratio of Tube Length to Diameter = ν12ο ν10ο

--

-- 23i -- 23i

WA

TER

RA

TIN

G P

AR

AM

ETER

S

30i Jw – Colburn Heat Transfer Factor for Water from Fig. 17 using ν30gο and ν30hο (or calculate from equation ? on Fig. 17)

--

Form 410-5

SOLUTION PROCEDURE


GENERAL PROCEDURE


(Nr)


(qs)

STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.



VALUES

-- 23j -- 23j

30j Prw – Prandtl Number for Water = ν30aο x ν30cο ν30bο

--

-- 23k -- 23k 30k Prw 2/3 - = (ν30jο) 2/3 --

-- 23l -- 23l 30l (Φtw/Φw) .14 – Viscosity Ratio = (ν30eο/ν30cο) .14 --

-- 23m -- 23m 30m Stw – Stanton Number for Water = ν30iο ν30kο x ν30lο

--

-- 23n -- 23n 30n fw = Film Heat Transfer Coefficient for Water = ν30mο x ν30aο x ν30fο

Btu/h – ft2 - ΕF [w/m2 Α ΕC]

-- 24 -- 24

WA

TER

RA

TIN

G P

AR

AM

ETER

S

31 Rw – Water Film Thermal Resistance = ν4ο/ν30nο h Α ft2 Α ΕF/Btu [m2 Α Εc/w]

-- -- -- 35a

CA

LCU

LATI

ON

S TO

S

OLV

E FO

R C

OIL

C

APA

CIT

Y (q

s)

42a ttw = Average Tube Wall Temperature (Calculated) For chilled water coils ≅ ν28ο + ν31ο x ν39ο ν33ο x ν35ο For hot water coils ≅ ν28ο - ν31ο x ν39ο ν33ο x ν35ο ν42aο must equal ν30dο within ∀ 10 ΕF [∀5.6 ΕC] for chilled water coils and ∀20 ΕF [∀11.1 ΕC] for hot water coils. If not, assume a new value for ν30dο and repeat calculations thru ν42aο

ΕF [ΕC]

SOLUTION PROCEDURE




STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

* 23 - 30 RaD + RmD - Combined Air Film Plus Metal Thermal Resistance

= ν26ο - ν29ο

Plot ν30ο vs ν19ο on logarithmic coordinates as shown in Fig. 4. This curve is used in obtaining application ratings for all sensible heat coils except steam coils.


[m2 ≅ ΕC/W]

* 24 ¤23 31 RaD – Air Film Thermal Resistance for Dry

Surface (From Fig. 1, knowing ν30ο )


[m2 ≅ ΕC/W]

* 25 - 32 Plot RaD vs Va on logarithmic coordinates as shown in Fig. 4. This curve is used in obtaining application ratings for all sensible heat coils except steam coils.

-- -- -- -- --

- 26 24 33 faD – Air-side Heat Transfer Coefficient 1 1 for Dry Surface = = RaD ν31ο


[W/m2 ≅ ΕC]

- - 25

CA

LCU

LATI

ON

S TO

DET

ERM

INE

HEA

T TR

AN

SFER

C

OEF

FIC

IEN

TS F

OR

USE

IN A

PPLI

CA

TIO

N R

ATI

NG

S

34 RmD – Total Metal Thermal Resistance of Fin and Tube (Assuming dry surface, obtain from Fig. 2 with ν33ο)


[m2 Α ΕC/W]

* These items apply when steam coil tests are used to determine RaD for hot water ratings.

¤ For fully-wetted coils, read value of RaD from Fig. 4 as determined from dry coil tests.

SOLUTION PROCEDURE




STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

- - 26 35 hm - Mean Air Enthalpy = 0.5 (ν10ο + ν12ο)

Btu per lb dry air

[KJ/Kg]

- - 27 36 C - Approximate Coil Characteristic

ν29ο + ν34ο = 0.243 ν31ο

(lb) (F) per Btu

[Kg ≅ ΕC/KJ]

- - 28 37 tsm - Approximate Mean Coil Surface

Temperature (From Fig. 9 with ν20ο , ν35ο , and ν36ο)

F

[ΕC]

- - 29 38 pc/"m -Approximate Air-Side Heat Transfer Multiplier for Wet Surface Coils

(From Fig. 8 with ν7ο and ν37ο)

--

- - 30 39 RaW - Air Film Thermal Resistance for Wet Surface Note: Assume this value for trial and error solution. Suggest initial value be same as ν31ο.


[m2 ≅ ΕC/W]

- - 31 40 faW - Approximate Air-Side Heat Transfer Coefficient for Wet Surface = ν38ο / ν39ο


[W/m2 ≅ ΕC]

- - 32

CA

LCU

LATI

ON

S TO

DET

ERM

INE

HEA

T TR

AN

SFER

C

OEF

FIC

IEN

TS F

OR

USE

IN A

PPLI

CA

TIO

N R

ATI

NG

S

41 RmW - Total Metal Thermal Resistance of Fin and Tube for Wet Surface (From Fig. 2 with ν40ο)


[m2 Α ΕC/W]

⎥⎦

⎤⎢⎣

⎡⟩⟨⟩⟨+⟩⟨

=31018.1

3429C

SOLUTION PROCEDURE




STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

- - 33 42 ν29ο + ν41ο C - Coil Charasteric = 0.243 ν39ο

(lb) (F) per Btu

[Kg ≅ ΕC/KJ]

- - 34

CA

LCU

LATI

ON

S TO

DET

ERM

INE

HEA

T TR

AN

SFER

C

OEF

FIC

IEN

TS F

OR

USE

IN A

PPLI

CA

TIO

N R

ATI

NG

S

43 "lt - Entering Air Dew Point Temperature

(From Psychrometric Chart with ν7ο, ν8ο, and ν9ο)

Calculation of Dew Point Temperature for Nonstandard Air Pressure* Where: ps = Air Pressure -------- p = Saturation Vapor

' Pressure at t l

from Steam Tables------------ p v = Saturation Vapor Pressure at Dew Point Temperature-----

F

[ΕC]

in. Hg abs

[Kpa abs]

⎥⎦

⎤⎢⎣

⎡⟩⟨⟩⟨+⟩⟨

=1

C39018.4129

⎥⎥⎦

⎤

⎢⎢⎣

⎡

−−−

−=t44.12830

)tt()'pp('pp

'l1s

v

⎥⎥⎦

⎤

⎢⎢⎣

⎡

⎥⎥⎦

⎤

⎢⎢⎣

⎡

−

−−−= '

l

'l1s

v t33.14.1548)tt()'pp(

'pp

Jordon & Priester, Refrigeration and Air Conditioning. 2nd Edition, 1956

SOLUTION PROCEDURE




STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

= Dew Point Temperature Is "

lt Saturation Temperature Corresponding to Saturation Vapor Pressure, pv, from Stream Tables ----

F [ΕC]

- - 35 44 tsl - Coil Surface Temperature on Entering Air Side (From Fig. 9 with ν10ο, ν14ο, and ν42ο unless ν7ο varies more than ∀0.3 in. Hg [∀1.014 Kpa] from 29.92 in. Hg [101.325 Kpa]. If it does, then determine ts1 by trial and error using equation:

ts1 = tw2 + C (h1 - hs1) .

Correct h 2l for ν7ο and use ν10ο , ν14ο, and ν42ο. For fully wetted coil, ν43ο ≧ ν44ο. If ν43ο < ν44ο, coil is partially wet and calculation procedures may be determined from Form 410-6.)

F

[ΕC]

- - 36

CA

LCU

LATI

ON

S TO

DET

ERM

INE

HEA

T TR

AN

SFER

C

OEF

FIC

IEN

TS F

OR

USE

IN A

PPLI

CA

TIO

N R

ATI

NG

S

45 hs1 - Saturated Air Enthalpy at ν7ο and ν44ο

Btu per lb dry air

[KJ/Kg]


GENERAL PROCEDURE


(Nr)


(qs)

STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.



VALUES

-- 35a -- --

50a ttw – Average Tube Wall Temperature (Calculated) For chilled water coils ν28ο + ν31ο x ν44ο ν33ο x ν50ο For hot water coils ν28ο - ν31ο x ν44ο ν33ο x ν50ο ν50aο must equal ν30dο within ∀ 10ΕF [5.6ΕC] for chilled water coils and ∀ 20ΕF [11.1ΕC] for hot water coils. If not, assume a new value for ν30dο and repeat calculations thru ν50aο

ΕF

[ΕC]

CA

LCU

LATI

ON

S TO

SO

LVE

FOR

RO

WS

DEE

P

-


GENERAL PROCEDURE

COLD WATER COILS

VOLATILE REFRIGERANT

COILS

PAR

TIA

LLY

W

ET

SUR

FAC

E

FULL

Y

WET

SU

RFA

CE

PAR

TIA

LLY

W

ET

SUR

FAC

E

FULL

Y

WET

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

31a 31a - - 47a Cpw - Specific Heat of Water - at ν46ο Btu/lb ≅ ΕF [KJ/kg ≅ ΕC]

31b 31b - - 47b kw - Thermal Conductivity of Water – at ν46ο Btu h ≅ ft ≅ ΕF [w/m ≅ ΕC]

31c 31c - - 47c Φw - Absolute Viscosity of Water – at ν46ο lb/h ≅ ft [mPa ≅ s]

31d 31d - - 47d ttw - Average Tube Wall Temperature (assumed) - For chilled water coils, initially assume ttw is 5ΕF to 10ΕF greater than ν46ο

ΕF [ΕC]

31e 31e - - 47e Φtw - Absolute Viscosity of Water – at ν47dο lb/h ≅ ft [mPa ≅ s]

31f 31f - - 47f Gw - Mass Velosity of Water = ν32ο/ν13ο lb/h ≅ ft2

[g/s ≅ m2]

31g 31g - - 47g Raw - Reynolds Number for Water = ν9ο x ν47fο ν12ο x ν47cο

- -

31h 31h - - 47h Ls/D1 = Ration of Tube Length of Diameter = 10 9

- -

31i 31i - -

CA

LCU

LATI

ON

S TO

SO

LVE

FOR

RO

WS

DEE

P

47i jw - Colburn Heat Transfer Factor for Water from Fig. 17 using ν47gο and ν47hο (or calculate from equation above on Fig. 17)

- -


GENERAL PROCEDURE

COLD WATER COILS


COILS

PAR

TIA

LLY

W

ET

SUR

FAC

E

FULL

Y

WET

SU

RFA

CE

PAR

TIA

LLY

W

ET

SUR

FAC

E

FULL

Y

WET

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.



VALUES

31j 31j - - 47j Prw - Prandtl Number for Water = ν47aο x ν47cο ν47bο

--

31k 31k - - 47k Prw 2/3 = (ν47jο) 2/3 --

31l 31l - - 47l (Φtw/Φw) .14 - Viscosity Ratio = (ν47eο/ν47cο) .14 --

31m 31m - - 47m stw = Stanton Number for Water = ν47Iο ν47kο x ν47lο

--

31n 31n - -

RA

TIN

G C

ON

DIT

ION

S &

DA

TA C

OM

PUTA

TIO

NS

47n fw = Film Heat Transfer Coefficient for Water = ν47mο x ν47aο x ν47fο

Btu/h ≅ ft2 ≅ ΕF [w/m

2 ≅ ΕC]

36a 36a - - 52a hm - Mean Air Enthalpy ≅ (ν26ο + ν30ο)/2 Btu/lb [KJ/Kg]

36b 36b - - 52b tsm - Mean Surface Temperature from Fig. 9 using ν52aο, ν52ο and ν46ο

ΕF [ΕC]

36c 36c - -

RA

TIN

G P

AR

AM

ETER

S

52c ttw - Average Tube Wall Temperature (Calculated) ≅ ν46ο + ν48ο (ν52bο - ν46ο) ν48ο + ν51ο

ν52cο must equal ν47dο within ∀ 10ΕF [∀5.6 ΕC], if not assume a new value for ν47dο and repeat calculations thru ν52cο

ΕF [ΕC]


GENERAL PROCEDURE

COLD WATER COILS


COILS

PAR

TIA

LLY

W

ET

SUR

FAC

E

FULL

Y

WET

SU

RFA

CE

PAR

TIA

LLY

W

ET

SUR

FAC

E

FULL

Y

WET

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.



VALUES

32 32 42 42 R

ATI

NG

CO

ND

S A

ND

DA

TA

CO

MPU

TATI

ON

S 48 Tube-Side Thermal Resistance

Rw = ν4ο/ν47nο For Water Coils

Rr - From Fig. 6 with ν45ο for Volatile Refrigerant Coils


[m2 ≅ ΕC/W]

33 33 43 43 49 RaD - Air Film Thermal Resistance for Dry Surface

(From Fig. 5 or 6 with ν16ο)


[m2 ≅ ΕC/W]

34 34 44 44 50 RaW - Air Film Thermal Resistance for Wetted

Surface (From Fig. 5 or 6 with ν16ο)


[m2 ≅ ΕC/W]

35 35 45 45

RA

TIN

G P

AR

AM

ETER

S

51 RmD - Metal Thermal Resistance for Dry Surface

(From Fig. 2 at fa = 1/ν49ο)


[m2 ≅ ΕC/W]

36 36 46 46 52 Approximate Coil Characteristic = ν48ο + ν51ο 0.243 x ν50ο

⎥⎦

⎤⎢⎣

⎡⟩⟨⟩⟨+⟩⟨

=50x018.15148

Note: This approximate coil characteristic is used to obtain

RmW in ν63ο .

(lb) (F) per Btu

[Kg ≅ ΕC/KJ]

SOLUTION PROCEDURE




STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

- - 41 50 Assume other values for ν39ο and repeat procedure through

ν49ο. Plot values of ν49ο vs ν39ο as shown in Fig.

12a. Two or more points shall be plotted so that Ao lies

between calculated values of Ac .

- - - - - -

- - 42

CA

LCU

LATI

ON

S TO

DET

ERM

INE

HEA

T TR

AN

SFER

C

OEF

FIC

IEN

TS F

OR

USE

IN

APP

LIC

ATI

ON

RA

TIN

GS

51 RaW - Air Film Thermal Resistance for Wet Surface

The point on the curve (Fig. 12a) as plotted in ν50ο ,

where Ac = Ao determines the RaW value which cor-

responds to ν19ο.


[m2 ≅ ΕC/W]

- - 43 52 Plot RaW vs Va (ν51ο vs ν19ο) on logarithmic coordinates

as shown in Figs. 5 and 6.

If the RaW curve is within ∀5 percent of the RaD curve,

RaD may be used to obtain application ratings for the

wetted surface portiono f all cooling and dehumidifying

coils.

- - - -

SOLUTION PROCEDURE




STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

- - 37 46 ts2 - Coil Surface Temperature on Leaving Air-Side

(From Fig. 9 with ν12ο , ν13ο , and ν42ο unless

ν7ο varies more than ∀0.3 in. Hg [∀1.014 Kpa]

from 29.92 in. Hg [101.325KPa]. If it does, then

determine ts2 by trial and error using equation:

ts2 = tw1 + C (h2 – hs2) .

Correct hs2 for ν7ο and use ν12ο , ν13ο , and ν42ο .)

F [ΕC]

- - 38

CA

LCU

LATI

ON

S TO

DET

ERM

INE

HEA

T TR

AN

SFER

C

OEF

FIC

IEN

TS F

OR

USE

IN

APP

LIC

ATI

ON

RA

TIN

GS

47 hs2 Saturated Air Enthalpy at ν7ο and ν46ο Btu per lb dry air [KJ/Kg]

- - 39 48 Δhm - Logarithmic Mean Enthalpy Difference between Air Stream and Coil Surface

⎥⎦

⎤⎢⎣

⎡⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨=

47124510In

)4712()4510(

Note: See Typical Thermal Diagram at end of Form.

Btu per lb dry air [KJ/Kg]

- - 40 49 Ac - Calculated External Surface Area

⎥⎦

⎤⎢⎣

⎡⟩⟨

⟩⟨⟩⟨=

⟩⟨⟩⟨⟩⟨

=48

18x39018.1A48

18x39243.0c

sq ft

[m2]

SOLUTION PROCEDURE




STEAM COILS

DR

Y

SU

RFA

CE

FULL

Y-

WET

TED

S

UR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

? 27 44

CA

LCU

LATI

ON

S O

F C

OIL

A

IR-S

IDE

PRES

SUR

E D

RO

P

53 Coil Air-Side Pressure Drop per Row Deep at Standard Conditions For dry surface: )pst = ν21ο/ν6ο Nr

For fully-wetted surface: )pst = ν22ο/ν6ο Nr

in. water per row

deep

[Pascal per row deep]

? 28 45 54 Plot ν53ο vs ν19ο on logarithmic coordinates as shown in

Figs. 3, 4, 5, and 6, depending on coil type. Plot both

dry and wet surface pressure drop in Figs. 5 and 6.

These curves are used for application ratings.

-- - - - -

SIGNED _____________________________________________________________ TITLE ____________________________________________________

TYPICAL THERMAL DIAGRAMS FOR STEAM AND WATER COILS

Sat. Steam Cond. Temp. tvm tvm t2 tl

tw1 tw2 t2 tl

SURFACE

TEM

PER

ATU

RE

OR

EN

THA

LPY

CALCULATION OF TUBE-SIDE PRESSURE DROPS FROM STEAM AND WATER TESTS


COMPANY ____________________________________________________________________ DATE _______________________________

SOLUTION PROCEDURE


COIL LINE _______________________________ COIL TYPE _____________________________ COIL SURFACE _____________________________________________________________________

STEAM COILS

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES TEST RUN NUMBER

1 1 1 DI - Tube Inside Diameter in. [mm]

2 2 2 Nt - Total Number of Tubes In Coil --

3 3 3 Nc - Number of Tube Circuits in Coil --

4 4 4 Aix - Total Cross-Sectional Fluid Flow Area Inside Tubes = 0.00545 (ν1ο) 2 x ν3ο

[Aix = 7.85 x 10- 7 (ν1ο) 2 x ν3ο ]

sq ft

[m2]

5 5 5 Lx - Straight Tube Length Per Pass in. [mm]

6 6 6 Kb - Equivalent Length of Coil Circuit Per Return Bend

in. [mm]

7 7

CO

IL P

HY

SIC

AL

DA

TA

Le - Total Equivalent Length of Coil Circuit

⎥⎦

⎤⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛−

⟩⟨⟩⟨

⟩⟨+⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨⟩⟨

⟩⟨= 1326

3250833.0

⎥⎦

⎤⎢⎣

⎡−

⟩⟨⟩⟨

⟩⟨+⟩⟨⟩⟨

⟩⟨= )]132(6)

325[001.0Le

ft 7

[m]



TEST RUN NUMBER

STEAM COILS WATER

COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

- 8 8 tw1 - Entering Water Temperature F [ΕC]

- 9 9 tw2 - Leaving Water Temperature F [ΕC]

- 10 10 twm - Mean Water Temperature F [ΕC]

8 - 11 tvm - Mean Steam Temperature F [ΕC]

- 11 12 ww - Water Flow Rate lb per hr [g/s]

9 - 13 ww - Steam Flow Rate lb per hr [g/s]

10 - 14 vvm - Average Saturated Steam Specific Volume cu ft per lb [m3/Kg]

- 12 15 (∆pw)T - Water Pressure Drop Across Coil at Test Conditions

ft of water

[KPa]

11 -

LAB

OR

ATO

RY

TES

T O

BSE

RV

ATI

ON

AN

D

CA

LCU

LATI

ON

S FR

OM

ASH

RA

E ST

AN

DA

RD

33

-78

FO

RM

S 33

TD-2

AN

D 3

3TD

-3

16 ∆pv - Steam Pressure Drop in Coil psi [KPa]

- 13 17 Vw - Average Standard Water Velocity Inside

Tubes = ⎥⎦

⎤⎢⎣

⎡⟩⟨

⟩⟨=

⟩⟨⟩⟨

4x000,000,112V

4x500,22412

w

ft per sec

[m/s]

12 -

CA

LCU

ALT

ION

AN

D

PLO

TTIN

G

18 wv/Nc - Steam Flow Rate Inside Tubes

= ν13ο/ν3ο

lb per (hr) (circuit)

[ (gram) per (second) (circuit)]



TEST RUN NUMBER

STEAM COILS WATER

COILS G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

19 ∆Ph (for Water Coils); ∆ph/vvm (for Steam Coils) - Header, Nozzles and Tube Entrance and Exit Losses – to be established by manufacturer

ft [KPa] (for water)

(lb)2

(In.)2 (ft)3

⎥⎥

⎦

⎤

⎢⎢

⎣

⎡

3)m(2)mm(

2)g(

(for steam)

13 14

20 Ft - Temperature Coorection Factor for tube Circuit Tube Circuit Water Pressure Drop (From Fig. 7 with ν10ο)

- 15 21 ∆pt/LeFt - Water Pressure Drop Inside Tubes

= WaterCoils20x71915

−⟩⟨⟩⟨⟩⟨−⟩⟨

ft water per ft equiv.

tube length

[KPa/m]

14 - 22 ∆ptv/Levvm - Pressure Drop Parameter for Steam Flow Inside Tubes = [ν16ο / (ν7ο x ν14ο)] - ν19ο / ν7ο

⎥⎥

⎦

⎤

⎢⎢

⎣

⎡

4)m(2)mm(

2)g(

4)ft(2.)in(

2)lb(

CA

LCU

LATI

ON

AN

D P

LOTT

ING

- 17 23 Plot ∆pt/LeFt vs Vw (ν21ο vs ν17ο) on logarithmic coordinates as shown in Fig. 4. This curve with Fig. 7 is sued for application ratings for either cold water or hot water coils.

-- - - - -

15 - 24 -- - - - - Plot Δ∆ptv/Levvm vs wv/Nc (ν22ο vs ν18ο) on logarithmic coordinates as shown in Fig. 3. This curve is used in obtaining steam coil application ratings.

CALCULATION OF REFRIGERANT-SIDE THEREMAL RESISTANCES FROM VOLATILE REFRIGERANT COIL TESTS


COMPANY ____________________________________________________________________ DATE _______________________________

SOLUTION PROCEDURE



DR

Y

SUR

FAC

E

FU

LLY

W

ETTE

D

SUR

FAC

E G

ENER

AL

CA

TEG

OR

Y

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS NUMERICAL VALUES

1 1 1 Ao - Total External Coil Surface (From Form 410-1)

sq ft [m2]

2 2 2 DI - Tube Inside Diameter (From Form 410-1) in. [mm]

3 3 3 Nt - Total Number of Tubes in Coil --

4 4 4 Lt - Coil Finned Tube Length Exposed to Air Flow in. [mm]

5 5 5 B - Surface Ration (From Form 410-1) --

6 6 6 Nc - Number of Tube Circuits in Coil --

7 7 7 Aix - Total Cross-Section Fluid Flow Area

Inside Tubes = 0.00545 (ν2ο) 2 x ν6ο

[Aix = 7.85 x 10-7 (ν2ο) 2 x ν6ο)

sq ft

[m2]

8 8 8 Lx - Straight Tube Length Per Pass in. [mm]

9 9

9 Le - Equivalent Length of Coil Circuit Per Return Bend

in. [mm]

Sheet 1 of 11 Form 410-4

SOLUTION PROCEDURE



TEST RUN NUMBER

DR

Y

SUR

FAC

E

FULL

Y

WET

TED

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

10 10 10

Le - Total Equivalent Length of Coil Circuit

ft

CO

IL P

HY

SIC

AL

DA

TA

[m]

11 11 11 Ps - Average Absolute Static Pressure at Test Coil in. Hg abs [KPa abs]

⎥⎦

⎤⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨−

⟩⟨⟩⟨

⟩⟨+⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨⟩⟨

⟩⟨= 1639

6380833.0

⎥⎥⎦

⎤

⎢⎢⎣

⎡⎥⎦

⎤⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨−

⟩⟨⟩⟨

⟩⟨+⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨⟩⟨

⟩⟨= 1639

638001.0Le

12 12 12 tl - Entering Air Dry-Bulb Temperature F [ΕC]

13 13 13 'lt - Entering Air Wet-Bulb Temperature

F [ΕC]

14 14 14 hi - Entering Air Enthalpy

Btu per lb dry air

[KJ/Kg]

15 15 15 t2 - Leaving Air Dry-Bulb Temperature F [ΕC]

16 16 16 h2 - Leaving Air Enthalpy Btu per lb dry aid [KJ/Kg]

17 17 17 Va - Standard Air Face Velocity ft per min [m/s]

18 18

LAB

OR

ATO

RY

TES

T O

BSE

RV

ATI

ON

S A

ND

CA

LCU

LATI

ON

S O

BTA

INED

FR

OM

ASH

RA

E ST

AN

DA

RD

33-

78, F

OR

MS

33TD

-1

AN

D 3

3TD

-4

18 Prc2 - Absolute Refrigerant Pressure Leaving Coil Circuits

psia

[KPa abs]



TEST RUN NUMBER

DR

Y

SUR

FAC

E

FULL

Y

WET

TED

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

19 19 19 )prc - Refrigerant Pressure Drop Through Coil Circuits

psi [KPa]

20 20 20 tr1 - Saturated Refrigerant Temperature Entering Coil Circuits

F [ΕC]

21 21 21 - Saturated Refrigerant Temperature Leaving '2rct

Coil Circuits

F [ΕC]

22 22 22 trc2 - Temperature of Superheated Refrigerant Leaving Coil Circuits = tr2

F [ΕC]

23 23 23 wr - Refrigerant Flow Rate

lb per hr [g/s]

24 24 24 qs - Average Sensible Cooling Capacity Btuh [W]

25 25

LA

BO

RA

TOR

Y T

EST

OB

SER

VA

TIO

NS

AN

D C

ALC

UA

LTIO

NS

OB

TAIN

ED

FRO

M A

SHR

AE

STA

ND

AR

D 3

3-78

, FO

RM

S 33

TD-1

AN

D 3

3TD

-4

25 qt - Average Total Cooling and Dehumidifying Capacity

Btuh [W]

26 26 26 qs/qt - Sensible Heat Ratio = ν24ο / ν25ο (If ν26ο << 0.95, coil surface is all wet or partically dry; if ν26ο ≧≥ 0.95 coil surface is fully dry)

--

27 27 27 vrc2 - Specific Volume of Saturated Refrigerant Leaving Coil Circuit (From Refrigerant Tables with ν18ο)

cu ft per lb

[m3/Kg]

28 28

CA

LCU

LATI

ON

S O

F R

EFR

IGEA

NT-

SID

E TH

ERM

AL

RES

ISTA

NC

ES

28 RaD + RmD - Combined Air Film Plus Metal Thermal Resistance (From Fig. 4 with ν17ο )


[m2 Α ΕC/W]

FORM 410-4

SOLUTION PROCEDURE



TEST RUN NUMBER

DR

Y

SUR

FAC

E

FULL

Y

WET

TED

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

29 -- 29 ∆tm - Overall Logarithmic Mean Temperature Difference = If other than thermal counterflow, determine the logarithm mean temperature difference from Figs. 13, 14 or 15.

F [ΕC]

30 -- 30 R - Overall Thermal Resistance = ν1ο x ν29ο ν25ο


[m2 Α ΕC/W]

⎥⎦

⎤⎢⎣

⎡⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨

21152012n1

)2115()2012(

31 -- 31 Rr - Film Thermal Resistance of Refrigerant = ν30ο - ν28ο


[m2 Α ΕC/W]

32 -- 32 fr - Refrigerant-Side Film Heat Transfer Coefficient = ν5ο / ν31ο


[W/m2 Α ΕC]

33 -- 33 qt/Nc - Refrigerant Loading Rate Per Tube Circuit = ν25ο / ν6ο

Btuh per circuit

[watt per circuit]

34 28

CA

LCU

LATI

ON

S O

F R

EFR

IGER

AN

T-SI

DE

THER

MA

L R

ESIS

TAN

CES

34 )prc/Levrc2 - Pressure Drop Parameter for Volatile Refrigerant

= ν19 ο ν10ο x ν27ο

⎥⎥⎦

⎤

⎢⎢⎣

⎡42

2

)m()mm()g(

FORM 410-4

2)lb(4)ft(2.)in(



TEST RUN NUMBER

DR

Y

SUR

FAC

E

FULL

Y

WET

TED

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY


DIMENSIONS 1

ITE

M N

O.

2 3 4

35 29 35 wr/Nc - Volatile Refrigerant Flow Rate Per

Tube Circuit = ν23ο / ν6ο

lb per hr per circuit

⎥⎥⎦

⎤

⎢⎢⎣

⎡

circuitperondsec

pergram

36 - 36 Plot Rr vs qt/Nc (ν31ο vs ν33ο) on logarithmic coordinates

as shown in Fig. 6.

-- - - - -

37 30 37 Plot Δpc/Levrc2 vs wr/Nc (ν34ο vs ν35ο) on logarithmic coordinates as shown in Fig. 6. This curve is used for application ratings of volatile refrigerant coils.

-- - - - -

- 31 38 RaW - Air Film Thermal Resistance for Wet Surface

(From Fig. 5 with ν17ο)

(hr) (sq ft) (F) per Btu [m2 Α ΕC/W]

32 39 fr (Assumed) - Refrigerant-Side Film Heat Surface Transfer Coefficient

Note: Assume this value for trial and error solution. Suggest initial trial value of 300.


[W/m2 Α ΕC]

-

- 33 40 Rr - Film Thermal Resistance of Refrigerant

= ν5ο / ν39ο


[m2 Α Εc/w]

- 34

CA

LCU

LATI

ON

S O

F R

EFR

IGER

AN

T-SI

DE

THER

MA

L R

ESIS

TAN

CES

41 RmW - Approximate Total Metal Thermal Resistance (Wetted Surface) (From Fig. 2 with faW = 1/ν38ο)


[m2 Α ΕC/W]

FORM 410-4 SOLUTION PROCEDURE



TEST RUN NUMBER

DR

Y

SUR

FAC

E

FULL

Y

WET

TED

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY


DIMENSIONS 1 2 3 4

ITE

M N

O.

- 35 42 C Δ- Approximate Coil Characteristic (for Wetted Surface)

⎥⎦

⎤⎢⎣

⎡⟩⟨⟩⟨+⟩⟨

=⟩⟨⟩⟨+⟩⟨

=38018.14140

C38243.0

4140

Note: This approximate value of C is used only to obtain the final value of RmW

in ν48ο.

(lb) (F)

per Btu

⎥⎦

⎤⎢⎣

⎡ °⋅KJ

CKg

- 36 43 hm - Mean Air Enthalpy = 0.5 (ν14ο + ν16ο) Btu per lb dry air [KJ/Kg

- 37 44 trm - Mean Refrigerant Temperature = 0.5 (ν20ο + ν21ο)

F [ΕC]

- 38 45 tsm - Approximate Mean Surface Temperature

(From Fig. 9 with ν42ο, ν43ο, and ν44ο)

F [ΕC]

- 39

CA

LCU

LATI

ON

S O

F R

EFR

IGER

AN

T-SI

DE

THER

MA

L R

ESIS

TAN

CES

46

p" c/m -Approximate Air-Side Heat Transfer Multiplier

for Wet Surface Coils (From Fig. 8 with ν11ο and ν45ο)

--

- 40 47 faW - Air-Side Heat Transfer Coefficient = ν46ο / ν38ο Btu per (hr) (sq ft) (F)

[W/m2 Α ΕC]

- 41 48 RmW - Total Metal Thermal Resistance of Fin and Tube for Wet Surface (From Fig .2 with 47)

((hr) (sq ft) (F) per Btu [m2 Α ΕC]

FORM 410-4



TEST RUN NUMBER

DR

Y

SUR

FAC

E

FULL

Y

WET

TED

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

- 42 49 C - Coil Charactertistic for Wetted Surface

⟩⟨⟩⟨+⟩⟨

=38243.04840

⎥⎦

⎤⎢⎣

⎡⟩⟨⟩⟨+⟩⟨

=38018.14840C

(lb) (F) per Btu

⎥⎦

⎤⎢⎣

⎡ °⋅KJ

CKg

- 43

CA

LCU

LATI

ON

S O

F R

EFR

IGER

AN

T-SI

DE

THER

MA

L R

ESIS

TAN

CES

50 "lt - Entering Air Dew Point Temperature

(From Psychrometric Chart with ν11ο , ν12ο, and ν13ο) Calculation of Dew Point Temperature for Nonstandard Air Pressure*

⎥⎥⎦

⎤

⎢⎢⎣

⎡

−−−

−= 'l

'll

's'

v t44.12830)tt()pp(pp

( ) ( )

⎥⎥⎦

⎤

⎢⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛

−

−−−=

'l

'll

's'

vt33.14.1548ttpp

pp

Where: ps = Air Pressure---------------

= Saturation Vapor 'p

Pressure at 'lt

from Steam Tables------------------

pv = Saturation Vapor

F

[ΕC]

Pressure at Dew Point Temperature---

in. Hg abs

{Kpa abs]

FORM 410-4



TEST RUN NUMBER

DR

Y

SUR

FAC

E

FULL

Y

WET

TED

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

= Dew Point Temperature "lt

Is Saturation Tem- perature Correspond- ing to Saturation Vapor Pressure, pv from Steam Tables --

F [ΕC]

- 44 51 tsl - Coil Suface Temperature on Entering Air Side (From Fig. 9 with ν14ο, ν20ο, and ν49ο unless ν11ο varies more than ∀0.3 in. Hg [∀1.014 KPa] from 29.92 in Hg. [101.325 Kpa]. If it does, then determine tsl by trial and error using equation: tsl = trl + C (hl - hsl). Correct hsl for ν11ο and use ν14ο, ν20ο, and ν49ο. For fully wetted coil ν50ο ≧ ν51ο. If ν50ο < ν51ο, coil is partially wet and calculation procedures may be determined from Form 410-6)

F [ΕC]

- 45 CA

LCU

LATI

ON

S O

F R

EFR

IGER

AN

T-SI

DE

THER

MA

L R

ESIS

TAN

CES

52 hsl - Saturated Air Enthalpy at tsl (From Air Enthalpy Btu per lb dry air

[KJ/Kg]

Tables with ν11ο and ν51ο)

FORM 410-4 SOLUTION PROCEDURE



TEST RUN NUMBER

DR

Y

SUR

FAC

E

FULL

Y

WET

TED

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

- 46 53 ts2 - Coil Surface Temperature on Leaving Air Side (From Fig. 9 with ν16ο, ν21ο, and ν49ο unless ν11ο varies more than ∀0.3 in. Hg [∀1.014 Kpa] from 29.92 in. Hg [101.325 Kpa]. If it does, then determine ts2 by trial and error using equation:

ts2 = tr2 +C (h2 - hs2).

Correct hs2 for ν11ο and use ν16ο, ν21ο, and ν49ο.)

F

[ΕC]

- 47 54 hs2 - Saturated Air Enthalpy at ts2 (From Air Enthalpy Tables with ν11ο and ν53ο)

Btu per lb dry air

[KJ/Kg]

- 48 55 ∆hm - Logarithmic Mean Enthalpy Difference

⎥⎦

⎤⎢⎣

⎡⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨=

54165214

ln

)5416()5214(

Btu per lb dry air

[KJ/Kg]

- 49

CA

LCU

LATI

ON

S O

F R

EFR

IGER

AN

T-SI

DE

THER

MA

L R

ESIS

TAN

CES

sq ft 56 Ac - Calculated External Surface Area of Coil = 0.243 (ν38ο x ν25ο/ν55ο)

[Ac = 1.018 (ν38ο x ν25ο / ν55ο)]

[m2]

FORM 410-4

SOLUTION PROCEDURE



TEST RUN NUMBER

DR

Y

SUR

FAC

E

FULL

Y

WET

TED

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O. ITEM DESCRIPTION


DIMENSIONS 1 2 3 4

- 50 57 Assume other values for ν39ο and repeat procedure

through ν56ο. Plot ν39ο vs ν56ο as in Fig. 12b.

Two or more points should be plotted so that Ao

lies between calculated values of Ac.

-- - - - -

- 51 58 fr - Refrigerant Side Film Heat Transfer Coefficient Note: The point on the curve (Fig. 12b), as plotted in ν57ο, where Ac = Ao

determines the value of fr corresponding

to the circuit loading, ν33ο.


[W/m2 Α ΕC]

- 52 59 Rr - Film Thermal Resistance of Refrigerant = ν5ο/ν58ο

(hr) (sq ft) (F) per Btu [m2 Α ΕC/W]

- 53

PLO

TS

60 Plot Rr vs qt/Nc (ν59ο vs ν33ο) on logarithmic coordinates as shown in Fig. 6. This curve is used to obtain application rating data.

-- - - - -

SIGNED __________________________________________________________ TITLE _________________________________________________________

Form 410- 9

sl'sl ht

rlt

l'l ht

2'2 ht

2s'2s ht

2rct

Form 4 0- 9 1

SUGGESTED FORM FOR RATING CALCULATION PROCEDURE FOR SENSIBLE HEAT AIR COILS


COMPANY ____________________________________________________________________ DATE _______________________________



GENERAL PROCEDURE

TO SOLVE FOR ROWS DEEP (Nr)

TO SOLVE FOR CAPACITY (qs)

STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

1 1 1 1 1 H - Coil Face Height in. [mm]

2 2 2 2 2 L - Coil Face Length in.

[mm]

3 3 3 3 3 Af - Coil Face Area sq ft [m2]

4 4 4 4 4 B - Surface Ration (From Form 410-1) -- 5 5 5 5 5 Nr - Number of Rows Deep -- 6 6 6 6 6 Nt - Total Number of Tubes in Coil -- 7 7 7 7 7 Nc - Parallel Tube Circuits in Coil -- 8 8 8 8 8 Ao/AfNr (sq ft ) per

(sq ft – F.A.) (row)

9 9 9 9

CO

IL P

HY

SIC

AL

DA

TA

9 Ao = ν8ο x ν3ο x ν5ο sq ft

Form 410- 9

10 10 10 10 10 Di - Tube Inside Diameter

in. [mm]



GENERAL PROCEDURE



STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

11 11 11 11 11 Aix - Total Cross Sectional Fluid Flow Area

Inside Tubes = 0.00545 (ν10ο2 x ν7ο)

[Aix = 7.85 x 10-7 (ν10ο x ν7ο)]

sq ft [m2]

12 12 12 12 12 Ls - Straight Tube Length Per Tube Pass in. [mm]

13 13 13 13 13 Kb - Equivalent Length of Coil Circuit Per Return Bend in.

[mm]

14 14 14 14

CO

IL P

HY

SIC

AL

DA

TA

14 Le - Total Equivalent Length of Coil Circuit

⎥⎦

⎤⎢⎣

⎡⎟⎠⎞

⎜⎝⎛ −⟩⟨+⎟

⎠⎞

⎜⎝⎛ ⟩⟨= 1

7613

76120833.0

⎥⎦

⎤⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎠⎞

⎜⎝⎛ −⟩⟨+⎟

⎠⎞

⎜⎝⎛ ⟩⟨= 1

7613

7712001.0Le

ft

[m]

15 15 15 15

NG

C

ON

DIT

I 15 Qa - Air Volume Flow at Standard Conditions scfm [std Ρ/s]

Form 410- 9

16 16 16 16 16 Va - Standard Air Face Velocity, ν15ο/ν3ο

Va = 0.001 x ν15ο/ν3ο]

ft per min [m/s]

17 17 17 17 17 tl - Entering Air Dry-Bulb Temperature F [ΕC]

- 18 - 18 18 Vw - Average Standard Water Velocity in Tubes ft per sec

[m/s



GENERAL PROCEDURE



STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

- 19 - 19 19 Twl - Entering Water Temperature F [ΕC]

18 20 18 20 20 Ps - Average Absolute Static Pressure at Coil in. Hg abs

[Kpa abs]

19 - 19 - 21 Pv1 - Inlet Steam Gage Pressure to Coil psig [Kpa gage]

20 - 20 - C

OIL

PH

YSI

CA

L D

ATA

22 - Inlet Steam Temperature to Coil 'vlt F

[ΕC]

21 - 21 -

SM

PR

OP

ERTI

E 23 Pvl - Coil Inlet Steam Pressure

= ν21ο + 0.491 ν20ο [Pvl = ν21ο + ν20ο]

psia

[Kpa abs)

Form 410- 9

22 - 22 - 24 tvl - Steam Saturation Temperature Entering Coil

(From ν23ο and Steam Property Tables)

F [ΕC]

23 - 23 - 25 vvl - Steam Specific Volume Entering Coil

(From ν22ο, ν23ο and Steam Property Tables) = vv2 for rating convenience

cu ft per lb

[m3/Kg]

24 - 24 - 26 hvl - Enthalpy of Steam Entering Coil

(From ν22ο, ν23ο and Steam Property Tables)

Btu per lb

[KJ/Kg]



GENERAL PROCEDURE



STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

25 - 25 -

STEA

M

PRO

PER

TIES

27 hf2 - Enthalpy of Steam Condensed Leaving Coil

(From ν23ο and Steam Property Tables as-

suming hfl = hf2 for rating convenience)

Btu per lb

[KJ/Kg]

- 21 - 21

WA

TER

RA

TIN

G

PAR

AM

ETER

S 28 twm - Mean Water Temperature Inside Tubes

- When solving for rows deep, this value is known (assume cpw = 1.000 for this calculation)

- When solving for capacity, this value must be approximated (Suggest twm be 5 F [2.8ΕC to 10 F [5.6ΕC] from twl

F

[ΕC]

Form 410- 9

- 22 - 22 29 ww - Water Flow Rate = 224,500 x ν11ο x ν18ο

[ww = 1,000,000 x ν11ο x ν18ο]

lb per hr

[g/s]

- 23 - 23 (hr) (sq ft) (F) per Btu

[m2 Α ΕC/W]



GENERAL PROCEDURE



STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

- 24 - 24 31 (hr) (sq ft) (F) per Btu

[m2 Α ΕC/W]

- 25 - 25

WA

TER

RA

TIN

G

PAR

AM

ETER

S

32 RaD + RmD - Combined Air Film Plus Metal Thermal

Resistance (From Fig. 4 with ν16ο


[m2 Α ΕC/W]

Form 410- 9

26 26 26 26 33 R - Overall Thermal Resistance between Air – and (hr) (sq ft) (F) per Btu Tube-Side Fluid = ν31ο + ν32ο for Water

Coils (From Fig. 3 knowing ν16ο for Steam [m2 Α ΕC/W] Coils)



GENERAL PROCEDURE



STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

- - 27 27

CC

UO

NS

TO S

OLV

E FO

R C

OIL

C

APA

CIT

Y 34 M - Air-to-Tube Fluid-Side Heat Capacity Ratio

⎥⎦

⎤⎢⎣

⎡

⟩⟨

⟩⟨=

⟩⟨

⟩⟨=

29cx15x2.1

M29

cx15x5.4 pp

--

Form 410- 9

- - 28 28 35 Co - Heat Transfer Exponent

⎥⎥⎦

⎤

⎢⎢⎣

⎡

⟩⟨⟩⟨⟩⟨

=⟩⟨⟩⟨

⟩⟨=

33x15xc2.19C

33x15xc5.49

po

p

--

- - 29 29 36 E - Air-Side Effectiveness

- at ν34ο and ν35ο = 0 and Fig. 13 for Steam Coils

- at ν34ο, ν35ο, and Fig. 13 for One-Row Water Coils

- at ν34ο, ν35ο, and Fig. 14 for Two-Row Water Coils

- at 34, 35, and Fig. 15 for Three-Row or Greater Counterflow Water Coils

--



GENERAL PROCEDURE



STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

Form 410- 9

27 27 30 30 37 Δto - Initial Air-to-Field Temperature Difference

= ν19ο - ν17ο - For Air-Heating Water Coils = ν17ο - ν19ο - For Air-Cooling Water Coils = ν24ο - ν17ο - For Steam Coils

F

[ΕC]

- - 31 31 38 qs - Coil Sensible Heat

= 4.5 cp x ν15ο x ν36ο x ν37ο [ qs = 1.2 cp x ν15ο x ν36ο x ν37ο ]

Btuh

[W]

- - 32 32 39 )ta - Air Temperature Rise or Drop Across Coil

⎥⎥⎦

⎤

⎢⎢⎣

⎡

⟩⟨=Δ

⟩⟨=

15xc2.138t

15xc5.438

pa

p

F

[ΕC]

- - 33 34 40 t2 - Leaving Air Temperature at Coil

= ν17ο + ν39ο (For Air Heating) = ν17ο - ν39ο (For Air Cooling)

F

[ΕC]

- - 33 34 CA

LCU

LATI

ON

S TO

SO

LVE

FOR

CO

IL C

APA

CIT

Y (q

s)

41 )tw - Water Temperature Rise or Drop Across Coil

= ν18ο / ν29ο

F

[ΕC]



GENERAL PROCEDURE



GEN

ERA

L C

ATE

G I

TEM

N

O.


DIMENSIONS

NUMERICAL VALUES

Form 410- 9

STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

- - - 35 42 *twm - Average Water Temperature Inside Tubes

= ν19ο - 0.5 x ν41ο - For Air-Heating Coil = ν19ο + 0.5 x ν41ο - For Air-Cooling Coil

F

[ΕC]

28 28 - - 43 qs - Coil Sensible Heat (Known) Btuh

[W]

29 29 - - 44 )ta - Air Temperature Rise or Drop Across Coil

⎥⎥⎦

⎤

⎢⎢⎣

⎡

⟩⟨=Δ

⟩⟨=

15xc2.143t

15xc5.443

pa

p

F

[ΕC]

30 30 - - 45 t2 - Leaving Air Temperature at Coil

= ν17ο + ν44ο For Air-Heating Coil = ν17ο - ν44ο For Air-Cooling Coil

F

[ΕC]

- 31 - - 46 )tw - Water Temperature Rise or Drop Across Coil

= ν43ο / ν29ο

F

[ΕC]

CA

LCU

LATI

ON

S TO

SO

LVE

FOR

RO

WS

DEE

P

- 32 - - 47 tw2 - Leaving Water Temperature at Coil

= ν19ο - ν46ο - For Air-Heating Coil

= ν19ο + ν46ο - For Air-Cooling Coil

F

[ΕC]

* ν42ο must equal ν28ο within ∀5 F [∀2.8]. If not, assume a new value for ν28ο and repeat calclations through ν42ο.



NUMERICAL VALUES

Form 410- 9

GENERAL PROCEDURE



STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

31 33 - - 48 M - Air-to-Tube Fluid-Side Heat Capacity Ratio

= ν46ο / ν44ο - For Water Coils = 0 - For Steam Coils (for rating convenience)

--

32 34 - - 49 E - Air-Side Effectiveness

= ν44ο / ν37ο

--

33 35 - - 50 Co - Heat Transfer Exponenet (Air-to-Tube Fluid)

- From Fig. 13 or 14 or 15 with ν48ο and ν49ο

- Fig. 13 for One-Row Coils

- Fig. 14 for Two-Row Coils

- Fig. 15 for Coils with three rows or more

--

34 36 - - 51 Nrc - Calculated Row Depth Required

⟩⟨⟩⟨⟩⟨⟩⟨⟩⟨⟩⟨

=44x3x8

50x33x43

--

CA

LCU

LATI

ON

S TO

SO

LVE

FOR

RO

WS

DEE

P

35 37 - - 52 Nt - Integral Coil Row Depth Installed --

Form 410- 9



GENERAL PROCEDURE



STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

36 38 34 36 53 )pst/Nr - Air-Side Pressure Drop Per Row Deep at Standard Conditions (From Fig. 3 or 4 with ν16ο)

in. waterrow

[pascal per

row]

37 39 35 37 54 Fa - Air-Side Pressure Drop Correction Factor

⟩⟨

⎥⎦⎤

⎢⎣⎡ ⟩⟨+⟩⟨+⟩⟨

+=

20x71.172

454017460

⎥⎥⎥⎥

⎦

⎤

⎢⎢⎢⎢

⎣

⎡

⟩⟨

⎟⎠⎞

⎜⎝⎛ ⟩⟨⟩⟨+⟩⟨

+=

20x909.22

45or401715.273Fa

--

38 40 36 38 55 ()pa)JOB - Air-Side Pressure Pressure Drop at Job Conditions

(Constant wa) = ν52ο x ν53ο x ν54ο

in water

[Pa]

39 - 37 -

CA

LCU

LATI

ON

S TO

SO

LVE

FOR

RO

WS

DEE

P

56 wv - Total Steam Condensate Mass Flow Rate Through

Coil = ν38ο or ν43ο ν26ο or ν27ο

lb per hr

[g/s]

Form 410- 9

40 - 38 - 57 wv/Nc - Steam Flow Rate Per Tube Circuit lb per (hr) (circuit)

[(gram) per sec- = ν56ο / ν7ο ond) (circuit)



GENERAL PROCEDURE



STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

41 41 39 39 Obtain Header, Nozzle and Entrance and Exit Losses for Water and Steam to be determined by manufacturer )ph/Fh - for Water Coils at 60ΕF Mean Water Temperature with ν18ο )ph/vvm - for Steam Coils

ft of water [kPa]

(lb)2

(in.)2 (ft)3

⎥⎥⎦

⎤

⎢⎢⎣

⎡32

2

)m()mm()g(

58

- 42 - 40 59 )pt/LeFt - Tube Circuit Water Pressure Drop Parameter at 60 F [15.6ΕC] Mean Water Temperature (From Fig. 4 with ν18ο ) (Ft = l)

ft water per ft

[KPa/m]

- 43 - 41

CA

LCU

LATI

ON

S TO

SO

LVE

FOR

RO

WS

DEE

P

60 Fh - Temperature Correction Factor for Header Water Pressure Drop (From Fig. 7 with ν28ο

--

Form 410- 9

- 44 - 42 61 Ft - Temperature Correction Factor for Water Pressure -- Drop (From Fig. 7 with ν28ο )

- 45 - 43 62 )pw)JOB - Water Pressure Drop Across Coil at Job Conditions

= ν58ο x ν60ο + ν14ο x ν59ο x ν61ο

ft water

[Kpa]



GENERAL PROCEDURE



STEAM COILS

HOT OR COLD

WATER COILS

STEAM COILS

HOT OR COLD

WATER COILS

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

42 - 40 - 63 )ptv/Lcvvm - Steam Pressure Drop Parameter (From Fig. 3 with ν57ο

(lb)2

(in.)2 (ft)4

⎥⎥⎦

⎤

⎢⎢⎣

⎡42

2

)m()mm()g(

43 - 41 -

TUB

E-SI

DE

PRES

SUR

E D

RO

P C

ALC

ULA

TIO

NS

64 psi )pv - Steam Pressure Drop Inside Tubes at Job Conditions = [(ν63ο x ν14ο) + ν58ο ] ν25ο [Kpa]

Form 410- 9

Signed ____________________________________________________________________ Title ____________________________________________________________________

SUGGESTED FORM FOR RATING CALCULATION PROCEDURE FOR COOLING AND DEHUMIDIFYING COILS ARI CERTIFICATION PROGRAM FOR FORCED-CIRCULATION AIR-COOLING AND AIR-HEATING COILS



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

STE

AM

C

OIL

S

FU

LLY

W

ET

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

1 1 1 1 1 H - Coil Face Height in. [mm]

2 2 2 2 CO

IL

PHY

SIC

AL

DA

TA

2 L - Coil Face Length

in. [mm]

Form 410- 9

3 3 3 3 3 Af - Coil Face Area sq ft [m2]

4 4 4 4 4 B - Surface Ration (From Form 410-1) --

5 5 5 5 5 Nr - Number of Rows Deep (if known) --

6 6 6 6 6 Nt - Total Number of Tubes in Coil (if known) --

7 7 7 7 7 Nc - Parallel tube Circuits in Coil (if known) --

8 8 8 8 8 Ao/AfNr (sq ft) per

(sq ft – F.A.) (row)

[(sq metre) per] [(sq metre-F.A.)

(Row)



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

CLA

LY

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

STE

AM

C

OIL

S

FU

LLY

W

ET

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

9 9 9 9 9 Di - Tube Inside Diameter in. [mm]

10 10 10 10 CO

IL

PHY

SIC

AL

DA

TA

10 Ls - Straight Tube Length Per Tube Pass in. [mm]

Form 410- 9

11 11 11 11 11 Kb - Equivalent Length of Coil Circuit Per Return Bend in. [mm]

12 12 12 12 12 Ao - ν8ο x ν3ο x ν5ο (if known) sq ft [m2]

13 13 13 13 13 Aix - Total Cross-Sectional Fluid Flow Area

Inside Tubes = 0.00545 (ν92ο x ν7ο)

[Aix = 7.85 x 10-7 (ν9ο2 x ν7ο)]

sq ft [m2]

14 14 14 14 14 Le Total Equivalent Length of Coil Circuit

⎥⎦

⎤⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛−

⟩⟨⟩⟨

⟩⟨+⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨⟩⟨

⟩⟨= l7611

76100833.0

⎥⎥⎦

⎤

⎢⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛−

⟩⟨⟩⟨

⟩⟨+⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨⟩⟨

⟩⟨= 17611

7610001.0Le

ft

[m]

15 15 15 15 15 Qa - Air Volume Flow at Standard Conditions scfm [std Ρ/s]

16 16 16 16 RA

TIN

G C

ON

DIT

ION

S A

ND

DA

TA C

OM

UPA

TTIO

NS

16 Va - Standard Air Face Velocity = ν15ο/ν3ο

[Va = 0.001 x ν15ο/ν3ο

ft per min [m/s]



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

Form 410- 9

17 17 17 17 17 tl - Entering Air Dry-Bulb Temperature F [ΕC]

18 18 18 18 18 - Entering Air Wet-Bulb Temperature 'lt F

[ΕC]

19 19 - - 19 Vw - Average Standard Water Velocity in Tubes ft per sec [m/s]

20 20 - - 20 twl - Entering Water Temperature F

[ΕC]

- - 19 19 21 tr2 - Saturated Suction Refrigerant Temperature at Coil Outlet Note: For rating convenience, it is assumed that there is no temperature drop from coil circuits to coil outlet.

F [ΕC]

- - 20 20 22 - Superheated Refrigerant Temperature at Coil Outlet '2rt

Note: For rating convenience, it is assumed that there is no temperature drop from coil circuits to coil outlet.

F

[ΕC]

21 21 21 21 23 Ps - Average Absolute Static Pressure at Coil in. Hg abs [Kpa abs]

- - 22 22

RA

TIN

G C

ON

DIT

ION

S A

ND

DA

TA C

OM

PUTA

TIO

NS

24 tro - Refrigerant Temperature Entering the Coil Control Device (Equal to the refrigerant condensing

F [ΕC]

temperature)



GENERAL PROCEDURE

COLD WATER COILS


COILS GEN

ERA

L C

ATE

G I

TEM

N

O.


DIMENSIONS

NUMERICAL VALUES

Form 410- 9

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

- - 23 23 25 hro - Enthalpy of Refrigerant Entering Coil

Control Device (From ν24ο and Refrigerant Tables)

Btu per lb [KJ/Kg]

22 22 24 24 26 hl - Entering Air Enthalpy (From ν17ο, ν18ο, and ν23ο)

Btu per lb [KJ/Kg]

23 23 25 25 27 60wa - Standard Air Flow Rate = 4.50 x ν15ο

[1000wa = 1.2 x ν15ο ]

lb per hr [g/s]

24 24 26 26 28 Case I - If ν29ο is known, determine ν30ο at ν29ο saturated and ν23ο . Then calculate ν31ο = ν27ο (ν26ο - ν30ο).

Case II - If ν31ο is known, determine ν30ο and then ν29ο. ν30ο = ν26ο – ν31ο/ν27ο. Case III - If ν5ο is known, assume ν31ο or ν29ο, find ν30ο and then ν29ο or ν31ο, respectively.

--

25 25 27 27 RA

TIN

G C

ON

DIT

ION

S A

ND

DA

TA C

OM

PUTA

TIO

NS

29 - Leaving Air Wet-Bulb Temperature '2t

F [ΕC]



NUMERICAL VALUES

Form 410- 9

GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

26 26 28 28 30 H2 - Leaving Air Enthalpy

If qt is known, h2 = ν26ο - ⟩⟨27

q t

Btu per lb [KJ/Kg]

27 27 29 29 31 qt - Total Heat Capacity of Coil

= ν27ο (ν26ο - ν30ο)

Enter numerical value if known.

If not known, assume a numberical value for a trial and error solution.

Btuh [W]

28 28 - - 32 ww - Water Flow Rate = 224,500 x ν13ο x ν19ο

[ww = 1,000,000 x ν13ο x ν19ο]

lb per hr [g/s]

29 29 - - 33 tw2 - Leaving Water Temperature = ν20ο + ν31ο/ν32ο F [ΕC]

- - 30 30 34 Pr2 - Absolute Pressure of Refrigerant at Coil Outlet (From Refrigerant Tables with ν21ο)

psia [KPa abs]

- - 31 31 RA

TIN

G C

ON

DIT

ION

S A

ND

DA

TA C

OM

PUTA

TIO

NS

35 hr2 - Enthalpy of Saturated Refrigerant Vapor at Coil Outlet Pressure (From Refrigerant Tables with ν21ο. Assumed saturated for rating convenience.)

Btu per lb

[KJ/Kg]

Form 410- 9



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

- - 32 32 36 vr2 - Specific Volume of Saturated Refrigerant Vapor at Coil Outlet Pressure (From Refrigerant Tables with ν21ο. Assumed saturated for rating convenience.

cu ft per lb

[m3/Kg]

- - 33 33 37 wr - Refrigerant Flow Rate = ν31ο/(ν35ο - ν25ο) lb per hr [g/s]

- - 34 34 38 wr/Nc - Refrigerant Flow Rate Per Tube Circuit

= ν37ο/ ν7ο

lb per (hr) (circuit)

⎥⎥⎦

⎤

⎢⎢⎣

⎡

)circuit()ond(sec

per)gram(

- - 35 35

RA

TIN

G C

ON

DIT

ION

S A

ND

DA

TA C

OM

PUTA

TIO

NS

39 )prc/Levr2 - Refrigerant Pressure Drop Parameter


42

2

)ft(.)in()lb(

( )( ) ( ) ⎥

⎥⎦

⎤

⎢⎢⎣

⎡42

2

mmmg

Form 410- 9

- - 36 36 40 )prh/vr2 - Outlet Header Refrigerant Pressure Drop Parameter with ν17ο) ( )

32

2

)ft(.)in(lb

⎥⎥⎦

⎤

⎢⎢⎣

⎡32

2

)m()mm()g(



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

- - 37 37 41 pr1 - Absolute Pressure of Refrigerant at Coil Inlet, ν34ο + ν36ο [(ν14ο x ν39ο) + ν40ο]

psia

[Kpa abs]

- - 38 38 42 prc2 - Absolute Pressure of Refrigerant Leaving Coil Circuit = ν34ο + ν36ο x ν40ο)

psia [Kpa abs]

- - 39 39 43 trc2 - Saturated Refrigerant Temperature Leaving Coil

Circuit (From ν42ο and Refrigerant Tables) F

[ΕC]

- - 40 40

RA

TIN

G C

ON

DIT

ION

S A

ND

DA

TA

CO

MPU

TATI

ON

S

44 tr1 - Entering Refrigerant Temperature (From Saturated Refrigerant Tables with ν41ο)

F [ΕC]

Form 410- 9

- 41 41 45 qt/Nc - Refrigerant Circuit Loading Rate = ν31ο/ν7ο

Btu per (hr) (circuit) [watt per circuit]

30 30 - - 46 twm - Mean Water Temperature in Coil

= 0.5 (ν20ο + ν33ο)

F [ΕC]

31 31 - - 47 fw - Water-Side Film Heat Transfer Coefficient

2.0

8.0

)9()19()46011.01(150

⟩⟨⟩⟨⟩⟨+

=


[W/m2 Α ΕC]



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

(hr) (sq ft) 32 32 42 42 48 Tube-Side Thermal Resistance

Rw = ν4ο/ν47nο For Water Coils

Rr - From Fig. 6 with ν45ο for Volatile Refrigerant Coils

(F) per Btu

[m2 Α ΕC/W]

33 33 43 43

RA

TIN

G C

ON

DIT

ION

S A

ND

DA

TA

CO

MPU

TATI

ON

S

49 RaD - Air Film Thermal Resistance for Dry Surface



[m2 Α ΕC/W]

Form 410- 9

34 34 44 44 50 RaW - Air Film Thermal Resistance for Wetted Surface



[m2 Α ΕC/W]

35 35 45 45 51 RmD - Metal Thermal Resistance for Dry Surface

(From Fig. 2 at fa = 1/ν49ο)


[m2 Α ΕC/W]

36 36 46 46 52 Approximate Coil Charactertistic =

50x243.05148 ⟩⟨+⟩⟨

⎥⎦

⎤⎢⎣

⎡⟩⟨⟩⟨+⟩⟨

=50x018.15148

Note: This approximate coil characteristic is used to obtain RmW in ν63ο.

(lb) (F) per Btu

[Kg Α ΕC/KJ]

Form 410- 9



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

37 37 47 47 R

ATI

NG

PA

RA

MET

ERS

53 Y - Ratio of Tube-Side Temperature Difference to Air Enthalpy Difference

CoilsWaterFor30262033

−⟩⟨−⟩⟨⟩⟨−⟩⟨

=

CoilsfrigerantReVolatileFor30262144

−⟩⟨−⟩⟨⟩⟨−⟩⟨

=

(lb) (F) per Btu

[Kg Α ΕC/KJ]

Form 410- 9

38 38 48 48 54 tl - Entering Air Dew Point Temperature (From Psy- chrometric Chart with ν17ο, ν18ο, and ν23ο) Calculation of Dew Point Temperature for Nonstandard Air Pressure*

⎥⎥⎦

⎤

⎢⎢⎣

⎡

⟩⟨−⟩⟨−⟩⟨−⟩⟨

−=1844.12830

)1817()p23(pp

''

v

⎥⎥⎦

⎤

⎢⎢⎣

⎡

⎥⎥⎦

⎤

⎢⎢⎣

⎡

⟩⟨−⟩⟨−⟩⟨−⟩⟨

−=1833.14.1548

)1817()p23(pp

''

v

⎪⎪⎭

⎪⎪⎬

⎫

−−−−=

−−−⟩⟨=

eTemperaturintPoDewatessurePrVaporSaturationp

TablesSteamfrom,18atessurePrVaporSaturationp:Where

v

= Dew Point Temperature is Satu- "lt

ration Temperature Corresond- ing to Saturation Vapor Pressure, Pv, from Steam Table-------------

F [ΕC]

in. Hg abs

[Kpa abs]



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

SU

RFC

E

39 39 49 49

G

PAR

AM

ETE 55 - Saturation Enthalpy at Dew Point (From "

lh

Psychrometric Charts with ν54ο and ν23ο)

Btu per lb

[KJ/Kg]

Form 410- 9

Btu per lb 40 40 50 50 56 Approximate Air Enthalpy at Boundary Conditions

⟩⟨+⟩⟨

⟩⟨⟩⟨+⟩⟨⟩⟨+⟩⟨−⟩⟨=

5352)55x52()26x53(3354

For Water Coils

⟩⟨+⟩⟨

⟩⟨⟩⟨+⟩⟨⟩⟨+⟩⟨−⟩⟨=

5352)55x52()26x53(4454

For Refrigerant Coils

Note: If ν56ο ≧ ν26ο, coil is fully wet. For this condition, use ν56ο = ν26ο. If ν56ο < ν26ο,

[KJ/Kg]

coil is partially dry.

41 41 51 51 57 Approximate Tube-Side Temperature at Dry-Wet Bounday

= ν33ο - ν53ο (ν26ο - ν56ο) - For Water Coils

= ν44ο - ν53ο (ν26ο - ν56ο) - For Refrigerant Coils

F

[ΕC]



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

Form 410- 9

42 42 52 52 58 Mean Tube-Side Temperature for Fully Wet Coil or Wet Portion of Partially Dry Coil

= 0.5 (ν20ο + ν57ο) - For Partially Dry Water Coil

= 0.5 (ν20ο + ν33ο) - For Fully Wet Water Coil

= 0.5 (ν21ο + ν57ο) - For Partially Dry Volatile Refrigerant Coils

= 0.5 (ν21ο + ν44ο) - For Fully Wet Volatile Refrigerant Coils

F

[ΕC]

43 43 53 53 59 Approximate Mean Air Enthalpy for Fully Wet Coil or Wet Portion of Partially Dry Coil

= 0.5 (ν30ο + ν56ο) - For Partially Dry Coil

= 0.5 (ν26ο + ν30ο) - For Fully Wet Coil

Btu per lb

[KJ/Kg]

44 44 54 54 60 Approximate Mean Surface Temperatures for Fully Wet Coil or Wet Portion of Partially Dry Coil (From Fig . 9 with ν52ο, ν58ο and ν59ο)

F

[ΕC]

45 45 55 55 61 m"/cp - Air-Side Heat Transfer Multiplier for Wet Surface (From Fig. 8 with ν60ο and ν23ο)

--

46 46 56 56

RA

TIN

G P

AR

AM

ETER

S

62 faW - Air-Side Thermal Conductance for Wet Surface = ν61ο/ ν50ο


[W/m2 Α ΕC]



GENERAL PROCEDURE

COLD WATER COILS


COILS GEN

ERA

L C

ATE

G I

TEM

N

O.


DIMENSIONS

NUMERICAL VALUES

Form 410- 9

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

47 47 57 57 63 RmW - Metal Thermal Resistance for Wet Surface


(sq ft) (hr) (F) per Btu

[m2 Α ΕC/W]

48 48 58 58 64 C - Coil Characteristic for Wetted Surface

⟩⟨⟩⟨+⟩⟨

=50243.06348 ⎥

⎦

⎤⎢⎣

⎡⟩⟨⟩⟨+⟩⟨

=50018.16348C

Note: This is final value for rating convenience.

(lb) (F) per Btu

[Kg Α ΕC/KJ]

49 49 59 59 R

ATI

NG

PA

RA

MET

ERS

65 hB - Air Enthalpy at Boundary

⟩⟨+⟩⟨

⟩⟨⟩⟨+⟩⟨⟩⟨+⟩⟨−⟩⟨=

5364)55x64()26x53(3354

For Water Coils

⟩⟨+⟩⟨

⟩⟨⟩⟨+⟩⟨⟩⟨+⟩⟨−⟩⟨=

5364)55x64()26x53(4454

For Volatile Refrigerant Coils

If ν65ο < ν26ο, surface is particlaly dry, proceed to ν66ο.

If ν65ο ≧ ν26ο, surface is fully wet, proceed to ν71ο.

Btu per lb

[KJ/Kg]



GENERAL PROCEDURE

NUMERICAL VALUES

Form 410- 9

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

50 - 60 - 66 qtD - Capacity for Dry Portion of Coil

= ν27ο (ν26ο - ν 65ο)

Btuh [W]

51 - 61 - 67 tB - Air Dry-Bulb Temperature at Bounday

⟩⟨

⟩⟨−⟩⟨=

27x243.06617 ⎥

⎦

⎤⎢⎣

⎡⟩⟨

⟩⟨−⟩⟨=

27x018.16617t B

Note: This is final value for rating convenience.

F

[ΕC]

52 - 62 - 68 Tube-Side Temperature at Boundary

twB = ν33ο - ν53ο (ν26ο - ν65ο) – For Water Coils

trB = ν44ο - ν53ο (ν26ο - ν65ο) - For Refrigerant Coils

F

[ΕC]

53 - 63 -

RA

TIN

G P

AR

AM

ETER

S

69 ∆tm - Logarithmic Mean Temperature Difference for Dry Portion of Coil

Water

For

68673317

In

)6867()3317(−

⎥⎦

⎤⎢⎣

⎡⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨=

F

[ΕC]

For

68674417

In

)6867()4417(−

⎥⎦

⎤⎢⎣

⎡⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨=

Form 410- 9



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

54 - 64 - 70 AcD - Calculated External Surface Area for Dry Portion of Coil

⟩⟨

⟩⟨+⟩⟨+⟩⟨⟩⟨=

69)514948(66

sq ft [m2]

55 50 65 60 71 qtW - Capacity for Wet Portion of Coil

= ν31ο - ν66ο - For Partially Wet Coils

= ν31ο - For fully Wet Coils

Btuh

[W]

56 51 ¤

66 61

RA

TIN

G P

AR

AM

ETER

S

72 tsl - Surface Temperature at Air Entering Side of Wet Portion. From Fig. 9 with: ¤ - ν23ο, ν26ο, ν33ο, and ν64ο) - For Totally Wet Water Coils

- ν23ο, ν26ο, ν44ο, and ν64ο) - For Totally Wet Volatile Refrigerant Coils

= tsB = ν54ο for Partially Dry Water and Refrigerant Coils

F

[ΕC]

Fig. 9 can be used for determining the surface temperature provided the rating calculations are bsed on a standard barometric pressure of 29.92 in. Hg [101.325 Kpa] ∀0.3 in. Hf [∀1.014 Kpa]. If the barometric pressure is not within this range, then it is necessary to determine the surface temperature by trial and error, using the following equation: ts = tt + C (h - hx). Assume a value for ts and correct the corresponding hs at saturation for the barometric pressure.

Form 410- 9



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

57 ¤

52 ¤

67 ¤

62 ¤

73 ts2 - Surface Temperature at Air Leaving Side of Wet Portion. From Fig. 9 with:

- ν20ο, ν23ο, ν30ο, and ν64ο for Water Coils

- ν21ο, ν23ο, ν30ο, and ν64ο for Volatile Refrigerant Coils

F [ΕC]

58 53 68 63 74 hsl - Enthalpy of Saturated Air at Air Entering Side of Wet Portion

- From ν23ο and ν72ο - For Fully Wet Coils

= hsB = ν55ο - For Partially Dry Coils

Btu per lb

[KJ/Kg]

59 54 69 64

RA

TIN

G P

AR

AM

ETER

S

75 hs2 - Enthalpy of Saturated Air at ν23ο and ν73ο Btu per lb

[KJ/Kg]

Fig. 9 can be used for determining the surface temperature provided the rating calculations are based on a standard barometric pressure of 29.92 in. Hg [101.325 Kpa] ∀0.3 in. Hg [∀1.014 Kpa]. If the barometric pressure is not within this range, then it is necessary to determine the surface temperature by trial and error, using the following equation: ts = tr + C (h - hs). Assume a value for tx and correct the corresponding hs at saturation for the barometric pressure.

Form 410- 9



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

60 55 70 65 76 )hm - Logarithmic Mean Enthalpy Difference between Air Stream and Wetted Surface

⎥⎦

⎤⎢⎣

⎡⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨=

75307426In

)7530()7426(

⎥⎦

⎤⎢⎣

⎡⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨=

75307465In

)7530()7465(

Btu per lb

[KJ/Kg]

61 56 71 66 RA

TIN

G P

AR

AM

ETER

S

77 AcW - Calculated External Surface Area for Fully Wet Coil or Wet Portion of Coil

= 0.243 x ν50ο x ν71ο/ν76ο

[AcW = 1.018 x ν50ο x ν71ο/ν76ο]

sq ft

[m2]

Form 410- 9

78 Ac - Total Calculated External Surface Area

= ν77ο + ν70ο for Partially Wet Coil

= ν77ο for Fully Wet Coil

Note: For Case I and II in ν28ο, complete ν79ο.

For Case III in ν28ο, complete ν80ο and ν81ο.

sq ft

[m2]

62 57 72 67



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

63 58 73 68

CA

CU

LATI

ON

FO

R N

O. O

F R

OW

S FO

R

CA

SES

I & II

79 Nr - Required Number of Rows of Coil Tubes in

Direction of Air Flow ⟩⟨⟩⟨

⟩⟨=

8x378

--

64 59 74 69

CA

LCU

LATI

ON

OF

CA

PAC

ITY

FO

R C

ASE

II

I

80 If ν78ο ≷ ν12ο, assume a new value of qt ≷ ν31ο. Repeat calculations from ν26ο through ν78ο. Plot calculated values of ν78ο against assumed values of ν31ο as shown in Fig. 12c.

--

Form 410- 9

65 60 75 70 81 Determine actual value of qt from plot ν80ο with Ac = ν12ο Btuh

[W]

66 61 76 71 82 c - Heat Transfer Exponent --

⟩⟨⟩⟨

⟩⟨=

27x49x58.1460x12 ⎥

⎦

⎤⎢⎣

⎡⟩⟨⟩⟨

⟩⟨=

27x492.10181000x12C

67 62 77 72

CA

LCU

LATI

ON

S TO

D

ETER

MIN

E A

IR

LEA

VIN

G D

RY

-BU

LB

TEM

PER

ATU

RE

83 e-c - Heat Transfer Factor = e-ν82ο

--



GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

NUMERICAL VALUES

Form 410- 9

68 63 78 73 84 h2 - Leaving Air Enthalpy of Actual Value of qt

⟩⟨

⟩⟨⟩⟨−=

2781or31

26

Note: Knowing ν18ο or ν26ο, ν17ο, ν83ο, and ν84ο, t2 can be determined from the following procedure.

Btu per lb

[KJ/Kg]

69 64 79 74 85 h - Saturated Enthalpy at Effective Surface

Temperature = ⟩⟨−

⟩⟨⟩⟨−⟩⟨−⟩⟨

830.184or3026

26

Btu per lb

[KJ/Kg]

70 65 80 75 86 t - Effective Surface Temperature from Psychro- metric Chart with ν23ο and ν85ο

F

[ΕC]

71 66 81 76 CA

LCU

LATI

ON

S TO

DET

ERM

INE

AIR

LEA

VIN

G

DR

Y-B

ULB

TEM

PER

ATU

RE

87 t2 - Air Leaving Dry-Bulb Temperature = ν86ο + (ν17ο - ν86ο) ν83ο

F

[ΕC]



GENERAL PROCEDURE

COLD WATER COILS


COILS GEN

ERA

L C

ATE

GO

RY

ITE

M

NO

.


DIMENSIONS

NUMERICAL VALUES

Form 410- 9

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

72 67 82 77 88 )psw/Nr - Air-Side Pressure Drop Per Row at Standard Conditions (Use wet surface for partially dry and fully wet coils.)

- From Fig. 5 with ν16ο for Water Coils

- From Fig. 6 with ν16ο for Volatile Refrigerant Coils

in water per row

[Pascal per row]

73 68 83 78 89 FA - Dry Surface Air-Side Pressure Drop Correction

Factor = ⟩⟨

⟩⟨⟩⟨+23x71.17

)8717(5.0460

⎥⎦

⎤⎢⎣

⎡⟩⟨

⟩⟨+⟩⟨+=

23x909.2)8717(5.015.273FA

--

74 69 84 79

A

IR-S

IDE

PRES

SUR

E D

RO

P C

ALC

ULA

TIO

NS

90 ( )JOBapΔ - Air-Side Pressure Drop at Job Conditions (constant wa)

= ν88ο x ν89ο x (ν5ο or ν79ο)

in. water

[Pa]

75 70 - - 91 )pt/LeFt - Tube Circuit Water Pressure Drop Parameter at 60 F [15.6ΕC] Mean Water Temperature (From Fig. 4 with ν19ο)

ft water per ft

[KPa/m]

76 71 - -

TUB

E-SI

DE

PRES

SUR

E D

RO

P C

ALC

ULA

TIO

NS

ft water 92 )ph/Ft - Header, nozzle and tube entrance and exit losses to be established by manufacturer at 60F mean water temperature with νΕ19ο

[KPa]



NUMERICAL VALUES

Form 410- 9

GENERAL PROCEDURE

COLD WATER COILS


COILS

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFA

CE

PA

RTI

ALL

Y

WET

S

UR

FAC

E

FU

LLY

W

ET

SU

RFC

E

GEN

ERA

L C

ATE

GO

RY

ITE

M N

O.


DIMENSIONS

72 - - 93 Fh - Temperature Correction Factor for Header Water Pressure Drop (From Fig. 7 with ν46ο)

73 - - 94 Ft - Temperature Correction Factor for Tube Circuit Water Pressure Drop (From Fig. 7 with ν46ο)

--

79 74 - - 95 )pw JOB - Water Pressure Drop Across Coil at Job Conditions

= ν92ο x ν93ο + (ν14ο x ν91ο x ν94ο)

ft water

[Kpa]

- 85 80

A

IR-S

IDE

PRES

SUR

E D

RO

P C

ALC

ULA

TIO

NS

TUB

E-SI

DE

PRES

SUR

E D

RO

P C

ALC

ULA

TIO

NS

96 )pr - Refrigerant Pressure Drop Through Coil = ν36ο x ν39ο x ν14ο

psi

[Kpa]

Signed _________________________________________________________________ Title ______________________________________________________________________

Form 410- 9

CALCULATION OF HEAT TRANSFER COEFFICIENT AND FRICTION FACTOR FOR GLYCOL* COILS ARI CERTIFICATION PROGRAM FOR FORCED-CIRCULATED AIR-COOLING AND AIR-HEATING COILS

COMPANY DATE

COIL LINE COIL TYPE COIL SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

.


DIMENSIONS

NUMERICAL VALUES

1

Ao – Total External Coil Surface (From Form 410-1)

sq ft [m2]

2

Di – Tube Inside Diameter (from Form 410-1)

in [mm]

3

Nt – Total Number of Tubes in Coil

--

4

Lt – Coil Finned Tube Length Exposed to Air Flow

in [mm]

5

B – Surface Ratio (From Form 410-1)

--

6

Nc – Number of Tube Circuits in Coil

--

CO

IL P

HY

SIC

AL

DA

TA

7

Aix – Total Cross-Section Fluid Flow Area Inside Tubes = .00545 (ν2ο)2 × ν6ο [Aix = 7.85 × 10-7 (ν2ο)2 × ν6ο]

sq ft [m2]

*The term “Glycol” refers to ethylene glycol solutions only.

Form 410- 9

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

8

Ls = Straight Tube Length per Pass in [mm]

9

Kb – Equivalent Length of Coil Circuit Per Return

in [mm]

10

Le – Total Equivalent Length of Coil Circuit

⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎠

⎞⎜⎝

⎛−

⟩⟨⟩⟨

⟩⟨+⎟⎠

⎞⎜⎝

⎛⟩⟨⟩⟨

⟩⟨ 1639

63808330.

⎥⎥⎦

⎤

⎢⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎠

⎞⎜⎝

⎛−

⟩⟨⟩⟨

⟩⟨+⎟⎠

⎞⎜⎝

⎛⟩⟨⟩⟨

⟩⟨= 1639

6380010Le .

ft [m]

TEST RUN NUMBER

1 2 3 4 5 6

11

pS– Average Absolute Static Pressure at Coil

In Hg abs

[kPa]

12

t1 – Entering Air Dry-Bulb Temperature

°F [°C]

13

1t′ – Entering Air Wet-Bulb Temperature

°F [°C]

14

h1 - Entering Air Enthalpy

Btu per lb [kJ/kg]

15

t2- Leaving Air Dry-Bulb Temperature

°F [°C]

16

Glycol Concentration

Percent by weight

17

Va – Standard Air Face Velocity

ft per min

[m/s]

Form 410- 9

TEST RUN NUMBER G

ENER

AL

CA

TEG

OR

Y

ITEM

NO

.


DIMENSIONS

1 2 3 4 5 6

18 tg1 – Entering Glycol Temperature °F [°C]

19 tg2 – Leaving Glycol Temperature °F [°C]

20 tgm – Mean Glycol Temperature = 0.5 (ν18ο + ν19ο) °F [°C]

OB

SER

VA

TIO

NS

AN

D

CA

LCU

LATI

ON

S

21 wg – Glycol Flow Rate lb per h [g/s]

22 qs – Average Sensible Cooling Capacity Btuh [W]

23 Δtm – Overall Logarithmic Mean Temperature Difference ( ) ( )

⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨=

18151912

18151912

ln

If other than thermal counterflow, determine the logarithmic mean temperature difference from Figures 13, 14, or 15

°F [°C]

24 R – Overall Thermal Resistance =

⟩⟨⟩⟨×⟩⟨

22231

Btu

Fftsqh o

[m2 ⋅ °C/W]

25 RaD + RmD - Combined Air Film Plus Metal Thermal Resistance (From Figure 4 with ν17ο) Btu

Fftsqh o

[m2 ⋅ °C/W]

26 Rg – Film Thermal Resistance of Glycol = ν24ο - ν25ο Btu

Fftsqh o

[m2 ⋅ °C/W]

CA

LCU

LATI

ON

S O

F G

LYC

OL

THER

MA

L R

ESIS

TAN

CE

27 fg – Glycol Film Heat Transfer Coefficient = ν5ο / ν26ο Fftsqh

Btuo

[W/ m2 ⋅ °C]

GEN

ERA

L ITE M

ITEM DESCRIPTION

DIMENSIONS TEST RUN NUMBER

Form 410- 9

1 2 3 4 5 6

28 ttw – Average Tube Wall Temperature = ν20ο + [ν26ο / ν24ο] × ν23ο

°F [°C]

29

μtw – Absolute Viscosity of Glycol at ν16ο and ν28ο

lb per ft h [mPa ⋅ s]

30

μg – Absolute Viscosity of Glycol at ν16ο and ν20ο


31

dg – Specific Gravity of Glycol at ν16ο and ν20ο

--

32

cpg – Specific Heat of Glycol at ν16ο and ν20ο

Btu per lb °F [KJ/kg ⋅ °C]

33

kg – Thermal Conductivity of Glycol at ν16ο and ν20ο Fftsqh

Btuo

[W/ m2 ⋅ °C]

34

(μtw / μg) .14 – Viscosity Ratio = (ν29ο /ν30ο).14

--

35

Pr – Prandtl Number = (ν32ο × ν30ο) / ν33ο

--

36

Pr 2/3 = (ν35ο)2/3

--

37

Cg – Mass Velocity of Glycol

lb per sq ft h

[g/m2 ⋅ s]

C

ALC

ULA

TIO

NS

OF

GLY

CO

L TH

ERM

AL

RES

ISTA

NC

E

38 νg – Kinematic Viscosity of Glycol = ν30ο / (224,500 × ν31ο) [νg = ν30ο / ν31ο]

sq ft per sec

[mm2 /s]

GEN

ERA

L ITE M

ITEM DESCRIPTION

DIMENSIONS TEST RUN NUMBER

Form 410- 9

1 2 3 4 5 6

39 j – Colburn Heat Transfer Factor for Glycol = [ν27ο / (ν32ο × ν37ο)] (ν23ο × ν34ο)

--

40 Vg – Glycol Velocity Inside Tubes =

⟩⟨×⟩⟨

3150022437

,

⎥⎦

⎤⎢⎣

⎡⟩⟨

⟩⟨= 310000001

37Vg ,,

ft per sec

[m/s]

41 Re – Reynolds Number for Glycol =

⟩⟨×⟩⟨×⟩⟨

3812240

⟩⟨

⟩⟨×⟩⟨×=

382401000Re

--

42 Δpg – Glycol Pressure Drop

ft of glycol [kPa]

43 Δph – Header and Tube Entrance and Exit Loss – Established by the Manufacturer

ft of glycol [kPa]

44

Δpt /Le – Glycol Pressure Drop Inside Tubes

= ⟩⟨

⟩⟨−⟩⟨10

4342

ft of glycol per ft equiv. tube length

[kPa/m]

45

f’ – Friction Factor for Glycol

[ ] ⎥⎥⎦

⎤

⎢⎢⎣

⎡

⟩⟨×⟩⟨

⟩⟨×⟩⟨×=

⟩⟨×⟩⟨

⟩⟨×⟩⟨×=

3440442000450f

3440442341

22.'.

--

46

Plot j vs Re on Logarithmic Coordinates as Shown in Figure 16

-

-

-

-

-

-

CA

LCU

LATI

ON

OF

HEA

T TR

AN

SFER

AN

D P

RES

SUR

E D

RO

P F

AC

TOR

S FO

R P

LOTT

ING

-

-

-

-

- 47 Plot f’ vs Re on Logarithmic Coordinates as Shown in Figure

16

-

Form 410- 9

SUGGESTED FORM FOR RATING CALCULATION PROCEDURE FOR SENSIBLE HEAT AIR COILS WITH ETHLYENE GLYCOL SOLUTIONS

ARI CERTIFICATION PROGRAM FOR FORCED-CIRCULATED AIR-COOLING AND AIR-HEATING COILS

COMPANY DATE

SOLUTION PROCEDURE STEPS

FOR SPECIFIC COIL APPLICATION


GENERAL PROCEDURE


(qS)

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

.


TO SOLVE FOR ROWS

DEEP (NR)

DIMENSIONS

NUMERICAL VALUES

1

1

1

H – Coil Face Height

in [mm]

2

2

2

L – Coil Face Length

in [mm]

3

3

3

Af – Coil Face Area

sq ft [m2]

4

4

4

B – Surface Ration (from Form 410-1)

--

-

5

5

Nr – Number of Rows Deep

--

-

6

6


--

5

7

7

Nc – Parallel Tube Circuits in Coil

--

6

8

8

Ao / Af Nr

(sq ft) per (sq ft – F.A.)

(row) [(sq metre) per

(sq metre – F.A.) (row)]

CO

IL P

HY

SIC

AL

DA

TA

9

Ao = ν8ο × ν3ο × ν5ο

sq ft [m2]

-

9

Form 410- 9



GENERAL PROCEDURE

TO SOLVE FOR ROWS

DEEP (Nr)

TO SOLVE FOR

CAPACITY (qs)

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

7 10 10 Di – Tube Inside Diameter in [mm]

8

11

11

Aix – Total Cross-Sectional Fluid Flow Area Inside Tubes = 0.00545 (ν10ο2 × ν7ο) [Aix = 7.85 × 10 –7 (ν10ο2 × ν7ο)]

sq ft [m2]

9

12

12

Ls – Straight Tube Length per Tube Pass

in [mm]

10

13

13

Kb – Equivalent Length of Coil Circuit per Return Bend

in [mm]

11

14

CO

IL P

HY

SIC

AL

DA

TA

14

Ls /Di – Ratio of Tube Length to Diameter = ν12ο / ν10ο

--

12

15

15

Qa – Air Volume Flow at Standard Conditions

scfm [l/s]

13

16

16

Va – Standard Air Face Velocity, ν15ο / ν3ο [Va = 0.001 × ν15ο / ν3ο]

ft per min

[m/s]

14

17

17

t1 – Entering Air Dry-Bulb Temperature

°F [°C]

15

18

18

tg1 - Entering Ethylene Glycol Solution Temperature

°F [°C]

16

19

RA

TIN

G C

ON

DIT

ION

S

19

Δto – Initial Air-to-Ethylene Glycol Solution Temperature = ν17ο - ν18ο for Air-Cooling Coils ν18ο - ν17ο for Air-Heating Coils

°F [°C]

Form 410- 9



GENERAL PROCEDURE

TO SOLVE FOR ROWS

DEEP (Nr)

TO SOLVE FOR

CAPACITY (qs)

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

17 20 20 pS – Average Absolute Static Pressure at Coil in Hg abs [kPa abs]

18

21

21

wg – Total Ethylene Glycol Solution Flow Rate

lb per h

[g/s]

19

22

22

wg /Nc – Ethylene Glycol Solution Flow Rate per Circuit = ν21ο / ν7ο

lb per (h) (circuit)

[(gram) per (second) (circuit)]

20

--

23

qs – Coil Sensible Heat (known)

Btuh [W]

21

--

24

Δta – Air Temperature Rise or Drop Across

Coil = ⎥⎥⎦

⎤

⎢⎢⎣

⎡

⟩⟨×⟩⟨

Λ⟩⟨×

⟩⟨15c21

23t

15c5423

pa

p ..

°F [°C]

22

--

25

t2 – Leaving Air Temperature at Coil = ν17ο - ν24ο for Air-Cooling Coils = ν17ο + ν24ο for Air-Heating Coils

°F [°C]

23

23

RA

TIN

G C

ON

DIT

ION

S

26

Ethylene Glycol Concentration

percent by weight

Form 410- 9



GENERAL PROCEDURE

TO SOLVE FOR ROWS

DEEP (Nr)

TO SOLVE FOR

CAPACITY (qs)

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

24 24 27 tgm – Mean Ethylene Glycol Solution Temperature - when solving for rows deep this value must be

calculated by trial and error using ν26ο and determining cpg for various values of tgm with the following equations:

pg

gm c2122318t

×⟩⟨×⟩⟨

+⟩⟨= for Air-Cooling Coils

pg

gm c2122318t

×⟩⟨×⟩⟨

+⟩⟨= for Air-Heating Coils

- when solving for capacity, this value must be approximated (suggest tgm be 5 °F [2.8 °C] to 10 °F [5.6 °C] from ν18ο)

°F [°C]

25

25

28

cpg – Specific Heat for Ethylene Glycol Solution at ν26ο and ν27ο

Btu /lb ⋅ °F [KJ/kg ⋅ °C]

26

26

29

dg – Specific Gravity of Ethylene Glycol Solution at ν26ο and ν27ο

--

27

27

30

kg – Thermal Conductivity of Ethylene Glycol Solution at ν26ο and ν27ο

FfthBtu

o−−

[W/m ⋅ °C]

ETH

YLE

NE

GLY

CO

L SO

LUTI

ON

PR

OPE

RTI

ES A

ND

CA

LCU

LATI

ON

S

31

28 28

μg – Absolute Viscosity of Ethylene Glycol Solution at ν26ο and ν27ο = centipoise × 2.42


SOLUTION PROCEDURE STEPS FOR SPECIFIC COIL

APPLICATION

GENERAL PROCEDURE

Form 410- 9

TO SOLVE FOR ROWS

DEEP (Nr)

TO SOLVE FOR

CAPACITY (qs)

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

29 29 32 νg – Kinematic Viscosity of Ethylene Glycol Solution = ν31ο / (224,500 × ν29ο) [νg = ν31ο / ν29ο]

sq ft per sec

[mm2/s]

30

30

33

Gg – Mass Velocity of Glycol = ν21ο / ν11ο

lb per sq ft h [g/s ⋅ m2]

31

31

34

Vg – Ethylene Glycol Solution Velocity Inside Tubes =

⎥⎦

⎤⎢⎣

⎡⟩⟨×

⟩⟨=

⟩⟨×⟩⟨

29000000133V

2950022433

g ,,,

ft per sec

[m/s]

32

32

35

Re – Reynolds Number for Ethylene Glycol Solution

= ⎥⎦

⎤⎢⎣

⎡⟩⟨

⟩⟨×⟩⟨×=

⟩⟨×⟩⟨×⟩⟨

3210341000R

32121034

e

--

33

33

36

Pr – Prandtl Number for Ethylene Glycol Solution

= ⟩⟨

⟩⟨×⟩⟨30

3128

--

34

34

37

Pr

2/3 = (ν36ο) 2/3

--

35

35 ET

HY

LEN

E G

LYC

OL

SOLU

TIO

N P

RO

PER

TIES

AN

D C

ALC

ULA

TIO

NS

38

j = Colburn Heat Transfer Factor for Ethylene Glycol Solution at ν35ο and ν14ο and Figure 16

--

36

36

GEN

ERA

L C

ALU

CU

-LA

TIO

NS

39

RaD + RmD – Combined Air Film Plus Metal Thermal Resistance (From Figure 4 with ν16ο)

BtuFftsqh o

[m2 ⋅ °C/W]


APPLICATION

GENERAL PROCEDURE

Form 410- 9

TO SOLVE FOR ROWS

DEEP (Nr)

TO SOLVE FOR

CAPACITY (qs)

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

37 37 40 M - Air-to Ethylene Glycol Solution Heat Capacity

Ratio = ⎥⎦

⎤⎢⎣

⎡⟩⟨×⟩⟨

×⟩⟨×=

⟩⟨×⟩⟨

⟩⟨×

2821c1521

M2821

c1554 1p ..

--

38

--

41

E – Air-side Effectiveness = ν24ο / ν19ο

--

39

--

42

co – Heat Transfer Exponent (Air-to-Ethylene Glycol Solution) – From Figure 13 or 14 or 15 with ν40ο and ν41ο

--

40

--

43

Δtm – Overall Mean Temperature Difference = ν24ο / ν42ο

°F [°C]

41

38

44

ttw – Average Tube Wall Temperature

- when solving for rows deep this temperature must be approximated, suggest ttw = ν27ο + .5 × ν43ο for Air-Cooling Coils ttw = ν27ο + .5 × ν43ο for Air-Heating Coils

- when solving for capacity, suggest this temperature be approximated using ttw about 10 °F[5.6 °C] to 15 °F[8.3 °C] from ν18ο

°F [°C]

GEN

ERA

L C

ALC

ULA

TIO

NS

45

42 39 μtw - Absolute Viscosity of Ethylene Glycol Solution

at ν26ο and ν44ο



APPLICATION

GENERAL PROCEDURE

Form 410- 9

TO SOLVE FOR ROWS

DEEP (Nr)

TO SOLVE FOR

CAPACITY (qs)

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

43 40 46 (μtw /μg) .14 – Viscosity Ratio = (ν45ο / ν31ο).14 --

44

41

47

fg – Ethylene Glycol Solution Film Heat Transfer

Coefficient = ⟩⟨×⟩⟨

⟩⟨×⟩⟨×⟩⟨4637

383328 Fftsqh

Btuo

[W/ m2 ⋅ °C]

45

42

48

Rg – Film Thermal Resistance of Ethylene Glycol Solution = ν4ο / ν47ο

BtuFftsqh o

[m2 ⋅ °C/W]

46

43

49

R – Overall Thermal Resistance = ν39ο + ν48ο

BtuFftsqh o

[m2 ⋅ °C/W]

47

--

GEN

ERA

L C

ALC

ULA

TIO

NS

50

*ttw – Average Tube Wall Temperature = ν27ο + (ν48ο / ν49ο) (ν43ο) for Air-Cooling Coils = ν27ο - (ν48ο / ν49ο) (ν43ο) for Air-Heating Coils

°F [°C]

48

--

51

Nrc – Calculated Row Depth Required

= ⟩⟨×⟩⟨×⟩⟨⟩⟨×⟩⟨×⟩⟨

2483424923

--

49

--

52

Nr – Integral Coil Row Depth Installed

--

50

--

CA

LCU

LATI

ON

S TO

SO

LVE

FOR

RO

WS

DEE

P

53


--

*ν50ο must equal ν44ο within ±3 °F [∀ 1.7 °C]. If not, assume a new value for ν44ο and repeat calculations through ν50ο.


APPLICATION

GENERAL PROCEDURE

Form 410- 9

TO SOLVE FOR ROWS

DEEP (Nr)

TO SOLVE FOR

CAPACITY (qs)

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

-- 44 54 co – Heat Transfer Exponent (Air-to-Ethylene Glycol Solution) =

⎥⎥⎦

⎤

⎢⎢⎣

⎡

⟩⟨×⟩⟨×⟩⟨

=⟩⟨×⟩⟨×

⟩⟨4915c54

9c4915c54

9

po

p ..

--

--

45

55

E – Air Side Effectiveness from Figure 13 or 14 or 15 with ν40ο and ν54ο

--

--

46

56

Δta – Air Temperature Rise or Drop Across Coil = ν55ο × ν19ο

°F [°C]

--

47

57

Δtg – Ethylene Glycol Solution Temperature Rise or Drop Across Coil = ν56ο × ν40ο

°F [°C]

--

48

58

Δtm – Overall Mean Temperature Difference = ν56ο / ν54ο

°F [°C]

--

49

59

*tgm – Mean Ethylene Glycol Solution Temperature *tgm = ν18ο + .5 × ν57ο for Air-Cooling Coils *tgm = ν18ο - .5 × ν57ο for Air-Heating Coils

°F [°C]

CA

LCU

LATI

ON

S TO

SO

LVE

FOR

CA

PAC

ITY

60

*ttw – Average Tube Wall Temperature *ttw = ν59ο + [ν48ο / ν49ο] ν58ο for Air-Cooling

-- 50

Coils *ttw = ν59ο - [ν48ο / ν49ο] ν58οfor Air-Heating Coils

°F [°C]

*ν59ο must equal ν27ο and ν60ο must equal ν44ο within ± 3 °F [±1.7 °C]. If not, assume new values for ν27ο and ν44ο and repeat calculations through ν60ο.


APPLICATION

GENERAL PROCEDURE

Form 410- 9

TO SOLVE FOR ROWS

DEEP (Nr)

TO SOLVE FOR

CAPACITY (qs)

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

-- 51 61 qs – Coil Sensible Heat = 4.5 cp × ν15ο × ν56ο [qs = 1.2 cp × ν15ο × ν56ο]

Btuh [W]

-- 52

CA

LCU

LATI

ON

S TO

SO

LVE

FOR

C

APA

CIT

Y

62 t2 – Leaving Air Temperature at Coil = ν17ο - ν56ο for Air-Cooling Coils = ν17ο + ν56ο for Air-Heating Coils

°F [°C]

51 53 63 Δpst /Nr – Air Side Pressure Drop Per Row Deep at Standard Conditions (From Figure 3 or 4 with ν16ο)

rowwaterin

[Pa / row]

52 54 64 Fa – Air-side Pressure Drop Correction Factor

[ ]

⎥⎥⎥⎥

⎦

⎤

⎢⎢⎢⎢

⎣

⎡⎟⎠⎞

⎜⎝⎛

=

⟩⟨×

⟩⟨⟩⟨+⟩⟨+

=

⟩⟨×

⟩⟨⟩⟨+⟩⟨+

2090922

62or251715273

aF

20711762or2517460

.

.

.

--

53 55 65 (Δpa)Job– Air Side Pressure Drop at Job Conditions (constant wa) = [ν63ο × ν64ο] × ν5ο orν52ο

in water [Pa]

54 56

G

ENER

AL

CA

LCU

LATI

ON

S

66 Le – Total Equivalent Length of Coil Circuit

= ⎥⎦

⎤⎢⎣

⎡⎟⎠

⎞⎜⎝

⎛⎟⎠

⎞⎜⎝

⎛−

⟩⟨

⟩⟨⟩⟨⟩⟨+

⟩⟨

⟩⟨⟩⟨⟩⟨ 1

753or6

137

53or6120833.

ft [m]

55

57

67

f’ – Friction Factor for Ethylene Glycol Solution from Figure 16 at ν35ο

--

Form 410- 9



GENERAL PROCEDURE

TO SOLVE FOR ROWS

DEEP (Nr)

TO SOLVE FOR

CAPACITY (qs)

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

56

58

68

Δpt /Le – Ethylene Glycol Solution Pressure Drop Inside Tubes

⎥⎥⎦

⎤

⎢⎢⎣

⎡

⟩⟨×⟩⟨⟩⟨×⟩⟨

=⟩⟨×

⟩⟨×⟩⟨×⟩⟨=

10000450463467

10341463467 22

..


[kPa]

57

59

69

Δph – Header and Tube Entrance and Exit Loss- Established by the Manufacturer

ft of glycol

[kPa]

G

ENER

AL

CA

LCU

LATI

ON

S

(Δpg ) JOB – Ethylene Glycol Solution Pressure Drop Across Coil at Job Conditions = (ν66ο × ν68ο) + ν69ο

ft of glycol

[kPa] 58 60 70

Form 410- 9

SUGGESTED FORM FOR RATING CALCULATION PROCEDURE FOR COOLING AND DEHUMIDIFYING COILS, WITH ETHYLENE GLYCOL* SOLUTION, ARI CERTIFICATION PROGRAM FOR FORCED-CIRCULATION AIR-COOLING AND AIR-HEATING COILS

COMPANY DATE




GENERAL PROCEDURE

WET SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

.


PARTIALLY WET

SURFACE DIMENSIONS

NUMERICAL VALUES

1

1

1

H – Coil Face Height

in [mm]

2

2

2

L – Coil Face Length

in [mm]

3

3

3

Af – Coil Face Area

sq ft [m2]

4

4

4

B – Surface Ration (from Form 410-1)

--

5

5

5

Nr – Number of Rows Deep (if known)

--

6

6

6

Nt – Total Number of Tubes in Coil (if known)

--

7

7

7

Nc – Parallel Tube Circuits in Coil (if known)

--

8

8

8

Ao / Af Nr

(sq ft) per (sq ft – F.A.)

(row) [(sq metre) per

(sq metre – F.A.) (row)]

9

9

9

Di - Tube Inside Diameter

in [mm]

10

10

Ls – Straight Tube Length Per Tube Pass

in [mm]

10

11

11

CO

IL P

HY

SIC

AL

DA

TA

11

Kb – Equivalent Length of Coil Circuit Per Return Bend

in [mm]

Form 410- 9


APPLICATION

GENERAL PROCEDURE

PARTIALLY WETTTED SURFACE

FULLY

WETTTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

12 12 12 Ao = ν8ο × ν3ο × ν5ο (if known) sq ft [m2]

13

13

13

Aix – Total Cross-Sectional Fluid Flow Area Inside Tubes = 0.00545 (ν9ο2 × ν7ο) [Aix = 7.85 × 10 –7 (ν9ο2 × ν7ο)]

sq ft [m2]

14

14

14

Le – Total Equivalent Length of Coil Circuit

⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎠

⎞⎜⎝

⎛−

⟩⟨⟩⟨

⟩⟨+⎟⎠

⎞⎜⎝

⎛⟩⟨⟩⟨

⟩⟨ 17611

761008330.

⎥⎥⎦

⎤

⎢⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎠

⎞⎜⎝

⎛−

⟩⟨⟩⟨

⟩⟨+⎟⎠

⎞⎜⎝

⎛⟩⟨⟩⟨

⟩⟨= 17611

76100010Le .

ft [m]

15 15

CO

IL P

HY

SIC

AL

DA

TA

15 Ls/Di– Ratio of Tube Length to Diameter = ν10ο / ν9ο

--

16

16

16

scfm [l /s]

Qa – Air Volume Flow at Standard Conditions

17

17

17

Va – Standard Air Face Velocity = ν16ο / ν3ο [Va = 0.001 × ν16ο / ν3ο]

ft per min

[m/s]

18 t1 – Entering Air Dry-Bulb Temperature °F [°C]

19

19

19

1t′ - Entering Air Wet-Bulb Temperature

°F [°C]

20

20

20

wg- Total Ethylene Glycol Solution Flow Rate

lb per h

[g/s]

21

21

21

tg1 – Entering Ethylene Glycol Solution Temperature

°F [°C]

22

22

RA

TIN

G C

ON

DIT

ION

S A

ND

DA

TA

CO

MPU

TATI

ON

S

22

in Hg abs Ps – Average Absolute S. P. at Coil [kPa abs]

Form 410- 9


APPLICATION

GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

.

ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

23 23 23 h1= Entering Air Enthalpy (from ν18ο, ν19ο & ν22ο) Btu per lb [kJ/kg]

24 24 R

ATI

NG

CO

ND

ITIO

NS

&

DA

TA

CO

MPU

TATI

ON

24 Wg / Nc – Ethylene Glycol Solution Flow Rate per circuit = ν20ο / ν7ο,

sq ft [m2]

25

25

RA

TIN

G C

ON

DIT

ION

S, P

AR

AM

ETER

S &

D

ATA

CO

MPU

TATI

ON

S

25

1t ′′ – Entering Air Dew Point Temperature (from psychrometric chart with ν18ο, ν19ο & ν22ο Calculation of Dew Point temperature for non std. air pressure*:

( ) ( )( ) ⎟⎟

⎠

⎞⎜⎜⎝

⎛⟩⟨−

⟩⟨−⟩⟨′−⟩⟨−′=

1944128301918p22pvP

.

( ) ( )

( ) ⎥⎥⎦

⎤

⎢⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨−⟩⟨−⟩⟨′−⟩⟨

−′=1933141548

1918p22pvP..

where: p’ = Saturation Vapor Pressure at ν19ο, from Steam Tables…. Pv = Saturation Vapor Pressure at Dew Point Temperature…. 1t ′′ = Dew Point Temperature is Saturated Temperature corresponding to Pv , from Steam Tables…

°F [°C]

In Hg abs [kPa abs]

°F [°C]

26 26 26 1h ′′ = Saturated Enthalpy at Dew Point (from Psychrometric Chart with ν22ο / ν25ο)

Btu per lb [kJ /kg]

* Jordan and Prelester, Refrigeration and Air Conditioning, 2nd Edition, 1956

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

27 27 27 RaD – Air Film Thermal Resistance for Dry Surface (from Figure 5 or 6 with ν17ο)

(h) (sq ft) (F) per Btu [m2 ⋅ °C/W]

28 28 28 RaW – Air Film Thermal Resistance for Wetted Surface (from Figure 5 or 6 with ν17ο)


29 29 29 RmD – Metal Thermal Resistance for Dry Surface (from Figure 2 at fa = 1/ν27ο)


30 30 30 Ethylene Glycol Concentration Percent by weight

31 31 31 60 wa – Standard Air Flow Rate = 4.5 × ν16ο [1000 wa = 1.2 × ν16ο]

lb per h [g/s]

32 32 32 Case I - If ν33ο is known, determine ν34ο at ν33ο saturated, and ν22ο. Then calculate ν35ο = ν31ο (ν23ο - ν34ο). Case II - If ν35ο is known, determine ν34ο and then ν33ο. ν34ο = ν23ο - ν35ο / ν31ο. Case III - If ν5ο is known, assume ν35ο or ν33ο find ν34ο and then ν33ο or ν35ο respectively.

--

33

33

33

2t ′ – Leaving Air Wet-Bulb Temperature

°F [°C]

RA

TIN

G C

ON

DIT

ION

S, P

AR

AM

ETER

S A

ND

DA

TA

CO

MPU

TATI

ON

S

34

34 34

2h - Leaving Air Enthalpy – It qt is known,

⟩⟨

−⟩⟨=31q

23h t2

Btu per lb [kJ / kg]

Form 410- 9


APPLICATION

GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

35 35 35 qt – Total Heat Capacity of Coil = ν31ο (ν23ο - ν34ο) If not known, assume value for trial and error solution

Btu [W]

36 36 36 tgm – Mean Ethylene Glycol Solution Temperature – when capacity is know, this value must be calculated by trial and error using ν30ο and determining cpg for various values of tgm using the following equation:

pg

gm c2023521t

×⟩⟨×⟩⟨

+⟩⟨=

°F [°C]

37 37 37 cpg – Specific Heat of Ethylene Glycol Solution at ν30ο and ν36ο

Btu per (lb °F) [kJ / kg °C]

38 38 38 dg – Specific Gravity of Ethylene Glycol Solution at ν30ο and ν36ο

--

39 39 39 kg – Thermal Conductivity of Ethylene Glycol Solution at ν30ο and ν36ο [ ]CmW

FfthBtu

°⋅°⋅⋅

/

40 40

RA

TIN

G C

ON

DIT

ION

S, P

AR

AM

ETER

S A

ND

DA

TA

CO

MPU

TATI

ON

S

40 μg – Absolute Viscosity of Ethylene Glycol Solution at ν30ο and ν36ο [Note: μg (lb / ft ⋅ h) = 2.42 × μg (centipoise)]

lb per (ft h)

[mPa ⋅ s]

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

41 41 41 νg – Kinematic Viscosity of Ethylene Glycol Solution = ν40ο / (224,500 × ν38ο)

⎥⎦

⎤⎢⎣

⎡⟩⟨⟩⟨

=ν3840

g

sq ft per sec

[mm2 /s]

42 42 42 Gg – Mass Velocity of Glycol = ν20ο / ν13ο lb per (sq ft – h) [g m2 ⋅ s]

43 43 43 Vg – Ethylene Glycol Solution Velocity Inside

Tubes = ⎥⎦

⎤⎢⎣

⎡⟩⟨×

⟩⟨=

⟩⟨×⟩⟨

38000000142

3850022442

,,V

, g

ft per sec

[m/s]

44 44 44 Re – Reynolds Number for Ethylene Glycol Solution

⎥⎦

⎤⎢⎣

⎡⟩⟨

⟩⟨×⟩⟨=

⟩⟨×⟩⟨×⟩⟨

=41

943x1000R4112

943e

--

45 45 45 Pr – Prandtl Number for Ethylene Glycol Solution

= ⟩⟨

⟩⟨×⟩⟨39

4037

--

46 46 46 Pr2/3 = (ν45ο) 2/3 --

47 47 47 j – Colburn Heat Transfer Factor for Ethylene Glycol Solution at ν44ο and ν15ο from Figure 16

--

RA

TIN

G C

ON

DIT

ION

S, P

AR

AM

ETER

S A

ND

DA

TA

48 48 48 tg2 – Leaving Ethylene Glycol Solution Temperature = ν21ο + ν35ο / (ν20ο × ν37ο)

°F [°C]

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

49 49 49 Y –Ratio of Tube-Side Temperature Difference to Air Enthalpy Difference = (ν21ο - ν48ο / (ν23ο - ν34ο)

( ) ( )Btuper

Flb °

[kg ⋅ °C/kJ]

50 50 50 ttw – Average Tube Wall Temperature (Approximate when solving for rows deep or capacity) assume 10 to 15 °F [5.6 to 8.3 °C] from ν36ο

°F [°C]

51 51 51 μtw – Absolute Viscosity of Ethylene Glycol Solution at ν30ο and ν50ο

lb per ft h [mPa ⋅s]

52 52 52 (μtw / μg).14 – Viscosity Ratio = (ν51ο / ν40ο).14 --

53 53 53 fg – Ethylene Glycol Solution Film Heat Transfer

Coefficient = ⟩⟨×⟩⟨

⟩⟨×⟩⟨×⟩⟨5246

474237

Btu per (h) (sq ft) (°F)

[W/m2 ⋅ °C]

54 54 54 Rg – Film Thermal Resistance of Ethylene Glycol Solution = ν4ο / ν53ο

(h) (sq ft) (°F) per Btu

[m2 ⋅ °C/W]

55 55

RA

TIN

G C

ON

DIT

ION

S, P

AR

AM

ETER

S A

ND

DA

TA

55 Approximate Coil Characteristic =

⎥⎦

⎤⎢⎣

⎡⟩⟨×⟩⟨+⟩⟨

⟩⟨×⟩⟨+⟩⟨

2801812954

2824302954

..

used to obtain Rmw in ν63ο

(lb) (°F) per Btu [kg ⋅ °C/kJ]

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

56 56 56 Approximate Air Enthalpy at Boundary Conditions ( ) ( )

⟩⟨+⟩⟨⟩⟨×⟩⟨+⟩⟨×⟩⟨+⟩⟨−⟩⟨

5549265523494825 =

If ν56ο > ν23ο use ν56ο = ν23ο since coil is fully wet

Btu per lb [kJ /kg]

57 57 57 Approximate Tube Side Temperature at Dry-Wet Boundary = ν48ο - ν49ο (ν23ο - ν56ο)

°F [°C]

58 58 58 Mean Tube Side Temperature = 0.5 (ν21ο + ν57ο) for partially dry coil = 0.5 (ν21ο + ν48ο) for fully wet coil

°F [°C]

59 59 59 Approximate Mean Air Enthalpy of Wetted Section = 0.5 (ν56ο + ν34ο) for partially dry coil = 0.5 (ν23ο + ν34ο) for fully wet coil

Btu per lb [kJ/kg]

60 60 60 Approximate Mean Surface Temperature for Fully Wetted Coil or Wet Portion of Partially Dry Coil (from Figure 9 with ν55ο, ν58ο, and ν59ο)

°F [°C]

61 61 61 m” /cp – Air-Side Heat Transfer Multiplier for Wet Surface (from Figure 8, with ν60ο and ν22ο)

--

62 62

RA

TIN

G C

ON

DIT

ION

S, P

AR

AM

ETER

S A

ND

DA

TA

62 faw – Air-Side Thermal Conductance for Wet Surface = ν61ο / ν28ο

(Btu per (h) (sq ft) (°F)

[W/m2 ⋅ °C]

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

63 63 63 Rmw – Metal Thermal Resistance for Wet Surface (from Figure 2 with ν62ο})

(sq ft) (h) (°F) per Btu

[m2 ⋅ °C/W]

64 64 64 C – Coil Characteristic for Wetted Surface

= ⎥⎦

⎤⎢⎣

⎡⟩⟨×⟩⟨+⟩⟨

=⟩⟨×⟩⟨+⟩⟨

2801816354C

2824306354

..

(lb) (°F) per Btu

[kg ⋅ °C/kJ]

65 65 65 hB – Air Enthalpy at Boundary

= ( ) ( )⟩⟨+⟩⟨

⟩⟨⟩⟨+⟩⟨×⟩⟨+⟩⟨−⟩⟨6449

266423494825

If ν65ο < ν23ο, surface is partially dry If ν65ο ≥ ν23ο, surface is fully wet

Btu per lb [kJ/kg]

66 66 66 hm – Mean Air Enthalpy = 0.5 (ν23ο + ν34ο) For partially Dry Coil: If ν66ο ≥ ν65ο Complete items ν67ο and ν68ο If ν66ο < ν65ο, complete items ν69ο, ν70ο and ν71ο For Fully Wet Coils complete items ν69ο, ν70ο and ν71ο (See Figures on Last Page of This Form)

Btu per lb [kJ/kg]

67 -- RA

TIN

G C

ON

DIT

ION

S, P

AR

AM

ETER

S A

ND

DA

TA

67 tm – Air Dry Bulb Temperature Where Tube Side Temperature Equals tgm

= ν48ο - (0.5 × ν35ο) / (0.243 × ν31ο) = ν48ο - (0.5 × ν35ο) / (1.018 × ν31ο)

°F [°C]

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

68 -- 68 * ttw – Average Tube Wall Temperature = ν36ο + ν54ο (ν67ο - ν36ο / (ν27ο + ν29ο + ν54ο)

°F [°C]

69 67 69 tsm – Surface Temperature Where Tube Side Temperature Equals tgm

From Figure 9 with ν22ο, ν36ο, ν64ο, and ν66ο

°F [°C]

70 68 70 hsm – Enthalpy of Saturated Air at ν69ο and ν22ο Btu per lb [kJ/kg]

71 69 71 *ttw – Average Tube Wall Temperature = ν36ο + ν54ο (ν66ο - ν70ο) / (0.243 × ν28ο) = ν36ο + ν54ο (ν66ο - ν70ο) / (1.018 × ν28ο)

°F [°C]

72 -- 72 qtD – Capacity for Dry Portion of Coil = ν31ο (ν23ο - ν65ο)

Btuh [W]

73 -- 73 tB – Air Dry-Bulb Temperature at Boundary

= ⎥⎦

⎤⎢⎣

⎡⟩⟨×

⟩⟨⟩⟨=

⟩⟨×⟩⟨

−⟩⟨310181

7218t312430

7218 B ..

°F [°C]

74 --

RA

TIN

G C

ON

DIT

ION

S, P

AR

AM

ETER

S A

ND

DA

TA

74 tgB – Tube Side Temperature at Boundary Temperature Equals tgm

= ν48ο - ν49ο (ν23ο - ν65ο)

°F [°C]

* ν68ο or ν71ο must equal ν50ο within ± 3 °F [± 1.7 °C]. If not assume a new value for ν50ο and repeat calculations through ν68ο or ν71ο.

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

75 -- 75 Δtm – Logarithmic Mean Temperature Difference for Dry Portion of Coil

= ( ) ( )

⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨

74734818

74734818

ln

°F [°C]

76 -- 76 AcD – Calculated External Surface Area for Dry Portion of Coil

= ( )

⟩⟨⟩⟨+⟩⟨+⟩⟨⟩⟨

7554292772

sq ft [m2]

77 70 77 qtW – Capacity for Wet Portion of Coil = ν35ο - ν72ο for partially wet coils = ν35ο for fully wet coils

Btuh [W]

78 71 78 ts1 – Surface Temperature at Air Entering Side of Wet Portion = tsB = ν25ο for partially dry coils From Figure 9 with ν22ο, ν23ο, ν48ο and ν64ο for fully wet coil

°F [°C]

79 72 79 ts2 – Surface Temperature at Air Leaving Side of Wet Portion from Figure 9 with ν21ο, ν22ο, ν34ο, and ν64ο

°F [°C]

80 73 80 hs1 – Enthalpy of Saturated Air at ν78ο and ν22ο

Btu per lb

[kJ/kg]

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

81 74 81 hs2 – Enthalpy of Saturated Air at ν79ο andν22ο Btu per lb [kJ/kg]

82 75 82 Δhm – Logarithmic Mean Enthalpy Difference between Air Stream and Wetted Surface

= ( ) ( )

⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨

81348023In

81348023 For Fully Wet Coil

= ( ) ( )

⎟⎟⎠

⎞⎜⎜⎝

⎛⟩⟨−⟩⟨⟩⟨−⟩⟨

⟩⟨−⟩⟨−⟩⟨−⟩⟨

81348065In

81348065 For Partially Dry Coil

Btu per lb

[kJ/kg]

83 76

RA

TIN

GS

PAR

AM

ETER

S A

ND

DA

TA

CO

MPU

TATI

ON

S

83 AcW – Calculated External Surface Area for Fully Wet Coil or Wet Portion of Coil = 0.243 × ν28ο × ν77ο / ν82ο [Acw = 1.018 × ν28ο × ν77ο / ν82ο]

sq ft [m2]

84 77 84 Ac – Total Calculated External Surface Area = ν83ο + ν76ο for partially wet coils = ν83ο for fully wet coil Note: For Case I and II in ν32ο, complete ν86ο For Case III in ν32ο, complete ν86ο and ν87ο

sq ft [m2]

85 78

CA

LC. R

OW

S –

FOR

R

OW

S I A

ND

II

85 Nr – Required Number of Coil Tubes in Direction of

Air Flow =⟩⟨×⟩⟨

⟩⟨83

84

--

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

86 79 86 If ν84ο ≠ ν12ο, assume a new value of qt ≠ ν35ο Repeat calculations from ν32ο through ν84ο. Plot calculated values of ν84ο. Against assumed values of ν35ο as Shown in Figure 12c.

--

87 80 87 Determine actual value of qt from plot ν86ο with Ao = ν12ο.

Btuh [W]

88 81

CA

LC. R

OW

S FO

R C

ASE

II

I 88 c- Heat Transfer Exponent

= ⎥⎦

⎤⎢⎣

⎡⟩⟨×⟩⟨×

⟩⟨=

⟩⟨×⟩⟨××⟩⟨

3127018112c

312758146012

..

--

89 82 89 e-c – Heat Transfer Factor = eν-88ο --

90 83 90 h2 – Saturated Enthalpy at Effective Surface Temperature

= ⟩⟨−

⟩⟨⟩⟨−⟩⟨−⟩⟨

890190or342323

.

Btu per lb

[kJ/kg]

91 84 91 sh - Saturated Enthalpy at Effective Surface

Temperature = ⟩⟨−

⟩⟨⟩⟨−⟩⟨−⟩⟨

890190or342323

.

Btu per lb

[kJ/kg]

92 85

CA

LCU

LATI

ON

S TO

DET

ERM

INE

AIR

LEA

VIN

G D

RY

-BU

LB

TEM

PER

ATU

RE

92 st - Effective Surface Temperature From

Psychrometric Chart with ν22ο and ν91ο.

°F [°C]

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

93 86 93 t2 – Air leaving Dry Bulb Temperature = ν92ο + (ν18ο - ν92ο) ν89ο

°F [°C]

94 87 94 Δ psw /Nr - Air Side Pressure Drop per Row Deep at Standard Conditions (Use Wet Surface for Partially Dry and Fully Wet Coils.) - From Figure 5 with ν17ο

in water per row

[Pascal per row]

95 88

AIR

SID

E PR

ESSU

RE

DR

OP

CA

LCA

LCU

LATI

ON

S 95 Fa - Air Side Pressure Drop Correction Factor

= ( )⟩⟨×

⟩⟨+⟩⟨+227117

931850460..

( )⎥⎦

⎤⎢⎣

⎡⟩⟨×

⟩⟨+⟩⟨+=

22909293185015273Fa .

..

--

96 89 96 (Δpa)JOB – Air Side Pressure Drop at Job Conditions (Constant wa) ν94ο × ν95ο × (ν5ο or ν85ο)

in water

[Pa]

97 90 97 f’ – Friction Factor for Ethylene Glycol Solution from Figure 16 at ν44ο

--

98 91

TUB

E SI

DE

PRES

SUR

E D

RO

P C

ALC

ULA

TIO

NS

98 ΔPt /Le – Ethylene Glycol Solution Pressure Drop Inside tubes

= ⎥⎦

⎤⎢⎣

⎡

⟩⟨×⟩⟨×⟩⟨×⟩⟨

=Δ⟩⟨−

⟩⟨×⟩⟨−⟩⟨9000450

524397LeP9341

524397 2

t

2

./

.


[kPa/m]

Form 410- 9



GENERAL PROCEDURE

PARTIALLY

WETTED SURFACE

FULLY

WETTED SURFACE

GEN

ERA

L C

ATE

GO

RY

ITEM

NO

. ITEM DESCRIPTION


DIMENSIONS

NUMERICAL VALUES

99 92 99 Δph - Header and Tube Entrance and Exit Loss – Established by the Manufacturer

ft of glycol

[kPa]

100 93

TUB

E SI

DE

PRES

SUR

E D

RO

P C

ALC

UL.

100 (Δpg) JOB – Ethylene Glycol Solution Pressure Across ft of glycol Coil at Job Conditions

[kPa] = (ν14ο × ν98ο) + ν99ο Signed Title

Form 410- 9

TYPICAL THERMAL COUNTERFLOW DIAGRAMS FOR PARTIALLY DRY ETHYLENE GLYCOL SOLUTION COILS

For ν66ο < ν65ο

SURFACE

For ν66ο > ν65ο

tg1

t1, h1

tsm, hsmt”1

ts2, hs2

ts1

tsB, hsB

tgm

tg2

tgB

ttw

ts2, hs2

hm

tB, hB

Wet PortionDry Portion

TEM

PER

ATU

RE

OR

EN

THA

LPY

tgm

tg2

tgB

tsB, hsB

t”1

ttwts2, hs2

t2, h2

hm

tB, hB

t h Dry Portion1, 1 Wet Portion

TEM

PER

ATU

RE

OR

EN

THA

LPY

ts1

tsm, hsm

tg1

Form 410- 9

SURFACE

Form 410- 9

PRODUCTION COIL LINE CERTIFICATION


COMPANY DATE This will certify that the coils lines listed below have been rated on the basis of tests on production coils, or prototypes which are identical to the coils which will be produced.

TUBE COIL LINE

DESIGNATION

PRODUCTION (P) OR

PROTOTYPE (PX)

FLUID USED O.D.

in SPACING

sf /sr

ARRANGEMENT – Parallel or Staggered

CONSTRUCTION

FIN CONFIGURATION

Form 410- 9

Signed Title

FORCED-CIRCULATION AIR-COOLING AND AIR …ahrinet.org/App_Content/ahri/files/Certification/OM...

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Transcript of FORCED-CIRCULATION AIR-COOLING AND AIR …ahrinet.org/App_Content/ahri/files/Certification/OM...