DESIGNER’S GUIDE POWER-FIN BOILER

D ES IG N ER’S G U IDE P O W ER - F IN ® B O I L E R5 0 0 , 0 0 0 – 2 , 0 0 0 , 0 0 0 B t u / h r

Dear Specifier/Project Manager,

At Lochinvar, we have long recognized the importance of innovation to any

product or service. Those who enter into business must also accept the challenge

of meeting constantly changing needs.

The designer’s guide you are now holding has been designed to make it more

convenient for you to select the perfect Lochinvar boiler for your projects and

provide correct specifications for your teams.

All information has been organized and presented in a succinct, easy-to-use

manner, so you can use and share information confidently and with minimal

effort.

However, it is important to remember that this guide is not intended to replace our

installation manual. Installers should still refer to our installation manual for

specific installation instructions.

We hope our manual will make your work easier and more productive.

As always, we greatly appreciate your input on additional improvements for the

future.

Thanks once again for specifying the Lochinvar family of quality standard

and custom-built water heaters and boilers.

Sincerely,

Lochinvar Corporation

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L o c h i n v a r D E S I G N E R’ S G U I D E P O W E R - F I N B O I L E R 6 1 5 - 8 8 9 - 8 9 0 0 1

Table of ContentsAir Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23Boiler Operating Temperature Control . . . . . . . . . . .24Building Management Controls . . . . . . . . . . . . . . . .25Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2Combustion & Ventilation Air . . . . . . . . . . . . . . . . . . .5Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6Determining Total "Free" Area . . . . . . . . . . . . . . . . . .5Electrical Requirements . . . . . . . . . . . . . . . . . . . . . .25Gas Bleeds & Vents . . . . . . . . . . . . . . . . . . . . . . . .17Gas Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16General Venting . . . . . . . . . . . . . . . . . . . . . . . . . . . .6Location of Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . .2Low Water Temperature Systems . . . . . . . . . . . . . . .21Primary / Secondary Piping . . . . . . . . . . . . . . . . . .19Relief Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20Special System Design and Control Applications . . .18Systems with Low Water Volume . . . . . . . . . . . . . . .23Variable Flow Pumps . . . . . . . . . . . . . . . . . . . . . . .20Venting Options . . . . . . . . . . . . . . . . . . . . . . . . . . .10Venting Overview . . . . . . . . . . . . . . . . . . . . . . . . . . .8Water Flow Requirements and System Piping

Design Considerations . . . . . . . . . . . . . . . . . . . . .18Water Velocity Control . . . . . . . . . . . . . . . . . . . . . .17

Figures & Tables IndexFIG. 1 Clearances From Combustibles . . . . . . . . . .3FIG. 2 Boiler Equipment And Control Orientation . .4FIG. 3-6 Combustion And Ventilation Air . . . . . . . . .5FIG. 7 Multiple Unit Barometric Damper Installation 9FIG. 8 Conventional Negative Draft Venting . . . .10FIG. 9 Vertical Directaire W/ Sidewall Air Inlet . .10FIG. 10 Vertical Directaire W/ Rooftop Air Inlet . . .11FIG. 11 Vertical Negative Draft Venting . . . . . . . . .11FIG. 12 Vertical Positive Pressure Venting . . . . . . . .11FIG. 13 Horizontal Directaire W/ Rooftop Air Inlet 12FIG. 14 Horizontal Directaire W/ Sidewall Air Inlet

in a Different Pressure Zone . . . . . . . . . . .12FIG. 15 Sidewall Venting . . . . . . . . . . . . . . . . . . .12FIG. 16 Vertical Direct Vent . . . . . . . . . . . . . . . . . .13FIG. 17 Horizontal Direct Vent . . . . . . . . . . . . . . .13FIG. 18 Location Of Sidewall Vent Termination . . . .15FIG. 19 Heat Exchanger Head Loss . . . . . . . . . . .18FIG. 20 Boiler Temperature Rise Chart . . . . . . . . . .18

FIG. 21 Primary / Secondary System Piping . . . . .19FIG. 22 High Flow System Piping . . . . . . . . . . . . .20FIG. 23 Low Temperature Bypass - On/Off . . . . . .21FIG. 24 Low Temperature Bypass - Modulation . . . .21FIG. 25 Heating / Chilled Water System . . . . . . . .22FIG. 26 Buffer Tank Piping . . . . . . . . . . . . . . . . . .23

TABLE A Clearances From Combustibles . . . . . . . . . .3TABLE B Power-Fin Venting Configurations . . . . . . . .8TABLE C Flue & Combustion Air Pipe Sizes . . . . . . .10TABLE D Sidewall Air Inlet Kits . . . . . . . . . . . . . . . .10TABLE E Sidewall Vent Kits . . . . . . . . . . . . . . . . . .12TABLE F Horizontal Direct Vent Kits . . . . . . . . . . . .13TABLE G Inlet Gas Pressure Requirements . . . . . . . .16TABLE H Gas Supply Pipe Sizing . . . . . . . . . . . . . .17TABLE I Minimum & Maximum Flow Rates . . . . . . .17TABLE J Water Flow Requirements . . . . . . . . . . . . .18TABLE K Pipe Capacity . . . . . . . . . . . . . . . . . . . . .24TABLE L Amp Draw . . . . . . . . . . . . . . . . . . . . . . .25

Boiler Piping DiagramsPrimary / Secondary . . . . . . . . . . . . . . . . . . . . . . .A1Multiple Unit - Primary / Secondary . . . . . . . . . . . .A2Low Temperature Boiler Bypass - On/Off . . . . . . . . .A3Low Temperature Boiler Bypass - Modulating . . . . . .A4

CODESThe equipment shall be installed inaccordance with those installation regulationsin force in the local area where the installationis to be made. These shall be carefullyfollowed in all cases. Authorities havingjurisdiction should be consulted beforeinstallations are made.

In the absence of such requirements, theinstallation shall conform to the latest edition ofthe National Fuel Gas Code, ANSI Z223.1.Where required by the authority havingjurisdiction, the installation must conform toAmerican Society of Mechanical EngineersSafety Code for Controls and Safety Devicesfor Automatically Fired Boilers, ASME CSD-1.Where required by the authority havingjurisdiction, the installation must complywith the Canadian Association Code,CAN/CGA-B149.1 and/or B149.2 and/orlocal codes.

LOCATION OF UNITThese units are suitable for indoorinstallation only. Venting options andconfigurations are illustrated in theventing section.

Indoor units must be installed so that the ignition system components are protected from water (dripping, spraying,rain, etc.) during appliance operation andservice (circulator replacement, controlreplacement, etc.).

2 L o c h i n v a r D E S I G N E R’ S G U I D E P O W E R - F I N B O I L E R 6 1 5 - 8 8 9 - 8 9 0 0

Lochinvar

• Water Velocity

(See page 17 for minimum and

maximum flow rates.)

• Piping Requirements and

Specialties

(See page 19 - 22 for piping

application requirements.)

• Low Water Temperature System

(See page 21 for piping and

design recommendations.)

• System and Boiler Control

(See page 24 - 25 boiler operating

and temperature control.)

• Air Elimination

(See page 23 for air removal

information.)

In designing a hotwater heating system,

pay special attention to:

1.

Locate the unit so that if the water connections should leak, water damagewill not occur. When such locations cannotbe avoided, it is recommended that asuitable drain pan, adequately drained, beinstalled under the unit. The pan must notrestrict combustion air flow.

Allow sufficient space in the back of boiler for servicing pipe connections,pump, and other auxiliary equipment,as well as the unit.

The unit must be placed on a level floor; combustible floor locationsmay be used.

NOTE: For multiple boiler installations you

must allow a minimum clearance of 6” on

both sides for pump mounting.

2.

3.

4.


(TABLE A) - CLEARANCES FROM COMBUSTIBLES

Location ClearancesRight Side 0"Rear 6" (24" for service)Left Side 0"Front ALCOVE* (24" for service)Top 6" (24" for service)Flue 2"Hot Water Pipes 1"

* Alcove is a closet without a door.

Under no circumstances is the

manufacturer to be held responsible

for water damage in connection with

this unit or any of its components.

(FIG. 1) CLEARANCES FROM COMBUSTIBLE CONSTRUCTION


Lochinvar

(FIG. 2) BOILER EQUIPMENT AND CONTROL ORIENTATION

PB1500-2000

PB501-1300

GASCONNECTION

ELECTRICALCONNECTION INLET

AIR

SYSTEMSUPPLY

HEAT EXCHANGERDRAINS

FLUE

DIAGNOSTICPANEL

SYSTEMRETURN

GASCONNECTION

ELECTRICALCONNECTION INLET

AIR

SYSTEMSUPPLY

HEAT EXCHANGERDRAINS

FLUE

SYSTEMRETURN

DIAGNOSTICPANEL


COMBUSTION &VENTILATION AIRProvisions for combustion and ventilation airmust be in accordance with Section 5.3,Air For Combustion And Ventilation, of thelatest edition of the National Fuel Gas CodeANSI Z223.1, or applicable provisions ofthe local building codes.

If air is taken directly from outside the building with no duct (FIG. 3):A. Combustion air opening, one squareinch per 4000 Btu/hr input. This openingmust be located within 12” of thebottom of the enclosure.B. Ventilation air opening, one squareinch per 4000 Btu/hr input. This openingmust be located within 12” of the top ofthe enclosure.

If air is taken from another interior space(FIG. 4), each opening specified above

should have a net free area of one squareinch for each 1000 Btu/hr input.

If combustion and ventilation air is takenfrom the outdoors using a duct to deliverthe air to the mechanical room (FIG. 5),each opening should have a net freearea of one square inch per 2000Btu/hr input.

If a single combustion air opening isprovided to bring combustion air indirectly from the outdoors (FIG. 6), theopening should have a net free area ofone square inch per 3000 Btu/hr input. This opening must be located under 12”of the top of the enclosure.

(FIG. 3) COMBUSTION AIR DIRECT FROM OUTSIDE

(FIG. 6) COMBUSTION AIR DIRECT FROM OUTSIDESINGLE OPENING

(FIG. 5) COMBUSTION AIR THROUGH DUCTWORK

(FIG. 4) COMBUSTION AIR FROM AN INTERIOR SPACE

1.

2.

3.

4.

CAUTION: Under no circumstancesshould the equipment room be under anegative pressure, when atmosphericcombustion equipment is installed in theroom.

EXAMPLE OF

SIZING FOR

COMBUSTION

& VENTILATION

AIR OPENINGS

(BOILER WITH

1,000,000

Btu/hr INPUT):

When combustion and

ventilation air is taken

from directly outside the

building (FIG. 3), divide

the total Btu/hr by

4,000. This yields 250

sq.in. of “Free Area”

without restriction.

1,000,000 ÷ 4,000 =

250 sq.in.

Since the air opening is

50% closed due to

screens and louvers, the

total opening must be

multiplied by 2.

250 sq.in. x 2 =

500 sq.in.

This project requires one

Ventilation Air Opening

with a net “Area” of

500 square inches with

louver dimensions of

20” x 25” and one

Combustion Air Opening

with a net “Area” of

500 square inches with

louver dimensions of

20” x 25”.


CONTAMINANTSCombustion air drawn from an interioror exterior space must be free of anychemical fumes which could be corrosive tothe boiler. Burning chemical fumes results inthe formation of corrosive acids which attackthe boiler, cause improper combustion andpremature failure of the boiler and vent.

These fumes are often present in areaswhere refrigerants, salts, and solvents areused. Therefore, be mindful of swimmingpool equipment, water softening, andcooling system placement.

VENTINGGeneralVent installations for connection to gas ventsor chimneys must be in accordance withPart 7, "Venting of Equipment," of the latestedition of the National Fuel Gas Code,ANSI Z223.1, or applicable provisionsof the local building codes.

The connection from the appliance vent tothe stack must be as direct as possible andsized correctly. The horizontal breeching ofa vent must have at least 1/4" rise perlinear foot. The horizontal portions shouldalso be supported for the design and weightof the material employed to maintainclearances, prevent physical damage andseparation of joints.

The connection from the appliance vent tothe stack or vent termination outside thebuilding must be made with appropriatevent category connectors and sized

according to vent sizing tables (FAN column)in the latest edition of the National Fuel GasCode.

The vent and accessories, such as firestopspacers, thimbles, caps, etc., must beinstalled in accordance with the ventmanufacturer's listing. The vent connectorand firestop must provide correct spacing tocombustible surfaces and seal to the ventconnector on the upper and lower sides ofeach floor or ceiling through which the ventconnector passes.

Any improper operation of the commonventing system in an existing building shouldbe corrected when new equipment isinstalled, so the installation conforms to thelatest edition of the National Fuel Gas Code,ANSI Z223.1.

When resizing any portion of the commonventing system, it should be resized toapproach the minimum size as determinedusing the appropriate tables in the NationalFuel Gas Code.

The weight of the venting system must notrest on the unit. The venting system must beadequately supported in compliance withlocal codes and other applicable codes.

Vent TerminationsThe vent terminal should be vertical andexhaust outside the building at least 2 feet(0.6 m) above the highest point of the roofwhen within a 10 foot (3.05 m) radius.

Lochinvar

IMPORTANT!

This appliance is a high

efficiency unit. It

operates at an efficiency

level which could yield a

condensing condition.

Care should be taken in

providing the proper

venting and employing

the best principles of

application and sizing.

WARNINGThe entire vent system

should not be sized

based on the vent

connection diameter. For

proper vent design and

sizing consult the

National Fuel Gas Code

under “fan assisted”.

Additionally, vertical terminations must be aminimum of 3 feet (0.9 m) above the roofline, and when less than 10 feet (3.05 m)from a parapet wall must be a minimum of2 feet (0.61 m) higher than the parapet wall.

Vent caps should have a minimum clearanceof 4 feet (1.2 m) horizontally from, and inno case above or below [unless a 4 feet(1.2 m) horizontal distance is maintained],electric meters, gas meters, regulators andrelief equipment.

Maintain a distance of at least 3 feet (0.9m) above any forced air inlet within 10 feet(3.05 m) and a distance of at least 4 feet(1.2 m) below, 4 feet (1.2 m) horizontallyfrom, or 1 foot (30 cm) above any door,window or gravity air inlet.

Do not terminate the vent in a window well,stairwell, alcove, courtyard or other recessedarea. The vent can not terminate belowgrade. The bottom of the vent terminal shallbe located at least 12 inches (30 cm) abovegrade and clear of snow, ice, leaves orother debris.

The distance of the vent terminal fromadjacent public walkways, adjacentbuildings, windows, and building openingsmust be consistent with the National FuelGas Code Z223.1 or in Canada, the latestedition of CGA Standard B149 InstallationCode for Gas Burning Appliances andEquipment.

Masonry ChimneysA masonry chimney must be properly sizedand lined for the installation of a highefficiency gas fired appliance. Venting ofa high efficiency appliance into a cold,oversized and unlined masonry chimney canresult in operational and safety problems. Astandard masonry chimney must not be usedto vent the products of combustion from thishigh efficiency gas fired appliance.

A masonry chimney must be carefullyinspected to determine its suitability forthe venting of flue products.

An unlined chimney must be relined withan approved chimney liner system when anew appliance is being attached to it. Metallicliner systems (Type "B" double-wall or flexibleor rigid metallic liners) are recommended fornon-condensing, negative draft systems.

Sealed, metallic, corrosion resistant linersystems (single-wall, double-wall, flexible orrigid metallic liners) rated for use with a highefficiency, Category IV appliances must beused with positive pressure systems.

Corrosion resistant chimney liner systemsare typically made from a high grade ofcorrosion resistant stainless steel such asAL29-4C. The corrosion resistant liner must beproperly sized and fully sealed throughout theentire length contained within the masonrychimney. Both the top and bottom of themasonry chimney must be capped and sealedto provide a dead air space around the liner.


IMPORTANT!

The vent cap should

have a minimum

clearance of 4 feet

horizontally from

electric meters, gas

meters, regulators, air

inlets and air relief

equipment. Additionally,

the vent cap should

never be located above

or below these items,

unless a 4 foot

horizontal distance

is maintained.

NOTE:

An unlined masonry

chimney must not be

used to vent flue

products from this

high efficiency

appliance.


VENTING OVERVIEWCATEGORY I, DOUBLE-WALL, B-VENT(ON/OFF – “F” FIRING CODE)

Vertical Negative Draft Venting witha vertical rooftop termination and combustionair supplied from the equipment room.

Vertical DirectAire Venting uses avertical negative draft flue with a rooftoptermination for flue products and a combustionair pipe from the sidewall or rooftop.

CATEGORY IV, AL29-4C VENT MATERIAL(MODULATING – “M” FIRING CODE)

Vertical Negative Draft Venting witha vertical rooftop termination and combustionair supplied from the equipment room.

Vertical Positive Pressure Ventingwith a vertical rooftop termination andcombustion air supplied from the equipmentroom.

Vertical DirectAire Venting with avertical rooftop termination for flue productsand a combustion air pipe from the sidewallor rooftop.

Horizontal DirectAire Venting usesthe unit’s internal fan to exhaust the flueproducts out a sidewall vent termination with acombustion air pipe from the rooftop or from asidewall other than where the flue terminates.

Sidewall Venting uses the unit’s internalfan to exhaust the flue products out to asidewall vent termination with combustion airsupplied from the equipment room.

Horizontal or Vertical DirectVenting - uses the unit's internal fan toexhaust the flue products out to a sidewall orrooftop vent termination with a separatesealed combustion air pipe to the outdoors.This system terminates both the flue andcombustion air inlet on the same surface andin the same pressure zone.

COMMON VENTING SYSTEMSCategory IV positive pressure vent systemsCANNOT be combined with negative draftCategory I or II vent systems under anycircumstances. The vent from Category Iappliances CANNOT be combined with theflue from Category II appliances unless theentire vent system for all units uses corrosionresistant, Category IV vent materials.

Lochinvar

CAUTION!

Vent connectors

serving appliances

vented by natural

draft must not be

connected into any

portion of

mechanical draft

systems operating

under a positive

pressure.

(TABLE B) POWER-FIN VENTING CONFIGURATIONSVERTICAL VERTICAL

FIRING VERTICAL VERTICAL DirectAire DirectAireBTU/HR CODE FIRING NEGATIVE POSITIVE w/ ROOFTOP w/ SIDEWALL HORIZONTAL VERTICAL HORIZONTALINPUT PREFIX CONTROLS DRAFT PRESSURE AIR INLET AIR INLET DirectAire SIDEWALL DIRECT VENT DIRECT VENT

500,000 F ON/OFF CAT. I *CAT. IV CAT. I CAT. I CAT. IV CAT. IV CAT. IV CAT. IV

500,000 M MODULATING CAT. II *CAT. IV CAT. II CAT. II CAT. IV CAT. IV CAT. IV CAT. IV

750,000 F ON/OFF CAT. I *CAT. IV CAT. I CAT. I CAT. IV CAT. IV CAT. IV CAT. IV

750,000 M MODULATING CAT. II *CAT. IV CAT. II CAT. II CAT. IV CAT. IV CAT. IV CAT. IV

1,000,000 F ON/OFF CAT. I *CAT. IV CAT. I CAT. I CAT. IV CAT. IV CAT. IV CAT. IV

1,000,000 M MODULATING CAT. II *CAT. IV CAT. II CAT. II CAT. IV CAT. IV CAT. IV CAT. IV

1,300,000 F ON/OFF CAT. I *CAT. IV CAT. I CAT. I CAT. IV CAT. IV CAT. IV CAT. IV

1,300,000 M MODULATING CAT. II *CAT. IV CAT. II CAT. II CAT. IV CAT. IV CAT. IV CAT. IV

1,500,000 M MODULATING --- CAT. IV CAT. IV CAT. IV CAT. IV CAT. IV CAT. IV CAT. IV



NOTE:

Firing Code “F”

indicates the boiler has

ON/OFF firing control

operation only. This

firing code is only

available on boilers with

inputs from 500,000 to

1,300,000 Btu/hr.

Firing Code “M”

indicates the boiler has

MODULATING firing

control operation only.

This firing code is

available on boilers with

inputs from 500,000 to

2,000,000 Btu/hr.

NOTES: Category II venting configurations must be installed with corrosion resistant vent material.* When installed with optional vent reducer.

A barometric damper must be installed oneach unit when common venting multiplenegative draft appliances. Only Category Iand Category II negative draft appliancesmay be common vented. Positive pressure,Category IV vents CANNOT be combinedwithout the use of an engineered exhaustevacuation system such as a LochinvarIntelli-Vent system.

DIRECTAIRE AND DIRECT VENT SYSTEMSDirect Vent and DirectAire Vent Systems areinstalled with specific flue pipe materialrequirements based on the type of firingcontrols used on the unit. Direct Vent andDirectAire systems both use a separatecombustion air pipe to the outdoors. The DirectVent System terminates both the flue andcombustion air inlet in the same pressure zone.The DirectAire Vent System may terminate theflue and combustion air inlet in differentpressure zones. The flue outlet and combustionair inlet may terminate with either a sidewallor a rooftop termination based on the specificventing option selected.

DIRECTAIRE SYSTEMSA DirectAire vent system uses a flue to thesidewall or rooftop with a separatecombustion air inlet pipe to the outdoors. TheDirectAire vent system may terminate the flueand the combustion air inlet pipe in differentpressure zones in any one of threeconfigurations.

• The flue on the rooftop and combustion air inlet on the sidewall. (FIG. 9)

• The flue on the sidewall and combustion air inlet on the rooftop. (FIG. 13)

• The flue on the sidewall and the combustion air inlet on a sidewall other than the sidewall where the flue is located. (FIG. 14)

Units with ON/OFF burner controls utilizingCategory I, negative draft venting may beconfigured as a DirectAire system and mayhave both the flue and air inlet terminated onthe rooftop in the same pressure zone. (SeeFIG. 10) DirectAire vent systems require theinstallation of specific venting materials.Rooftop flue gas termination caps andcombustion air inlets must be purchasedlocally. Sidewall flue gas termination caps andcombustion air inlets must be purchased fromthe appliance manufacturer as per CSAInternational requirements.

DIRECT VENT SYSTEMSA Direct Vent system uses a flue to the sidewallor rooftop with a separate combustion air inletpipe from the outdoors. The Direct Vent systemterminates the flue and the combustion air inletpipe on the same surface and in the samepressure zone in one of two configurations.

(1) The flue on the rooftop and combustion air inlet on the rooftop. (FIG. 16)

(2) The flue on the sidewall and combustion air inlet on the sidewall. (FIG. 17)

Direct Vent systems require the installation ofspecific venting materials. Rooftop flue gastermination caps and combustion air inletsmust be purchased locally. Sidewall flue gastermination caps and combustion air inletsmust be purchased from the appliancemanufacturer as per CSA Internationalrequirements.


CAUTION!

In cold climates,

flue products will

produce a noticeable

plume. Carefully

select the location of

vent caps for vertical

and horizontal

applications.

(FIG. 7) MULTIPLE UNIT BAROMETRICDAMPER INSTALLATION


VENTING OPTIONSON/OFF FIRING CONTROL -CATEGORY I VENT MATERIAL

Vertical Negative Draft VentingOnly units with ON/OFF burner controls maybe vented with Category I, Type “B” ventmaterial. The flue must terminate at therooftop. Combustion air is supplied from theequipment room. The installation of the ventmust conform to the latest edition of theNational Fuel Gas Code, ANSI Z223.1, inCanada, the latest edition of CGA StandardB149 Installation Code for Gas BurningAppliances and Equipment. The vent systemmust maintain a negative draft within thespecified range of 0.2 to 0.8 inches of watercolumn.

DirectAire Vertical with Sidewall AirInletVertical DirectAire vent systems are installedwith the flue terminating at the rooftop and aseparate combustion air inlet pipe at thesidewall to draw air from the outdoors. Theflue outlet and combustion air inlet terminate in

different pressure zones. The maximuminstalled length of the combustion air inlet pipeand flue gas vent pipe from the appliance tothe point of termination, outside of thebuilding, must not exceed a maximum of 50equivalent feet (15.2m) in length. Subtract 5feet (1.5m) of equivalent length for each 90°elbow and 2-1/2 feet (0.7m) of equivalentlength for each 45° elbow installed. The flueand air inlet sizes for Vertical DirectAiresystems with Sidewall Air Inlet are listed inTABLE C. This venting option uses a venttermination constructed from materialspurchased locally by the installer and asidewall air inlet purchased from themanufacturer. The part numbers for therequired sidewall air inlet cap kit are listed inTABLE D.

Lochinvar

(FIG. 8) CONVENTIONAL NEGATIVE DRAFT VENTING

(FIG. 9) DIRECTAIRE VERTICAL W/SIDEWALL AIR INLET

(TABLE C) – FLUE & COMBUSTIONAIR PIPE SIZES

MODEL AIR REDUCED VENTNUMBER INLET FLUE FLUE REDUCERPB0501 5" 7" 4" DRH2435PB0751 5" 9" 5" DRH2436PB1001 6" 10" 6" DRH2437PB1300 6" 12" 8" DRH2438PB1500 6" 8" -- --PB1700 8" 8" -- --PB2000 8" 10" -- --

(TABLE D) – SIDEWALL AIR INLET KITS

MODEL AIR AIR INLETNUMBER INLET CAP

PB0501 5" SAK3003

PB0751 5" SAK3003

PB1001 6" SAK3000

PB1300 6" SAK3000

PB1500 6" SAK3000

PB1700 8" SAK3001

PB2000 8" SAK3001

DirectAire Vertical with Rooftop Air InletThe flue outlet and combustion air inletterminate on the rooftop in the same pressurezones, but when installed with a negativedraft, Category I vent system, does not meetthe specifications of a direct vent system. Themaximum installed length of the combustionair inlet pipe from the appliance to the point oftermination, outside of the building, must notexceed a maximum of 50 equivalent feet(15.2m) in length. Subtract 5 feet (1.5m) ofequivalent length for each 90° elbow and 2-1/2 feet (0.7m) of equivalent length for each45° elbow installed. The air inlet cap consistsof two 90° elbows installed at the point oftermination for the air inlet pipe.

NOTE: For units with ON/OFF burnercontrols (PB0501-1300) the maximuminstalled length of the flue gas vent pipefrom the appliance to the terminationcap is limited only by the requirement tomaintain a negative draft within thespecified range of 0.2 to 0.8 inches ofwater column.

MODULATING FIRING CONTROL -CATEGORY IV VENT MATERIAL

Vertical Negative Draft Venting Units with Modulating burner controls ventedwith a negative draft vent system are classifiedas Category II appliances and must be ventedwith Category IV corrosion resistant ventmaterial. The vent connection is made directlyto the back of the unit using an AL29-4Ccorrosion resistant vent pipe. The flue mustterminate at the rooftop. Combustion air issupplied from the equipment room. Note: Themodulation of the burner may result in fluegas temperatures below dew point whichmay form condensate in the flue.

Vertical Positive Pressure VentingUnits with Modulating burner controls that usetheir internal combustion fan to force the flueproducts out the vent system are classified asCategory IV, positive pressure appliances andmust be vented with sealed, Category IVcorrosion resistant vent material. The ventconnection is made directly to the back of theunit using an AL29-4C corrosion resistant ventpipe. The flue must terminate at the rooftop.Combustion air is supplied from the equipmentroom.


(FIG. 12) VERTICAL POSITIVE PRESSURE VENTING

(FIG. 11) VERTICAL NEGATIVE DRAFT VENTING

(FIG. 10) DIRECTAIRE VERTICAL W/ROOFTOP AIR INLET

DirectAire HorizontalDirectAire Horizontal vent systems areinstalled with the flue terminating at thesidewall, using Category IV vent materials,and a separate combustion air inlet pipe atthe rooftop, or at the sidewall to draw airfrom the outdoors. The flue outlet andcombustion air inlet terminate in differentpressure zones. The maximum installedlength of the combustion air inlet pipe andflue gas vent pipe from the appliance to thepoint of termination, outside of the building,must not exceed a maximum of 50equivalent feet (15.2m) in length. Subtract 5feet (1.5m) of equivalent length for each 90°elbow and 2-1/2 feet (0.7m) of equivalentlength for each 45° elbow installed. The flueand air inlet sizes for Horizontal DirectAiresystems are listed in TABLE C. This ventingoption uses a sidewall vent termination and asidewall air inlet purchased from theappliance manufacturer as per CSAInternational requirements, or a rooftop airinlet constructed from materials purchased

locally by the installer. The part numbers forthe required sidewall vent cap kit are listed inTABLE E. The part numbers for the requiredsidewall air inlet cap kit are listed in TABLE D.

Sidewall VentingA sidewall venting system (FIG. 15) uses theunit’s internal combustion fan to force the flueproducts out a sidewall vent cap. The unit’sinternal fan generates a positive draftpressure to exhaust the flue products.Combustion air is drawn from the equipmentroom. The connection from the appliance flueoutlet to the sidewall vent cap must be madewith Category IV type vent materials for bothON/OFF and Modulating models. TheCategory IV flue from this applianceCANNOT be combined with the vent fromany other appliance. The flue must be adedicated stack and must have all vent jointsand seams sealed gastight. The maximuminstalled length of the flue from the applianceto the point of termination, outside of thebuilding, must not exceed a maximum of 50

Lochinvar


(FIG. 14) DIRECTAIRE HORIZONTAL W/ SIDEWALL AIRINLET IN A DIFFERENT PRESSURE ZONE

(FIG. 13) DIRECTAIRE HORIZONTALW/ ROOFTOP AIR INLET

(FIG. 15) SIDEWALL VENTING

(TABLE E) – SIDEWALL VENT KITS

MODEL FLUE VENT REDUCED VENT CAP W/NUMBER SIZE CAP FLUE REDUCERPB0501 7" SVK3027 4" SVK3056

PB0751 9" SVK3049 5" SVK3057

PB1001 10" SVK3029 6" SVK3058

PB1300 12" SVK3050 8" SVK3059

PB1500 8" SVK3028 -- --

PB1700 8" SVK3028 -- --

PB2000 10" SVK3029 -- --

equivalent feet (15.2m) in length. Subtract 5feet (1.5m) of equivalent length for each 90°elbow and 2-1/2 feet (0.7m) of equivalentlength for each 45° elbow installed. Thisventing option uses a sidewall venttermination purchased from the appliancemanufacturer as per CSA Internationalrequirements. The part numbers for therequired sidewall vent cap kit are listed inTABLE E. Each kit includes the vent cap forinstallation on an exterior sidewall foroperation of a single appliance only.

Direct Vent Vertical SystemA Vertical Direct Vent System is installed witha Category IV flue and a separate air inletpipe to draw combustion air from theoutdoors. The combustion air inlet cap andflue gas vent cap must be located on thesame rooftop surface and in the samepressure zone. The maximum installed lengthof the combustion air inlet pipe and flue gasvent pipe from the appliance to the point oftermination, outside of the building, must notexceed a maximum of 50 equivalent feet(15.2m) in length. Subtract 5 feet (1.5m) of

equivalent length for each 90° elbow and 2-1/2 feet (0.7m) of equivalent length for each45° elbow installed. A Direct Vent systemMUST have a dedicated air inlet pipe. Airinlet pipes for multiple units CANNOT becombined. This venting option uses a venttermination and air inlet constructed frommaterials purchased locally by the installer.The air inlet cap consists of two 90° elbowsinstalled at the point of termination for the airinlet pipe.

Direct Vent Horizontal SystemsA Horizontal Direct Vent system is installedwith a Category IV flue and a separate airinlet pipe to draw combustion air from theoutdoors. The combustion air inlet cap andflue gas vent cap must be located on thesame sidewall surface and in the samepressure zone. The maximum installed lengthof the combustion air inlet pipe and flue gasvent pipe from the appliance to the point oftermination, outside of the building, must notexceed a maximum of 50 equivalent feet(15.2m) in length. Subtract 5 feet (1.5m) ofequivalent length for each 90° elbow and

L o c h i n v a r D E S I G N E R’ S G U I D E P O W E R - F I N B O I L E R 6 1 5 - 8 8 9 - 8 9 0 0 1 3

(FIG. 16) DIRECT VENT VERTICAL

(FIG. 17) DIRECT VENT HORIZONTAL

WARNINGNo substitutions of flue

pipe or vent cap

material are allowed

when direct venting.

Such substitutions would

jeopardize the safety

and health of building

inhabitants.

NOTE:

Units with ON/OFF

burner controls utilize

Category IV vent

material when

installed in

a Direct Vent

configuration.

(TABLE F) – DIRECT VENT HORIZONTAL KITS

MODEL AIR DIRECT VENT REDUCED DIRECT VENT KITNUMBER INLET FLUE KITS FLUE W/ REDUCERPB0501 5" 7" HDK3033 4" HDK3040

PB0751 5" 9" HDK3034 5" HDK3041

PB1001 6" 10" HDK3035 6" HDK3042

PB1300 6" 12" HDK3036 8" HDK3043

PB1500 6" 8" HDK3021 -- --

PB1700 8" 8" HDK3022 -- --

PB2000 8" 10" HDK3023 -- --


2-1/2 feet (0.7m) of equivalent length foreach 45° elbow installed. A Direct Ventsystem MUST have a dedicated air inletpipe. Air inlet pipes for multiple unitsCANNOT be combined. The connectionfrom the appliance flue outlet to the sidewallvent cap must be made with Category IVtype vent materials for both ON/OFF andModulating models. This venting option usesa sidewall vent termination and a sidewallair inlet purchased from the appliancemanufacturer as per CSA Internationalrequirements. The part numbers for therequired horizontal direct vent kit are listed inTABLE F. Each kit includes the vent cap andair inlet for installation on an exterior sidewallfor operation of a single appliance only.

Air Inlet Pipe MaterialsThe following air inlet pipe materials areacceptable: PVC, CPVC, ABS, Dryer Vent or SealedFlexible Duct (not recommended for rooftopair inlet), galvanized steel vent pipe withjoints and seams sealed and type “B” double-wall vent with joints and seams sealed. Theair inlet pipe must be sealed. Proper sealingof the air inlet pipe ensures that combustionair will be free of contaminants and suppliedin proper volume. When a sidewall orvertical rooftop combustion air supply systemis disconnected for any reason, the air inletpipe must be resealed to ensure thatcombustion air will be free of contaminantsand supplied in proper volume.

Air Inlet Cap InstallationIncorrect installation and/or location of theair inlet cap may allow the discharge of flueproducts to be drawn into the combustionprocess of the unit. This may result inincomplete combustion and potentially

hazardous levels of carbon monoxide in theflue products. This will cause operationalproblems with the unit and may result inpossible spillage of flue products that cancause personal injury, death or propertydamage.

Location of a Sidewall Air Inlet CapThe termination point of the sidewall air inletmust be located a minimum of 12 inches(0.30 m) above ground level and abovenormal levels of snow accumulation. Thepoint of termination for the sidewall air inletcap must be located a minimum of 3 feet(0.91m) horizontally and 12 inches (0.30 m)below the point of any flue gas termination ifthe air inlet is located within a 10 foot (3.05m) radius of the flue outlet. The sidewall airinlet cap must not be installed above asidewall flue outlet if it is located within a 10foot (3.05m) radius of the flue outlet. Thesidewall air inlet cap must not be installedcloser than 10 feet (3.05m) from an insidecorner of an L shaped structure. The sidewallair inlet cap assembly must adequatelyprotect the combustion air inlet from windand weather.

Location of Rooftop Air Inlet CapThe termination point of the rooftop air inletmust be located a minimum of 12” (0.30 m)above the roof or above normal levels ofsnow accumulation. The point of terminationfor the air inlet cap must be located aminimum of 3 feet (0.91m) below any pointof flue gas termination if the air inlet islocated within a 10 foot (3.05m) radius ofthe flue outlet. The rooftop air inlet cap mustnot be installed closer than 10 feet (3.05 m)from an inside corner of an L shapedstructure. The rooftop air inlet cap assemblymust adequately protect the combustion airinlet from wind and weather.

Lochinvar

EXAMPLE OF

COMBINED AIR

INLET SIZING:

Two 5" (12.7cm) air inlet

pipes, 19.63 in² (126.6

cm²) in free area each,

have a total combined

free area of 39.26 in²

(253.3 cm²). These two

pipes require an 8" (20.3

cm) common air inlet

pipe, with 50.26 in²

(324.3 cm²) of free area.

Combined Combustion Air Inlet Pointsfor DirectAire Systems OnlyThe air inlet pipes from multiple appliancescan be combined into a single commonconnection if the common air inlet pipe has across sectional area equal to, or greaterthan, the total area of all air inlet pipesconnected to the common air inlet pipe. Theair inlet point for multiple units must beprovided with an exterior opening which hasa free area equal to, or greater than, thetotal area of all air inlet pipes connected tothe common air inlet. This exterior openingfor combustion air must connect directly tothe outdoors. The total length of thecombined air inlet pipe must not exceed amaximum of 50 (15.2m) equivalent feet. Youmust deduct the restriction in area providedby any screens, grills or louvers installed inthe common air inlet point. Screens, grills, orlouvers installed in the common air inlet canreduce the free area of the opening from25% to 75% based on the materials used asper CSA International requirements.

Note: A Direct Vent system MUSThave a dedicated air inlet pipe. Airinlet pipes for multiple Direct Ventunits CANNOT be combined.

Location of a Sidewall VentTerminationThe vent cap shall terminate at least 3 feet(0.91m) above any forced air inlet within 10feet (3.05m). The vent shall terminate at least4 feet (1.22m) below, 4 feet (1.22m)horizontally from, or 1 foot (0.30m) aboveand 2 feet (0.60m) horizontally from anydoor, window, or gravity air inlet to thebuilding. The sidewall vent termination mustbe at least 8 feet (2.4m) horizontally fromany combustion air intake located above thesidewall termination cap. Do not terminatethe vent in a window well, stairwell, alcove,courtyard, or other recessed area. The ventcannot terminate below grade. The vent shallnot terminate directly above a publicwalkway due to the normal formation ofwater vapor in the combustion process.Horizontal terminations must not be locatedover areas of pedestrian or vehicular traffic.The vent system shall terminate at least 1 foot(0.30m) above grade, above normal snowlevels and at least 7 feet (2.13m) abovegrade when located adjacent to publicwalkways. The vent terminal shall not beinstalled closer than 3 feet (0.91m) from aninside corner of an L-shaped structure. Thevent cap should have a minimum clearanceof 4 feet (1.22m) horizontally from and in nocase above or below, unless a 4 foot(1.22m) horizontal distance is maintainedfrom electric meters, gas meters, regulatorsand relief equipment. Flue gas condensatecan freeze on exterior walls or on the ventcap. Frozen condensate on the vent cap canresult in a blocked flue condition. Somediscoloration to exterior building surfaces canbe expected. Adjacent brick or masonrysurfaces should be protected with a rustresistant sheet metal plate.


Lochinvar

(FIG. 18) LOCATION OF A SIDEWALL VENT TERMINATION


Lochinvar

GAS SUPPLYProviding proper gas volume and correct gaspressure is essential for trouble free operation.The gas lines must be properly sized for thetotal gas consumption requirements of all gasappliances on the project. Refer to TABLE Hfor low pressure natural gas pipe sizing.Verify required gas pipe size with your localgas utility supplier.

All units can be operated on either naturalgas or LP gas systems. The type of gas beingsupplied should be indicated in the projectequipment schedules. Refer to TABLE G for themaximum allowable and minimum allowableinlet gas pressure requirements for bothnatural gas and LP gas systems.

All gas piping and components must besized, installed and furnished per allapplicable NFPA, National Fuel Gas Code,ANSI Standards, CSA / AGA Standards,National Board of Fire Underwriters and alllocal requirements and applicable ordinancesor codes.

High Altitude ApplicationsAtmospheric pressure decreases as the heightabove sea level increases. At any altitudeabove sea level, a cubic foot will contain lessgas than a cubic foot at sea level. Thus, theheating value of a cubic foot of fuel gas will

decrease as height above sea level increases.Specific gravity of a gas with respect to sealevel also decreases with altitude. Thesechanges in heating value and specific gravitytend to offset each other. However, aselevation above sea level is increased, thereis less oxygen per cubic foot of air. Therefore,heat input rate should be reduced in anappliance above 2000 feet; ratings shouldbe reduced at the rate of 4 percent for each1000 feet above sea level.

IMPORTANT GAS SYSTEM DESIGNPOINTS:

The supplied gas pressure regulator(s) aredesigned for low pressure gas service. Ifthe inlet gas pressure exceeds 6 oz. (10"wc) a properly sized lock-up type high gaspressure regulator (HGPR) must beinstalled. The lock-up type HGPR must be installedas far as possible from the gas appliancewith a minimum of eight to ten feet fromthe unit’s inlet gas connection. On gas supply systems greater than 2 psi,the HGPR must include an overprotectiondevice (OPD), as specified by thedesigner, and installed per the regulatormanufacturer’s requirements.All gas piping must be sized per the localgas piping code requirements and thelocal gas utility supplier. The piping to any gas appliance shouldnever be less than the inlet gas connection. A trap (drip leg) should be provided in theinlet gas piping connection to the boiler.

1.

2.

3.

5.

6.

4.

EXAMPLE OF

HIGH ALTITUDE

APPLICATIONS

For example, if a unit’s

input is 1,000,000

Btu/hr at sea level, the

rated input at 4000 feet

of elevation can be

calculated by derating

input 4% per 1000 feet

above sea level.

[Btu/hr Input]

[1.00 - (Elevation /

1000' x 0.04)] =

Btu/hr Input at Specified

Elevation [1,000,000]

[1.00 - (4000' / 1000'

x 0.04)] = Btu/hr Input

at 4000' Elevation

[1,000,000] [0.84] =

840,000 Btu/hr Input at

4000' Elevation

(TABLE G) – INLET GAS PRESSURENATURAL LP

PB0501 Max. Allowable 10.5" 13"- 1300 Min. Allowable 4" 11"

PB1500 Max. Allowable 10.5" 13"- 2000 Min. Allowable 4" 4"


Lochinvar

A manual main gas shut off valve shouldbe provided outside the unit jacket,upstream of the main gas valve. On LP gas systems, properly sized LP tanksmust be provided to ensure the requiredvolume of gas is provided to eachappliance. In Canada, heat input is derated 10%from 2,000 - 4,500 ft, over 4,500 ft.derate must be in accordance with localauthorities. Consult factory for installationsat higher elevations.

GAS BLEEDS AND VENTSAll bleeds and vents from factory installedgas valves and regulators are vented to theatmosphere, outside of the fan pressurizedinner chamber. Gas train controlrequirements and / or local codes mayrequire routing of these bleeds and vents tothe atmosphere, outside of the building. Anyrequired gas vent lines must be sized perNFPA 54/ANSI Z223.1 National Fuel Gas

Code, acceptable engineering practices andmust meet all local requirements andapplicable ordinance or codes.

WATER VELOCITY CONTROLTo ensure proper velocity through the heatexchanger, it is necessary to regulate thetemperature rise across the heat exchanger frominlet to outlet. (This must be adjusted on initialinstallation and periodically rechecked.) With the correct temperature rise across theheat exchanger, you may be assured of theproper velocity in the tubes and long lifeand economical operation from the boiler.

7.

8.

9.

(TABLE H) GAS SUPPLY PIPE SIZINGLength of Pipe In Straight Feet

Nominal IronPipe Size, Inches 10 20 30 40 50 60 70 80 90 100 125 150 175 200

369 256 205 174 155 141 128 121 113 106 95 86 79 74

697 477 384 328 292 267 246 256 210 200 179 164 149 138

1,400 974 789 677 595 543 502 472 441 410 369 333 308 287

2,150 1,500 1,210 1,020 923 830 769 707 666 636 564 513 472 441

4,100 2,820 2,260 1,950 1,720 1,560 1,440 1,330 1,250 1,180 1,100 974 871 820

6,460 4,460 3,610 3,100 2,720 2,460 2,310 2,100 2,000 1,900 1,700 1,540 1,400 1,300

11,200 7,900 6,400 5,400 4,870 4,410 4,000 3,800 3,540 3,300 3,000 2,720 2,500 2,340

23,500 16,100 13,100 11,100 10,000 9,000 8,300 7,690 7,380 6,870 6,150 5,640 5,130 4,720

Maximum capacity of pipe in thousands of Btu per hour for gas pressures of 14 Inches Water Column (0.5 PSIG) or less and a pressuredrop of 0.05 Inch Water Column (NAT GAS, 1025 Btu per Cubic Foot of Gas, based on 0.60 specific gravity gas).

11/4

3/4

11/2

1

3

4

21/2

2

(TABLE I) – MINIMUM & MAXIMUMBOILER FLOW RATES

MODEL MIN. FLOW MAX. FLOWNUMBER (GPM) (GPM)PB0501 23 75PB0751 32 75PB1001 43 75PB1300 56 75PB1500 65 90PB1700 75 90PB2000 87 90

Heat Exchanger Water VelocityThe flow rate will be based on the requiredtemperature rise across the heat exchanger.TABLE I provides the minimum and maximumwater flow rate data for each model. Toensure the required water velocity throughthe heat exchanger, it is necessary toregulate the temperature rise across the heatexchanger. The temperature rise or ΔT is thedifference between the inlet watertemperature and the outlet watertemperature. TABLE J lists water flow rates(GPM) and pressure drop head loss (FT.HD.) at various temperature rises (ΔT) foreach model. Lochinvar requires the designtemperature rise for each boiler be adjustedin the field on initial system start up. Withthe correct temperature rise across the heater

exchanger, the design engineer and ownerwill be assured of the proper velocity in theheat exchanger tubes and a long life witheconomical boiler operation.

WATER FLOWREQUIREMENTS & SYSTEMPIPING DESIGNCONSIDERATIONSLow mass copper tube boilers require aconstant fixed water flow through the heatexchanger to ensure proper operation. Dueto the relatively small amount of watercontained within the boiler heat exchanger,both the entering water temperature and


Lochinvar

(TABLE J) – WATER FLOW REQUIREMENTS

TEMPERATURE RISE 20°F ΔΔT 25°F ΔΔT 30°F ΔΔT 35°F ΔΔT 40°F ΔΔTINPUT OUTPUT GPM FT. HD. GPM FT. HD. GPM FT. HD. GPM FT. HD. GPM FT. HD.

500,000 435,000 44 1.8 35 1.2 29 0.8 25 0.7 22 0.5750,000 652,500 66 5.7 53 3.1 44 2.1 38 1.5 33 1.0

1,000,000 870,000 88* 11.8 70 7.2 59 4.5 50 3.1 44 2.11,300,000 1,131,000 114* 19.9 91* 14.7 75 9.5 65 6.4 57 5.51,500,000 1,305,000 105* 13.9 88 9.8 75 7.7 66 6.31,700,000 1,479,000 120* 19.2 100* 14.1 85 10.2 75 7.92,000,000 1,740,000 117* 20.2 100* 14.9 88 11.9

*Cupro-Nickel Heat Exchanger required for GPM above Max. flow limits.

NOTE:

Care should be

taken to measure

temperature rise and

maintain proper water

velocity in the heat

exchanger.

(FIG. 19) – HEAT EXCHANGER HEAD LOSS

(FIG. 20) – BOILER TEMPERATURE RISE CHART


Lochinvar

pump flow rate must be evaluated during thedesign of the heating system. Each boilerwill require a constant speed pump with fullport balance valve to provide a constantwater flow rate through each boiler. Thereare several additional factors that must beconsidered during the design stages.

Full System Water Flow Through BoilerLochinvar boilers are capable ofoperating within the design water flowrates for the building heating system.However, to allow for the most efficientand trouble free operation, the boilerwater flow and system return watertemperature entering the boiler must beconsidered and evaluated by the designengineer. All components of the hydronicheating system; minimum/maximumsystem water flows, minimum systemreturn water temperatures, system pumpsizing, pump type, system pipe sizing,piping layout and system temperaturecontrol components must be evaluated tomeet the boiler’s operating requirements.

Primary/Secondary Piping SystemTo ensure a constant water flow througheach boiler, a primary (boiler)/secondary(building) piping arrangement should beutilized and each boiler must be supplied bya constant speed pump. The pump shouldnot be allowed to operate when the boiler isnot operating. Following good engineeringpiping practices, the boilers must be pipedin parallel, not in series, to enable eachboiler to receive the same entering watertemperature. The primary (boiler)/secondary (building)pumping system incorporates two tees whichare hydraulically located very close to eachother. The tees are used for supply andreturn connections to each boiler. Theconnections should be located hydraulicallyclose enough so that the pressure drop isnearly zero. Minimizing the pressure dropbetween the two connections enables thesystems to become hydraulically separated.This segment of pipe is called the decoupleror common pipe. This separation betweenthe two piping loops allows each to actindependently from one another. It is veryimportant not to install any shut-off orbalance valves in this common pipe.Whenever the primary/secondary pipingloops are properly installed, both pipingloops will operate independently from eachother. With this arrangement the primarypiping loop can utilize constant speedpumps, while the secondary piping loop caneither be constant speed or variable speedpumps.

(FIG. 21) PRIMARY/SECONDARY SYSTEM PIPING

SPECIAL SYSTEM DESIGNAND SYSTEM CONTROLAPPLICATIONSThere are several system design and systemcontrol options available to the engineer whendesigning a hydronic heating system. Thesedesign, control and operational variables mustbe evaluated to ensure a hydronic heatingsystem that will operate trouble free.

Variable Flow Pumps in Secondary(Distribution) PipingOne of most important points of concern iswith the secondary loop maintaining aminimum water flow equal to, or greater than,the minimum water flow in the primary loop.The minimum water flow is established by thetotal number of boilers and water flowrequired through each boiler. After requiredminimum flow is determined additionalvariables need to be evaluated. These are:type of secondary loop controls; minimumpump speed; 3-way or 2-way valves onterminal devices; and the size of the minimumflow by-pass at the end of loop. Additionalinformation and design assistance is availablefrom Lochinvar.

Water Flow SwitchThis unit is equipped with a factory installedwater flow switch in the discharge piping. Aminimum of 20 GPM is required to make theswitch and turn off the low water flow light.This flow switch meets most code requirementsfor a low water cutoff device on boilersrequiring forced circulation for operation.Verify code requirements with local officials.

Relief ValveThe boiler is supplied with a pressure-reliefvalve, sized in accordance with ASMErequirements.

Jacket DrainThis boiler is provided with a drain tube whichshould be directed to a convenient drain in theevent that sweating occurs on start up. Lowtemperature systems require special piping toprevent condensation (See Low TemperatureWater Return Systems).

Low Flow SystemsWhen the system flow rate is less than theminimum flow required for proper boileroperation, the Power-Fin boiler should beinstalled with a primary/secondary pipingsystem. This will allow the installation of asecondary-circulating pump sized specificallyto provide a higher flow rate through theboiler and the secondary loop piping toensure proper operation. See“Primary/Secondary Piping” for installationand piping requirements.


Lochinvar

IMPORTANT!

EXAMPLE

OF VARIABLE

SPEED PUMP

REQUIREMENTS:

4 - PBN2000

(Min. Flow = 87 GPM)

The combined "minimum"

flow for the boiler

system is

87 GPM x 4 = 348 GPM.

A variable speed pump

must not reduce the

system flow rate below

348 GPM

(FIG. 22) HIGH FLOW SYSTEM PIPING

NOTE:

A minimum flow by-

pass should always be

located at the end of a

piping loop to ensure

that the full BTU

capacity of the

secondary piping loop is

utilized. A by-pass loop

located too close to the

boiler could cause the

boiler to lock out on

high limit.

High Flow SystemsWhen the flow rate of the system exceeds themaximum allowable flow rate through theboiler (TABLE I), Boiler bypass piping shouldbe installed. The bypass will divert therequired portion of the system flow to theboiler and bypass excess system flow. Thiswill effectively reduce boiler flow to anacceptable rate and increase system flow. Thebypass piping should be sized equal to thesystem piping. Figure 22 depicts the properpiping arrangement for the boiler bypass.

Low Water Temperature SystemsWhen non-condensing boilers are utilized, theminimum return low water temperatureprotection requirement must be evaluated toprevent condensation from occurring in theboiler. Any non-condensing boiler and

venting system will develop operationalproblems when exposed to return watertemperatures back from the system below140°F. For many years, a low watertemperature system has been defined as anysystem designed to operate below 140°F.The system return water temperatures typicallyrange from 60°F to 120°F. These areapplications such as: water source heatpump systems, radiant floor systems,greenhouse and soil heating and irrigationsystems, process and manufacturingoperations, swimming pool and spa systems.Other systems not normally considered “lowwater temperature” type systems are creatingmany, many operational problems becausethe total system operation and control havenot been thoroughly taken into considerationand evaluated. These systems were designedto operate at 180°F supply and 160°F returnon the secondary piping loop(s). However,Building Management Systems (BMS) arenow controlling the entire heating system toprovide the following:

•Night Set Back is commonly used to reset the secondary loop water temperature to maintain the interior space of the building to 55°F. If the return water temperature drops below 140°F, condensation will occur in the boiler and vent system.

•Night Shut Down and Weekend Shut Down of the entire heating system is another type of energy conservation conceptdesigned into the control system. As a result of “cold starts” and the extended length of time required to operate with return water temperature below 140°F, condensation will occur in the boiler and vent system.


Lochinvar

IMPORTANT!

An ON/OFF boiler

may be protected

with either a manual

bypass valve or a

3-way valve, but

a Modulating boiler

MUST be protected

with a 3-way

valve ONLY.

(FIG. 23) LOW TEMPERATURE BYPASS SYSTEM PIPINGF9 - ON/OFF FIRING ONLY

(FIG. 24) LOW TEMPERATURE BYPASS SYSTEM PIPINGM9 - MODULATION ONLY

•Indoor / Outdoor Air Reset of the secondary loop water temperature. If the reset schedule minimum return water temperature is below 140°F condensation will occur in the boiler and vent system.

All of these system designs and controloptions must be evaluated by the designengineer and the determination for lowtemperature water protection made to ensureproper operation of the boiler and ventsystem. The design and installation into thereturn water piping of a self contained 3-way, automatic, thermostatic, Lochinvar LTVlow temperature protection valve, factorypre-set to maintain 140°F inlet water to theboiler regardless of the system return watertemperature and approved by-pass pipingwill ensure low water temperature protectionfor each boiler.

SPECIAL DESIGNAPPLICATIONSAir Conditioning Re-Heat SystemWhen used in connection with arefrigeration system, the boiler must beinstalled so the chilled medium is piped in

parallel with the boiler and with appropriatevalves to prevent the chilled medium fromentering the boiler. The piping system of thehot water boiler (when connected to heatingcoils located in air handling units where theymay be exposed to refrigerated aircirculation) must be equipped with flowcontrol valves or other automatic means toprevent gravity circulation of the boiler waterduring the cooling cycle.

The heating coil must be vented at the highpoint and the hot water from the boilermust enter the coil at this point. Due to thefast heating capacity of the boiler, it is notnecessary to provide a duct-stat to delaycirculator operation; also, omit thermal flowchecks, as the boiler is cold when theheating thermostat is satisfied. This providesgreater economy overall by maintainingstandby heat.


Lochinvar

(FIG. 25) HEATING/CHILLED WATER SYSTEM


LochinvarAIR REMOVALAn air separation device should be placedin the installation piping, on the suctionside of the system pump, to eliminatetrapped air in the system. Locate a systemair vent at the highest point in the system.Additionally, a properly sized expansiontank is required. Air charged, diaphragm-type compression tanks are common. Theexpansion tank must be installed close tothe boiler and on the suction side of thesystem pump to ensure proper operation.

SYSTEMS WITH LOW WATERVOLUMEThe use of a buffer tank to prevent boilershort cycling should be evaluated during thedesign phase. Short cycling is a normally theresult of an insufficient volume of water inthe system. Boiler cycle time is controlled bythe system water volume and thetemperature differential. No more than sixboiler cycles per hour is recommended to

ensure maximum boiler system efficiencyand protection from condensation in the ventstack. If the boiler is allowed to operate fora minimum run time greater than the wettime of the stack, the full efficiency of theboiler and heating system can be achievedand nuisance problems eliminated. Toprevent short cycling, the heat supplied bythe boiler must equal the heat used by theload. Boiler heating systems are sized toprovide the heat load required on thecoldest days of the year. On most days theoutside temperatures are above the minimumdesign conditions and system heating loadsare much less due to heating zone usage orhumidity control. These are periods whenshort cycling of the boilers is most common.

In order to ensure the boilers will not have ashort cycling problem and the heatingsystem will operate at maximum efficiency,certain system factors must be taken intoconsideration.

(FIG. 26) BUFFER TANK PIPING


The following must be evaluated:Minimum Boiler InputMinimum System LoadHeating System Total Water VolumeMinimum Desired Run Time of BoilersBoiler Water Temperature Rise

Use the following to calculate the required

minimum water system volume:

Desired Run Time x (Minimum Boiler Input -

Minimum System Load)

Boiler Temperature Rise x 8.33 x 60

Minutes per Hour

The total system water volume can becalculated from TABLE K for gallons per footfor various diameters of pipe and the totallengths of pipe on the system. Once thisnumber is determined, simply subtract thetotal system water volume from the minimumsystem water volume required. This will det-ermine the size of a buffer tank if required.Whenever a buffer tank is used, the tankbecomes the coupling device between theprimary piping loop and the secondarypiping loop. This primary/secondary buffertank can also be the low velocity area in thesystem and allow any entrained air to beseparated from heated water system.

Not all hydronic heating will require a buffertank. Lochinvar recommends all hydronicheating systems be evaluated to ensure aproper volume of water. This is especiallyimportant on systems with zones requiringlow heating loads, reheat systems andsystems being utilized for building humiditycontrol. When the short cycling issue isaddressed in the design stage, and the

required volume of system water isavailable, the low mass hydronic heatingboiler with fan assisted combustion willprovide many years of dependable, troublefree operation.

BOILER OPERATINGTEMPERATURE CONTROLIn the absence of a remote temperaturecontrol or Building Management System, afactory installed digital operator controls theboiler operating temperature. This selfcontained control has the sensing elementfor the operator placed in a bulb wellinstalled in the outlet side of the heatexchanger top header. Due to the locationof the temperature sensor, the control willgenerally require a lower temperature setpoint to achieve the desired discharge watertemperature from the boiler. The exacttemperature set point is based on systemrequirements.

Lochinvar

(TABLE K) – PIPE CAPACITY

Pipe GallonsSize per Foot

1/2" 0.016

3/4" 0.023

1" 0.040

1-1/4" 0.063

1-1/2" 0.102

2" 0.170

2-1/2" 0.275

3" 0.390

3-1/2" 0.530

4" 0.690

5" 1.100

6" 1.500

EXAMPLE OF

BUFFER TANK

SIZING:

PBN1001 Boiler

Run Cycle = 10 Min.

Temp. Rise = 40°F

Min. Load = 100,000 Btu/Hr

(10) (870,000 - 100,000)

divided by

40 x 8.33 x 60

= 385 Gallons

NOTE:

The buffer tank may also

be used as an air

elimination device in the

secondary piping loop.

BUILDING MANAGEMENTSYSTEM CONTROLSTo ensure maximum boiler system efficiency, itis recommended the building managementsystem enable/disable the factory suppliedboiler control system, based on ambient airtemperature. This will allow proper boileroperation and lead/lag control resulting ingreater system efficiency and reducedfluctuations in the loop water temperature.Whenever the building management system iscontrolling the heating system operation, atime delay of 2 to 5 minutes must allow allpumps in the system to run before shut downto allow any residual heat in the boilers to bedissipated. Proper sensor location is critical toensure a properly operating system. Thetemperature sensors should be located in thesupply and return piping of the secondaryloop.

A building management system control maybe connected directly to the boiler. The boileris equipped with a terminal strip to allow easyconnection remote temperature controller.Connection to the terminal strip will allow thecontroller to enable/disable the 24 VACcontrol circuit, turning the boiler on and offbased on building and system demands.

ELECTRICALREQUIREMENTS(North America)The appliance is wired for 120 volts.

All wiring between the unit and fieldinstalled devices shall be made of typeT wire [63°F (35°C) rise].

The pump must run continuously whenthe unit is firing.

It is recommended that the boiler andpump be wired on separate circuits withproperly sized circuit breakers.

(TABLE L) – AMP DRAW

MODEL FAN CONTROLLER APPROX. TOTALNUMBER AMPS @120 VAC

PB0501 4.0 2.7 6.7

PB0751 4.0 2.7 6.7

PB1001 4.0 2.7 6.7

PB1300 4.0 2.7 6.7

PB1500 2.2 4.5 6.7

PB1700 2.7 4.0 6.7

PB2000 2.7 4.0 6.7

1.

2.

3.


Lochinvar

BOILER PIPING

DIAGRAMS

L o c h i n v a r D E S I G N E R’ S G U I D E P O W E R - F I N B O I L E R 6 1 5 - 8 8 9 - 8 9 0 0

PIPING DIAGRAM PRIMARY/SECONDARY BOILER PIPING

PRESSURE REDUCING VALVE FULL PORTBALL VALVE

RELIEF VALVE CHECK VALVE TEE ELBOW

EXPANSION TANK TANK FITTING SYSTEM PUMP LOW WATERCUTOFF

UNION AIR SEPARATOR

L E G E N D

*AS CLOSE AS PRACTICAL – 12" OR 4 PIPEDIAMETERS MAXIMUM DISTANCE BETWEENMANIFOLD CONNECTIONS TO SYSTEM.

This illustration is for concept only and should not be used for any actual installation without engineeringor technical advice from a licensed engineer. All necessary equipment may not be illustrated.

L o c h i n v a r D E S I G N E R ’ S G U I D E P O W E R - F I N B O I L E R 6 1 5 - 8 8 9 - 8 9 0 0 A1

A2 L o c h i n v a r D E S I G N E R ’ S G U I D E P O W E R - F I N B O I L E R 6 1 5 - 8 8 9 - 8 9 0 0

PIPING DIAGRAM MULTIPLE UNIT-PRIMARY/SECONDARY




UNION AIR SEPARATOR

L E G E N D



PIPING DIAGRAM LOW TEMPERATURE BOILER BYPASS PIPING (F9 - ON/OFF FIRING ONLY)



L E G E N D


PRIMARY / SECONDARY BOILER PIPING WITH BYPASS FOR LOW TEMPERATURE OPERATION.



UNION AIR SEPARATOR

L o c h i n v a r D E S I G N E R ’ S G U I D E P O W E R - F I N B O I L E R 6 1 5 - 8 8 9 - 8 9 0 0 A3

PIPING DIAGRAM LOW TEMPERATURE BOILER BYPASS PIPING (M9 - MODULATION)



L E G E N D


PRIMARY / SECONDARY BOILER PIPING WITH BYPASS FOR LOW TEMPERATURE OPERATION.



UNION AIR SEPARATOR

A4 L o c h i n v a r D E S I G N E R ’ S G U I D E P O W E R - F I N B O I L E R 6 1 5 - 8 8 9 - 8 9 0 0

Notes:

Lochinvar Corporation • 615-889-8900 / Fax 615-547-1000

www.Lochinvar.com

PB-DG-05 5M-5/06-Printed in U.S.A.

DESIGNER’S GUIDE POWER-FIN BOILER

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