External Duct Sealing - Practical Application & Hands On Demo · According to the EPA, leaking duct...
Transcript of External Duct Sealing - Practical Application & Hands On Demo · According to the EPA, leaking duct...
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Improving Energy Efficiency and IndoorAir Quality with HVAC
Duct Sealants
Copyright © 2018 NADCA, All Rights ReservedNo part of this publication may be reproduced or distributed by any means, electronic or mechanical, including photocopy, recording, or any other information storage and retrieval system, without prior written consent from the publisher.
Presenters
Frank ForrestTimothy D. Eorgan
Disclaimer
This presentation is not intended to be a comprehensive program covering all
aspects of this topic. All technicians are encouraged to read and follow all applicable
standards, codes and regulations related to this topic.
� It is the responsibility of each individual contractor to follow local building codes
and licensing requirements and to work safely in accordance with OSHA
guidelines.
� It is the contractor’s responsibility to take proper precautions on each project to prevent cross contamination. Always take the health and safety of the building
occupants into consideration before you conduct any cleaning procedures.
� All of the following tips are only general tips. They do not cover every situation
and it is your responsibility to adapt these tips to the individual system you are working on.
� The Instructor is not responsible in any way for the work you perform after
viewing this slide show. You are responsible for your own work.
� The views and opinions following are the instructors opinions and not necessarily
the official position of the National Air Duct Cleaners Association.
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Objectives
� Briefly describe environmental concerns over energy issues and explain how HVAC air leakage contributes to these concerns
� Describe the reasons why sealing ductwork is critical to maximizing HVAC system efficiency
� Explain duct sealing options and list the advantages of each
� Business � How to sell an upgraded system to include sealing� What to look for� Ball park costing to seal
Briefly describe environmental concerns over energy issues and explain how HVAC air leakage contributes to these concerns
Objective 1
Energy Consumed
Data Source: ©2010-2011 2030 Inc. / Architecture 2030. All Rights Reserved
Buildings consume about ½ the global demand of
energy ($) and materials that produce by-product
greenhouse gases (GHG). Slowing the growth rate of GHG emissions and then reversing it is the key
to addressing climate change
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Electricity –Building Operations
Data Source: ©2010-2011 2030 Inc. / Architecture 2030. All Rights Reserved
Electrical Energy Consumption in Commercial Buildings
Cost of Leakage
NEBB uses $1.30 per sq.ft.
What rule of thumb do you use for cfm per sq.ft.?
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Energy and Duct
Leakage
According to the EPA, leaking duct systems account for approximately 30% of energy loss in residential and commercial buildings.
Describe the reasons why sealing ductwork is critical to maximizing HVAC system efficiency
Objective 2
Duct Leakage
*EER =Energy Efficiency Ratio ; SEER = Seasonal Energy Efficiency Ratio
� Lawrence Berkeley National Laboratory (LBNL): duct leakage exceeded the ASHRAE recommended leakage classes by roughly a factor of 20.
� Duct Leakage Tests*
� 6% duct leakage per California Energy Commission building standards reduces EER* by 7% and SEER* by 14% 13 SEER = 11 SEER
� 15% duct leakage per Energy Star ® reduces EER* by 18% and SEER* by 24% 13 SEER = 9+ SEER
� 30% duct leakage common of many US homes reduces EER* by 36% and SEER* by 42% 13 SEER = 7.5 SEER
2012 ASHRAE Annual Conference June 23–27, San Antonio, TXRobert Mowris, P.E., Robert Eshom, A.S., Ean Jones, B.S. VERIFIED™, Inc.ASHRAE TC 6.3Session Title: HVAC Installation and Maintenance: Challenges and Uncertainties in Field and Laboratory
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Duct Leakage
� Over 2 billion dollars annually in energy loss through leaky ductwork just in commercial buildings.
� Light commercial buildings tend to have significantly higher duct leakage rates than large commercial buildings. Light commercial buildings typically are not commissioned (unlike larger buildings), so duct leakage problems are not identified and fixed. In addition, smaller commercial building projects may not involve an HVAC design engineer.
� Also, identified as a major source of energy loss in residential buildings.
Duct Leakage & Energy Issues
When Ducts Leak
� Reduces System Capacity
� Reduces Life of HVAC Unit (runs longer/more often)
� Creates Hot/Cold spots (inconsistent heating and cooling) which also reduces thermal comfort of occupants
� All factors Use more energy
&
Increases Utility Costs
Energy Loss
Noted at the joints by the black residue
spiral duct
slip and drive seam
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Energy Loss
Noted at the joints by the black residue
spiral duct
What are you Sealing?
� Equipment
� AHU
� Heat exchangers
� VAV
� Accessories
� fire dampers
� dampers� heaters
� HW coils
� etc.
� Duct System
� Riser/chase duct
� All floors? Partial system?
� Round duct or rectangular ? Both?
Test Setup for Leakage Test
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Seal off the ATU to Trunk Joint
Test up to VAV Box
Tester Connected to Duct System –EXISTING SYSTEM
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Tester Connected to Duct System –NEW SYSTEM
Explain duct sealing options and list the advantages of eachObjective 3
UL Criteria:
Mastics for
Sealing
Ductwork
Testing parameters required by UL-181
� Surface Burning Characteristics
� Burn Test
� Mold Growth and humidity
� Temperature Test
� Pressure Test
� Shear Adhesion
� Tensile Joint Strength
� Peel Adhesion
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Mastic Quality Control
� Often one year or less – some maybe only 6 months.
� Installer should verify that shelf life has not been exceeded.
� All mastic products should be labeled with a lot number to insure that the key physical properties of each batch meets published specifications.
Mastic Quality Control
Each lot # must be tested at the quality control lab
wet sample preparation cured sample ready for testing
Sample tested and passed no cracking or delamination
IAQ and VOCs
� Mold Growth and VOC thresholds� while zero VOCs sounds good - this does not
prevent mold growth.
� VOCs� water based sealants with minimal VOCs
� Less than 250g/l for water based sealants
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Options
� Mastic� Water based or
� Solvent based
and
� Brushed or
� Sprayed
� Rolled Mastic Sealant
Mastic -attributes and benefits
• Faster application
• More consistent application
• Good for odd angles -• UV or non UV rated
• Service temperature range
• Mildew resistant
• Viscosity
• Freeze/thaw stability
• Cure Time• Rated to what pressure class –up to 10”
w.g.
• Seal Classes- SMACNA-ABC
• UL listed –Flame and Smoke data
• LEED criteria
• LA approved• FDA approval of base polymers
• Water or solvent based
Mastic -Brushed
� Reinforced� always water based
� can only be used for sheet metal (and ductboard applications with a scrim)
� Meets both UL 181A-M and UL181B-M
� Non-reinforced� either water based or solvent based
� use for flex duct and sheet metal; meets UL 181B-M
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Mastic Brushed Application Process
Click image to play video
Mastic Brushed Application Process
Avoid over-working
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Drive and Drive transverse joint-uncured sealant at 45 minutes dry time. Pressure tested to 6-inch w.c.
Corner-uncured sealant at 40 minutes dry time. Pressure tested to 6-inch w.c.
Over-pressure before curing –“volcano”
Mastic -Sprayed
�Only non-reinforced
�Used for flex duct and sheet metal
�Always water based - low VOC
�Meets UL 181B-M
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Mastic Spray Application Process
Click image to play video
Not your everyday duct tape
Rolled Mastic Sealant CharacteristicsProvides a water-resistant instant bond that seals most
surfaces and conforms to surface variations.
� Minimum thickness 17 mils up to 30mils
� Type of backing – foil faced or fabric
� UV or non UV rated
� Peel Strength
� Tensile strength
� Bonding time - immediate
� Flexibility
� Mildew resistant
� Rated to what pressure class –up to 10” w.g. .
� Service temperature range
� Seal Classes- SMACNA- A,B,& C
� LA approved
� Paintable
� No VOC – only true zero VOC sealant
� Use for low and medium pressure flex duct and sheet metal
� Ideal for Replacement Applications
� Easy to Use with No Mess
� Approved for Indoor and
Outdoor Use
Rolled Mastic Sealants
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Rolled Sealant –Application Process
Rolled Sealant – Application Process
Click image to play video
Rolled Sealant – Finished Applications
Example
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Example
Example
Example
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Example
Combined Systems
� Orlando, Florida - Rosen Shingle Creek Hotel
� Design Challenges:� High humidity
� Increased atmospheric salinity
� Existing building
Combined
Rolled
Sealants
and Mastic
System
� Reduced moisture going into duct system
� Reduced air leakage and energy loss
4/13/2012
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Combined Rolled Sealants and Mastic System LA Job Corp, 1031 South Hill St.
Combined
Rolled
Sealants
and Mastic
System
Combined Rolled
Sealant and Mastic
System
�Critical applications; Pharmaceutical laboratories where vivarium air is up to $10.00/cubic ft.
�Hospitals
�Semiconductor manufacturers
�Corrosive environments
�Water concerns
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Which Sealant to Use?Product Use Base
Pressure
ClassesRecommended Application
Ind
oo
r
Ou
tdo
or
So
lve
nt
Wa
ter
Pre
ssu
res
1/2
" -
6"
wg
Pre
ssu
res
6"
-1
0"
wg
Ro
un
d D
uct
Ov
al
Du
ct
Re
cta
ng
ula
r D
uct
Alu
min
um
Du
ct (
Cle
an
ed
)
Sta
inle
ss S
tee
l *
Fle
xib
le D
uct
Rid
ge
d F
ibe
rgla
ss D
uct
bo
ard
4 B
olt
Co
nn
ect
ion
s
Rid
ge
d P
VC
Co
ate
d D
uct
(A
bo
ve
Gro
un
d)
Rid
ge
d P
VC
Co
ate
d D
uct
(B
elo
w G
rou
nd
)
Mastic Duct Sealants
Non-Reinforced Water-Based Mastic
(UL 181 B-M)• • • • • • • • • • • •
Non-Reinforced Water-Based Spray Applied Mastic (UL
181 B-M)• • • • • • • • • • • •
Reinforced Water-Based Mastic 181
(UL 181 A-M) (UL 181 B-M)• • • • • • • • • • • • •
Solvent Based Mastic (UL 181 B-M) • • • • • • • • • •
Elastomeric Rolled Sealants**
Foil Faced Rolled Sealants UL 181-BFX) • • N/A • • • • • • • • • •
Foil Faced Rolled Sealants (UL 723) • • N/A • • • • • • • • • • •
Where to Seal: Longitudinally
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Joint Sealants
� Longitudinal Joint Sealants
� Solvent-based permanently tacky seam sealant
� Very thick so must be pumped
� Flammable due to solvents
� Water-based seam sealant
� Higher viscosity close to a spray able
� Non-flammable – ASTM E84 0/0
� Fab shop application where they are manufacturing Pittsburgh, snap-lock or similar style metal duct seams.
Where to Seal: Transversely
1
2
3
4
3
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• Select a test pressure not in excess of the
pressure class rating of the duct. (Usually the actual operating pressure.)
Test Pressure?
Business
• How to sell an upgraded system to include sealing
• What to look for
• Ball park costing to seal
Objective 4
How to sell an upgraded to the system you are cleaning.
Meeting the latest code and energy savings
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ASHRAE 90.1
�World’s most adopted building energy code
�Basis for International Energy Conservation Code (IECC)
Seal Classes – SMACNA
Sheet Metal and Air Conditioning Contractors National Association—
Std.90.1; 2010 All ducts are required to be constructed to Seal Class A
2009 & 2012 International Energy Conservation Code-IECC ; All Residential is tested; Commercial < 3” must be sealed but not tested. over 3” must be sealed
and tested at 25 % surface area or greater.
Because safety codes, energy codes, and standards are developed independently, the most recent edition of a code or standard may not have been adopted by a local jurisdiction. HVAC designers must know which code compliance obligations affect their designs. If aprovision conflicts with the design intent, the designer should resolve the issue with local building officials
COMMERCIAL- 12/17 https://www.energycodes.gov/status-state-energy-code-adoption
RESIDENTIAL12/17
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Applicable Leakage Classes
What to look for during your initial site appraisal (?)
As NADCA members you will recognize the following pictures and typical problem
locations
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Where to Seal
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Where to Seal
Where to Seal
Most duct leakage occurs at the connections to registers, plenums, or branches and duct wall penetrations.
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Ball park costing to seal
Bucket & Brush Application
Time per piece/distance
Duct type Corners Longitudinal Seams Transverse Joints
4 Bolt Flange 1.2 minutes per corner 1.2 minutes per foot 50 seconds per foot
TDC/TDC 1.2 minutes per corner 0.5 minutes per foot 20 seconds per foot
Slip & Drive N/A 1 minute per foot 40 seconds per foot
Rolled Sealant Application
Time per piece/distance
Duct type Corners Longitudinal Seams Transverse Joints
4 Bolt Flange 1 minute per corner 0.66 minutes per foot 4.4 minutes per foot
TDC/TDC 1 minute per corner 0.66 minutes per foot 1.5 minutes per foot
Slip & Drive N/A 0.66 minutes per foot 3 minutes per foot
Spray Application
Time per piece/distance
Duct type Corners Longitudinal Seams Transverse Joints
4 Bolt Flange 0.4 minutes per corner 0.4 minutes per foot 20 seconds per foot
TDC/TDC 0.4 minutes per corner 0.17 minutes per foot 7 seconds per foot
Slip & Drive N/A 0.285 minutes per foot 14 seconds per foot
4 Bolt Flange TDC/TDF Flange Slip & Drive
Sealing TypeTotal Cost (Labor & Product) Sealing Type
Total Cost (Labor & Product) Sealing Type
Total Cost (Labor & Product)
Bucket & Brush $296.28 Bucket & Brush $224.11 Bucket & Brush $191.55
If Rolled $1,079.00 If Rolled $500.83 If Rolled $668.00
If Sprayed $176.78 If Sprayed $134.14 If Sprayed $139.03
Combination 701/Mastic (B&B) $1,375.28
Combination 701/Mastic (B&B) $724.94
Combination 701/Mastic (B&B) $859.55
Combination 701/Mastic (Spray) $1,255.78
Combination 701/Mastic (Spray) $634.97
Combination 701/Mastic (Spray) $807.03
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Improving
Energy Efficiency and
Indoor
Air Quality with HVAC Duct
Sealants
Presenter Contact Information
• Timothy D. Eorgan• [email protected]
• (972) 442-6545
Improving
Energy Efficiency and
Indoor
Air Quality with HVAC Duct
Sealants
• Frank Forrest• [email protected]
• (972) 442-6545
Thank you for
Participating!