8/29/2018. Improving Energy Efficiency and Indoor Air Quality with HVAC Duct Sealants. Presenters. Disclaimer. Frank Forrest. Timothy D.

Transcription

1 Improving Energy Efficiency and Indoor Air Quality with HVAC Duct Sealants Copyright 2018 NADCA, All Rights Reserved No 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 Timothy D. Eorgan Frank Forrest 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. Disclaimer 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. 1

2 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 Objective 1 Briefly describe environmental concerns over energy issues and explain how HVAC air leakage contributes to these concerns 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 Energy Consumed Data Source: Inc. / Architecture All Rights Reserved 2

3 Electricity Building Operations Data Source: Inc. / Architecture 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.? 3

4 reduces Energy and Duct Leakage According to the EPA, leaking duct systems account for approximately 30% of energy loss in residential and commercial buildings. Objective 2 Describe the reasons why sealing ductwork is critical to maximizing HVAC system efficiency Lawrence Berkeley National Laboratory (LBNL): duct leakage exceeded the ASHRAE recommended leakage classes by roughly a factor of 20. Duct Leakage *EER =Energy Efficiency Ratio ; SEER = Seasonal Energy Efficiency Ratio 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 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, TX Robert 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 4

5 Over 2 billion dollars annually in energy loss through leaky ductwork just in commercial buildings. Duct Leakage 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 slip and drive seam Noted at the joints by the black residue spiral duct 5

6 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 6

7 Seal off the ATU to Trunk Joint Test up to VAV Box Tester Connected to Duct System EXISTING SYSTEM 7

8 Tester Connected to Duct System NEW SYSTEM Objective 3 Explain duct sealing options and list the advantages of each 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 8

9 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. wet sample preparation cured sample ready for testing Mastic Quality Control Sample tested and passed no cracking or delamination Each lot # must be tested at the quality control lab 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 9

10 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 10

11 Mastic Brushed Application Process Click image to play video Mastic Brushed Application Process Avoid overworking 11

12 Drive and Drive transverse jointuncured sealant at 45 minutes dry time. Pressure tested to 6-inch w.c. Over-pressure before curing volcano Corneruncured sealant at 40 minutes dry time. Pressure tested to 6-inch w.c. Mastic - Sprayed Only non-reinforced Used for flex duct and sheet metal Always water based -low VOC Meets UL 181B-M 12

13 Mastic Spray Application Process Click image to play video Not your everyday duct tape Provides a water-resistant instant bond that seals most Rolled Mastic Sealant Characteristics 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 Rolled Mastic Sealants 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 13

14 Rolled Sealant Application Process Rolled Sealant Application Process Click image to play video Rolled Sealant Finished Applications Example 14

15 Example Example Example 15

16 Example Orlando, Florida - Rosen Shingle Creek Hotel Design Challenges: High humidity Increased atmospheric salinity Existing building Combined Systems Reduced moisture going into duct system Reduced air leakage and energy loss 4/13/2012 Combined Rolled Sealants and Mastic System 16

17 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 17

18 Product Use Base Which Sealant to Use? Pressure Classes Recommended Application Indoor Outdoor Solvent Water Pressures 1/2" -6" wg Pressures 6" -10" wg Round Duct Oval Duct Rectangular Duct Aluminum Duct (Cleaned) Stainless Steel * Flexible Duct Ridged Fiberglass Ductboard 4 Bolt Connections Ridged PVC Coated Duct (Above Ground) Ridged PVC Coated Duct (Below Ground) 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: Longitudi nally 18

19 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

20 Test Pressure? Select a test pressure not in excess of the pressure class rating of the duct. (Usually the actual operating pressure.) Objective 4 Business How to sell an upgraded system to include sealing What to look for Ball park costing to seal How to sell an upgraded to the system you are cleaning. Meeting the latest code and energy savings 20

21 ASHRAE 90.1 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. 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 Because safety codes, energy codes, and standards are developed independently, the most recent edition of a code or standard maynot have been adopted by a local jurisdiction. HVAC designers must know which code compliance obligations affect their designs. If a provision conflicts with the design intent, the designer should resolve the issue with local building officials COMMERCIAL-12/17 RESIDENTIAL 12/17 21

22 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 22

23 23

24 Where to Seal 24

25 Where to Seal Most duct leakage occurs at the connections to registers, plenums, or branches and duct wall penetrations. Where to Seal 25

26 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 minutes per foot 14 seconds per foot 4 Bolt Flange TDC/TDF Flange Slip & Drive Sealing Type Total Cost (Labor & Product) Sealing Type Total Cost (Labor & Product) Sealing Type Total Cost (Labor& Product) Bucket & Brush $ Bucket & Brush $ Bucket & Brush $ If Rolled $1, If Rolled $ If Rolled $ If Sprayed $ If Sprayed $ If Sprayed $ Combination 701/Mastic (B&B) $1, Combination 701/Mastic (B&B) $ Combination 701/Mastic (B&B) $ Combination 701/Mastic (Spray) $1, Combination 701/Mastic (Spray) $ Combination 701/Mastic (Spray) $

27 Improving Energy Efficiency and Indoor Air Quality with HVAC Duct Sealants Presenter Contact Information Improving Energy Efficiency and Indoor Air Quality with HVAC Duct Sealants Timothy D. Eorgan (972) Frank Forrest (972) Thank you for Participating! 27