New Technology for Efficient Multifamily Building Envelope Sealing
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Webinar sharing report findings including aerosol sealing cost-effectiveness in multifamily buildings and recommendations on how utilities and contractors can take advantage of this new sealing application.
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New Technology for Efficient Multifamily Building Envelope Sealing
- 1. New Technology for Efficient Multifamily Building Envelope Sealing Dave Bohac PE | Director of Research June 2017
- 2. Welcome Conservation Applied Research & Development (CARD) Webinar Mary Sue Lobenstein, R&D Program Administrator Marysue.Lobenstein@state.mn.us
- 3. Minnesota Applied Research & Development Fund Purpose to help Minnesota utilities achieve 1.5 % energy savings goal by: • Identifying new technologies or strategies to maximize energy savings; • Improving effectiveness of energy conservation programs; • Documenting CO2 reductions from energy conservation programs. Minnesota Statutes §216B.241, Subd. 1e.
- 4. CARD RFP Spending by Sector thru FY2017 • 8 Funding Cycles • Nearly 380 proposals • 92 projects funded Multi-sector (21) 25.3% Commercial (36) 37.6% Residential 1-4 unit (15) 18.7% Industrial (10) 8.6% Multifamily 5+ unit (4) 6.6% Agricultural (6) 3.1%
- 5. New Technology for Efficient Multifamily Building Envelope Sealing Dave Bohac PE | Director of Research June 2017
- 6. Pg. 6 Multifamily Experience • Facility assessments of over 2,000 buildings in Minnesota • Completed over 20 research projects
- 7. Pg. 7 Multifamily Research Projects PROJECT ANTICIPATE FINDINGS • Condensing boiler optimization Available • Multifamily ventilation optimization Available • Multifamily aerosol envelope air sealing Available • Indoor pool optimization Fall 2017 • Demand controller recirculation loop Fall 2017 • Through-wall furnace/AC packages Fall 2017
- 8. Multifamily Envelope Sealing Opportunity: • Existing. Thousands of leaky units built before any tightness requirements. • New Construction. • Lowrise - moderately tight with ventilation. • Highrise – limited tightness requirement.
- 9. Benefits: • Reduced air infiltration energy costs • Reduced odor transfer & improved IAQ • Improved comfort from reduced drafts • Reduced noise transmission (neighbors and outside) • Improved envelope durability • Reduced stack effect
- 10. Envelope Sealing Challenges: • Existing buildings. No/difficult/costly access to distributed air leaks. 10% to 30% reduction is challenging. • New Construction. Single family approaches only recently starting to carry over to multifamily buildings. How can we do this more effectively for both exterior leakage and compartmentalization?
- 11. Envelope Tightness Requirements: • Minnesota Energy Code (2015). • SF and 1 to 3 story MF: 3.0 ACH50 • 4+ story MF: 0.4 cfm75/sf • Green Communities (MHFA). EPA ENERGY STAR for multifamily high rise = 0.3 cfm50/sf (4 – 8 ACH50) • LEED. • Prerequisite. 1-3 story: 3.0 ACH50; 4-8 story: 0.3 cfm50/sf; 9+ story: continuous air barrier. • Secondhand smoke. 9+ story prereq. & credits typically met by either Materials (0.004 cfm75/sf) or Assemblies (0.04 cfm75/sf) prescriptive options
- 12. Pg. 12 Envelope Aerosol Sealing • Pressurize apartment • Spray air sealing fog • Sealant particles build up on gaps as they flow through the leaks Similar to process used for aerosol duct sealing
- 13. How does it do that? No, really? (animation video here) Sealant is low VOC: GREEN Guard Gold Certified for use in California school and health care facilities. Sealant is a synthetic acrylic – typically rolled or sprayed on for monolithic, elastomeric exterior air barrier. Diluted for aerosol application.
- 14. Aerosol Benefits: • Automatically finds and seals leaks • Very effective at sealing small, diffuse leaks • Continuous update of leakage during sealing • Reliably meet air tightness requirements • Potential savings for avoided conventional air sealing (?)
- 15. Pg. 15 Study Objectives: Demonstrate sealing capability and evaluate commercialization • Demonstrate - measure leakage and noise transmission reduction & identify sealing locations • Document – work time • Innovate - how to incorporate into sealing strategy, pre-seal “large” leaks and protect horizontal surfaces as necessary • Model - energy savings and effect on ventilation 1. Sealed 18 units in 3 new construction buildings 2. Sealed 9 units in 3 existing buildings
- 16. Pg. 16 Project Team • Center for Energy and Environment • Ben Schoenbauer and Jim Fitzgerald • Kirk Kolehma and Megan Hoye • UC Davis Western Cooling Efficiency Center • Curtis Harrington • Mark Modera and Jose Garcia • The Energy Conservatory (TEC)
- 17. Pg. 17 Aerosol Sealing Process: All In One Visit 1. Walk thru to identify pre-sealing & protection requirements (prior to sealing visit?) 2. Pre-seal large gaps & temporary sealing (as necessary) 3. Site work prep – cover horizontal surfaces (as necessary) 4. Set up sealing equipment 5. Perform sealing 6. Remove coverings 7. Clean surfaces (as necessary) 8. Post-sealing air leakage test 9. Air leakage test when unit finished – research only
- 18. Pg. 18 Site Work Prep: pre-seal wide gaps Sprinkler head Plumbing penetration
- 19. Pg. 19 Site Work Prep: pre-seal wide gaps Range electric line Low-voltage wiring
- 20. Pg. 20 Site Work Prep: pre-seal wide gaps AC Line set Duct – narrow enough to leave?
- 21. Pg. 21 Site Work Prep: pre-seal wide gaps Construction Plumbing Electrical Mechanical Floor wall connection Showerhead penetration Range plug Line sets for HVAC Sprinkler penetration Sink penetrations Electric baseboards Vent duct penetrations Waste line penetrations Low voltage wiring Fresh air duct penetration Clothes washer connections Additional wiring penetrations Combustion and exhaust air penetrations Toilet water connection PTAC wall penetration Kitchen water connection Gas line penetrations (range, HVAC, laundry) 1 to 2 hours/unit
- 22. Pg. 22 Site Work Prep: baseboards Seal before quarter round, caulk after? What about leaky wood floors?
- 23. Pg. 23 Site Work Prep: temporary sealing Exterior doors Combustion ventsExhaust fan ducts Plumbing penetrations Fill traps or cover waste line openings Shower handles
- 24. Pg. 24 Site Work Prep: temporary sealing Construction Plumbing Electrical Mechanical Door frames Bathroom handles Intercom Bath fan Floors (i.e. finished hardwood) Drains Low voltage outlets Kitchen fan Exterior doors (not used for fan frame) Waste lines Smoke detectors Additional ventilation Large holes/openings in the envelope Alarms Combustion and exhaust air Windows (leaky) Sprinkler heads PTAC openings Outdoor air intakes Forced air registers Forced air returns
- 25. Pg. 25 Site Work Prep: cover horizontal finished surfaces Ideal: drywall mud/tape no other finishes (bare floor better) Not ideal: ready for occupancy
- 26. Pg. 26 Site Work Prep: cover horizontal finished surfaces
- 27. Pg. 27 Site Work Prep: cover horizontal finished surfaces Construction Plumbing Electrical Mechanical Finished floors Tub or shower surrounds and floors Ceiling Fans Top surface of baseboard heating Window sills Toilets, sinks, other bathroom pieces Light switches Window meeting rail and muntins Plumbing fixtures Light fixtures Door tops and hardware Sprinkler heads Top surface of baseboards, trims, and molding Horizontal surfaces of cabinets and built-ins Temporary seals & covers: 3 to 7 hours/unit
- 28. Pg. 28 Site Work: Set-up, Seal & Breakdown • Blower door and nozzles • 100Pa pressurization • ~ 90% RH maintained • Open windows & purge 6 to 7 hours/unit Remove Covers & Pack-up • Care to not disturb seals • Minimal clean-up 1.5 to 3.5 hours
- 29. Pg. 29 Site Work Prep: how long does it take? 14 to 22 hours: researchers still learning
- 30. Pg. 30 Site Work Preparation Opportunities to reduce labor time • Pre-sealing: new construction – GC or sub completes • Unit preparation: select time during construction when: • Minimum horizontal surfaces to protect • Leaks are accessible • Seals will be durable • Sealing time: new generation of more portable equipment is being developed & stop when no longer cost effective. 1 person oversees sealing. • Breakdown/clean-up: minimize surfaces to cover and better positioning of spray nozzles
- 31. Pg. 31 Sealed Penetrations Plumbing Penetrations
- 32. Pg. 32 Sealed Penetrations Sprinkler Head Kitchen exhaust fan
- 33. Pg. 33 Sealed Penetrations Electrical Boxes
- 34. Pg. 34 Sealed penetrations: black light photos Floor/wall Joint Electrical Boxes
- 35. Pg. 35 Sealed penetrations: black light photos Sprinkler Head Recessed Light
- 36. Pg. 36 Leakage Reduced Over Injection Period ACH50 pre: 2.0 – 2.9, post: 0.2 – 0.7; 71% to 94% reduction New construction Floor area: 900 to 1,300sf Needed to meet 0.3 cfm50/sf or about 5 – 7 ACH50 Building B
- 37. Pg. 37 Sealing Rate Stop time? Building B
- 38. Pg. 38 Leakage Reduced Over Injection Period ACH50 pre: 7.1 – 8.4, post: 0.9 – 1.4; 82% to 89% reduction New construction Floor area: 350 to 420sf Sealed 4 in one day Building C - Hotel
- 39. Pg. 39 Leakage Reduced Over Injection Period ACH50 pre: 12.0 – 17.2, post: 1.4 – 10.5; 39% to 88% reduction Existing units Floor area: 230 to 250sf Sealed 4 in one day Large leak behind kitchen cabinet Building D – Affordable Housing
- 40. Pg. 40 Leakage Results: 18 New Construction Units Average leakage: pre= 3.9 ACH50, post= 0.7 ACH50 54% to 95% below code requirement, average= 77%
- 41. Pg. 41 Leakage Results: New Construction Reduction: 67% to 94%, average = 81%
- 42. Pg. 42 Leakage Results: 9 Existing Units Average leakage: pre= 14.6 ACH50, post= 4.8 ACH50 6 of 9 within 15% of new construction code requirement
- 43. Pg. 43 Leakage Results: Existing Units Reduction: 39% to 89%, average = 68%
- 44. Pg. 44 Leakage Results: Where Are the Leaks? Interior wall to hallway 5x leakier than others (cfm50) (cfm50/ft2) Percent of Total ID Ext & Below Adj Units Comm Ext & Below Adj Units Comm Ext & Below Adj Units Comm A404 93 42 63 0.09 0.08 0.49 47% 21% 32% A406 94 30 83 0.09 0.06 0.64 45% 15% 40% A407 88 48 63 0.09 0.10 0.49 44% 24% 32% A408 98 53 47 0.09 0.11 0.37 49% 27% 24% A409 87 47 86 0.09 0.10 0.67 40% 21% 39% A411 105 58 38 0.10 0.12 0.29 52% 29% 19% Average 94 46 63 0.09 0.09 0.49 46% 23% 31% New Construction Building A About a quarter of leakage to adjoining units and a third to common space (hallways) All units on the fourth (top) floor
- 45. Pg. 45 Over half of the leakage is to the hallway Leakage Results: Where Are the Leaks? About 13% of leaks to units on same floor and a little more to units above and below Total (ACH50) Percentage of Total Leakage Floor ID (cfm50) Total Exter Exter Comm Left Right Up Down Red. B206 494 3.58 0.28 8% 46% 19% 9% 12% 7% 29% B207 580 4.21 0.73 17% 51% 12% 2% 12% 6% 43% B208 957 5.97 0.46 8% 76% 4% 5% 4% 3% 57% B209 648 3.97 0.99 25% 58% 2% 0% 11% 5% 42% B210 784 4.04 0.33 8% 58% 7% 9% 12% 6% 50% B211 757 4.98 1.07 22% 45% 9% 0% 13% 11% 43% Average 703 4.46 0.64 15% 56% 9% 4% 11% 6% 44% New Construction Building B Compartmentalization requirement: < 0.3 cfm50/sf
- 46. Pg. 46 Leakage Results: Where Are the Leaks? 8% of leakage to units on same floor New Construction Building C Total Adjacent Unit Remainder ID (cfm50/ft2) (cfm50/ft2) (%) (cfm50/ft2) (%) CA 0.29 0.12 8% 0.33 92% CB 0.33 0.12 7% 0.39 93% CC 0.34 0.12 7% 0.39 93% CD 0.29 0.12 8% 0.33 92% Min 0.29 0.12 7% 0.33 92% Average 0.31 0.12 8% 0.36 92%
- 47. Pg. 47 Leakage Results: Where Are the Leaks? Exterior is 2/3 of leakage Existing Building D (ACH50) (cfm50/ft2) % of Total ID Total Ext. Int. Total Ext. Int. Ext. Int. D 106 12.1 7.3 4.7 0.40 1.10 0.20 61% 39% D 201 14.4 9.7 4.6 0.53 1.37 0.23 68% 32% D 202 12.4 6.8 5.6 0.38 1.25 0.21 55% 45% D 206 17.2 10.2 7.0 0.58 1.53 0.31 59% 41% D 301 12.4 10.4 2.0 0.40 0.67 0.13 84% 16% D 302 12.0 9.9 2.2 0.37 0.67 0.12 82% 18% Average 13.4 9.0 4.4 0.44 1.10 0.20 68% 32% Exterior is 5x leakier than interior
- 48. Pg. 48 Reduced Noise Transmission • Sound transmission testing was conducted in a MF building in NY • Seal was an effective sound barrier between 800-5000 Hz – reduction of 7 to 14dB • Human voice frequency falls between 300-3000 HZ • Helps to meet Building Code (IBC) requirement of 50 STC Human Voice
- 49. Pg. 49 • 6-Story building model • Floor plan: • 4 Units per floor • 1 Elevator shaft • 1,200sf floor area • Construction: • DOE reference model construction • Window to wall ratio: 20% EnergyPlus Model
- 50. Pg. 50 • Four ventilation strategies investigated • Exhaust only • Exhaust with some supply • Balanced • No ventilation • Individual unit exhaust fans and balanced ventilators Model – Ventilation Method
- 51. Pg. 51 Envelope leakage (total): • Existing Building • Leaky: 9.5 ACH50 (existing data) • Sealed: 3 ACH50 (MN code?) • New Building • Compliant: 3 ACH50 (MN code?) • Tight: 0.6 ACH50 (Passive House) Model – Leakage ACH50 Exterior Interior Floor/Ceiling Door 9.5 43% 34% 13% 9% 3 47% 18% 5% 29% 0.6 47% 18% 5% 29% Table 1: Leakage distribution used in models
- 52. Pg. 52 Results – Ventilation Flows 0 20 40 60 80 100 120 Exhaust Only Exhaust & Some Supply Balanced No Vent AirFlowrate(CFM) 9.5 ACH50 3 ACH50 0.6 ACH50 Vent Fan Flow MN Code Req't Annual building average fresh airflow per unit 0.6 ACH50 – 96 cfm50; 50cfm exhaust = 20 Pa depressurization 0.35ach, 63 cfm (MN code)
- 53. Pg. 53 Results – Interior Flows 0 5 10 15 20 25 Exhaust Only Exhaust & Some Supply Balanced No Vent AverageFlowfromAdjoiningApartment(CFM) 9.5 ACH50 3 ACH50 0.6 ACH50
- 54. Pg. 54 Results – Summary Table New Buildings 80% reduction Existing Buildings 68% Reduction Heating Savings (therms/year) 60 - 75 40 - 200 Heating Savings ($/year) $33 - $44 $23 - $120 • Impact of sealing air leaks in apartment buildings in Minneapolis Exterior leakage reduced from 3.0 to 0.6 ACH50 Little or negative impact on cooling energy Low savings: Total leakage reduced from 9.5 ACH50 to 3 ACH50 New construction: balanced ventilation Existing buildings: exhaust only typically acceptable
- 55. Pg. 55 Conclusions • Effectively seals gaps < 1/2” to 5/8” • New construction • 81% reduction & 77% below code • Reduce to below code reliably & w/o excessive QC • Need balanced ventilation • Use to reduce cost of conventional sealing methods • Existing units • 68% reduction & 6 of 9 comply with new code (3 ACH50) • Heating savings= 40 - 200 therms/yr (Minnesota) • Target leakier units. Need exhaust ventilation. • Improved IAQ – 85% reduction in flows from other units • Change in occupancy – needs development
- 56. Pg. 56 Ongoing Work Large Building Sealing with Department of Defense • WCEC project with Aeroseal • Sealing existing commercial buildings on military bases • Lab testing of seal strength and durability • Modeling energy savings due to large-building sealing Aeroseal AeroBarrier Commercialization • Announced at 2017 RESNET conference • Currently in advanced field trials • Available Q1 2018 • For more information visit www.aeroseal.com/aerobarrier
- 57. Aerosol Sealing in New Construction
- 58. Approach Key Issues: • Previous Building America projects showed 60% to 95% improvements in envelope tightness. • Sealing typically applied after drywall in place. No experience with ability to replace current sealing methods. Approach: • Iterative approach with multiple builders – when & what to eliminate • Assess current sealing methods for a MN & CA builder and develop two approaches for each • Net cost and tightness will be evaluated against standard methods • Process repeated with second set of houses for first builders and a set of houses for additional builders.
- 59. Progress and AccomplishmentsLessons Learned (Builder Kickoff Meeting): • Builders interested in sealing after mechanical penetrations/before insulation and drywall • Eliminate 4 ml poly interior and use low perm paint for interior vapor retarder? • Seal ducts from outside > in? • Ductwork exposed to interior • Plug duct boots & create opening to outside; protect furnace • Change rim joist spray foam approach? • Likely to need help working with code officials to approve some changes
- 60. Pg. 60 Audience Question & Answer
- 61. CARD Project Resources Link to Aerosol Sealant Project Report CARD Web Page (https://mn.gov/commerce/industries/energy/utilities/cip/applied-research-development/) For Reports use CARD Search Quick Link For Webinars use CARD Webinars & Videos Quick Link
- 62. Upcoming CARD Webinars: • June 22: Improving Effectiveness of Energy Recovery Ventilation • July 12: Small Embedded Data Center Program Pilot • July 26: Statewide Commercial Behavior Segmentation & Potential • August 17: Expanding New Construction Design Assistance Statewide If you have questions or feedback on the CARD program contact: Mary Sue Lobenstein marysue.lobenstein@state.mn.us 651-539-1872 CARD Webinar Thanks for Participating
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- 66. Dave Bohac | Director of Research dbohac@mncee.org
Hinweis der Redaktion
- Welcome to this Conservation Applied Research and Development (CARD) Webinar. I am Mary Sue Lobenstein, the R&D Program Administrator at the Minnesota Department of Commerce, Division of Energy Resources. This webinar is one in an ongoing series designed to summarize the results from research projects funded by Minnesota’s Applied Research and Development Fund.
- The Applied Research and Development Fund was established in the Next Generation Energy Act of 2007. Its purpose is to help Minnesota utilities achieve their 1.5% energy savings goal by: Identifying new technologies or strategies to maximize energy savings; Improving the effectiveness of energy conservation programs; and Documenting CO2 reductions from energy conservation programs.
- $2.6 million of this fund is set aside annually for the CARD program which awards research grants in a competitive Request for Proposal (RFP) process. Since the legislation was enacted, the CARD program has: Had 8 funding cycles, with 22 RFPs posted; Received nearly 380 proposals; and Funded 92 research projects, representing over $21 million in research dollars. As you can see by the pie chart, projects funded to date have been in all building sectors. The subject of today’s webinar is a project which demonstrated a new aerosol envelope sealing technology in multifamily buildings. It will be presented by Dave Bohac from the Center for Energy and Environment.
- CEE has been involved in MF since early 1980s Started w research on boiler controls and identification of other opportunities (study published 1984) Ran programs in MN, also involved for a while with Focus on Energy.
- We are involved in CARD grant research funded through the Division of Energy Resources. We’re also involved with a benchmarking pilot, through a company called EnergyScoreCards. We have about 500 MF bldgs throughout the state enrolled in this. The idea is we’ll see if providing MF building owners and managers with a benchmark of their energy usage, compared to similar buildings, will provide energy savings in itself, sort of like an OPOWER for MF buildings.
- Reduced stack effect Possibly an expedited process Reduced noise transfer Reduced odor transfer/improved IAQ Increased comfort Increased energy efficiency
- Reduced air infiltration >> reduced space heating and cooling costs Reduced odor transfer/improved IAQ Increased comfort Reduced noise transfer Improved envelope durability Reduced stack effect
- Concept: A recently developed technology at UC Davis for -automating the envelope sealing process -process involves briefly pressurizing a building to normal testing pressures while applying an aerosol “fog” to the building interior. -As the air escapes through leaks in the exterior shell of the building (including leaks between apartments), the aerosolized sealant is transported to the leaks, and seals them as it tries to escape. -Existing blower door equipment is used to facilitate the sealing process as well as to provide real-time feedback and a permanent record of the sealing that is occurring. -This technology is thus capable of simultaneously measuring, locating, and sealing leaks in a building envelope (using aerosol particles has been successfully tested in the laboratory and demonstrated in full-scale applications. The aerosol envelope sealing e providing permanent documentation of the sealing process.)
- This project was conducted by the Center for Energy and Environment in Minnesota and the UC Davis Western Cooling Efficiency Center in California. There were a number of people at CEE who assisted with the field work and data analysis. In addition, Jose Garcia worked with Curtis on the building modelling and Mark Modera has developed both the process of using aerosol sealing for ducts and envelopes. This work was funded by the Minnesota Dept of Commerce as part of their grant program to help MN utilities identify methods to reach their energy savings goals.
- 2 near term applications: new construciton, post drywall/tape. Rehabs : at time of carpet/cabinets Seal windows? Dave will confirm Gaps filled with fiberglass seal? Tried that. Yes, it appears that will work. Any gap 3/8” or narrower. Duct board in aeroseal process of sealing ducts and it works on duct board. Dave will email uc davis guy. Mark Modera at UC Davis developed this technology. Remain sticky/stain over time? A lot of durability testing on duct sealant. Little degradation over time. This sealant has been used for other applications (tremco is manufacturer). Lots of prep work Cover all horizontal surfaces nozzles should be placed, at a minimum, in every bedroom and living area of the apartment nozzles generate a spray jet that travels about 8 feet Cleanable from surfaces
- How is RH maintained? Airflow is monitored and RH of incoming air and heat provided—to determine how much liquid should be injected. At commercialization—this will be automated. Nozzle pressure 60 psi and 90 psi and liquid flow rates between 20 ml/min and 50 ml/min Heating the air in the dwelling will increase the water carrying capacity of the air which allows for higher sealant injection rates and reduced sealing times. Equipment: modified blowerdoor panel, with 2 holes for duct blaster and opening for cables (injection lines, power cords, etc) ductblaster on outside, connected to heater on inside. Protects duct blaster from getting sealant on it. UC davis is looking for manufacturer to commercialize this.
- Pre-sealing: 1 – 2 hrs; Unit Prep (coverings & temp seals): 3 – 7 hours; Seal: 6 – 7 hrs; removal: 1.5 – 3 hrs; post test: 0.5 hr; additional cleanup: 0 to 5 hours. Total: 14 to 22 hours (by researchers who are learning)
- How do you know when to stop? Monitor rate of sealing—looking into this to optimize the cost / benefit. What’s the goal? If energy savings, then stop earlier. If goal is reducing sound transmission, or air transfer, then go longer. Most took 2 hours, ones that went longer had some issues with heater, equipment.
- How do you know when to stop? Monitor rate of sealing—looking into this to optimize the cost / benefit. What’s the goal? If energy savings, then stop earlier. If goal is reducing sound transmission, or air transfer, then go longer. Most took 2 hours, ones that went longer had some issues with heater, equipment.
- Overall, the sealing worked very well. These bars show the pre and post total unit air leakage for the units in the new construction buildings. The solid bars are the pre value and the hashed bars the post. The percent reduction ranged from 67% to 94% with an average of 81% and average post ACH50 of 0.69. The units were 54% to 95% tighter than new code requirement of 3.0 ACH50 (using the total leakage). The tightest unit was 25 cfm50.
- The sealant worked very well, sealing the units 54% to 95% tighter than new code requirement of 3.0 ACH50. Blower door fan was measuring between 25 cfm to 114 cfm at 50 pascals after sealing. Approx 1,000ft2 apts Before air-sealing tightness: 2.0-2.9 ACH50 (433 CFM50)
- The sealing was also very effective for almost all of the existing units. The percent reduction ranged from 39% to 89% with an median of 75% and median post ACH50 of 3.15.
- Efficiency units with an average floor area of 450sf. Before sealing they had an average leakage of 204 cfm50, 3.2 ACH50 and 0.12 cfm50/sf. We conducted guarded leakage tests before the sealing. For those tests we started with a compartmentalization test that measured the leakage of the entire unit – including exterior walls, interior walls and the floor and ceiling. Then we put a second blower door in the adjoining unit and pressurized it at the same time as the unit we were testing. We used the decrease in the leakage of the test unit as an estimate of the leakage to the adjoining unit. Then we repeated that for all of the adjoining units and the hallway or common area. This allowed us to split out the leakage between the adjoining units, the common space, and the exterior and unit below (the units below weren’t completed so we couldn’t pressurize those). We also divided the leakage to each of those spaces by the surface area to get the normalized leakage. This showed that the leakage per sf through the common wall was 5x greater than the leakage per sf to the adjoining units and to the exterior. So the common wall was relatively leaky. Overall, about a quarter of the total leakage was to the adjoining units and a third to the common area. A little less than half was to the outside and floor below.
- This was the first building that we sealed. It was required to meet the EPA Energy Star for High Rise MF compartmentalization requirement of 0.3 cfm50/sf. We performed the pre-sealing tests before the gypcrete floor was poured. Over half of the leakage was to the common area or hallway.
- Sound transmission was conducted for sealing that was performed in NY apartments. They found a 7 to 14dB reduction in higher frequencies – which is significant since a 10dB reduction means a 10 times reduction in the sound intensity.
- Average exhaust flow rate for apartments on each of the six floors for four of the models simulated (CZ12)
- For the leaky buildings with mechanical ventilation, about 20 – 25% of the air coming into the unit came from neighbors and the hallway. Tightening to 3 ACH50 drops that down to 3 – 5% and 0.6 ACH50 almost eliminates it. For building w/no mechanical ventilation and leaky (9.5 ACH50), almost half of the air came from neighbors and hallway.
- About a 20 – 30% savings for new construction w/balanced ventilation Project existing building: Median pre-leakage of 14 ACH50 reduced to 3.2 ACH50
- We’ve demonstrated that aerosol envelope sealing can produce much tighter envelopes than possible by conventional sealing methods. However, further work is necessary to determine the best application of this method. We will be working with two builders in MN and two in CA to determine the tradeoffs for when during the construction process the sealing is applied. In addition, we will be looking for current sealing methods that could be eliminated when the aerosol sealing is applied to offset some or all of the cost of the aerosol sealing. So there could be little or NO net cost for the aerosol sealing.
- While previous projects have shown that aerosol envelope sealing can significantly reduce leakage, there is work left to be done to determine best methods for its application for SF new construction. For example, the sealing has always been applied after insulation and drywall is complete and there hasn’t been any work to see what manual sealing could be eliminated and still produce tight houses. We are going to be working with two builders in MN and two in CA. We will be assessing their current air sealing strategies and provide them a demo of the aerosol sealing method. Then we’ll sit down with them to discuss options for when to seal in the construction process and what current sealing they’d be comfortable removing from their process. We will track costs and compare aerosol sealed houses to ones that go through their normal construction process. This will be done in an iterative fashion so that what we learn in the early portion of the project will be applied to later houses.
- All of the builders were interested in applying the sealing BEFORE insulation and drywall. Sheathing and windows installed – need top on house to complete air barrier- either poly or drywall on ceiling. MN builders often do this in winter so that they can heat the house during construction. Aerosol creates air barrier and use low Perm paint – might not need interior poly sheet. May also allow different approach insulating rim joists than spray foam Might be possible to use this process to seal ductwork. Seal when ductwork is still exposed. Seal registers and use ERV duct to open ducts to outside so that there is pressure across the ducts. The seal would be created on the OUTSIDE of the ducts. Expect that building officials may have concerns with some of these approaches and our project team will work proactively with them All builders expressed interest. None have committed yet. We had a meeting with another production builder yesterday and we should know by the end of the week whether they will participate.
- Thank you for attending this CARD webinar. You can download the final report on this project from the direct link on this slide. The link for the CARD web page is also on this slide. The web page has various resources and information related to the CARD program and to CARD research projects, including links to this and other recorded CARD webinars and final reports. Use the quick links indicated to help you navigate to what you are looking for.
- Thanks again for participating today! Before we leave, I want to take this opportunity to mention a few upcoming CARD webinars that might also interest you: June 22 – CEE will conduct a webinar on Improving the Effectiveness of Commercial Energy Recovery Ventilation Systems July 12 – CEE and Wisconsin Energy Conservation Corporation will conduct a webinar on the Small Embedded Data Center Program Pilot July 26 – Illume Advising will conduct a webinar on the Statewide Commercial Behavior Segmentation and Potential project August 17 – The Weidt Group will conduct a webinar on a pilot program on Expanding New Construction Design Assistance Statewide Please contact me if you want more information on how to sign up for any of these webinars or if you have questions or feedback on the CARD program.
- Applications for the program up front