際際滷

際際滷Share a Scribd company logo

Air Sealing and Ventilation Improvements for Multifamily Buildings

Center for Energy and Environment
Center for Energy and Environment

Air sealing and ventilation improvements can help reduce odor transfer between units in multifamily buildings. Testing found significant air leakage and flow between units. A study of 6 buildings treated units by sealing leaks between units, such as around plumbing and electrical fixtures. This reduced the fraction of air coming from adjoining units by an average of 75% according to tracer gas tests. Proper ventilation of odor sources and reductions in air pressure differences between units can help limit unwanted air movement.

1 of 106
Downloaded 18 times
Air sealing and ventilation improvements for multifamily buildings Jim Fitzgerald Dave Bohac Center for Energy and Environment Better Buildings: Better Business Conference February 2, 2012
Better air quality through sealing leaks between units and ventilation improvements What causes problems? Air leakage & air flow rate measurements 6 building CEE study Air sealing and ventilation case studies Maybe save energy too
What causes problems? Sometimes people smoke (and cook and ??)
Convert to smoke-free building Association of Nonsmokers - Minnesota http://www.mnsmokefreehousing.org/ 500+ smoke-free apartment buildings listed in Minnesota
Owners cooking odors are worst problem W h a t ty p e o f o d o r o r co n ta m in a n t is th e m o st co m m o n so u rce o f o b je ctio n a b le a ir in b u ild in g s y o u m a n a g e ? c o o k in g o d o rs to b a c c o o d o rs o th e r none d o n 't k n o w 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50%
How big are air flows between units? Pacific Northwest: Building average 13 to 26% air from other units Individual units as high as 35%Francisco & Palmiter (1994) NJ mid-rise: 4th floor 22% from other units Harrje et al (1988) West Coast: 4% air from adjoining units Feustal & Diamond (1988) Multi-zone Tracer Gas Studies
How big are air leaks between units? Minnesota: Modera et al. (1986) 52% air leaks between units 1900s low-rise masonry Chicago: Diamond et al. (1986) Similar results to Minnesota 1900s low-rise Sweden: Levin (1988) 12 to 36% air leaks between units 3 Swedish apartment buildings
What are the driving forces to move air into and though buildings?
What are the driving forces? Winter Stack Effect In at the bottom and out the top Taller Building => Bigger Effect
What are the driving forces? Wind Effect In on windward side and out on leeward side Taller Building => Bigger Effect
What are the driving forces? Mechanical System Effect Mechanical ventilation is required by code: bathrooms, corridors & some kitchens Exhaust ventilation => draws air into an apartment Flow imbalances can also cause air to move from one apartment to another
Does it help for a smoker in a lower floor unit to open a window? Not upstairs neighbor Pressure in smokers unit will be about the same as outside, which increases pressure to upstairs and increases flow from smokers unit to upstairs
How does the air travel between units? Anyway it can! Gaps in walls, floors, mechanical chases In at the bottom and out the top Some are accessible and others too diffuse or inaccessible for sealing
Most openings are small and diffuse Gaps around sink plumbing
Baseboards and sprinkler heads
Chemical smoke moves out of baseboard leak Clear acrylic caulk required plus moving bookcases, etc
Gaps along baseboard under carpet
Gaps behind baseboard heaters
Bathroom exhaust fans Gaps around bath fan
Recessed Light Fixtures Leaky (2.5 si) Tight (0.1 si)
Hidden high rise chases = large uncontrolled flows
Air Sealing and Ventilation Improvements for Multifamily Buildings
Can practical air sealing and ventilation treatments reduce secondhand smoke (SHS) transfer? 6 dissimilar buildings common to local multifamily building types This research project was funded in part by ClearWay Minnesota, funded by proceeds from the Minnesota tobacco settlement. These findings are solely the responsibility of the authors and do not necessarily represent the official views of ClearWay Minnesota.
General approach to reduce odor transport between apartments and improve air quality Ventilate the source Capture source before transported Reduce transport between apartments Seal building leaks Reduce driving force - pressure difference Ventilate receivers apartment
General approach to reduce odor transport between apartments and improve air quality Ventilate Seal Ventilate
Minnesota SHS transfer study 1930s Duplex 8-Plex 1970 1964 12-Plex
Minnesota SHS transfer study 2001 New 4 story 1982 138 unit 1999 11 story
Quantify Building tests + Before and after fan pressurization tests + Total effective leakage area of apartment + Fraction of leakage area to outside and to other units Page 28
Guarded Zone Multiple Fan Air Leakage Test 1: Total Leakage 3: 1 3= Leak to Left T est 1 T est 1 T est 2 T est 2 U n it A U n itU n it A B U n itU n it B C U n it C U n it A U n itU n it A B U n itU n it B C U n it C T est 1 T est 1 T est 2 T est 2 U n it A U n it U n it A B U n it U n it B C U n it C U n it A U n it U n it A B U n it U n it B C U n it C Q B1 Q B1 Q A2 Q B2 Q A2 Q B2 Fan Fan Fan Fan Fan Fan Q B1 Q B1 Q A2 Q B2 Q A2 Q B2 C om m on A rea C om m Fan A rea on Fan C om m on A rea Fan C om m on AFan Fan rea Fan 50 50 50 50 Q B to tal = Q B1 Q B to tal = Q B1 Q B to A = Q B1 - Q B2 Q B to A = Q B1 - Q B2 C om m on A rea C om m on A rea C om m on A rea C om m on A rea T est 3 T est 3 T est 4 T est 4 2: 1 2= Leak to Right U n it A U n itU n it A B 50 Q B to tal = Q B 1 U n itU n it B C Q 50 B to tal = Q B1 U n it C U n it A U n itU n it A Q B 50 B to A 4: 1 4= Leak to Out = Q B1 - Q B2 U n itU n it B C Q 50 B to A = Q B1 - Q B2 U n it C T est 3 T est 3 T est 4 T est 4 U n it A U n it U n it A B U n it U n it B C U n it C U n it A U n it U n it A B U n it U n it B C U n it C Q B3 Q C3 Q B3 Q C3 Q B4 Q B4 Fan Fan Fan Fan Fan Fan Q B3 Q C3 Q B3 Q C3 Q B4 QB Q C om m 4 Q C om 4 4 m C om m on A rea C om m Fan A rea on Fan Fan C om m on A rea Fan C om m on A rea Fan Fan Fan Fan 50 50 50 50 Q B to C = Q B1 - Q B3 Q B to C = Q B1 - Q B3 Q = Q B4 B exterio r Q = Q B4 B exterio r Q C om m 4 Q C om m 4 C om m on A rea C om m on A rea C om m on A rea C om m on A rea Fan Fan 50 50 50 50 Q B to C = Q B1 - Q B3 Q B to C = Q B1 - Q B3 Q B exterio r = Q B4 Q B exterio r = Q B4 Up to 6 tests per unit
Quantify Building tests + Before and after fan pressurization tests + Total effective leakage area of apartment + Fraction of leakage area to outside and to other units + Before and after tracer gas tests + Week long average tests + Passive perfluorocarbon tracers + Nicotine + Particles + Measure exhaust ventilation flow + Measure before/after treatments + Up to 7 units per building Page 30
Tracer gas tests show considerable air movement between apartments Fraction of Air Coming From Adjoining Units Compared to Total Inflow Pre-Treatment (%) After Sealing (% Building Min Median Max Min Median Duplex 6% 16% 35% 26% 65% 8-Plex 1% 3% 24% 12-Plex 1% 12% 26% 138 Unit 1% 11% 25% 1% 7% 11 Story 2% 5% 12% 1% 2% 4 Story 1% 2% 10% 0% 2% All Units 1% 5% 26% 65% 0% 3% One-week tracer gas measurements
How Does the Fraction Vary by Floor? Fraction of Air Coming From Adjoining Units Compared to Total Inflow Range Median Top-floor units: 2 to 26% 16% Mid-floor units: 1 to 20% 5% Lowest-floor units: 1 to 4% 2% One-week tracer gas measurements
Total air leakage of individual units Ref. Flow Rate(cfm50) Ref. Flow Rate(cfm50) ELA (si) ELA (si) NELA (si/100 sf) Min Building Max Median Min Min Median Median Max Max Min Min Median Median Max Max <Min 1.25 2,101 Duplex 2,636 2,368 2,101 115 2,368 130 2,636 145 115 3.16 130 3.56 145 3.97 3.16 0% 837 8 Plex 1,031 1,008 837 46 1,008 55 1,031 57 46 1.93 55 2.04 57 2.46 1.93 0% 731 917 Plex 1,318 12 731 40 917 50 1,318 72 40 1.61 50 2.02 72 2.90 1.61 0% 390 665 Unit 754 138 (1999) 390 21 665 37 754 41 21 0.86 37 1.01 41 2.06 0.86 88% 376 454 Story 958 11 (1982) 376 21 454 25 958 53 21 0.57 25 0.76 53 2.14 0.57 86% 921 4 Story 1,559 1,156 (2001) 921 51 1,156 63 1,559 86 51 1.05 63 1.85 86 2.30 1.05 14% 376 861 Buildings All 2,636 376 21 861 47 2,636 145 21 0.57 47 1.66 145 3.97 0.57 22% ELA equivalent leakage area, reference 4Pa & coef. = 1 LEED Green Building Rating system for MF SHS control requires ELA divided by wall & floor & ceiling area to be less than 1.25 si/100 sf Blower door air leakage tests
Fraction of air leakage to adjacent units Total To Adjacent Units Building ELA (si) ELA (si) (%) Duplex 130 26 20% 8 Plex1 55 28 59% 12 Plex1 50 28 57% 138 Unit 37 5 16% 11 Story 25 8 26% 4 Story 64 All Buildings 47 9 27% 1 - leakage to adjacent units includes leakage to common area Blower door air leakage tests
Leakage Area of Individual Units 712 34 1.8 612 28 1.1 514 512 510 28 1.3 24 0.5 33 Elevator 2.5 1.1 4.4 414 412 410 34 2.4 22 0.1 53 11 Story Building 1.0 2.3 4.2 314 312 310 21 3.0 25 1.3 33 1.2 212 23
Air Sealing and Ventilation Improvements for Multifamily Buildings
General approach to reduce odor transport between apartments and improve air quality Ventilate Seal Ventilate
Air sealing treatments Focus on leaks between units (not exterior) Seal as much is practical 3 to 8 hours/unit. Average cost of about $700/unit Blower door test to monitor total leakage Use visual/smoke puffer diagnostics sometimes aided by blower door. Tried IR in limited cases
Total and shared leakage CFM50/unit Existing After Treatments Total Shared Total Shared Duplex 2409 466 1881 601 8-plex 1032 475 916 307 12-plex 918 507 769 247 138 unit 641 90 639 88 New 4 story 1150 25 900 20 11 story 556 120 417 108 Blower door air leakage tests
Modest overall reductions in leakage between apartment units but some were significant Range Median Duplex: small change 8-plex: 21 to 44% 35% 12-plex: 14 to 70% 55% New 138-unit: 0 to 23% small change New 4-story: 0 to 20% 11-story: 0 to 56% 23% Blower door air leakage tests
Mechanical ventilation observations Often provided only by occupant-operated (highly intermittent-typically off) bath fans Many bath fans are better noise-generators than air movers, even when new Apartment bath fans are not maintained (corrosion, dirt) Apartment exhaust flows are rarely balanced
Continuous ventilation in code Old Codes Kitchens: 0 CFM OR 100+ CFM Baths: 50 CFM 2012 International Mech. Code Kitchens: 25 CFM Bathrooms: 20 CFM ASHRAE 62.1 -2010 5 cfm per person + 0.06cfm/sq ft Kitchens: 50 cfm Kitchenettes: 0.30 cfm/sq ft Toilets: 25cfm
Corridor supply choices Minimum 0.05 cfm/sq ft corridor area (IBC) Minimum 0.06 cfm/sq ft corridor area ASHRAE 62.1-2010 Supply all ventilation to corridor & exhaust from units Original design flow (typically higher) Confirm with local code official
Ventilation treatments for study Install effective (and quiet) exhaust fans with capacity of at least 30 to 45cfm Convert intermittent exhaust to continuous exhaust Balance exhaust air flows to reduce ventilation driving force between units
Ventilation treatments Quiet, Continuous Ventilation Constant Air Regulator Quiet Ceiling Exhaust Multi-point
Ventilation rate increased substantially Median Ventilation Rate (cfm) Existing After Treatments Duplex: 28 (12 to 43) 43 (35 to 50) 8-plex: 38 (19 to 58) 50 (26 to 79) 12-plex: 38 (23 to 75) 73 (57 to 157) New 138-unit: 26 (15 to 47) 41 (31 to 53) 11-story: 28 (18 to 79) 69 (45 to 124) 4-story*: 45 (26 to 61) 48 (22 to 88) Average 34 54 min to max *only one unit with added fan 60% Increase One-week tracer gas measurements
Original ventilation system may be a direct path for smoke transfer (11 story, 138 unit, 4 story ducts) More smoke is captured near source Dilution reduces concentration in nonsmokers or receivers unit Cleaner air, same transfer rate
Effect of Treatments: Air Transfer Fraction of Incoming Air From Adjoining Units Existing After Treatments Top-floor: 16% (2 to 26%) 13% (0 to 42%) Mid-floor: 5% (1 to 20%) 2% (0 to 12%) Lowest-floor: 2% (1 to 4%) 7% (1 to 19%) One-week tracer gas measurements
Effect of Treatments 65% of the units had decreased air transfer 60% increase in ventilation rate 80% of tenants: SHS drift was less frequent and less severe
Air Sealing and Ventilation Improvements for Multifamily Buildings
Rooftop fan with multiple inlets 8-Plex Building 1 fan serves 4 units Page 51
47 53 Before 28 32 26 17 9 32 After 25 26 28 26 23 26 27 24 Page 52
Non-smokers fan pulls from smokers open plumbing chase Page 53
Why do our clothes smell like smoke? Open Neighbors between bathtub tubs Page 54
Is better good enough? + Unit #3 contaminants in unit #7 decreased by factor of five +Fraction of air from unit #3 to #7 reduced from 11% to 6% +Unit #3 ventilation rate increased 158% + Marked reduction of SHS odors per tenants + Will owners pay for it? Who can do the work? Page 55
Ongoing Success: 67 Buildings in Condo Complex of Tested 8-plex + Condo Maintenance team trained to respond to smoke complaints in additional buildings. + Smoker is back-charged for repair costs + 20 additional units have been completed to date + 15 more units are scheduled + Huge improvement in livability + Common areas air quality improved Page 56
Details of Ongoing work Existing Conditions + Typical complaint has smoker on lower level with fan off and large bypasses venting smoke into chases. + Non-smoker on upper level often had higher exhaust fan flows which increased airflow from chase into unit. Stack effect enhances this flow in winter. Practical & Effective Work + Seal major bypasses, 1-4 person hours + Ventilation modifications + Nonsmoker: replace fan damper with CAR + Smoker: remove fan damper and omit CAR for higher capture. + Typical flows are 25cfm in nonsmoker and 75cfm in smokers unit. Page 57
Rooftop fan with multiple inlets: high rise case study Many residents said fans didnt work Page 58
PRV Fan on roof Duct chase top of vent chase Inside details Not sealed Page 59
Vent louvers opened by dial Inlet register on bathroom wall or ceiling Page 60
Unit Number FLOOR 0 1 2 3 4 5 6 7 8 9 10 11 12 14 15 16 17 11 3 3 3 3 3 3 0 3 3 3 3 -1 3 3 0 3 3 10 3 3 3 3 3 3 3 3 3 3 3 -1 2 3 0 3 3 9 3 3 3 2 2 3 3 3 3 3 3 -1 2 3 0 0 2 8 2 3 3 0 2 3 2 3 3 3 -1 0 0 3 2 2 2 7 2 3 2 1 2 3 2 1 3 2 2 0 2 3 2 0 2 6 2 2 2 2 2 1 2 2 2 0 2 0 0 2 -1 0 2 5 2 2 2 3 -1 2 -1 2 2 0 0 2 2 2 -1 2 0 4 0 2 2 0 3 2 1 2 2 1 2 1 0 0 0 -1 0 3 1 -1 2 -1 2 2 2 1 2 1 0 2 1 0 0 0 0 2 2 0 2 -1 2 2 0 2 -1 2 0 0 2 2 0 2 0 1 2 2 2 2 2 2 0 0 2 Page 61
Each apartment duct in shaft Obstructs flow from below Roof slab over top unit at shaft entry into fan baffle Page 62
Drywall joints open between restrictions. No suction left for design flow. Page 63
Ventilation System Problems + Restrictions caused most of the air to be drawn from upper apartments + Duct leaks also reduced flow from lower apartments and caused air to be drawn from unknown sources Page 64
Floor Press Flow Notes 11 -74 28 10 -45 27 9 -15 14 8 -10.8 14 7 -9.5 10 6 na 5 +1.2 + stinks 4 +0.1 + smoker 3 +0.3 + stinks 2 -2.8 4 1 -5.3 8 Page 65
Exhaust duct provided direct route for smoke transfer Smoke blew in my face as I tested the CAR in the 5th floor with the roof fan on. I called the office to postpone the post installation tracer gas test Page 66
Solutions worked through on 4 shafts + Remove minimum of central duct restrictions, provide 3 sub ducts to upper 2 floors. + Install constant air regulators or designed orifice plates on inlets in apartments. + Seal drywall ductwork with Aeroseal technology. Test and adjust to balance flows at low prv speed. Thanks to Don Stevens for noticing fire code issue Page 67
Before After car/cut Floor Press Flow floor Press Flow (203cfm) 11 -74 28 11 -102 25 10 -45 27 10 -54 20 9 -15 14 9 -53 21 8 -10.8 14 8 -59 21 7 -9.5 10 7 -54 21 6 na 6 -39 19 5 +1.2 + stinks 5 test -28 16 4 +0.1 + smoker 4 smoker -23.5 15 (39, 75open) 3 +0.3 + stinks 3 test -23.8 15 2 -2.8 4 2 -23.4 15 1 -5.3 8 1 -23.4 15 Page 68
Total flow 506cfm, 81% leaks Unit flow 93, none from lower 5 floors Page 69
Aeroseal=> equal flow in every unit 221cfm from units 279cfm total Better results when run past normal residential stop point to reach 0 leakage Page 70
Page 71
Sub duct or fire damper required Fire damper requires steel framework not present in this shaft. Rebuilding is required cost prohibitive in this case. A sheet metal sub duct extending 22 above fan inlet is allowed in building code. 3 diameter will provide less restriction to shaft air flow. Page 72
Remove restrictions in 2 top inlets and provide 3 sub ducts Page 73
3 sub duct in place after Aeroseal Page 74
3 orifice plate allows balancing with CAR , or tape to desired flow at lower stack pressure with less noise at top. Page 75
Floor Car P Unit Car P Unit First shaft pre cfm Aero Cfm Aeroseal 11 -74 28 -75 21 Sub duct repair 10 -45 27 -65 20 and CAR 9 -15 14 -63 20 installation 8 -10.8 14 -56 20 7 -9.5 10 -52 20 6 na -49 20 5 +1.2 + -42 20 4 +0.1 + -42 20 Looks 3 +0.3 + -42 20 promising 2 -2.8 (4) -42 20 1 -5.3 (8) -44 20 Fan flow 506 93 280 221 Page 76
What does this cost, who pays, who can do it? Licensed mechanical contractor required for all duct alterations. Aeroseal franchisee required for duct sealing. (Maint. prep ok) Performance contractor/ consultant for design, balancing, QC $300 per unit or $3,200 for 1 shaft minimum, $5,000 for 2 shafts Changes to the building are an Association responsibility. Airsealing in unit is responsibility of individual condo owner Page 77
Individual supply and very low leakage required for best control If an occupant opens a window to let smoke out air can come in and blow smoke into adjacent units. At 30F we measured a lower unit change pressure from from -0.7pa to hall to +24pa to hall by opening 1 window. Some flow still came in from under the kitchen kickboard @+2pa to hall. The occupant complained about intermittent smoke. Total air leakage down to 283cfm50 after work. Some individuals may not tolerate any smoke transfer, a large improvement may not be enough. Page 78
Hidden chase openings often difficult to access
Add mineral wool fire-safing to high rise shaft openings
Seal with listed fire barrier
138 unit, little connection pre Page 82
Low leakage between units Guarded-Zone Measured Air Leakage Rates Oaks: Pre-Treatment 324 323 unit # 322 321 601 9 680 total leakage 17 574 3 622 +/-1 +/-13 +/-3 1 -13 unit/unit leakage 44 224 +/-7 223 +/-11 222 +/-4 221 leakage precision 21 688 71 734 33 661 65 654 +/-7 +/-4 28 -4 2 64 124 +/-14 Guest +/-12 123 +/-15 122 +/-12 121 609 35 390 37 606 51 664 93 683 +/-8 +/-2 +/-8 Page 83
Foam plumbing openings Page 84
Seal baseboard behind tack strip Page 85
Seal ductwork from registers Page 86
Vent blocked : View inside smokers fan duct in attic. Page 87
Vent blocked: Roof damper frozen shut on same fan Page 88
CARs in fan duct in attic, smokers open for higher flow Page 89
2 point system over guest and 224 3 point systems over 23(s) and 22 stacks U nit flow U nit flow U nit flow 323 24cfm 322 25cfm 224 21cfm 223 20cfm 222 22cfm G uest 26cfm 123 28cfm 122 20cfm Page 90
Page 91
All ducts and bypasses in joist space in 4 story Page 92
Aeroseal ducts in joist chase Page 93
Individual conditioning: + Duct fresh air intake to return with fan recycler and mech. damper + Point source exhaust Page 94
Wall behind baseboard open Page 95
Floor Edge Open To Joist space Page 96
New continuous duty fan in kitchen: source of odor complaint. Page 97
Airsealing in unit above and source unit credited with 90% reduction of odor. Baseboards, pipes, recessed lites Cook below opens windows when cooking- negates fan effect. Page 98
Recommendations Seal large openings between units Balanced, 30 45cfm continuous exhaust ventilation Consider extra ventilation in smokers unit
Additional slides In at the bottom and out the top
Kitchen option for cooking source In different project after work Cooking moisture was an issue in 15% of units Continuous kitchen fan option needed VenMar developed (UL) a quiet continuous range hood
Kitchen option for cooking source Quiet Range Hood Replace existing fans with continuous quiet range hood Lo or high speed, no off Less than 20 watts consumed at 34 cfm High: 100,175 , or 225cfm
Additional Information Canada Mortgage and Housing Corporation Fact Sheet: Solving Odour Transfer Problems in Your Apartment http://www.cmhc.ca/en/co/reho/reho_002.cfm
2-part Foam Seals Plumbing Chase Stop Vertical Air Transfer In Plumbing Wall Inject Foam Along Top of Wall Patched, primed 12-plex Shared leakage reduced about 50% from 507 to 247 cfm50
Easy air flow is possible through framing around pipes, etc Page 105
Note Improvements are possible. Managing expectations is important. Page 106

More Related Content

Air Sealing and Ventilation Improvements for Multifamily Buildings

  • 1. Air sealing and ventilation improvements for multifamily buildings Jim Fitzgerald Dave Bohac Center for Energy and Environment Better Buildings: Better Business Conference February 2, 2012
  • 2. Better air quality through sealing leaks between units and ventilation improvements What causes problems? Air leakage & air flow rate measurements 6 building CEE study Air sealing and ventilation case studies Maybe save energy too
  • 3. What causes problems? Sometimes people smoke (and cook and ??)
  • 4. Convert to smoke-free building Association of Nonsmokers - Minnesota http://www.mnsmokefreehousing.org/ 500+ smoke-free apartment buildings listed in Minnesota
  • 5. Owners cooking odors are worst problem W h a t ty p e o f o d o r o r co n ta m in a n t is th e m o st co m m o n so u rce o f o b je ctio n a b le a ir in b u ild in g s y o u m a n a g e ? c o o k in g o d o rs to b a c c o o d o rs o th e r none d o n 't k n o w 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50%
  • 6. How big are air flows between units? Pacific Northwest: Building average 13 to 26% air from other units Individual units as high as 35%Francisco & Palmiter (1994) NJ mid-rise: 4th floor 22% from other units Harrje et al (1988) West Coast: 4% air from adjoining units Feustal & Diamond (1988) Multi-zone Tracer Gas Studies
  • 7. How big are air leaks between units? Minnesota: Modera et al. (1986) 52% air leaks between units 1900s low-rise masonry Chicago: Diamond et al. (1986) Similar results to Minnesota 1900s low-rise Sweden: Levin (1988) 12 to 36% air leaks between units 3 Swedish apartment buildings
  • 8. What are the driving forces to move air into and though buildings?
  • 9. What are the driving forces? Winter Stack Effect In at the bottom and out the top Taller Building => Bigger Effect
  • 10. What are the driving forces? Wind Effect In on windward side and out on leeward side Taller Building => Bigger Effect
  • 11. What are the driving forces? Mechanical System Effect Mechanical ventilation is required by code: bathrooms, corridors & some kitchens Exhaust ventilation => draws air into an apartment Flow imbalances can also cause air to move from one apartment to another
  • 12. Does it help for a smoker in a lower floor unit to open a window? Not upstairs neighbor Pressure in smokers unit will be about the same as outside, which increases pressure to upstairs and increases flow from smokers unit to upstairs
  • 13. How does the air travel between units? Anyway it can! Gaps in walls, floors, mechanical chases In at the bottom and out the top Some are accessible and others too diffuse or inaccessible for sealing
  • 14. Most openings are small and diffuse Gaps around sink plumbing
  • 16. Chemical smoke moves out of baseboard leak Clear acrylic caulk required plus moving bookcases, etc
  • 19. Bathroom exhaust fans Gaps around bath fan
  • 20. Recessed Light Fixtures Leaky (2.5 si) Tight (0.1 si)
  • 21. Hidden high rise chases = large uncontrolled flows
  • 23. Can practical air sealing and ventilation treatments reduce secondhand smoke (SHS) transfer? 6 dissimilar buildings common to local multifamily building types This research project was funded in part by ClearWay Minnesota, funded by proceeds from the Minnesota tobacco settlement. These findings are solely the responsibility of the authors and do not necessarily represent the official views of ClearWay Minnesota.
  • 24. General approach to reduce odor transport between apartments and improve air quality Ventilate the source Capture source before transported Reduce transport between apartments Seal building leaks Reduce driving force - pressure difference Ventilate receivers apartment
  • 25. General approach to reduce odor transport between apartments and improve air quality Ventilate Seal Ventilate
  • 26. Minnesota SHS transfer study 1930s Duplex 8-Plex 1970 1964 12-Plex
  • 27. Minnesota SHS transfer study 2001 New 4 story 1982 138 unit 1999 11 story
  • 28. Quantify Building tests + Before and after fan pressurization tests + Total effective leakage area of apartment + Fraction of leakage area to outside and to other units Page 28
  • 29. Guarded Zone Multiple Fan Air Leakage Test 1: Total Leakage 3: 1 3= Leak to Left T est 1 T est 1 T est 2 T est 2 U n it A U n itU n it A B U n itU n it B C U n it C U n it A U n itU n it A B U n itU n it B C U n it C T est 1 T est 1 T est 2 T est 2 U n it A U n it U n it A B U n it U n it B C U n it C U n it A U n it U n it A B U n it U n it B C U n it C Q B1 Q B1 Q A2 Q B2 Q A2 Q B2 Fan Fan Fan Fan Fan Fan Q B1 Q B1 Q A2 Q B2 Q A2 Q B2 C om m on A rea C om m Fan A rea on Fan C om m on A rea Fan C om m on AFan Fan rea Fan 50 50 50 50 Q B to tal = Q B1 Q B to tal = Q B1 Q B to A = Q B1 - Q B2 Q B to A = Q B1 - Q B2 C om m on A rea C om m on A rea C om m on A rea C om m on A rea T est 3 T est 3 T est 4 T est 4 2: 1 2= Leak to Right U n it A U n itU n it A B 50 Q B to tal = Q B 1 U n itU n it B C Q 50 B to tal = Q B1 U n it C U n it A U n itU n it A Q B 50 B to A 4: 1 4= Leak to Out = Q B1 - Q B2 U n itU n it B C Q 50 B to A = Q B1 - Q B2 U n it C T est 3 T est 3 T est 4 T est 4 U n it A U n it U n it A B U n it U n it B C U n it C U n it A U n it U n it A B U n it U n it B C U n it C Q B3 Q C3 Q B3 Q C3 Q B4 Q B4 Fan Fan Fan Fan Fan Fan Q B3 Q C3 Q B3 Q C3 Q B4 QB Q C om m 4 Q C om 4 4 m C om m on A rea C om m Fan A rea on Fan Fan C om m on A rea Fan C om m on A rea Fan Fan Fan Fan 50 50 50 50 Q B to C = Q B1 - Q B3 Q B to C = Q B1 - Q B3 Q = Q B4 B exterio r Q = Q B4 B exterio r Q C om m 4 Q C om m 4 C om m on A rea C om m on A rea C om m on A rea C om m on A rea Fan Fan 50 50 50 50 Q B to C = Q B1 - Q B3 Q B to C = Q B1 - Q B3 Q B exterio r = Q B4 Q B exterio r = Q B4 Up to 6 tests per unit
  • 30. Quantify Building tests + Before and after fan pressurization tests + Total effective leakage area of apartment + Fraction of leakage area to outside and to other units + Before and after tracer gas tests + Week long average tests + Passive perfluorocarbon tracers + Nicotine + Particles + Measure exhaust ventilation flow + Measure before/after treatments + Up to 7 units per building Page 30
  • 31. Tracer gas tests show considerable air movement between apartments Fraction of Air Coming From Adjoining Units Compared to Total Inflow Pre-Treatment (%) After Sealing (% Building Min Median Max Min Median Duplex 6% 16% 35% 26% 65% 8-Plex 1% 3% 24% 12-Plex 1% 12% 26% 138 Unit 1% 11% 25% 1% 7% 11 Story 2% 5% 12% 1% 2% 4 Story 1% 2% 10% 0% 2% All Units 1% 5% 26% 65% 0% 3% One-week tracer gas measurements
  • 32. How Does the Fraction Vary by Floor? Fraction of Air Coming From Adjoining Units Compared to Total Inflow Range Median Top-floor units: 2 to 26% 16% Mid-floor units: 1 to 20% 5% Lowest-floor units: 1 to 4% 2% One-week tracer gas measurements
  • 33. Total air leakage of individual units Ref. Flow Rate(cfm50) Ref. Flow Rate(cfm50) ELA (si) ELA (si) NELA (si/100 sf) Min Building Max Median Min Min Median Median Max Max Min Min Median Median Max Max <Min 1.25 2,101 Duplex 2,636 2,368 2,101 115 2,368 130 2,636 145 115 3.16 130 3.56 145 3.97 3.16 0% 837 8 Plex 1,031 1,008 837 46 1,008 55 1,031 57 46 1.93 55 2.04 57 2.46 1.93 0% 731 917 Plex 1,318 12 731 40 917 50 1,318 72 40 1.61 50 2.02 72 2.90 1.61 0% 390 665 Unit 754 138 (1999) 390 21 665 37 754 41 21 0.86 37 1.01 41 2.06 0.86 88% 376 454 Story 958 11 (1982) 376 21 454 25 958 53 21 0.57 25 0.76 53 2.14 0.57 86% 921 4 Story 1,559 1,156 (2001) 921 51 1,156 63 1,559 86 51 1.05 63 1.85 86 2.30 1.05 14% 376 861 Buildings All 2,636 376 21 861 47 2,636 145 21 0.57 47 1.66 145 3.97 0.57 22% ELA equivalent leakage area, reference 4Pa & coef. = 1 LEED Green Building Rating system for MF SHS control requires ELA divided by wall & floor & ceiling area to be less than 1.25 si/100 sf Blower door air leakage tests
  • 34. Fraction of air leakage to adjacent units Total To Adjacent Units Building ELA (si) ELA (si) (%) Duplex 130 26 20% 8 Plex1 55 28 59% 12 Plex1 50 28 57% 138 Unit 37 5 16% 11 Story 25 8 26% 4 Story 64 All Buildings 47 9 27% 1 - leakage to adjacent units includes leakage to common area Blower door air leakage tests
  • 35. Leakage Area of Individual Units 712 34 1.8 612 28 1.1 514 512 510 28 1.3 24 0.5 33 Elevator 2.5 1.1 4.4 414 412 410 34 2.4 22 0.1 53 11 Story Building 1.0 2.3 4.2 314 312 310 21 3.0 25 1.3 33 1.2 212 23
  • 37. General approach to reduce odor transport between apartments and improve air quality Ventilate Seal Ventilate
  • 38. Air sealing treatments Focus on leaks between units (not exterior) Seal as much is practical 3 to 8 hours/unit. Average cost of about $700/unit Blower door test to monitor total leakage Use visual/smoke puffer diagnostics sometimes aided by blower door. Tried IR in limited cases
  • 39. Total and shared leakage CFM50/unit Existing After Treatments Total Shared Total Shared Duplex 2409 466 1881 601 8-plex 1032 475 916 307 12-plex 918 507 769 247 138 unit 641 90 639 88 New 4 story 1150 25 900 20 11 story 556 120 417 108 Blower door air leakage tests
  • 40. Modest overall reductions in leakage between apartment units but some were significant Range Median Duplex: small change 8-plex: 21 to 44% 35% 12-plex: 14 to 70% 55% New 138-unit: 0 to 23% small change New 4-story: 0 to 20% 11-story: 0 to 56% 23% Blower door air leakage tests
  • 41. Mechanical ventilation observations Often provided only by occupant-operated (highly intermittent-typically off) bath fans Many bath fans are better noise-generators than air movers, even when new Apartment bath fans are not maintained (corrosion, dirt) Apartment exhaust flows are rarely balanced
  • 42. Continuous ventilation in code Old Codes Kitchens: 0 CFM OR 100+ CFM Baths: 50 CFM 2012 International Mech. Code Kitchens: 25 CFM Bathrooms: 20 CFM ASHRAE 62.1 -2010 5 cfm per person + 0.06cfm/sq ft Kitchens: 50 cfm Kitchenettes: 0.30 cfm/sq ft Toilets: 25cfm
  • 43. Corridor supply choices Minimum 0.05 cfm/sq ft corridor area (IBC) Minimum 0.06 cfm/sq ft corridor area ASHRAE 62.1-2010 Supply all ventilation to corridor & exhaust from units Original design flow (typically higher) Confirm with local code official
  • 44. Ventilation treatments for study Install effective (and quiet) exhaust fans with capacity of at least 30 to 45cfm Convert intermittent exhaust to continuous exhaust Balance exhaust air flows to reduce ventilation driving force between units
  • 45. Ventilation treatments Quiet, Continuous Ventilation Constant Air Regulator Quiet Ceiling Exhaust Multi-point
  • 46. Ventilation rate increased substantially Median Ventilation Rate (cfm) Existing After Treatments Duplex: 28 (12 to 43) 43 (35 to 50) 8-plex: 38 (19 to 58) 50 (26 to 79) 12-plex: 38 (23 to 75) 73 (57 to 157) New 138-unit: 26 (15 to 47) 41 (31 to 53) 11-story: 28 (18 to 79) 69 (45 to 124) 4-story*: 45 (26 to 61) 48 (22 to 88) Average 34 54 min to max *only one unit with added fan 60% Increase One-week tracer gas measurements
  • 47. Original ventilation system may be a direct path for smoke transfer (11 story, 138 unit, 4 story ducts) More smoke is captured near source Dilution reduces concentration in nonsmokers or receivers unit Cleaner air, same transfer rate
  • 48. Effect of Treatments: Air Transfer Fraction of Incoming Air From Adjoining Units Existing After Treatments Top-floor: 16% (2 to 26%) 13% (0 to 42%) Mid-floor: 5% (1 to 20%) 2% (0 to 12%) Lowest-floor: 2% (1 to 4%) 7% (1 to 19%) One-week tracer gas measurements
  • 49. Effect of Treatments 65% of the units had decreased air transfer 60% increase in ventilation rate 80% of tenants: SHS drift was less frequent and less severe
  • 51. Rooftop fan with multiple inlets 8-Plex Building 1 fan serves 4 units Page 51
  • 52. 47 53 Before 28 32 26 17 9 32 After 25 26 28 26 23 26 27 24 Page 52
  • 53. Non-smokers fan pulls from smokers open plumbing chase Page 53
  • 54. Why do our clothes smell like smoke? Open Neighbors between bathtub tubs Page 54
  • 55. Is better good enough? + Unit #3 contaminants in unit #7 decreased by factor of five +Fraction of air from unit #3 to #7 reduced from 11% to 6% +Unit #3 ventilation rate increased 158% + Marked reduction of SHS odors per tenants + Will owners pay for it? Who can do the work? Page 55
  • 56. Ongoing Success: 67 Buildings in Condo Complex of Tested 8-plex + Condo Maintenance team trained to respond to smoke complaints in additional buildings. + Smoker is back-charged for repair costs + 20 additional units have been completed to date + 15 more units are scheduled + Huge improvement in livability + Common areas air quality improved Page 56
  • 57. Details of Ongoing work Existing Conditions + Typical complaint has smoker on lower level with fan off and large bypasses venting smoke into chases. + Non-smoker on upper level often had higher exhaust fan flows which increased airflow from chase into unit. Stack effect enhances this flow in winter. Practical & Effective Work + Seal major bypasses, 1-4 person hours + Ventilation modifications + Nonsmoker: replace fan damper with CAR + Smoker: remove fan damper and omit CAR for higher capture. + Typical flows are 25cfm in nonsmoker and 75cfm in smokers unit. Page 57
  • 58. Rooftop fan with multiple inlets: high rise case study Many residents said fans didnt work Page 58
  • 59. PRV Fan on roof Duct chase top of vent chase Inside details Not sealed Page 59
  • 60. Vent louvers opened by dial Inlet register on bathroom wall or ceiling Page 60
  • 61. Unit Number FLOOR 0 1 2 3 4 5 6 7 8 9 10 11 12 14 15 16 17 11 3 3 3 3 3 3 0 3 3 3 3 -1 3 3 0 3 3 10 3 3 3 3 3 3 3 3 3 3 3 -1 2 3 0 3 3 9 3 3 3 2 2 3 3 3 3 3 3 -1 2 3 0 0 2 8 2 3 3 0 2 3 2 3 3 3 -1 0 0 3 2 2 2 7 2 3 2 1 2 3 2 1 3 2 2 0 2 3 2 0 2 6 2 2 2 2 2 1 2 2 2 0 2 0 0 2 -1 0 2 5 2 2 2 3 -1 2 -1 2 2 0 0 2 2 2 -1 2 0 4 0 2 2 0 3 2 1 2 2 1 2 1 0 0 0 -1 0 3 1 -1 2 -1 2 2 2 1 2 1 0 2 1 0 0 0 0 2 2 0 2 -1 2 2 0 2 -1 2 0 0 2 2 0 2 0 1 2 2 2 2 2 2 0 0 2 Page 61
  • 62. Each apartment duct in shaft Obstructs flow from below Roof slab over top unit at shaft entry into fan baffle Page 62
  • 63. Drywall joints open between restrictions. No suction left for design flow. Page 63
  • 64. Ventilation System Problems + Restrictions caused most of the air to be drawn from upper apartments + Duct leaks also reduced flow from lower apartments and caused air to be drawn from unknown sources Page 64
  • 65. Floor Press Flow Notes 11 -74 28 10 -45 27 9 -15 14 8 -10.8 14 7 -9.5 10 6 na 5 +1.2 + stinks 4 +0.1 + smoker 3 +0.3 + stinks 2 -2.8 4 1 -5.3 8 Page 65
  • 66. Exhaust duct provided direct route for smoke transfer Smoke blew in my face as I tested the CAR in the 5th floor with the roof fan on. I called the office to postpone the post installation tracer gas test Page 66
  • 67. Solutions worked through on 4 shafts + Remove minimum of central duct restrictions, provide 3 sub ducts to upper 2 floors. + Install constant air regulators or designed orifice plates on inlets in apartments. + Seal drywall ductwork with Aeroseal technology. Test and adjust to balance flows at low prv speed. Thanks to Don Stevens for noticing fire code issue Page 67
  • 68. Before After car/cut Floor Press Flow floor Press Flow (203cfm) 11 -74 28 11 -102 25 10 -45 27 10 -54 20 9 -15 14 9 -53 21 8 -10.8 14 8 -59 21 7 -9.5 10 7 -54 21 6 na 6 -39 19 5 +1.2 + stinks 5 test -28 16 4 +0.1 + smoker 4 smoker -23.5 15 (39, 75open) 3 +0.3 + stinks 3 test -23.8 15 2 -2.8 4 2 -23.4 15 1 -5.3 8 1 -23.4 15 Page 68
  • 69. Total flow 506cfm, 81% leaks Unit flow 93, none from lower 5 floors Page 69
  • 70. Aeroseal=> equal flow in every unit 221cfm from units 279cfm total Better results when run past normal residential stop point to reach 0 leakage Page 70
  • 72. Sub duct or fire damper required Fire damper requires steel framework not present in this shaft. Rebuilding is required cost prohibitive in this case. A sheet metal sub duct extending 22 above fan inlet is allowed in building code. 3 diameter will provide less restriction to shaft air flow. Page 72
  • 73. Remove restrictions in 2 top inlets and provide 3 sub ducts Page 73
  • 74. 3 sub duct in place after Aeroseal Page 74
  • 75. 3 orifice plate allows balancing with CAR , or tape to desired flow at lower stack pressure with less noise at top. Page 75
  • 76. Floor Car P Unit Car P Unit First shaft pre cfm Aero Cfm Aeroseal 11 -74 28 -75 21 Sub duct repair 10 -45 27 -65 20 and CAR 9 -15 14 -63 20 installation 8 -10.8 14 -56 20 7 -9.5 10 -52 20 6 na -49 20 5 +1.2 + -42 20 4 +0.1 + -42 20 Looks 3 +0.3 + -42 20 promising 2 -2.8 (4) -42 20 1 -5.3 (8) -44 20 Fan flow 506 93 280 221 Page 76
  • 77. What does this cost, who pays, who can do it? Licensed mechanical contractor required for all duct alterations. Aeroseal franchisee required for duct sealing. (Maint. prep ok) Performance contractor/ consultant for design, balancing, QC $300 per unit or $3,200 for 1 shaft minimum, $5,000 for 2 shafts Changes to the building are an Association responsibility. Airsealing in unit is responsibility of individual condo owner Page 77
  • 78. Individual supply and very low leakage required for best control If an occupant opens a window to let smoke out air can come in and blow smoke into adjacent units. At 30F we measured a lower unit change pressure from from -0.7pa to hall to +24pa to hall by opening 1 window. Some flow still came in from under the kitchen kickboard @+2pa to hall. The occupant complained about intermittent smoke. Total air leakage down to 283cfm50 after work. Some individuals may not tolerate any smoke transfer, a large improvement may not be enough. Page 78
  • 79. Hidden chase openings often difficult to access
  • 80. Add mineral wool fire-safing to high rise shaft openings
  • 81. Seal with listed fire barrier
  • 82. 138 unit, little connection pre Page 82
  • 83. Low leakage between units Guarded-Zone Measured Air Leakage Rates Oaks: Pre-Treatment 324 323 unit # 322 321 601 9 680 total leakage 17 574 3 622 +/-1 +/-13 +/-3 1 -13 unit/unit leakage 44 224 +/-7 223 +/-11 222 +/-4 221 leakage precision 21 688 71 734 33 661 65 654 +/-7 +/-4 28 -4 2 64 124 +/-14 Guest +/-12 123 +/-15 122 +/-12 121 609 35 390 37 606 51 664 93 683 +/-8 +/-2 +/-8 Page 83
  • 85. Seal baseboard behind tack strip Page 85
  • 86. Seal ductwork from registers Page 86
  • 87. Vent blocked : View inside smokers fan duct in attic. Page 87
  • 88. Vent blocked: Roof damper frozen shut on same fan Page 88
  • 89. CARs in fan duct in attic, smokers open for higher flow Page 89
  • 90. 2 point system over guest and 224 3 point systems over 23(s) and 22 stacks U nit flow U nit flow U nit flow 323 24cfm 322 25cfm 224 21cfm 223 20cfm 222 22cfm G uest 26cfm 123 28cfm 122 20cfm Page 90
  • 92. All ducts and bypasses in joist space in 4 story Page 92
  • 93. Aeroseal ducts in joist chase Page 93
  • 94. Individual conditioning: + Duct fresh air intake to return with fan recycler and mech. damper + Point source exhaust Page 94
  • 95. Wall behind baseboard open Page 95
  • 96. Floor Edge Open To Joist space Page 96
  • 97. New continuous duty fan in kitchen: source of odor complaint. Page 97
  • 98. Airsealing in unit above and source unit credited with 90% reduction of odor. Baseboards, pipes, recessed lites Cook below opens windows when cooking- negates fan effect. Page 98
  • 99. Recommendations Seal large openings between units Balanced, 30 45cfm continuous exhaust ventilation Consider extra ventilation in smokers unit
  • 100. Additional slides In at the bottom and out the top
  • 101. Kitchen option for cooking source In different project after work Cooking moisture was an issue in 15% of units Continuous kitchen fan option needed VenMar developed (UL) a quiet continuous range hood
  • 102. Kitchen option for cooking source Quiet Range Hood Replace existing fans with continuous quiet range hood Lo or high speed, no off Less than 20 watts consumed at 34 cfm High: 100,175 , or 225cfm
  • 103. Additional Information Canada Mortgage and Housing Corporation Fact Sheet: Solving Odour Transfer Problems in Your Apartment http://www.cmhc.ca/en/co/reho/reho_002.cfm
  • 104. 2-part Foam Seals Plumbing Chase Stop Vertical Air Transfer In Plumbing Wall Inject Foam Along Top of Wall Patched, primed 12-plex Shared leakage reduced about 50% from 507 to 247 cfm50
  • 105. Easy air flow is possible through framing around pipes, etc Page 105
  • 106. Note Improvements are possible. Managing expectations is important. Page 106