presented at 2012 Wisconsin Better Buildings meeting

1. Air sealing and ventilation
improvements for multifamily
buildings
March 2, 2012
Jim Fitzgerald
Dave Bohac
Center for Energy and Environment
Better Buildings: Better Business Conference

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
What type of odor or contaminant is the most common source of
objectionable air in buildings you manage?
0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50%
cooking odors
tobacco odors
other
none
don't know

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%
 NJ mid-rise: 4th floor – 22% from other units
 West Coast: 4% air from adjoining units
Francisco & Palmiter (1994)
Harrje et al (1988)
Feustal & Diamond (1988)
Multizone tracer gas measurements

7. How big are air leaks between units?
 Minnesota: Modera et al. (1986)
• 52% air leaks between units
• 1900’s low-rise masonry
 Chicago: Diamond et al. (1986)
• Similar results to Minnesota
• 1900’s low-rise
 Sweden: Levin (1988)
• 12 to 36% air leaks between units
• 3 Swedish apartment buildings
Blower door air leakage tests

8. What are the driving forces to
move air into and though
buildings?

9. What are the driving forces?
Winter
Stack Effect
Taller Building => Bigger Effect
In at the bottom and
out the top

10. What are the driving forces?
Wind Effect
In on windward side and
out on leeward side
Taller Building => Bigger Effect

11.  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
What are the driving forces?
Mechanical System Effect

12. Does it help for a smoker in a lower floor unit
to open a window?
Not upstairs neighbor
Pressure in smoker’s unit
will be about the same as
outside, which increases
pressure to upstairs and
increases flow from
smoker’s unit to upstairs

13. In at the bottom and out the
top
 Anyway it can!
 Gaps in walls, floors, mechanical chases
 Some are accessible and others too diffuse or
inaccessible for sealing
How does the air travel between units?

14. Gaps around
sink plumbing
Most openings are small and diffuse

15. Baseboards and sprinkler
heads

16. Chemical smoke moves out of baseboard leak
Clear acrylic caulk required plus moving bookcases, etc

17. Gaps along
baseboard under
carpet

18. Gaps behind
baseboard heaters

19. Gaps around bath fan
Bathroom exhaust fans

20. Leaky (2.5 si)
Tight (0.1 si)
Recessed Light Fixtures

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 receiver’s apartment

25. General approach to reduce odor transport
between apartments and improve air quality
 Ventilate
 Seal
 Ventilate

26. Duplex 8-Plex
12-Plex
1930s
1970
1964
Minnesota SHS transfer study

27. New 4 story
138 unit
11 story
1982
2001
1999
Minnesota SHS transfer study

28. Page 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

29. Guarded Zone Multiple Fan Air Leakage Test
Up to 6 tests per unit
Test 1 Test 2
Unit A Unit B Unit C Unit A Unit B Unit C
QB1 QA2 QB2
Common Area Common Area
Q50
B total = QB1 Q50
B to A = QB1 - QB2
Test 3 Test 4
Unit A Unit B Unit C Unit A Unit B Unit C
QB3 QC3 QB4
QComm4
Common Area Common Area
Q50
B to C = QB1 - QB3 Q50
B exterior = QB4
Fan Fan Fan
Fan Fan Fan
Fan
Test 1 Test 2
Unit A Unit B Unit C Unit A Unit B Unit C
QB1 QA2 QB2
Common Area Common Area
Q50
B total = QB1 Q50
B to A = QB1 - QB2
Test 3 Test 4
Unit A Unit B Unit C Unit A Unit B Unit C
QB3 QC3 QB4
QComm4
Common Area Common Area
Q50
B to C = QB1 - QB3 Q50
B exterior = QB4
Fan Fan Fan
Fan Fan Fan
Fan
Test 1 Test 2
Unit A Unit B Unit C Unit A Unit B Unit C
QB1 QA2 QB2
Common Area Common Area
Q50
B total = QB1 Q50
B to A = QB1 - QB2
Test 3 Test 4
Unit A Unit B Unit C Unit A Unit B Unit C
QB3 QC3 QB4
QComm4
Common Area Common Area
Q50
B to C = QB1 - QB3 Q50
B exterior = QB4
Fan Fan Fan
Fan Fan Fan
Fan
Test 1 Test 2
Unit A Unit B Unit C Unit A Unit B Unit C
QB1 QA2 QB2
Common Area Common Area
Q50
B total = QB1 Q50
B to A = QB1 - QB2
Test 3 Test 4
Unit A Unit B Unit C Unit A Unit B Unit C
QB3 QC3 QB4
QComm4
Common Area Common Area
Q50
B to C = QB1 - QB3 Q50
B exterior = QB4
Fan Fan Fan
Fan Fan Fan
Fan
1: Total Leakage
2: 1 – 2= Leak to Right
3: 1 – 3= Leak to Left
4: 1 – 4= Leak to Out

30. Page 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

31. Tracer gas tests show considerable air
movement between apartments
Fraction of Air Coming From Adjoining
Units Compared to Total Inflow
Building Min Median Max Min Median
Duplex 6% 35% 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% 65% 0% 3%
Pre-Treatment (%) After Sealing (%
26%16%
26%
One-week tracer gas measurements

32. Range Median
Top-floor units: 2 to 26% 16%
Mid-floor units: 1 to 20% 5%
Lowest-floor units: 1 to 4% 2%
How does the fraction vary by floor?
Fraction of Air Coming From Adjoining Units
Compared to Total Inflow
One-week tracer gas measurements

33. Total air leakage of individual units
Min Median Max Min Median Max Min Median Max < 1.25
2,101 2,368 2,636 115 130 145 3.16 3.56 3.97 0%
837 1,008 1,031 46 55 57 1.93 2.04 2.46 0%
731 917 1,318 40 50 72 1.61 2.02 2.90 0%
390 665 754 21 37 41 0.86 1.01 2.06 88%
376 454 958 21 25 53 0.57 0.76 2.14 86%
921 1,156 1,559 51 63 86 1.05 1.85 2.30 14%
376 861 2,636 21 47 145 0.57 1.66 3.97 22%
NELA (si/100 sf)Ref. Flow Rate(cfm50) ELA (si)
Building Min Median Max Min Median Max Min
Duplex 2,101 2,368 2,636 115 130 145 3.16
8 Plex 837 1,008 1,031 46 55 57 1.93
12 Plex 731 917 1,318 40 50 72 1.61
138 Unit 390 665 754 21 37 41 0.86
11 Story 376 454 958 21 25 53 0.57
4 Story 921 1,156 1,559 51 63 86 1.05
All Buildings 376 861 2,636 21 47 145 0.57
Ref. Flow Rate(cfm50) ELA (si)
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
ELA – equivalent leakage area, reference 4Pa & coef. = 1
(1999)
(1982)
(2001)
Blower door air leakage tests

34. Fraction of air leakage to adjacent units
Total
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
To Adjacent Units
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
2.5 1.1 4.4
414 412 410
34 2.4 22 0.1 53
1.0 2.3 4.2
314 312 310
21 3.0 25 1.3 33
1.2
212
23
Elevator
11 Story Building

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
60% Increase*only one unit with added fan
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
Median Ventilation Rate (cfm)
min to max
One-week tracer gas measurements

47. Cleaner air, same transfer rate
 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 nonsmoker’s
or receiver’s unit

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. 8-Plex: balance ventilation & air seal
Rooftop fan serves 4 units

52. 47 28 32 53
26 17 9 32
Uneven exhaust flow rates cause pressure difference & air flow between units
Before
Apartment exhaust flow rates
Powered roof
ventilator
8 plex

53. 25 26 28 26
23 26 27 24
47 28 32 53
26 17 9 32
Uneven exhaust flow rates cause pressure difference & air flow between units
Before
After
6
6
3 2
Added
Powered roof
ventilator
Apartment exhaust flow rates
Balanced exhaust flow rates reduces driving forces

54. Page 54
Open
between
tubs
Neighbor’s
bathtub
Why do our clothes smell like smoke?

55. Easy air flow is possible through framing
around pipes, etc

56. Page 56
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?

57. Page 57
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

58. Page 58
Details of Ongoing work
 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.
 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 smoker’s
unit.
Existing Conditions
Practical & Effective Work

59. Page 59
High rise case study: seal hidden shafts
& rooftop exhaust ventilation

60. Hidden chase openings often difficult to access

61. Add mineral wool fire-safing to high rise shaft openings

62. Seal with listed fire barrier

63. Page 63
PRV fan on roof – top of vent chase
Vent chase Operable register

64. Page 64
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
Unit Number
Register flow “tissue” test
- good - weak - ? - blow back
Shaft number
F
l
o
o
r

65. Page 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
Flow box measurement

66. Page 66
Obstructions: undersized floor cutout
full-sized subduct
Concrete floor Bathroom
vent
sub duct
The 144 sq. in. shaft area only
has 32 sq. in. for air flow.
c
Vent chase: 12” X 12” = 144 Sq. in.
8 x 8 cutout

67. Page 67
Obstructions: undersized floor cutout
full-sized subduct
Vent chase: 12” X 12” = 144 Sq. in.
Concrete floor Bathroom
sub duct –
replaced
with 3” for
more flow.
The 144
in2 shaft
only has
32 in2 for
air flow
8 x 8 cutout

68. Page 68
Drywall joints open

69. Page 69
Total: 506 cfm
From units: 93 cfm
Leaks: 413 cfm
No flow from lower 5 floors
Fan & register flow measurements

70. Page 70
Ventilation system problems
Restrictions cause most air to be drawn from
upper apartments
Duct leaks
• Air drawn from unknown sources
• Lower units no or reverse flow
Operable registers – occupant “balancing”
• No flow when closed
• Too high when open

71. Page 71
Ventilation system solutions
Reduce duct restrictions: 3” sub ducts to
upper 3 floors
Seal ductwork with Aeroseal technology
Install constant air regulators or designed
orifice plates at registers
Test and adjust fan flow to required duct
pressure
Thanks to Don Stevens for advising us of subduct code issue
Target: equal flow from all units

72. Page 72
Remove restriction and provide 3”
subducts for top 3 floors
Code: fire damper or sheet
metal sub duct extending
22” above fan inlet

73. Page 73
Aeroseal required for fan draw to reach
lower units Before After
Total: 506 279 cfm
From units: 93 221 cfm
Leaks: 413 58 cfm
Targets leaks

74. Page 74
Option used for test:
3” opening sized to
exact flow rate
Remove dampers, balance register flow
First option : “self-adjusting”
constant air regulator “CAR”
Production option:
fixed orifices – more to come

75. Page 75
Floor
Before After
Press Flow Press Flow
11 -74 28 -75 21
10 -45 27 -65 20
9 -15 14 -63 20
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
3 +0.3 + -42 20
2 -2.8 4 -42 20
1 -5.3 8 -44 20
Treatments
Subducts
Aeroseal
Orifice plates
Fan adjustment
Even flow after upgrades
Outcomes
Required ventilation
for all
Save 227cfm ($250 -
$500/year)
Reduce unit/unit flow
– smoke drift
17 fans ~ $4k - $8k

76. Page 76
Keep control fans on
Aethelometer Measurement of ETS
Particle Concentration in Nonsmoker's Apartment
-2
0
2
4
6
8
10
12
11/28 11/29 11/30 12/1 12/2 12/3 12/4 12/5 12/6
ETSParticleConcentration(mg/m3
)
Instrument precision
ETS odors logged by resident
Kitchen shaft central exhaust fan turned off at midnight
SHS odor threshold
Secondhand smoke monitored in 11th floor unit
SHS logged by resident

77. From research to production:
current options
 Spray seal ducts with mastic & seal fan curbs
 Orifice restrictors
 Efficient fan
 Clean or remove blockages

78. Current options
Spray sealing with mastic

79. Fan not connected - curb open
Current options: curb leakage
Total flow: 174 cfm
From units: 30 cfm
Airflow from building
shafts not exhaust grilles

80. Current options: stop curb leakage
Sealed
Total flow: 126 cfm
From units: 120 cfm

81. Current options
CARs failures: How soon? How often?
After 9 years – 1 in 3 plugged
Dust buildup in 9 months
Adjustment holes

82. Current options
Fixed orifices  Not prone to foul
 Can be cleaned
 Durable
 Sized for flow at target
pressure
 Mass - produced, low cost
 Allow lower operating
pressure (reduced duct leakage,
& fan power)
2
11/2
11/4
1

83. Current options
Fixed orifices – flow rate guideline
Inside Diameter
(in)
Pressure, in wc (Pa)
Nominal Actual
0.15
(36)
0.2
(50)
0.25
(62)
0.36
(90)
0.5
(124)
0.75
(186)
2 2.45 36 40 44 54
1.5 1.97 21 24 28 34 39 48
1.25 1.73 18 21 26 29 36
1 1.37 16 18 22
# stories* 3 to 7 5 to 10 6 to 12 9 to 18 12 to 25 to 25
*- building size for Minneapolis climate (20F average outside temp)

84. Current options: efficient fan
384
471
505
622
710
25 42 50
86
126
940
1143
1234
1508
1720
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 20 40 60 80 100 120
CFMandWatts
Static Pressure PA
CFM
Watts
RPM
Linear (CFM)
Linear (Watts)
EC style fan upgrade: lab test results
C 9" diam test
Static
Press (Pa)
Flow
(cfm)
Power
(watts)
63.6 in2 inlet area 29 384 25
(13 inlets 2.45 in) 44 471 42
(21 inlets 1.97 in) 50 505 50
(27 inlets 1.73 in) 78 622 86
(43 inlets 1.37 in) 100 710 126
Orifice Area= 64 sq in
Fixed Orifice Area= 64 sq in
Vary fan speed
400w to 50w saves 3000kwh/yr each

85. Exhaust grille on 12 story looks OK
Current options: blockages

86. Current options: blockages
Exhaust fan runs but DP low/high
Fan intake 20.9Pa too
low for flow needed
Fan outlet 221Pa to exterior
grille (side with resistance)
Check pressures

87. Current options: blockages
Access plugs from recent duct cleaning
Exhaust outlet plugged from inside
Hard to
see

88. Dirt obstructs flow: clean & adjust fan down
Current options: blockages
As found: 609 cfm After: 2,338cfm
Design flow: 1,780 cfm

89. Fan stops damper from opening
Current options: blockages

90. 300 inspected – 1 in 4 plugged
Current options: supply blockages

91. Exterior screen is clear. Hidden screen is forgotten
Current options: supply blockages
Pressure across grille 0.9 in wc
(221Pa)
Inspection: 18 of 46
Corridor supply intakes
obstructed

92. Nobody can keep this clean:
remove hidden screens
Current options: supply blockages

93. 138 unit: little unit to unit leakage

94. Meets LEED leakage guideline
Occupants still complain of smoke transfer
324 323 322 321
601 9 17 574 3 622
+/-1 +/-13 +/-3
1 44
224 +/-7 223 222 +/-4 221
21 688 71 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
Guarded-Zone Measured Air Leakage Rates
734
680
-13
+/-11
Oaks: Pre-Treatment
unit #
total leakage
unit/unit leakage
leakage precision
(cfm50)
Smoker
Non-
smoker

95. Vent blocked: view inside smoker’s fan
duct in attic

96. Vent blocked: roof damper frozen shut on
same fan

97. CARs in fan duct in attic, smokers open for
higher flow

98. Post treatment fan flows
Unit
Flow
(cfm)
Unit
Flow
(cfm)
Unit
Flow
(cfm)
323 24 322 25
224 21 223 20 222 22
Guest 26 123 28 122 20Smoker

99. 4 Story: duct leakage in ceiling joist space

100. All leakage into joist space

101. Aeroseal ducts in joist space

102. Leaks into joist space: lights & sprinklers

103. New continuous duty fan in kitchen:
source of odor complaint

104.  Continuous at 40cfm.
Installer sets high speed:
75, 160, or 390 cfm
 Less than 20 watts at low
speed
Continuous ventilation with kitchen hood
in 1 unit

105. Duct seal side-benefit
Backdraft potential reduced by Aeroseal
-4.5 pa before -1.5pa after
80%-ID furnace both into B vent natural draft water heater
Door closed
dryer+ AC fan on
in 1 unit

106. Recommendations
 Ventilate - source
 Seal - between
 Ventilate - receiver

107. Recommendations: ventilation
 Moderate/continuous/quiet – better than
intermittent
 Central exhaust: orifice, seal ducts, replace or
adjust fan
 Check for blockages and leaks

108. Recommendations: air sealing
 Seal between units
 Large, accessible leaks (unoccupied or new is better)
 Includes ducts and mechanical/plumbing
chases
Improvement possible –
can not eliminate transfer

109. In at the bottom and out the
top
Additional slides

110. 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

111. Fan not connected - curb open
Current options: curb leakage
Total flow: 174 cfm
From units: 30 cfm
Airflow from building shafts
not unit exhaust grilles

112. Current options: stop curb leakage
Sealed
Total flow: 126 cfm
From units: 120 cfm

113. 2-part Foam Seals Plumbing Chase
Stop Vertical Air Transfer In Plumbing Wall
Patched, primed
Inject Foam Along Top of Wall
12-plex
Shared leakage reduced about
50% from 507 to 247 cfm50

114. 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

115. Page 115
Note – Improvements are possible. Managing expectations is
important.

116. Page 116
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

117. Page 117
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.