Air Sealing and Ventilation Improvements for Multifamily Buildings - Fitzgerald and Bohac

Air sealing and ventilation improvements for multifamily

buildings

March 2, 2012

Jim FitzgeraldDave Bohac

Center for Energy and Environment

Better Buildings: Better Business Conference

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

http://www.mnsmokefreehousing.org/

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

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

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

What are the driving forces to move air into and though

buildings?

What are the driving forces?

WinterStack Effect

Taller Building => Bigger Effect

In at the bottom and out the top


Wind Effect

In on windward side and out on leeward side

Taller Building => Bigger 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


Mechanical System Effect

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


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?

Gaps around sink plumbing

Most openings are small and diffuse

Baseboards and sprinkler heads

Chemical smoke moves out of baseboard leakClear acrylic caulk required plus moving bookcases, etc

Gaps along baseboard under carpet

Gaps behind baseboard heaters

Gaps around bath fan

Bathroom exhaust fans

Leaky (2.5 si)

Tight (0.1 si)

Recessed Light Fixtures

Hidden high rise chases = large uncontrolled flows

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.

Study Objective

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


Ventilate

Seal

Ventilate

Duplex 8-Plex

12-Plex

1930s

1970

1964

Minnesota SHS transfer study

New 4 story

138 unit

11 story

1982

2001

1999

Minnesota SHS transfer study

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

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

Q50B total = QB1 Q50

B to A = QB1 - QB2

Test 3 Test 4


QB3 QC3 QB4

QComm4


Q50B to C = QB1 - QB3 Q50

B exterior = QB4

Fan Fan Fan

Fan Fan Fan

Fan

Test 1 Test 2


QB1 QA2 QB2



B to A = QB1 - QB2

Test 3 Test 4


QB3 QC3 QB4

QComm4



B exterior = QB4

Fan Fan Fan

Fan Fan Fan

Fan

Test 1 Test 2


QB1 QA2 QB2



B to A = QB1 - QB2

Test 3 Test 4


QB3 QC3 QB4

QComm4



B exterior = QB4

Fan Fan Fan

Fan Fan Fan

Fan

Test 1 Test 2


QB1 QA2 QB2



B to A = QB1 - QB2

Test 3 Test 4


QB3 QC3 QB4

QComm4



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

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

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 Max Min Median Max Min Median MaxDuplex 6% 35% 65% 19% 27% 34% -30% -9% 13%8-Plex 1% 3% 24% 3% 8% 42% -1% 5% 18%12-Plex 1% 12% 26% 9% 12% 17% -9% 1% 8%138 Unit 1% 11% 25% 1% 7% 22% 1% 1% 13% -12% -4% 0%11 Story 2% 5% 12% 1% 2% 9% 0% 1% 4% -11% -3% -1%4 Story 1% 2% 10% 0% 2% 7% -3% -1% 1%All Units 1% 5% 65% 0% 3% 22% 0% 8% 42% -30% -1% 18%

Pre-Treatment (%)

26%16%

26%

One-week tracer gas measurements

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


Total air leakage of individual units

Building Min Median Max Min Median Max Min Median Max < 1.25Duplex 2,101 2,368 2,636 115 130 145 3.16 3.56 3.97 0%8 Plex 837 1,008 1,031 46 55 57 1.93 2.04 2.46 0%12 Plex 731 917 1,318 40 50 72 1.61 2.02 2.90 0%138 Unit 390 665 754 21 37 41 0.86 1.01 2.06 88%11 Story 376 454 958 21 25 53 0.57 0.76 2.14 86%4 Story 921 1,156 1,559 51 63 86 1.05 1.85 2.30 14%

All Buildings 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 Median Max < 1.25Duplex 2,101 2,368 2,636 115 130 145 3.16 3.56 3.97 0%8 Plex 837 1,008 1,031 46 55 57 1.93 2.04 2.46 0%12 Plex 731 917 1,318 40 50 72 1.61 2.02 2.90 0%138 Unit 390 665 754 21 37 41 0.86 1.01 2.06 88%11 Story 376 454 958 21 25 53 0.57 0.76 2.14 86%4 Story 921 1,156 1,559 51 63 86 1.05 1.85 2.30 14%

All Buildings 376 861 2,636 21 47 145 0.57 1.66 3.97 22%

Ref. Flow Rate(cfm50)

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)


Fraction of air leakage to adjacent units

TotalBuilding 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


Leakage Area of Individual Units

712

341.8

612

281.1

514 512 510

28 1.3 24 0.5 332.5 1.1 4.4

414 412 410

34 2.4 22 0.1 531.0 2.3 4.2

314 312 310

21 3.0 25 1.3 331.2

212

23

Elevator

11 Story Building

Air Sealing and VentilationTreatment Results


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 TreatmentsTotal 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


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%


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 treatmentsQuiet, Continuous Ventilation

Constant Air Regulator

Quiet Ceiling ExhaustMulti-point

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


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

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%)


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

Case Studies

8-Plex: balance ventilation & air seal

Rooftop fan serves 4 units

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

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

66

3 2

Added

Powered roof ventilator

Apartment exhaust flow rates

Balanced exhaust flow rates reduces driving forces

Page 54

Open between tubs

Neighbor’s bathtub

Why do our clothes smell like smoke?

Easy air flow is possible through framing around pipes, etc

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?

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

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

Page 59

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

Hidden chase openings often difficult to access

Add mineral wool fire-safing to high rise shaft openings

Seal with listed fire barrier

Page 63

PRV fan on roof – top of vent chase

Vent chase Operable register

Page 64

FL

OO

R

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

Floor

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

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

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

Page 68

Drywall joints open

Page 69

Total: 506 cfm

From units: 93 cfm

Leaks: 413 cfm No flow from lower 5 floors

Fan & register flow measurements

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

Page 71

Ventilation system solutionsReduce 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

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

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

Page 74

Option used for test:3” opening sized to exact flow rate

Remove dampers, balance register flowFirst option : “self-adjusting” constant air regulator “CAR”

Production option: fixed orifices – more to come

Page 75

FloorBefore 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

TreatmentsSubductsAerosealOrifice platesFan adjustment

Even flow after upgrades

OutcomesRequired ventilation for allSave 227cfm ($250 - $500/year)Reduce unit/unit flow – smoke drift

17 fans ~ $4k - $8k

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

ET

S P

arti

cle

Con

cen

trat

ion

(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

From research to production:

current options

Spray seal ducts with mastic & seal fan curbs

Orifice restrictors

Efficient fan

Clean or remove blockages

Current options

Spray sealing with mastic

Fan not connected - curb open

Current options: curb leakage

Total flow: 174 cfmFrom units: 30 cfm

Airflow from building shafts not exhaust grilles

Current options: stop curb leakage

SealedTotal flow: 126 cfmFrom units: 120 cfm

Current options

CARs failures: How soon? How often?After 9 years – 1 in 3 plugged

Dust buildup in 9 months

Adjustment holes

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

Current options

Fixed orifices – flow rate guidelineInside Diameter

(in) Pressure, in wc (Pa)

Nominal Actual0.15(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)

Current options: efficient fan

384471 505

622710

25 42 50 86126

940

11431234

1508

1720

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 20 40 60 80 100 120

CFM

and

Watt

s

Static Pressure PA

CFM

Watts

RPM

Linear (CFM)

Linear (Watts)

EC style fan upgrade: lab test results

C 9" diam testStatic

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 inFixed Orifice Area= 64 sq inVary fan speed

400w to 50w saves 3000kwh/yr each

Exhaust grille on 12 story looks OK

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


Access plugs from recent duct cleaning

Exhaust outlet plugged from inside

Hard to see

Dirt obstructs flow: clean & adjust fan down


As found: 609 cfm After: 2,338cfm

Design flow: 1,780 cfm

Fan stops damper from opening


300 inspected – 1 in 4 plugged

Current options: supply blockages

Exterior screen is clear. Hidden screen is forgotten


Pressure across grille 0.9 in wc (221Pa)

Inspection: 18 of 46 Corridor supply intakes obstructed

Nobody can keep this clean:

remove hidden screens


138 unit: little unit to unit leakage

Meets LEED leakage guidelineOccupants 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-Treatmentunit #

total leakage

unit/unit leakage

leakage precision

(cfm50)

Smoker

Non- smoker

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

Vent blocked: roof damper frozen shut on same fan

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

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

4 Story: duct leakage in ceiling joist space

All leakage into joist space

Aeroseal ducts in joist space

Leaks into joist space: lights & sprinklers

New continuous duty fan in kitchen: source of odor complaint

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

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

Recommendations

Ventilate - source

Seal - between

Ventilate - receiver

Recommendations: ventilation

Moderate/continuous/quiet – better than intermittent

Central exhaust: orifice, seal ducts, replace or adjust fan

Check for blockages and leaks

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


Additional slides

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

Fan not connected - curb open

Current options: curb leakage

Total flow: 174 cfmFrom units: 30 cfm

Airflow from building shafts not unit exhaust grilles

Current options: stop curb leakage

SealedTotal flow: 126 cfmFrom units: 120 cfm

2-part Foam Seals Plumbing ChaseStop 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

Kitchen option for cooking sourceIn 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

Page 115

Tobacco Smoke Research: Tobacco Smoke Research: Preliminary RecommendationsPreliminary RecommendationsSeal what is possible around pipes,

baseboards, etc. – start in smokers unit

Provide continuous ventilation

Balance ventilation between units –possibly higher exhaust in smokers unit

Consider more extensive air sealing when apartments turn over or during remodeling

Note – Improvements are possible. Managing expectations is important.

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

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.

Technology

Air Sealing and Ventilation Improvements for Multifamily Buildings - Fitzgerald and Bohac