Residential Ventilation & IAQ Requirements for Existing Homes

History, ASHRAE 62.2, and the RTF’s Role

Regional Technical Forum October 13 th , 2009

History - BPA

1981

– • • Residential Weatherization Program allows air tightening measures if home: is site built has ventilated crawlspace • Does not have wood stove, foam insulation (formaldehyde), nor unvented combustion appliances – IAQ brochures given to homeowners – Concerns: Radon, combustion byproducts, formaldehyde

1984

– • “Expanded Residential Weatherization Program” RECORD OF DECISION allows house tightening measures (storm windows, wall insulation, weatherstripping, door treatments, etc.) if: Homeowner receives information on IAQ and how to reduce pollutants • Radon monitoring is provided to homeowners • Homes with tested high radon levels receive subsidy for mitigation – Concerns: Primarily Radon 1980 1985 1990 1995 2000

1989

– • • • • • “New Energy-Efficient Homes Program” RECORD OF DECISION requires: Exhaust fans in kitchens and baths Whole House mechanical ventilation Designated air supplies for combustion appliances IAQ information given to homeowner Building materials that meet HUD standards for formaldehyde emissions • Attention to radon and mitigation as necessary – Concerns: Radon and other indoor pollutants

1993

– • “Resource Programs” RECORD OF DECISION says: Radon no longer an issue for either new home efficiency programs nor existing home weatherization programs • Otherwise, 1984 and 1989 ROD’s should be followed • Also, manufactured homes may be allowed, if they follow the new homes ROD (1989).

– They’re subject to more stringent requirements because insulating manufactured homes is believed to decrease natural infiltration more than insulating site built homes 2005 2010

Today

– • Site Built Some air sealing measures require whole house ventilation • Other Wx measures don’t – • Manufactured Homes All measures require whole house ventilation – New Homes all require whole house ventilation 2

Current RTF IAQ Requirements Summary

Air Sealing Measure Insulation and Windows Measures PTCS Duct Sealing Heat Pump Conversions Multifamily New Construction Montana House Energy Star Homes Site Built Very Limited Ventilation Requirements. (exhaust fan ducts cannot terminate in attic or crawlspace) Whole House Ventilation System Required IF ACHn<0.45

No Ventilation Requirements; CO alarm required where combustion appliance inside.

No Requirements.

Whole House Ventilation System Required; Combustion Appliance Requirements.

Whole House Ventilation System Required; CAZ test or CO alarm requred where atm vented combustion appliance is inside heated space.

Spot Ventilation Required (Whole house required in OR); CAZ test required where atm vented combustion appliance is inside heated space.

Manufactured Homes Whole House Ventilation System Required and special requirements for combustion appliances.

Whole House Ventilation System Required.

No Ventilation Requirements; CO alarm required where combustion appliance inside.

No Requirements.

N/A N/A Whole House Ventilation System Required.

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What Is 62.2? (From ASHRAE’s Website)

ANSI/ASHRAE 62.2-2007 – Published standard. (Supersedes ANSI/ASHRAE 62.2-2004.)

Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings

1. PURPOSE: This standard defines the roles of and minimum requirements for mechanical and natural ventilation systems and the building envelope intended to provide acceptable indoor air quality in low-rise residential buildings.

2. SCOPE: This standard applies to spaces intended for human occupancy within single-family houses and multifamily structures of three stories or fewer above grade, including manufactured and modular houses. This standard does not apply to transient housing such as hotels, motels, nursing homes, dormitories, or jails.

2.1 This standard considers chemical, physical, and biological contaminants that can affect air quality. Thermal comfort requirements are not included in this standard (see ANSI/ASHRAE Standard 55-2004, Thermal Environmental Conditions for Human Occupancy).

2.2 While acceptable indoor air quality is the goal of this standard, it will not necessarily be achieved even if all requirements are met: a) because of the diversity of sources and contaminants in indoor air and the range of susceptibility in the population; b) because of the many other factors that may affect occupant perception and acceptance of indoor air quality, such as air temperature, humidity, noise, lighting, and psychological stress; c) if the ambient air is unacceptable and this air is brought into the building without first being cleaned (cleaning of ambient outdoor air is not required by this standard.); d) if the system(s) are not operated and maintained as designed, or e) when high-polluting events occur.

2.3 This standard does not address unvented combustion space heaters.

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• • • •

ASHRAE 62.2 – Basic Components

Whole Building Mechanical Ventilation System – Required CFM = 0.01 x Floor Area + 7.5 x [(Number of Bedrooms)+1] Note: adjustments are made for high occupant density and intermittent operation Local Mechanical Exhaust – Kitchens = 100 cfm – Bathrooms = 50 cfm (Note: Continuous operation also allowed at different rates) Other Requirements – Prescriptively seal house between attic, crawl, garage – Provide ventilation system instructions to homeowner – Combustion appliances • receive adequate combustion air • where atmospherically vented appliances are inside occupiable space, additional requirements if two largest exhaust fans have flow rate > 15cfm/100 square feet of floor area. – Total duct leakage must be < 6% of total fan flow at 25 Pa if ducts are located in the garage.

• PROPOSED SPEC: Required anywhere ducts are located outside the pressure boundary.

– Rooms must have ventilation openings (i.e. openable window area) of 4% of floor area or greater. (exceptions) – – Filtration requirements for systems that use ducts PROPOSED SPEC: CO alarm required (Out for public comment until Oct 26 th ) Equipment Requirements – Tested and rated for flow and sound according to HVI – Sound ratings: Continuous fans < 1 sone; Intermitent Fans < 3 sones – Use tested airflow; or use airflow rating at 0.25 in H20 with proper duct design 5

ASHRAE 62.2 – Existing Home Exceptions

• •

Inadequate Existing Bath/Kitchen Fans

–

An increase in whole-house ventilation rates can be used to overcome a deficiency in existing bath/kitchen fan flow rates.

Infiltration Credit

–

Existing homes with an effective infiltration rate greater than 2cfm/100ft

2

may use a portion of this “excess” infiltration to reduce the required whole house ventilation rate. Effective Infiltration is estimated based on:

•

House tightness (blower door test)

•

Climate

•

Building height

6

ASHRAE 62.2 Whole House Ventilation Requirements Calculator

Purpose: This calculator is intended to determine the required whole house ventilation fan flow rate for existing homes, according to ASHRAE Standard 62.2.

Instructions: A. Enter the necessary data into the green "Inputs" section of the calculator (Cells C15 through C33) B. Fix any inputs causing errors, as necessary. (cells B5:H8) C. The resulting required whole house flow rate, in cfm, is given in cell C11:12.

Results

Required Whole-House Fan Measured Flow Rate =>

39 cfm Inputs

House Floor Area House Volume Vertical Distance from lowest grade level to highest ceiling Number of Bedrooms Number of Bathrooms Number of Occupants Blower Door Test Performed?

Blower Door Tested CFM at 50Pa depressurization City

Whole House Fan on-time per cycle Whole House Fan off-time per cycle

Kitchen Exhaust Fan's Measured Airflow Rate Bathroom 1: Exhaust Fan's Measured Airflow Rate Bathroom 2: Exhaust Fan's Measured Airflow Rate 2,000 18,000 11 3 Yes 2 3 1 2100 OR - Astoria 25 25 25 25

24 0

50 25 25 25 sq.ft.

cubic feet feet bedrooms bathrooms people CFM50

hours hours

cfm cfm cfm Intermediate Outputs Leakage Area (ASTM 779, w/caveats 4 and 5) Normalized Leakage (ASHRAE Std 119) Effective AirChange Rate from Infiltration (ASHRAE Std 136) Effective Infiltration Flow Rate ASHRAE 62.2 Default Infiltration Credit Excess Infiltration Section 4.1 Whole House Ventilation Rate Section 4.1.1 Different Occupant Density Section 4.1.3 Infiltration Credit Section C3.3 Required Additional Airflow Mechanical Ventilation Air Requirement Fractional On-Time Cycle Time Fractional On-Time rounded down Ventilation Effectiveness Initial Room Airflow Deficit: Kitchen Initial Room Airflow Deficit: Bathroom 1 Initial Room Airflow Deficit: Bathroom 2 0.80

0.44

0.38

113 40 73 50 0 -36 25 39 1.00

24 1.00

1.00

50 25 25 cfm cfm cfm sq. ft.

ACH cfm cfm cfm cfm cfm cfm cfm cfm 7

ASHRAE 62.2 – Example Home #1

ASHRAE 62.2 Continuous Whole-House Ventilation Requirement

(2 bed/1 bath, 1-story, 1100 ft2, Portland) 150 100 50 0 0 0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

"Natural Air Exchange Rate" (ACHn = ACH50/20) 0.9

1

Measured Bath/Kitchen Fan Flow Rate

0cfm/0cfm 25cfm/50cfm 50cfm/100cfm _ Current RTF Standard Note: Current RTF standard for manufactured homes is always required and independent of ACHn. 8

ASHRAE 62.2 – Example Home #2

ASHRAE 62.2 Continuous Whole-House Ventilation Requirement

(3 bed/2 bath, 1-story, 1800 ft2, Portland) 150 100 50 0 0 0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

"Natural Air Exchange Rate" (ACHn = ACH50/20) 0.9

1

Measured Bath/Kitchen Fan Flow Rate

0cfm/0cfm 25cfm/50cfm 50cfm/100cfm _ Current RTF Standard Note: Current RTF standard for manufactured homes is always required and independent of ACHn. 9

ASHRAE 62.2 – Example Home #3

ASHRAE 62.2 Continuous Whole-House Ventilation Requirement

(4 bed/3 bath, 2-story, 2000 ft2, Portland) 150 10 100 50 0 0 0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

"Natural Air Exchange Rate" (ACHn = ACH50/20) 0.9

1

Measured Bath/Kitchen Fan Flow Rate

0cfm/0cfm 25cfm/50cfm 50cfm/100cfm _ Current RTF Standard Note: Current RTF standard for manufactured homes is always required and independent of ACHn.

ASHRAE 62.2 – Example Home #4

ASHRAE 62.2 Continuous Whole-House Ventilation Requirement

(4 bed/3 bath, 2-story, 2000 ft2, Portland) 150 11 100 50 0 0 0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

"Natural Air Exchange Rate" (ACHn = ACH50/20) 0.9

1

Measured Bath/Kitchen Fan Flow Rate

0cfm/0cfm 25cfm/50cfm 50cfm/100cfm _ Current RTF Standard Note: Current RTF standard for manufactured homes is always required and independent of ACHn.

Measure

Which Efficiency Measures Should Apply?

The subcommittee tentatively has agreed that everything except heat pumps should receive some kind of IAQ attention.

Negative effect on IAQ?

Comments Current RTF Requirements Mechanical Ventilation Required?

Attention to CO?

12 Air Sealing Yes Directly reduces infiltration in the building shell If ACHn < 0.45

No Duct Sealing Wall Insulation Window Replacement Yes Very Likely Very Likely Directly reduces infiltration of the HVAC system Insert-tube method is required. Dense-pack is allowed (and encouraged).

Caulking, etc. to reduce infiltration Attic Insulation Likely Specifications require prescriptive air-sealing Floor Insulation Likely Heat Pump Conversion Possible Heat Pump Upgrade No Specifications require prescriptive air-sealing Addition of ducts a) influences (likely to increase) infiltration rate and b) could cause backdrafting.

Unit was going to be replaced anyway No No (Yes for MH) No (Yes for MH) No (Yes for MH) No (Yes for MH) No No Yes No No No No No No

What do Others Require?

• •

ASHRAE 62.2

–

Wisconsin

–

California

–

Others?

Older Versions of ASHRAE (62-2001)

•

At least 0.35 ACH and 15 CFM per person

–

Low Income Weatherization Programs

–

Others?

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What might it look like to implement ASHRAE 62.2 for Wx Programs?

• • • •

ASHRAE 62.2 Whole House Ventilation Requirements Calculator

Purpose: This calculator is intended to determine the required whole house ventilation fan flow rate for existing homes, according to ASHRAE Standard 62.2.

Instructions: A. Enter the necessary data into the green "Inputs" section of the calculator (Cells C15 through C33) B. Fix any inputs causing errors, as necessary. (cells B5:H8) C. The resulting required whole house flow rate, in cfm, is given in cell C11:12.

Ventilation Rate Calculator Increased Costs

– – – – –

Blower Door Test Exhaust Fan Flow Tests Whole House Fan & Controller Installation CO Alarm (?) Training (LOTS of training)

Results

Required Whole-House Fan Measured Flow Rate =>

39 cfm Inputs

House Floor Area House Volume Vertical Distance from lowest grade level to highest ceiling Number of Bedrooms Number of Bathrooms Number of Occupants Blower Door Test Performed?

Blower Door Tested CFM at 50Pa depressurization City

Whole House Fan on-time per cycle Whole House Fan off-time per cycle

Kitchen Exhaust Fan's Measured Airflow Rate Bathroom 1: Exhaust Fan's Measured Airflow Rate Bathroom 2: Exhaust Fan's Measured Airflow Rate 2,000 18,000 11 3 2 3 Yes 1 2100 OR - Astoria

24 0

50 25 25 25 25 25 25 25 sq.ft.

cubic feet feet bedrooms bathrooms people CFM50

hours hours

cfm cfm cfm Intermediate Outputs Leakage Area (ASTM 779, w/caveats 4 and 5) Normalized Leakage (ASHRAE Std 119) Effective AirChange Rate from Infiltration (ASHRAE Std 136) Effective Infiltration Flow Rate ASHRAE 62.2 Default Infiltration Credit Excess Infiltration Section 4.1 Whole House Ventilation Rate Section 4.1.1 Different Occupant Density Section 4.1.3 Infiltration Credit Section C3.3 Required Additional Airflow Mechanical Ventilation Air Requirement Fractional On-Time Cycle Time Fractional On-Time rounded down Ventilation Effectiveness Initial Room Airflow Deficit: Kitchen Initial Room Airflow Deficit: Bathroom 1 Initial Room Airflow Deficit: Bathroom 2 0.80

0.44

0.38

113 40 73 50 0 -36 25 39 1.00

24 1.00

1.00

50 25 25 cfm cfm cfm sq. ft.

ACH cfm cfm cfm cfm cfm cfm cfm cfm

Oversight/Verification Incorporate ASHRAE 62.2 updates

????

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Discussion: RTF’s Role and Issues

• • • • • Does the RTF have adequate expertise in IAQ? If not, then who?

If we attempt to follow 62.2: – Can we get “close enough” on some requirements and are there some we can ignore?

– For which measures should 62.2 be required? – Should there be differences for single family, multifamily, or manufactured homes?

It’s one thing to have a spec, but how should IAQ requirements be verified? IAQ doesn’t save energy; will it receive attention?

Will the added cost/burden put a stop to Wx programs?

What about new construction?

Potential Options:

1.

Have subcommittee incorporate 62.2 into measure specifications, also set up quality assurance plan & requirements; 2.

3.

4.

Keep specs as they are; Pass this IAQ job on to someone else (BPA?, codes?); Suggest, but don’t require: Rely on letting the (informed) homeowner make the decision about what IAQ strategies to employ.

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