Residential Ventilation

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Residential Ventilation IAQ Requirements for
Existing Homes

• History, ASHRAE 62.2, and the RTFs Role
• Regional Technical Forum
• October 13th, 2009

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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

• 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

• Today
• Site Built
• Some air sealing measures require whole house
  ventilation
• Other Wx measures dont
• Manufactured Homes
• All measures require whole house ventilation
• New Homes all require whole house ventilation

• 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 RODs should be followed
• Also, manufactured homes may be allowed, if they
  follow the new homes ROD (1989).
• Theyre subject to more stringent requirements
  because insulating manufactured homes is believed
  to decrease natural infiltration more than
  insulating site built homes

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Current RTF IAQ Requirements Summary
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What Is 62.2? (From ASHRAEs 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 gt
  15cfm/100 square feet of floor area.
• Total duct leakage must be lt 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 26th)

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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/100ft2 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

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ASHRAE 62.2 Example Home 1

• Note Current RTF standard for manufactured homes
  is always required and independent of ACHn.

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ASHRAE 62.2 Example Home 2
Note Current RTF standard for manufactured homes
is always required and independent of ACHn.
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ASHRAE 62.2 Example Home 3
Note Current RTF standard for manufactured homes
is always required and independent of ACHn.
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ASHRAE 62.2 Example Home 4
Note Current RTF standard for manufactured homes
is always required and independent of ACHn.
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Which Efficiency Measures Should Apply?

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

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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?

• Ventilation Rate Calculator
• Increased Costs
• Blower Door Test
• Exhaust Fan Flow Tests
• Whole House Fan Controller Installation
• CO Alarm (?)
• Training (LOTS of training)
• Oversight/Verification
• Incorporate ASHRAE 62.2 updates
• ????

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Discussion RTFs 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?
• Its one thing to have a spec, but how should IAQ
  requirements be verified? IAQ doesnt save
  energy will it receive attention?
• Will the added cost/burden put a stop to Wx
  programs?
• What about new construction?
• Potential Options
• Have subcommittee incorporate 62.2 into measure
  specifications, also set up quality assurance
  plan requirements
• Keep specs as they are
• Pass this IAQ job on to someone else (BPA?,
  codes?)
• Suggest, but dont require Rely on letting the
  (informed) homeowner make the decision about what
  IAQ strategies to employ.