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Indoor Air Quality (IAQ)

Energy, Weatherization and Indoor Air Quality

Weatherization and other energy efficiency upgrades can have negative impacts on occupant health and safety if not accompanied by appropriate indoor air quality — IAQ — protections. With an increase in weatherization and energy efficiency improvement activities, consideration should be given to include incentives for ensuring that energy upgrades are accompanied by appropriate IAQ actions.

By addressing IAQ at the beginning of weatherization and/or retrofit efforts, greater energy savings can be achieved per house, pollutant exposure problems can be avoided, and public health can be protected. It also means decreasing the potential risks of additional costs to resolve IAQ problems related to retrofit activities, which decrease productivity and increase business costs for the weatherization industry.

The following overview summarizes IAQ challenges related to weatherization and energy efficiency retrofit activities, and highlights recommended solutions to help prevent IAQ problems during weatherization efforts.

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Weatherization Challenges

Indoor pollutant exposures may be increased due to air-tightening activities.

Tightening a building is essential for energy efficiency but may also have the unintended consequence of allowing contaminants that would otherwise be diluted in leaky homes to build up to unhealthy levels, including:

  • Combustion gases, including deadly carbon monoxide
  • Secondhand smoke in homes of smokers, or in attached multi-family dwellings adjacent to smokers
  • Hundreds of chemicals — volatile organic compounds, or VOCs — used in many building materials and consumer products.

Indoor pollutant exposures caused by improper retrofit activities.

Improperly conducted retrofits may disturb dangerous materials such as lead in paint and asbestos in flooring and insulation products.

Mold and moisture problems caused or exacerbated by retrofit activities.

If a retrofit does not properly address mold and moisture control, such as water vapor transport and condensation, significant moisture problems can occur in a retrofitted home. In addition, moisture-laden building materials can trap additional moisture in a retrofitted building.

Missed opportunities to improve indoor air quality during retrofit activities.

Home energy audit and retrofit activities often present opportunities for achieving IAQ improvements, yet these opportunities may be missed due to lack of information on IAQ and/or funding limitations. Although many weatherization and energy efficiency retrofit programs include minimum IAQ protections, they are generally not sufficient to improve IAQ. The following list highlights a few of the most commonly missed opportunities to improve IAQ during retrofit activities:

  • Fresh air ventilation system
  • Radon testing and mitigation
  • Removal or isolation of other pollutant sources, such as garage and attic pollutant sources, combustion gases, mold and pests.

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Indoor Air Quality Solutions

Investment in doing retrofit jobs properly will result in higher quality outcomes, far fewer building failures and health problems, and in most cases additional energy savings. Furthermore, the additional services required to prevent IAQ problems and improve public health require professional training and certification which can create more green jobs and will help sustain new green jobs through enhanced value and customer satisfaction.

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Recommended Actions

Establish minimum "do no harm" measures for energy retrofit and other building upgrade activities.

By establishing retrofit program minimum IAQ requirements accompanied by appropriate quality assurance, program activities can avoid the worst IAQ problems. The following recommended minimum IAQ criteria are a starting point for program development:

  • Inspection and diagnostic testing requirements to ensure ventilation systems work properly, house pressures are managed properly, and major indoor air pollutant sources are isolated or removed. These activities are best integrated with energy efficiency assessment activities.
  • Ventilation system requirements, compliant with ASHRAE Residential Ventilation Standard 62.2. This requirement is essential for achieving acceptable IAQ without severely limiting the energy savings potential. However, ventilation system installation can be a cost barrier, so appropriate incentives are recommended.
  • Additional air-sealing requirements for IAQ purposes, such as attic-ceiling and house-garage interfaces; foundation joints and cracks; Heating, Ventilating and Air Conditioning systems; and duct systems.

Provide IAQ guidelines, standards, tools and training appropriate for the needs of energy retrofit program participants.

Although many such guidance and tools already exist, the multi-faceted and complex nature of the IAQ field means that they are widely dispersed and potentially difficult for non-IAQ experts to identify or access. This will require IAQ expert involvement to ensure program standards, protocols and training curricula developed for these programs adequately address IAQ. EPA has developed the following comprehensive IAQ guidelines for addressing IAQ when carrying out renovations or energy efficiency upgrades in homes and schools:

image of indoor air quality publications

Reduce financial barriers to specification of IAQ measures during the weatherization and energy efficiency retrofit activities.

Traditionally, weatherization and energy efficiency retrofit activities are driven by costs and funds availability. Even when weatherization and home performance contractors recognize the need to address IAQ issues during the audit and retrofit processes, they frequently are unable to implement them because of restricted budgets. This has led to unintended IAQ problems and severe limitations in achievable energy. By allowing a modest increase in financial incentive payments per job to account for IAQ improvements, these limitations can be overcome, which will lead to increased energy efficiency achieved per house and improved IAQ and health for weatherization and home energy retrofit clients. Similarly, IAQ improvements should be factored into financing mechanisms used to encourage energy efficiency retrofits. Measures that should be considered for additional incentives and/or preferred financing include:

  • All of the recommended minimum IAQ requirements described above, including IAQ assessment fees, air-sealing, and ventilation system installation
  • Upgrades that improve both energy efficiency and IAQ, such as high-efficiency sealed-combustion furnaces and power-vented water heaters
  • Radon mitigation systems
  • Lead paint removal, especially then accompanied by energy savings, i.e., efficient window replacements
  • Moisture problem mitigation
  • Integrated Pest Management (IPM) services
  • Specification of low or no-VOC materials.

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More people are weatherizing (sealing and insulating) their homes and buildings to offset outdoor temperature changes and to help save energy by reducing the need for heating and cooling changes. Ventilation is an important part of a building’s heating and cooling system because it helps reduce indoor pollutants. Weatherizing without maintaining proper ventilation can negatively affect indoor air.

  • Moisture accumulates inside homes during everyday activities such as cooking, taking showers, and hanging wet laundry which increases the relative humidity level indoors. Without air ventilation, the humidity level remains high and can provide a breeding ground for mold, mites and bacteria.
  • Poor ventilation also can lead to increased indoor exposure to pollutants because there isn’t any exchange with outdoor air to dilute or remove the concentration of the pollutants:
  • If there is an increase in mold, bacteria or other pests due to higher humidity levels or changes in outdoor temperatures, people may use chemical products to combat infestations.

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