Air Sealing and Ventilation Go “Hand in Hand”
Indoor Air Quality
When creating an energy-efficient, airtight home by upgrading insulation and air sealing, irritants such as dust, allergens, mold and pests are prevented from entering the home, but there is an increased risk of existing indoor irritants or pollutants being trapped in the home, requiring mechanical ventilation.
It’s very important to be mindful of this during any energy retrofit project and make sure that your house meets air exchange standards, such as those recommended by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), which also help prevent the possibility of combustion appliance backdrafting.
Another component of indoor air quality is radon, a colorless, odorless gas. It is the second leading cause of cancer in the United States. Radon is emitted from nearly all soils. It can move through the air and into your home through cracks and holes. Your home traps the gas inside, where it can build up, exposing you to the risk of lung cancer.
With remodel projects like the Revitalize Home where you are sealing the home tight that may already have radon present, radon testing can help determine whether or not a mechanical ventilation system would be needed. The U.S. Environmental Protection Agency recommends including such a system if the radon levels in the home exceed 4 picocuries per liter of air (pCi/L). Testing at the Revitalize Home fell under that benchmark, and no additional mechanicals were required
Your home needs ventilation — the exchange of indoor air with outdoor air — to reduce indoor pollutants, moisture and odors. Contaminants such as formaldehyde, volatile organic compounds and radon can accumulate in poorly ventilated homes, causing health problems.
Unless properly ventilated, an airtight or weatherized home can seal in indoor air pollutants. Ventilation also helps control moisture as well as the possibility of combustion appliance backdrafting. To ensure adequate ventilation, ASHRAE says that a home’s living area should be ventilated at a rate of 0.35 air changes per hour or 15 cubic feet per person per minute, whichever is greater. Testing at the Revitalize Home exceeded the standard, and no additional mechanicals were required.
More information on Air Quality is available in downloadable format.