The term “indoor air quality” or IAQ has become widely used in recent years. It refers generally to the amount of pollution or “particulates” airborne inside buildings.
Why the sudden popularity? In part because new, affordable sensors that measure toxins in the air have revealed the pollution that surrounds us. We can now measure whether our air is safe, or loaded with CO2, volatile organic compounds (VOCs), and other unseen health risks.
What’s the answer to poor indoor air quality? First, reduce the sources of pollution, then add a combination of diffusion and filtration. That means paying close attention to cabinet materials, carpets, and finishes, then installing quiet bath fans, range hoods, filters and smart controls.
Here are some key products whose attributes help provide healthier indoor air:
Some modern building products operate passively. Housewraps fall under this description. These weather-resistant barriers allow water vapor to escape living spaces and wall cavities (where it might condense and encourage mold or mildew), at the same time preventing unwanted outdoor air from creeping into the home. Housewrap is only as good as its installation, however.
The Department of Energy says that housewrap must be taped at every seam. Otherwise, it may be 20 percent less efficient. It’s also important that housewrap not be left exposed to sun and wind for too long; these factors can degrade its effectiveness over time.
Carpets have come under close scrutiny for their environmental impacts—both in and out of the home. Most commercial carpets are made from some variation of synthetic, petroleum-based material. This material is often treated with other chemicals to improve stain resistance, wear or color retention. To make matters worse, many carpets are installed over highly toxic rubberized pads. They may also be glued to the floor with pungent adhesives.
That new carpet smell you recognize is not something you want in your home. It’s a sign that your floor is releasing unknown chemicals into your living space. A few of the larger carpet makers—notably Mohawk, Interface, and Shaw Industries have begun to approach carpets from a more eco-friendly perspective—not only recycling old carpets but also offering less toxic installation systems and products that have lower levels of off-gassing.
The EPA offers a few guidelines:
Recent EPA research found that carpet tiles can be a more
sustainable alternative than wall-to-wall products. If you stain a section, for example, you can remove and replace it. Also, you can “rotate” tiles from heavy use areas to light use areas. The EPA’s test building used Milliken 36” x 36” tile carpet and low-VOC adhesives to test these principles.
Carpeting is not the only source of VOCs and other harmful chemicals. After your new home or remodeling project is complete, make sure you don’t compromise indoor air quality with the products and furnishings you bring into the space. This goes for everything from furniture, which can contain flame retardants and formaldehyde, to cleaning products.
It may take a little research to ensure items are completely nontoxic. Some manufacturers have made it easier by revealing their products’ “ingredients” with either in-house labels or by seeking third-party certifications. Several organizations have developed standards that make it easier to specify and use low-emission products.
These include UL Environment, which developed the GREENGUARD standard and which maintains a database of thousands of certified products in 28 categories.
The carpet industry suggests that the average American family uses a vacuum cleaner at least once weekly, while about 10 percent of us vacuum our homes once or more per day. But the typical upright household vacuum cleaner may not be the solution to clearing the air in a home.
These upright units are not all created equal. Most lack an effective HEPA filtering system—the only reliable way to capture the fine particles that have been shown to be harmful to human health. On the contrary, a vacuum with a non-HEPA filter may simply toss tiny particles back into the air.
A whole-house vacuum solves this problem by actually taking unwanted particles outside the living space—into a garage or unfinished basement.
Chronic moisture can lead to mold growth. Exhaust fans excel at removing excess moisture that tends to build up in specific locations, such as bathrooms and kitchens. Kitchen range hoods also remove cooking contaminants.
These fans have become quite sophisticated and quiet; some manufacturers such as Panasonic offer “smart” models that adjust to changing moisture conditions, or that can sense when a room is occupied. Whole-house exhaust-only ventilation systems exist, but be aware that these rely on cracks and penetrations in the building envelope to supply the makeup air that replaces the exhausted air.
In tighter homes, this can create “negative pressure.” In general, we recommend using exhaust fans to supplement balanced whole-house ventilation systems.
You may have heard of energy recovery ventilator (ERVs) and their northern cousins, heat recovery ventilators (HRVs). This heat transfer technology is a key component of any “tight” house. Without them, modern houses would probably not be worth the foam, tape, and caulking with which they’re sealed.
These mechanical wonders take hot, unconditioned fresh air from outside, and pass it over a heat collecting medium, where it gets a partial cool-down before entering the home. A study by John Bower found that using a heat recovery ventilator with continuous ventilation cost a Minnesota homeowner just $86 a year. It cost $188 to do the same level of ventilation without an HRV.
Smoke from residential wood heaters contains fine particle pollution (PM) and other pollutants such as carbon monoxide, volatile organic compounds (VOCs) and benzene. Fortunately, newer, EPA-certified units burn much cleaner and are far more efficient.
The EPA first set emissions standards for wood heaters in 1988. In 2015, they strengthened these standards. The new limit for particulate emissions for catalytic and non-catalytic wood heaters is 4.5 grams per hour (g/h). In five years, the limit will drop to 2.5 g/h. The rule does not affect existing woodstoves.
If you are thinking about replacing your old stove, here are a few points to consider:
You can expect to use up to one-third less firewood with a new EPA-certified wood stove compared to an older, less efficient stove.
Newer, more efficient stoves burn cleaner, reducing creosote buildup and the risk of chimney fires.
Some regions host change-out programs and offer incentives for swapping out your old stove for a certified unit.
Some new certified stoves exceed EPA standards and produce emissions in the 1 to 4 g/h range.
Pellet stoves, which utilize compressed pellets made from wood or biomass for fuel, are among the cleanest-burning stoves on the market.
Gas and gas fireplace inserts, which do not require EPA certification, burn cleanly and produce few emissions.
Publisher’s Note: This content is made possible by our Today’s Homeowner Campaign Sponsors: Whirlpool, Vivint, myQ, Sonos and Jinko Solar . These companies take sustainability seriously, in both their products and their operations. Learn more about building and buying homes that are more affordable and less resource intensive.