December, 2013
Inspection News and Views from the American Society of Home Inspectors

Maintaining Air Quality During Winter Months



Maintaining Air Quality During Winter Months

By Jay Gregg, Pillar to Post Director of Marketing





Winter is naturally a time to shut doors and windows against the icy, outdoor chill and turn on the heat. It’s important during these cold, insular months to make sure your indoor air quality is at its peak. Improving the quality of the air at home can have a huge impact on staying healthy and comfortable throughout the winter, but homeowners often are not aware of that. Clean air relieves indoor allergies and may help ward off sickness, especially when hosting friends and family for the holidays. Educating clients on how to maintain optimum home air quality is one of the tasks a home inspector can take on when examining the state of a client’s home.

Homeowners may not necessarily notice their indoor air quality is suffering, but signs of such problems typically include unusual and noticeable odors, stale or stuffy air, noticeable lack of air movement, or the presence of molds and mildews. Another sign may be adverse health reactions after remodeling, weatherizing, using household and hobby products, moving into a new home or feeling markedly healthier when outside. Home inspectors may see further signs of poor indoor air quality if they notice dirty or faulty central heating or air-conditioning equipment, damaged flue pipes and chimneys, excessive humidity and unvented combustion air sources for fossil-fuel appliances.

Indoor air quality testing is one way in which home inspectors provide clients with a thorough understanding of the state of the air in their homes. Professional IAQ testing detects a vast number of pollutants in the home, including molds and allergens, smog, volatile organic compounds (VOCs), Legionella, bacteria, asbestos fibers, carbon dioxide and carbon monoxide. Homes can be extra susceptible to higher carbon monoxide levels if they have an indoor fireplace with an improperly ventilated flue or poor overall ventilation.

Home inspectors possess greater knowledge of air exchange systems than the average homeowner. Sometimes homes simply need more ventilation in order to maintain high air quality during the winter. Heat-recovery ventilators or energy-recovery ventilators both are effective options, but the final decision on the correct ventilation system varies from house to house. An inspector’s knowledge is essential in guiding homeowners to the best fit for their home and helping them parse the myriad options available to them.

Controlling humidity is another area in which inspectors are able to provide expert guidance difficult for homeowners to find on their own. High humidity levels can significantly contribute to mold and dust mite growth, and while dust mites are not something homeowners can eliminate entirely, their number can be decreased. Dust mites thrive in humidity levels above 50 percent, so ensuring the humidity in a home is not higher than that will diminish their growth.

Inspections always should confirm that air from clothes dryers, bathroom and kitchen fans is being vented outside the home. Blocked vents – and we have seen them, especially on roofs where homeowners doing their own repairs mistake them for holes – cause moist air to recirculate into the home. The resulting condensation can cause mold growth. If condensation around the home is obvious, dehumidifiers are a good way to maintain healthy humidity while waiting for or during more extensive repairs.

Homeowners also will want to keep as dust-free a home as they can during winter months, when air is being recycled throughout the home and carrying dust with it. Dust includes lint, bacteria, pollen, plant and mold spores, pet dander and more, making it one of the biggest irritants in your indoor air supply.

Furnace filters should be cleaned or replaced every two to three months. This is one task with which homeowners regularly fail to keep up. Inspectors can also guide clients to better filter choices; thick-media filters, such as the five- and six-inch pleated type, last longer than regular filters and provide better quality.

Regular dusting and vacuuming can help too. We all create an invisible dust cloud just walking through our homes. A high-quality furnace filter will reduce dust, but frequent vacuuming and dusting are also necessary to reduce irritation. All vacuum cleaners should be using a High Efficiency Particulate Air or HEPA filter, which also needs to be cleaned regularly to ensure its effectiveness.

Staying safe and healthy during the winter is a top priority for everyone and maintaining the indoor air quality of a home is the first step in that direction.


Jay Gregg


Jay Gregg is Pillar To Post’s director of marketing as well as a certified home inspector based in Orangeville, Ontario, Canada. Gregg began his relationship with Pillar To Post as a franchisee in 2005 and in 2011 became their director of marketing. Founded in 1994, Pillar To Post is now the largest home-inspection company in North America with over 400 franchisees, located in 47 states and eight Canadian provinces. For more information, please visit