Ventilation education

Indoor air quality is a homebuilding and renovation issue that's hard to get excited about. Top-of-the-line fresh air doesn't come in designer colours. It's not something that instantly boosts resale value, either. You can't brag about good air to dinner guests and expect it to promote your social standing. But don't let any of this fool you. Despite it's low profile, indoor air quality is as crucial as human health and the structural integrity of your building. It deserves top priority in construction and renovation plans because if you ignore it, modern homes can rot, making you sick in the process. This isn't just a scary story, it's fact.

One of the reasons indoor air quality is so easily misunderstood is because it's a new field. As building issues go, it's a youngster -- born in the 70's and coming of age only during the last 15 years . It's also a youngster of our own creation. The need to address indoor air quality is a byproduct of technical advances that make buildings more efficient by retaining heated and cooled air. But along with reduced drafts and lower energy costs come a troublesome, two-part mix of byproducts -- harmful vapourized chemicals and excess moisture. Indoor air quality awareness is all about helping your house breathe better so you can too. But as you'll see, the real issue goes beyond just moving bad air out and good air in.

It's no coincidence that hypersensitivity to indoor air contaminants rose at the same time houses were tightened due to skyrocketing energy costs 30 years ago. Indoor air quality plummeted along with heating bills when people moved into the first wave of energy efficient, poorly ventilated housing. In response to what scientists have since learned about air quality and human health -- and because Canadians spend over 90% of their time indoors -- Canada Mortgage and Housing Corporation (CMHC) developed the Healthy Housing concept. It's a way of looking at and managing the effects of housing on human health and the environment. The cornerstone of the Healthy Housing movement addresses both ventilation and the larger issue of indoor air quality. As it turns out, creating a healthy home depends as much on minimizing indoor air pollutants at source as it does on air movement and exchange.

The most common indoor pollutants include formaldehyde gas from building products, volatile organic compounds (VOCs) from paints, hobby activities, floor coverings and cleaning products, soil-borne gasses like radon, and invisible airborne particles that travel deep into the lungs.

Excessive interior moisture presents another air quality challenge. Although not harmful itself, moisture can trigger an explosion of microorganisms that can make you as sick as anything that oozes out of a chemical plant. Excess moisture also increases formaldehyde off-gassing. Control involves reducing in-home moisture production and maintaining ventilation rates sufficient to reduce indoor humidity to 25% to 35% relative humidity in winter. The best information resources I've seen on managing indoor air quality come from our own Canada Mortgage and Housing Corporation. The Clean Air Guide (item #6695E) and a video production called This Clean House (#VE057) are both excellent tools for learning exactly how to improve indoor air quality through sound household management practices.

The indoor air quality issue is yet another example of the fact that progress has its price. Yes, real gains have been made in home energy efficiency, but we also have to deal with the side effects of that progress. This means taking active responsibility for the quality of what we breathe. The air exchange that used to happen automatically through leaky doors and windows now takes planning, effort, equipment and understanding to replicate while minimizing energy loss. But it's worth the trouble. This attention to detail, craftsmanship and engineering know-how is what has made Canadians the best housed nation in the world. Doing things right has its rewards.