Did your mother ever tell you to go outside and
get some fresh air?
Well, it turns out she was right.
We are, especially at the moment, spending more time than ever in our homes. While this is the right thing to do to slow the spread of Covid-19, the air in your home might not be as healthy as you think. Poor indoor air quality can cause a staggering number of health problems, including infections, lung cancer and chronic lung diseases such as asthma. And while it may seem counter intuitive, new houses often have far worse indoor evironments than older homes.
Drafty old houses used to provide a great deal of natural ventilation. Air traveled in and out through gaps in the walls providing fresh air whether we wanted it or not. But for the sake of improved comfort and energy efficiency, we began closing these gaps, working to make our houses more air tight. While it lowered our utility bills, sealing up our homes had an unintended consequence on our health: our houses no longer had adequate ventilation.
This causes a few problems, the first of which is humidity. A family of four can create up to 20L of water vapour per day and if it is not removed, this excess moisture can lead to condensation, rotting and mold. Excess moisture has been linked to a number of serious health concerns including lung infections, asthma and even depression.
On the other end of the spectrum, the low indoor humidity level we experience during the winter months dries out our respiratory system and has been proven to significantly increase the rate of transmission for viruses and other airborne illness. This is all before we even acknowledge the problems caused by a build up of VOC’s, allergens, odors and other harmful substances.
So what is the solution?
When it’s warm outside, the easiest thing to do is to open a window, or better yet a few. Our Canadian climate however, limits our open-window time to a handful of months out of the year, meaning the rest of the time, we need to be ventilating mechanically.
Recognizing this need, the BC Building code requires all new dwellings to be equipped with a bath fan set to continually run at a low CFM. While this is better than nothing, there are unfortunately several major problems with this solution. A bath fan, located in a single room of the house will not be enough to properly remove stale air from around the entire home. The air it does remove is warm air that we have paid to heat, now being blown directly outside. This is provided of course that someone did not disconnect the fan immediately upon moving in, which is often among a new homeowners’ first order of business.
A much better solution is a mechanical system known as an HRV (Heat Recovery Ventilator). It is an engineered system designed to remove stale air and use the heat it recovers to warm the fresh air it brings in, thereby reducing the amount of energy lost in the process. While it may not be considered a requirement for new homes yet, a home equipped with one will have a much healthier indoor environment than a without.
In an existing home, installing this system may not be feasible. But when purchasing a home, it is an important feature to look for. We tend to focus on the things we can see like countertops and bathrooms or the things that will cost us money such as a roof that needs to be replaced. But what about a feature that could make a significant difference to our long term health? Isn't our health the reason we're all staying home?