It’s a frequent misconception that the air outside our homes is dirtier than the air inside. After all, outside there’s dust, pollution, allergens, you name it. But, in fact, the air inside can often be worse than outside and that can be a problem.
We Canadians spend up to 90 per cent of our time indoors, according to Health Canada, particularly in winter when we’re hibernating from the cold. And because it’s cold outside, we certainly aren’t airing out our homes by opening windows. Years ago, this wasn’t such an issue because our homes were rather leaky; that is, there was a fair bit of heat loss and ventilation of stale inside air that was replaced by fresher outdoor air because of the way our homes were built.
But today, homes are built and renovated much tighter than they used to be. That’s resulted in greater energy efficiency, but it also means our homes don’t breathe as much because they are sealed better.
So, what makes our indoor air dirty?
Partly, it’s our day-to-day living. Humidity builds up from showering, cooking, even breathing. When it can’t escape, that can lead to the growth of mould, which grows on just about anything and particularly likes drywall. Mould has been shown to lead to or worsen all kinds of respiratory issues. Too little humidity isn’t good either. It can result in things like a dry nose and throat, dry and itchy skin, and an increased risk of catching a cold.
Too high or too low humidity also isn’t good for your home. When it’s too high it can lead to condensation on your windows and walls, similar to when a cold drink “sweats” in the summer heat. And all that moisture can trigger mould growth. When humidity is too low, it can warp and shrink the wood in your home.
Besides affecting humidity, when your home can’t breathe, it also leads to a build-up of pollutants and toxins that can’t escape, things like dust mites and off-gassing of furniture, personal care products and household cleaners.
So, what should you do?
A quick fix is to open your windows for fresh air. But that defeats the point of having an energy-efficient home, and it’s rather uncomfortable in the middle of winter. Plus, we do get a lot of wild fluctuations in outdoor humidity levels in Ottawa, which makes it difficult to keep indoor humidity levels at the optimum level (30-50%).
The best thing to do is make sure you’re helping your home to breathe. And that means having a properly sized and properly installed HVAC system. HVAC stands for heating, ventilation and air conditioning. In many cases, that means ensuring mechanical ventilation in the form of a heat recovery ventilator or HRV, also known as a heat exchanger. HRVs take the stale air out of a home while bringing fresh air in. The heat or cool of the outgoing air is captured to be absorbed by the incoming air, without the two air streams mixing, to save the energy in your home.
There are also a few regular maintenance items you can do to help keep your home’s air clean:
- Vacuum often. Use either a central vac that vents outdoors or a standalone vacuum with a HEPA (high-efficiency particle air) filter to trap small particles.
- Clean the lint tray every time you use the dryer and check for lint buildup on the outside vent.
- Replace or clean your furnace filters regularly.
- Use your hood exhaust when cooking (and make sure it vents outdoors).
- Use your bathroom exhaust fan when showering.
- Keep your interior doors open and heating and air return vents clear of furniture to improve circulation.
- If you have an attached garage, avoid idling your car or snow blower in your garage.
Then, you can breathe easy.