Without letting fresh air in, there’s no road out for the air inside our homes — air that becomes thick with moisture.
Recovery ventilators help manage moisture levels with efficient air exchange
I’m a big believer in building healthy homes that keep our families safe. I talk about it a lot. These days, we’re building better, and building homes that are more airtight.
This is a good thing, because it makes heating and cooling our homes a lot easier (reducing those pesky drafts, potentially responsible for up to 30 per cent of a home’s heat loss.)
But can a building be too airtight?
Yes it can. Your home needs to breathe. Without letting fresh air in, there’s no road out for the air inside our homes — air that becomes thick with moisture. That moisture can start to do damage.
If your home can’t properly expel that moisture, it can get inside your walls and lead to problems with mould and rot in your building materials. But if you have an efficient air exchange in your home, which will cycle in fresh outdoor air, you can pull out the moisture filled air that we create every time we cook, clean, shower, or even breathe at home.
My No. 1 way to properly create that efficient air exchange is by installing a heat recovery ventilator — or even better, an energy recovery ventilator.
WHAT IS A HEAT RECOVERY VENTILATOR?
Your heat recovery ventilator (HRV) will either be connected to your existing forced air heating system, or a specially installed network of outdoor air ducts. It will feature two fans — one that expels the indoor air from your home to the outdoors, and another one that brings fresh outdoor air into your home.
Before that fresh air is distributed throughout your home, it will pass through a heat exchange core, that transfers heat from the outgoing stream of air to the incoming stream.
This creates an efficient heat exchange that reduces the energy necessary to warm the replacement air to a comfortable temperature.
When it’s running well, your HRV can recover up to 80 per cent of the heat from the outgoing stream — which can go a long way to reducing your ventilation and space-heating costs.
Now that’s smart.
ENERGY RECOVERY VENTILATORS
Taking things a step further than your HRV brings us to energy recovery ventilators (ERVs). These are varieties of HRVs that also have the ability to manage the moisture in the air that’s being pulled into your home. This means that in the winter, your ERV will transfer humidity from the air being extracted from your house, keeping your humidity levels relatively stable. During the hot summer months, the opposite happens, where moisture is pulled out from the incoming air — which reduces the work your air conditioner and dehumidifier have to do to keep things even.
ERVs are a great fresh-air solution to our cold Canadian winters, since the air coming from the outside can be very dry and mess with the humidity levels in our homes. When humidity falls severely, you may notice some shrinkage or warping of hardwood surfaces.
Low humidity can even have an effect on your personal health, with low humidity levels causing dry, itchy skin or feelings of congestion.
WHY ARE MY WINDOWS FOGGING?
Almost everything we do in our homes creates condensation. If your home isn’t properly equipped to deal with that condensation, one of the first places you’ll notice it may be in your windows. If you have wet or weepy windows, the source of the problem could be that the moisture and condensation we naturally create has no pathway to properly exit your home. That’s when you’ll start to notice a buildup of condensation on your window, or even water pooling on the window sill.
If you aren’t able to upgrade your systems to include an HRV just yet, there’s still something you can do to promote air exchange.
It’s pretty simple — just open your windows for a couple of minutes a day and let some fresh air flow in.
It won’t provide the same efficient heat energy exchange that you’ll get with an HRV, but it can still help you deal with minor condensation. This can alter your humidity levels, so I hope your humidifiers and dehumidifiers are up to the task. Watch Mike Holmes in his series, Holmes Makes It Right, on HGTV. For more information, visit makeitright.ca.