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Canadian cold climate homes need to be airtight. Airtightness limits the amount of potential condensation inside enclosures (attics, walls, etc). Airtightness also enables homeowners to control their indoor air quality (IAQ) and comfort. You know the old adage, “You can’t control a sieve!” 

However, as we make homes and buildings more tight for the above reasons we also realize that in the absence of good ventilation buildup of humidity, especially in crowded houses and very cold climates, can lead to poor IAQ and potential growth of mold. This sincerio led to the early development of the heat recovery ventilator (HRV) and energy recovery ventilator (ERV) in the Canadian in the 1960s. These appliances provide fresh air and balanced ventilation through mechanical means. They achieve this while simultaneously recovering up to 80% of lost heat in the home. It’s like having a fresh air machine that doesn’t make you feel uncomfortable nor does it cost a lot of money to run.   

In this video, Building Knowledge Canada President Gord Cooke visits a home with a smart thermostat and shows how to adjust ventilation according to the situation. 

Gord: So, we're very fortunate here in this house to have some really interesting controls. We've got a whole home monitor, with a smart thermostat, but let’s focus on the ventilation control. 

I want to simplify, for both you and your mechanical contractor, the decisions you want to help your homeowners make with respect to this control. Think about the number of people in the house cooking, breathing, sleeping, and so on—then ask, “Would I want fresh air? Yes.” 

This house's control has been set up to run at minimum ventilation (approx 7 CFM per person 24/7). But suppose we have extra folks over, maybe more cooking or cleaning? We can turn it to a higher speed. Ultimately, we can turn it to its highest possible speed, called “turbo”, for dealing with cooking odours or high-moisture events. 

It’s good to communicate clearly with homeowners that this is more about maintaining good IAQ and the health of occupants and less about optimizing energy performance. So, HVAC contractors and builders should ask, “When would you like fresh air in your home?” That will tell you when you're going to operate this control and at what speed. 

In summary, residents are going to get the most out of their HRV or ERV by knowing how it works and adjusting it from time to time. Our Builder 360° program is a way for contractors and builders to learn about new and emerging technologies and systems, such as HRVs and ERVs, to add value to their designs and help their clients get the most out of them.

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Connect with us anytime, and let us know what outstanding questions you might have on this subject.