what is an hrv

What is an HRV or Heat Recovery Ventilator

What is an HRV? You’re probably hearing about them more and more these days. HRVs, or Heat Recovery Ventilators, are arguably one of the least understood aspect of the modern R-2000 home. They just kind of hang there looking a lot like a deep freezer suspended from your mechanical room ceiling, with all sorts of hoses coming off of them, but what do you really know about it beyond that? What does it do? How does it work? Is it even working??  Fact is HRVs help to control the quality of the air in your home and are easier to use than you might think, but first let’s talk about what they do.

The HRV Helps Your Home Breathe

Prior to the 1970’s, homes were poorly insulated and drafty which meant when it came to heating your home you were battling constant inefficiencies, though it did allow for one benefit: the house could breathe. That natural draft allowed fresh air to enter the house through cracks and spaces left in the building, while exhausting stale air from the conditioned space at the same time. As time went on and builders learned how to make homes more energy efficient, they began sealing these cracks and insulating spaces better against elements such as air, water, heat, light and noise. Industry professionals refer to this as ‘sealing the building envelope’. One of the drawbacks, however, was the loss of the building’s ability to breathe. The solution: the HRV.

Simply put, an HRV ties into a forced air system and uses the heat energy of the stale indoor air it exhausts to warm fresh cool air from inside to limit the energy it would take to bring the fresh air back up to temperature while regulating humidity.

How To Use Your HRV

Before we begin talking about how to use your HRV, a brief note on when to use it: Heat Recovery Ventilators are just that. They are meant to be used from fall to spring to recover heat. HRVs don’t dehumidify, so to run your HRV at the same time as your air conditioner would cause the two appliances to run in opposition of each other. As Canada’s cooling season grows longer as a result of climate change, we may actually see a need to change from HRVs to ERVs, or Energy Recovery Ventilators, which transfer humidity from the indoor air to fresh air in the winter and removes humidity from the fresh and indoor air in the summer. That being said, from fall to spring, they operate similarly.

Next you will have to set your HRV controller to a comfortable humidity setting. If you’re not sure where to set it, try setting it to 45 and adjust it based on your personal comfort, but look out for condensation on your windows. Condensation indicates that there is too much humidity, and that your controller could be set too high.

When it comes to maintenance, your HRV contains removable filters that can usually be cleaned or replaced every 3 months. The only other thing to check on is if you go for an extended period of time without using your HRV, such as the summer or if you’re going to be away for an extended period of time and don’t need to use it, turn it on once in a while just to make sure the motor doesn’t get seized.