What Is a Heat Recovery Ventilator? Does Your Home Need One?

In the last few decades, homebuilders and homeowners have sought to make houses that are more energy efficient. Existing homes often get energy-efficient upgrades such as airtight windows, draft-resistant doors, and effective heating and cooling systems. Newly constructed homes sometimes come standard with these features, and some are almost entirely airtight.

These energy-efficient upgrades are good for the environment (and your utility bill), but even the most draft-resistant house needs proper ventilation. Without air circulating in and out of it, a home can accumulate allergens, pollutants, and even mold. Non-circulating air becomes stale, damp, and smelly.

One solution to the problem of poor air circulation in airtight, energy-efficient homes is a heat recovery ventilator, or HRV, which is now required in new construction homes throughout Manitoba.

What Do Heat Recovery Ventilators Do?

A heat recovery ventilator circulates air in a home, drawing in air from outside and expelling indoor air out. All air that moves through an HRV passes through a heat-exchange core. This heat-exchange core regulates the temperature of the air that the HRV releases into the home and sends back outside.

HRVs and their heat-exchange cores perform two different actions, depending on the season. During the cold winter months, an HRV's heat-exchange core captures the warmth from air leaving the home and transfers it to the cold air entering from outside. In this way, the home receives fresh air, but the fresh air is not frigid.

During the warmer seasons, the process occurs in the opposite direction. The incoming air leaves its heat in the heat-exchange core, and the outgoing air picks up that heat as it leaves. An HRV ensures that air inside the home stays at a comfortable temperature, no matter what time of year it is, without requiring much additional energy to regulate that air temperature.

Along with these air circulation and heat-exchange functions, an HRV also filters air to capture allergens and pollutants and keep them out of the home's air supply. Some HRVs also regulate air moisture levels. These HRV systems are called ERVs, or energy recovery ventilators.

An HRV attaches to the home's duct system and needs fans to circulate air throughout the house. It is also important for HRVs to have an internal defroster. Without a defroster, the incoming air can be so cold that it causes the heat-exchange core to freeze.

Which Homes Need Heat Recovery Ventilators?

Heat recovery ventilators are a more recent technology, but all new construct homes in Manitoba require them. HRVs have several advantages over other mechanical ventilation systems, which include:

  • Energy savings. The heat-exchange core in an HRV means homeowners must spend less money heating or cooling the ventilated air.
  • Air filtration. Unlike exhaust-only ventilation systems that just expel bad air at set intervals, HRVs filter out minute particles in the air to ensure better air quality.
  • Air pressure regulation. HRVs should give a home the same internal air pressure as exists outside the house. Balanced air pressure prevents walls from bowing in or out due to differences in air pressure.
  • HRVs are popular and effective in cold climates, which makes them a good option for an energy-efficient Canadian home. Contractors must install them in new Manitoba homes to give homebuyers the benefits of energy savings. A new HRV system is also a good final addition to an older home with recent upgrades for energy efficiency.

What Maintenance Steps Are Necessary to Care for an HRV?

When homeowners consider buying an HRV, they often wonder if these units are easy to maintain. HRVs should have regular maintenance, but the process for cleaning an HRV is not complicated.

Natural Resources Canada recommends taking the following steps to keep your HRV in optimal condition:

  1. Check air filters: To make sure your HRV’s filters are releasing clean air, you should examine its filters every 1-3 months. Some HRVs have filters you can remove and clean; others use filters that you have to replace.
  2. Inspect vents: Check these vents at least once every few months. Make sure no debris or other objects are blocking them from releasing and pulling in air.
  3. Clean the interior parts: To operate at maximum efficiency, your HRV's parts need regular cleanings. Consult your owner's manual for directions on how to safely clean the heat-exchange core, the fans, the duct grilles, and other parts. You can also ask a trained HRV technician to perform this cleaning.
  4. Have your HRV inspected annually: Your HRV will last longer if you have it examined by an HRV technician at least once a year. Make sure the technician has accreditation with the Heating, Refrigeration and Air Conditioning Institute of Canada (HRAI).

Who Should I Ask About an HRV for My House?

If your home already has an HRV, keep it in good condition so your home can rely on it for clean, comfortable air for years to come. And if your home doesn’t have an HRV yet? Call a home ventilation expert, like East Side Ventilation, if you think your home is a good candidate.