Last Updated on June 7, 2021
Your heat recovery ventilator (HRV) helps keep your house clean and healthy while reducing your heating bills! This hardworking piece of equipment is often overlooked, but it should become part of your overall home maintenance routine.
What is an HRV System?
An HRV, or Heat Recovery Ventilation System, is a home system that essentially works to regulate the quality of air in your home by not only replacing your home’s stale indoor air with fresh, filtered air from outside, but also helping to regulate condensation, temperature and humidity.
Cycling of air prevents your home from becoming too cold and damp due to poor ventilation and reduces the presence of condensation, mould, odours and even dust mites.
HRV systems also contain filters that keep particulates, such as pollen or dust, from entering your home.
Because of its ability to reduce condensation in the home, HRVs create a drier home, which is more efficiently heated and cooled. This efficiency means that in the long run, homeowners end up saving money on heating and cooling expenses.
While it’s true that your HRV system requires energy to run, this energy consumption is easily offset by the heat recovered from the exhaust air. Airtight homes equipped with HRV systems will also have substantially lower energy costs per year than having ventilation without heat recovery.
How Do HRV Systems Work?
Before maintaining your Heat Recovery Ventilation system, it helps to understand how it works. An HRV system works by using two fans:
- One fan draws the warm, stale and polluted air from the living areas of your home, through the HRV system, and releases it outside.
- The second fan then draws a continuous stream of cool, fresh air through the system and distributes it throughout your home.
As the warm air being expelled moves through the HRV system and passes the cool fresh air being drawn in, heat is being transferred from the outgoing stale air to the incoming fresh air. The core transfers heat from the outgoing stream the same way that the radiator in your car transfers heat from the engine’s coolant to the outside air. It’s composed of a series of narrow alternating passages through which incoming and outgoing airstreams flow.
As the streams move through, heat is transferred from the warm side of each passage to the cold, while the airstreams never mix. HRVs can recover up to 70-80% of the heat in the exhaust air – again, saving you money.
How To Clean & Maintain a Heat Recovery System
Your HRV cannot do all this hard work on its own — it needs your help! It only takes seven simple steps to keep your HRV working at peak performance.
Clean or Replace HRV Air Filters
The most important step in maintaining your HRV system is by regularly cleaning or replacing your HRV air filters. Dirty or clogged filters can lower the HRV’s efficiency and pollute the air cycling back into your home.
How Do I Clean An HRV Air Filter?
Clean your HRV air filters by following these steps:
- Turn off your HRV and unplug it
- Locate your filter(s) by removing/opening the door on the front of your HRV unit
- The filter(s) can be removed by sliding them forward from where they rest in the middle of the unit
- After removing the filter(s), clean off any large build-up with a vacuum cleaner
- Then, soak the filter(s) in warm water and dish soap
- Rinse and let dry before returning to the unit
How Often Should I Clean HRV Air Filters?
You should try to clean your Heat Recovery Ventilator air filters every 2 months or so to ensure that they’re working as efficiently as possible and aren’t introducing dust, dirt, and pollution into your home’s air.
When Should I Replace An HRV Air Filter?
Your HRV air filters should be replaced 1-2 times per year depending on how dirty they appear. After a thorough cleaning, if you see major signs of wear, it’s time to replace the filter.
Check Your HRV Outdoor Intake & Exhaust Hoods
Remove leaves, waste, or other obstructions that may be blocking the outside vents of your HRV. Without this airflow, your HRV won’t function properly. During winter make sure to clear any snow or frost buildup blocking outside vents.
Inspect the Condensate Drain
Check to see if your HRV has a condensate drain. It will be a pipe or plastic tube coming out of the bottom of the unit. If it does, slowly pour about two litres of warm clean water in each drain pan inside the HRV to make sure it is flowing properly, if not just simply clean the drain.
Clean the Heat Exchange Core
Check your HRV owner’s manual for instructions on cleaning the heat exchange core. Vacuuming the core and washing it with soap and water will help reduce dust that can build up inside the heat exchange core.
Clean Grilles and Inspect the Ductwork
Once a year, you should check the ductwork leading to and from your HRV. Remove and inspect the grilles covering the duct ends and vacuum inside the ducts. If a more thorough cleaning is required, call a certified service technician.
Service the Fans
Remove the dirt that has accumulated on the fan blades by gently brushing them.
Book Your Annual HRV Service
Your HRV should be serviced annually, much like your furnace. If you are not comfortable doing this yourself, contact a certified service technician accredited by the Heating, Refrigeration and Air Conditioning Institute of Canada (HRAI).
When to Replace Your Heat Recovery Ventilator
Even if you are meticulous with your HRV maintenance, your HRV will eventually reach the end of its lifespan around 10-15 years. During a professional inspection and service, your HVAC provider will let you know when it’s nearing time for replacement.
HRV vs ERV
HRV and ERV systems are just about the same thing, except that ERV systems actually dehumidify the fresh, incoming air. In Alberta, we have a dry climate with generally low humidity, so reducing the humidity isn’t as important as in other provinces with higher humidity.
How Much Does a New HRV System Cost in Alberta?
On average, an HRV system installation will run from $2,500 to $3,500, but some costs will vary widely depending on the specific situation. Another consideration is that HRV systems do consume electricity; though the cost is minimal – around $75/year.