hrv unit

A HRV unit

Much more than comfort

I’ll never forget visiting a 25-year-old home in Rockcliffe that had been built to Canada’s best green standards (R2000) at the time. I was there to look at some exterior renovations.

When I entered the home, I was surprised to note that there was a major issue with its indoor air quality. I noticed that an HRV control beside the thermostat was in the “off” position.

I asked the owner, a senior gentleman, why it was off. He said it was off when he bought the house, so he didn’t touch it.
I was curious. I asked if I could look at the system. I found that the HRV unit in the basement was unplugged.

As I opened the access door, I saw that the system was like new inside. It had no dirt, no dust. It had never operated.
I asked permission to operate it, and it ran without any issues.

The next day I received a phone call from the gentleman, thanking me for how fresh the air now felt in his home.

Is your HVAC system operating properly? How do you know? It’s difficult for the average homeowner to figure it out – until there’s no heat, air conditioning or hot water.

In addition to keeping you comfortable and safe, your HVAC system can account for 50 per cent of your home energy bill, so having it function as designed makes economic sense.

Today’s HVAC systems are becoming more complicated. Your home may have a combination of several of the following: furnace, boiler, on-demand or hot water tank, heat pump, geothermal, air conditioner, heat recovery ventilator (HRV), energy recovery ventilator (ERV), humidifier or dehumidifier. It may also have more than one control system – such as thermostat, HRV control and humidistat.

Your systems should have been designed, installed and commissioned, including balancing, and programmed for maximum energy efficiency.

The primary goal of commissioning is to verify that the HVAC and energy-related systems are installed, balanced, calibrated, and that they perform as the design intended. Recommissioning of the HVAC system is like an annual inspection to verify that the systems are still performing as the design intended. This is the opportunity to do adjustments, re-balancing, maintenance and repairs.

The benefits of commissioning and recommissioning includes lowered operating and maintenance costs, energy savings, improved indoor air quality and thermal comfort.


Except for filter replacement, checking switches or breakers, furnace maintenance should be left to a licensed professional.
Keep the area around your furnace clean and unobstructed. Inspect the intake/exhaust vent pipes to ensure they are clean and unobstructed.

Central Air Conditioner

Central air conditioners are designed to cool the entire house. The large compressor and outdoor coil are located outside of the home and are connected by refrigerant lines to the indoor coil mounted in the furnace or air handler.

Filter and coil maintenance can have a dramatic impact on system performance and service life. Dirty filters reduce airflow through the system. This reduction of airflow decreases system efficiency and capacity.

Clean or replace the air filter located at the furnace/air handler at least once every season. This can save you up to 15 per cent on utility costs and provide cleaner air for your home.

The outdoor coil should be vacuumed or brush-cleaned to clear it of dirt, leaves and grass clippings. (Be careful not to damage the fins.) It can also be carefully washed with a garden hose (but be careful not to get any electrical connections wet).

If, after attending to filter maintenance and coil cleaning, your central air conditioning does not appear to be doing its job, have it serviced by an HVAC professional. A small loss of refrigerant can cause a significant drop in efficiency.

Your thermostat setting should be adjusted when you are away or sleeping. This indoor thermostat should be set somewhat in the 22-25◦C, depending on your comfort level. A setting at the higher end of the range will result in low energy cost. If humidity level is low, the temperature setting can be at the higher end.

Take advantage of cool nights by switching off your AC and opening your windows.

Hot Water Heater

As water is pumped into your water heater tank, dirt, sediments and various minerals settle at the bottom. These build ups can quickly reduce your water heater efficiency and cost you in the long run. Your tank should be flushed annually according to manufacturer’s maintenance instructions. Be careful, as you are going to be dealing with gas/electricity and very hot water or steam.

A professional annual maintenance will also check the pressure relieve valve, examine the sacrificial anode, adjust temperature settings, burner and venting mechanism, etc.


  • Try to clean your filters at least every two months.
  • Check the outdoor and exhaust vents.
  • Check your owner’s manual for instructions on cleaning the heat exchange core.
  • Check the outdoor intake and exhaust hood seasonally to ensure that there are no obstructions such as leaves, snow or frost build ups blocking outside vents.
  • Check the condensate drain once a year to make sure there is no blockage.

Start by doing simple maintenance, such as replacing the air filter and making sure your AC unit is cleaned.

Your HVAC system is comparable to your car. Your car requires regular maintenance such as oil and filter changes and general service after a certain number of kilometres. The same goes for your HVAC system. Have your system inspected annually to keep it in tip-top shape.

HVAC maintenance companies offer various level of services. For example, Enercare has a protection plan for HVAC equipment which includes an annual maintenance service.

Take action to save energy, protect the environment and make your home safe.

Roy Nandram of RND Construction Ltd. contributed this article.