How to Keep Your HVAC System Running Efficiently During Montreal’s Summer Heat

When summer hits the West Island, your air conditioning system becomes the hardest-working machine in your home. But overuse, poor maintenance, or simple bad habits can reduce performance, increase your bills, and even shorten the lifespan of your system.

Here are 7 practical, HVAC-specific tips to help you keep your home cool while protecting your system from unnecessary strain.

1. Change or Clean Your Air Filter Regularly

This is the simplest — and most commonly ignored — step. A dirty filter restricts airflow, forcing your system to work harder to cool your home.

  • Check it every 30 days during peak use
  • If you have pets, allergies, or live near construction zones, you may need to replace it more often

💡 Pro tip: A clean filter can improve efficiency by up to 15%.

2. Use the “Auto” Setting on Your Thermostat

Set your HVAC system to "Auto" rather than "On."

  • Auto mode runs the fan only when the system is cooling
  • On mode keeps the fan running constantly, wasting energy and overworking the fan motor

This small change can reduce wear and lower your electricity bill.

3. Keep Vents and Registers Clear

Walk through your home and make sure all vents are:

  • Open and unblocked by furniture or curtains
  • Clean of dust, pet hair, or debris

Restricted airflow can lead to uneven cooling and pressure buildup inside the duct-work.

4. Raise the Thermostat by a Few Degrees

Setting your thermostat a few degrees higher than usual can dramatically reduce the load on your HVAC system.

Each degree cooler adds roughly 5–10% more energy use.

If you’re still feeling warm, use ceiling or floor fans to circulate the air — they help you feel cooler even at a higher temp.

5. Clean the Outdoor Unit (Condenser)

Your outdoor unit needs space and airflow to operate efficiently.
Do this:

  • Clear away grass, leaves, or dirt
  • Gently hose off the outside coils once a month
  • Maintain at least 2 feet of clearance on all sides

A dirty or blocked condenser can cause your system to overheat and cycle improperly.

6. Check for Leaky Ducts

If some rooms are consistently warmer than others, or your AC runs constantly without cooling well, you might have duct leaks.
Even small leaks can reduce cooling efficiency by 20–30%.

While full duct inspections are best done by pros, you can:

  • Look for disconnected or crushed ducts in attics or basements
  • Seal visible gaps with foil tape (not regular duct tape!)

7. Don’t Skip Professional Maintenance

You don’t need to upgrade your system to improve performance — but a yearly maintenance visit can go a long way.

Technicians can:

  • Test refrigerant levels
  • Clean internal components
  • Catch early signs of wear
  • Improve system efficiency and life span

Schedule maintenance before your system starts acting up — it’s usually cheaper than emergency repairs.

Final Thoughts

HVAC systems aren’t just “set and forget” machines. With a little regular care and smart usage, you can:

  • Improve cooling performance
  • Save on electricity
  • Avoid costly breakdowns — especially during a Montreal heatwave
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