Poor settings and overuse: the real enemies of your energy efficiency
When we think of air conditioning in Montreal, we immediately picture the relief it brings during heatwaves. But that comfort can quickly turn into a financial burden, especially if the system is misused, improperly sized, or poorly maintained. At AirGreen, we’ve seen firsthand that, in many cases, a sudden and unjustified spike in electricity consumption is directly tied to common usage mistakes or inadequate configurations of a wall-mounted air conditioner or central system.
In this article, we explain why a poorly managed air conditioner can cause your electricity bill to double in the middle of summer—and more importantly, how to avoid that through concrete practices drawn from our real-life HVAC service calls in Montreal, Laval, Longueuil, North Shore, and South Shore.
The main reasons behind excessive electricity consumption
1. An improperly sized unit for your space
One of the most common cases we encounter in the field involves undersized or oversized air conditioners. A 9,000 BTU unit installed in a 1,000 sq. ft. space will be forced to run non-stop to reach the desired temperature—leading to high consumption, premature wear, and inadequate comfort.
On the flip side, a 36,000 BTU system in a small room will cause short cycling, consuming more energy than needed without ever stabilizing the temperature.
Our AirGreen technicians always perform a precise heat load calculation to recommend the right model based on:
-
Exact square footage
-
Insulation level
-
Sun exposure
-
Number of occupants
2. Clogged or dirty filters
A simple dirty air filter is enough to double the energy usage of a wall-mounted air conditioner. When filters are clogged, the system has to work harder to circulate air, increasing runtime and electricity demand.
During our HVAC maintenance visits in Laval and Longueuil, it’s not uncommon to find filters that haven’t been cleaned in over a year. This not only drives up electric bills but also degrades indoor air quality.
3. Thermostat set too low
Each degree you lower the thermostat increases energy use by an average of 7 to 10%. Setting your air conditioner to 19°C during a heatwave—instead of the recommended 23–24°C—can have a massive impact on your bill, especially in older, poorly insulated Montreal homes.
We recommend using a smart thermostat, which we install in many of our projects across the North Shore. It allows you to:
-
Prevent extreme settings
-
Schedule cooling periods
-
Adjust performance based on outdoor temperature
4. Poorly maintained or outdated equipment
Some of our clients on the South Shore are still using units installed over 15 years ago without any structured HVAC maintenance. The result: dirty coils, worn-out fans, and outdated electronic components that waste energy.
In a recent case in Boucherville, a wall-mounted air conditioner from an unknown brand was using 40% more electricity than specified. After we replaced it with a Gree R32 18,000 BTU heat pump, consumption was cut in half—with vastly improved comfort.
Practical tips to reduce your summer bill
Have your system inspected before the heat hits
A full HVAC diagnostic can uncover:
-
Refrigerant leaks
-
Compressor issues
-
Efficiency loss due to dirt buildup
Our AirGreen teams offer this service across all areas of Montreal, Laval, and Longueuil, with clear reports and actionable recommendations.
Invest in a high-efficiency model
All the new models we install, such as Fujitsu R32 heat pumps, feature above-average SEER and HSPF ratings, enabling major savings while also qualifying for LogisVert rebates.
Schedule smart cooling cycles based on your routine
Avoid running your air conditioner at full power when no one is home. Thanks to the smart thermostats included in our packages across the North and South Shores, you can:
-
Start pre-cooling 30 minutes before returning home
-
Avoid peak-hour energy spikes
-
Set cooling zones based on occupied rooms
Case study: 37% electricity savings in Laval
For a residential client in Laval, our team replaced a standard 12,000 BTU wall-mounted air conditioner with a high-efficiency Midea EVOX G3 wall-mounted heat pump. We also adjusted the position of the outdoor unit to avoid direct sun exposure.
Along with the installation, we reprogrammed the cooling schedule to match the client’s actual occupancy habits. The result: a 37% drop in electricity consumption compared to the same period the previous year.
Why trust AirGreen
We don’t just sell and install air conditioners. We analyze your space, habits, energy needs, and optimize every detail. From Montreal to the North Shore, through Longueuil and the South Shore, our tailor-made HVAC approach helps our clients achieve optimal comfort while lowering their costs.
Conclusion: staying cool this summer shouldn't drain your wallet
At AirGreen, we believe a comfortable summer should never come with skyrocketing bills. With our technical expertise, on-site experience, and personalized solutions, we help you enjoy your wall-mounted air conditioner or heat pump with peace of mind—without wasting energy.
For a free evaluation of your HVAC system in Montreal, Laval, Longueuil, or anywhere on the North or South Shore, contact us today.