Can a wall-mounted air conditioner really make your Hydro bill skyrocket? Here’s what we’ve seen in Montréal.
At AirGreen, we know that one of the top concerns for homeowners in Montréal, Laval, Longueuil, the North Shore and South Shore is the electricity costs associated with running a wall-mounted air conditioner. This question comes up all the time: “Will my AC unit blow up my Hydro bill?” The answer, while nuanced, deserves a clear explanation — with facts, numbers, and most importantly, our real-world experience.
Why is energy consumption such a concern?
The Québec climate is extreme. Summers can get overwhelmingly hot, making air conditioning a must-have — especially in densely populated areas like Montréal or Laval. But this necessity often leads to worry: how much will it actually cost every month? And more importantly, how can you make a smart, economical choice?
The energy efficiency of today’s wall-mounted air conditioners
The wall-mounted air conditioners we install today — brands like Fujitsu, Gree, Sharp ZU, Senville, and Daikin — are nothing like the units from ten years ago. Most of these models feature inverter technology, which continuously adjusts the compressor’s power based on the temperature required. The result: reduced energy use, steady comfort, and less wear and tear.
Here’s a precise example: during a recent installation of a Sharp ZU1 18,000 BTU in Ville-Marie, our client was pleasantly surprised. Before the install, they were using a 10,000 BTU portable unit that consumed about 1.2 kWh/h. The new wall-mounted unit, despite being more powerful, only consumes around 0.45 kWh/h on average thanks to its variable speed motor. A real drop in their Hydro bill, with significantly better performance.
The real numbers: how much does it cost to run a wall-mounted air conditioner?
Let’s take a 12,000 BTU wall-mounted AC, running 8 hours a day for 30 days, at an average of 0.4 kWh/h:
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Monthly consumption: 96 kWh
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Estimated cost (Hydro-Québec, 2025 residential rate): $7.20 / month
Even a higher-capacity unit, like a 24,000 BTU model, used moderately, won’t cost more than $15 to $20/month, depending on insulation quality and usage habits.
Case study: Installation of a Gree Lomo 24,000 BTU in Saint-Hubert (South Shore)
A retired couple contacted us to replace two noisy, power-hungry window units. After conducting a full thermal assessment, we offered a unique solution: a single Gree Lomo 24,000 BTU wall-mounted unit, strategically placed to cool the open-concept areas of their bungalow.
Results:
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Energy use dropped by 38% from June to September.
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Hydro bill increased by only $15.62/month, based on their monitoring.
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Unmatched thermal comfort, with a noticeable drop in indoor humidity.
The impact of poor installations: pitfalls to avoid
We’ve seen many cases where poor installation led to unjustified energy overconsumption. Here are some common mistakes:
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Incorrect BTU sizing (too powerful or too weak)
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Poor placement (direct sun exposure, poorly ventilated area)
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Bad drainage, causing frequent restart cycles
At AirGreen, we always perform a precise thermal assessment before any installation. That’s how we ensure optimal performance with minimum consumption.
Grants and incentives: reduce your purchase costs
Installing an energy-efficient wall-mounted AC often qualifies you for government subsidies or incentives like Hydro-Québec’s LogisVert program. For example, a Fujitsu KZAH R-32 model could be eligible for up to $1,705 in financial aid, making it a much more cost-effective investment over time.
We help each of our clients through the grant application process, making sure every form is correctly completed and all criteria are met.
Practical tips to manage your AC’s energy use
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Close windows and curtains during the hottest hours.
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Use timers or a smart thermostat to program your unit.
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Regularly clean and maintain your unit: clean filters = better efficiency.
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Avoid setting the temperature too low (22–24 °C is ideal).
AirGreen: our commitment to responsible air conditioning
We’re proud to have helped hundreds of families and businesses in Montréal, Laval, Longueuil, the North Shore and South Shore with wall-mounted air conditioner installations that are tailored, efficient, and energy-conscious. Our approach is always based on three pillars:
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Customized thermal evaluation
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Top-performing, reputable brands
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Professional installation by certified technicians
In conclusion: affordable comfort, controlled bills
A properly chosen, properly installed, and properly used wall-mounted air conditioner is not an energy drain. On the contrary, it’s a smart investment, capable of providing exceptional comfort while keeping your Hydro bill in check. At AirGreen, our mission is clear: to provide you with efficient, long-lasting, and economical solutions, perfectly adapted to the reality of Montréal living.