The ideal temperature isn’t just a personal preference. How you set your wall-mounted air conditioner can have unexpected consequences on your thermal comfort, your electricity bill, and even the lifespan of your HVAC system. At AirGreen, our expertise in wall-mounted air conditioners in Montréal, Laval, Longueuil, on the North Shore and South Shore has given us clear insight into how just a few degrees of difference can affect our residential and commercial clients’ daily lives.
The 22 °C trap: when comfort comes at a cost
Many users set their wall-mounted air conditioner to 22 °C, hoping to maximize coolness. However, this choice isn’t always the best one.
In fact, for every degree below the outdoor temperature, the HVAC system has to work harder to maintain the setpoint. During extreme heat, setting your air conditioner to 22 °C when it’s 33 °C outside drastically increases the thermal load on the unit. The result? Higher energy consumption, premature wear and tear on the unit, and an excessive cold feeling that often leads to users turning it off and on repeatedly.
Why 25 °C is often the ideal balance point
Based on our on-site experience, keeping your system set to 25 °C in a well-insulated home equipped with a high-performance wall-mounted air conditioner allows you to maintain consistent comfort, while significantly reducing electricity use.
In a recent project in Longueuil, we installed a Gree Extreme 18,000 BTU wall-mounted heat pump in a single-family home. The customer was used to setting their old unit to 21–22 °C but followed our recommendation to set it at 25 °C as the new standard. Not only did their Hydro-Québec bill drop by over 18%, but they also reported better sleep quality and lower humidity levels indoors—without sacrificing comfort.
Consistency is key: avoid drastic shifts
Frequent temperature changes are one of the most harmful habits for your wall-mounted air conditioner. Constantly adjusting the setpoint (for example, from 27 °C during the day to 22 °C at night) forces the compressor to restart constantly, causing power spikes and reducing the system’s overall lifespan.
We recommend choosing a reasonable setpoint—between 24 and 26 °C—and keeping it stable, especially during heatwaves. For users who are sensitive to heat at night, activating the sleep mode or programming a slight drop (1 or 2 °C) is often enough to ensure a good night’s sleep without sacrificing energy efficiency.
What factors influence the ideal temperature setting?
Every HVAC installation is unique, and several elements should be considered when choosing the optimal temperature:
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Building orientation: A south-facing home in Montréal will require different cooling power than a shaded garden-level unit in Laval.
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Thermal insulation: A well-insulated house will better retain the cool air generated by the wall-mounted air conditioner.
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Indoor humidity levels: A high-performance wall-mounted unit, like the Fujitsu KZAH R-32, regulates humidity effectively, improving the cool feeling even at 25 °C.
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Number of occupants: The more people in a space, the more body heat is generated, which affects the perceived temperature.
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Type of system installed: An inverter wall-mounted heat pump is much more efficient at maintaining a stable temperature than an older on/off system.
Case study: optimization in Laval with a Fujitsu heat pump
In a duplex in Laval, we recently replaced an outdated central system with two Fujitsu KZAH R-32 12,000 BTU wall-mounted air conditioners. The homeowners had been setting their old central system to 21–22 °C just to feel comfortable.
With our guidance, they started using the eco mode, set their system to 24.5 °C, and activated the integrated dehumidifier to boost indoor comfort. Over the course of three months, their summer energy consumption dropped by 22%, and their overall satisfaction was higher than ever.
Avoid these common mistakes
We frequently encounter the following bad habits among our clients:
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Setting the unit to the lowest temperature possible upon startup, thinking it will cool the space faster — this unnecessarily overloads the system.
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Skipping regular maintenance: a dirty filter will reduce system performance, regardless of your setpoint.
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Leaving doors open: this causes cool air to spill into uncooled areas.
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Placing the thermostat near a window or heat source, which skews readings and disrupts the unit’s cycling.
At AirGreen, we address these issues during every installation by providing personalized explanations, hands-on demonstrations, and post-installation support. Our goal is to make every client confident and satisfied with their system.
Our practical tips for smarter use
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Keep your system set at a consistent 24–25 °C.
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Use your unit’s smart features (scheduling, presence sensors, eco mode).
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Book regular HVAC maintenance with our team to keep your system running efficiently.
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Ask our technicians for hands-on training during installation to get the most out of your equipment.
AirGreen: your trusted HVAC expert
At AirGreen, we don’t just install wall-mounted air conditioners — we help every client make an intelligent and sustainable energy transition. Whether you’re in Montréal, Laval, Longueuil, the North Shore, or the South Shore, our team advises you on the ideal temperature settings, best model choices, and available grant programs (such as Hydro-Québec’s LogisVert rebate).
Every degree counts. With AirGreen, it’ll be set just right.