The performance of a commercial air conditioner is often taken for granted—until the day it breaks down in the middle of a heatwave. Yet, before it gets to that point, several subtle warning signs may indicate an impending failure. At AirGreen, we frequently assist clients across Montréal, Laval, Longueuil, the North Shore, and the South Shore, who could have avoided a full breakdown if they had spotted these signs earlier. Here are the 6 subtle but alarming signs your commercial cooling system might be on the verge of giving out—and what you can do right now to avoid the worst.
A gradual increase in your energy bill
One of the first signs of an inefficient commercial air conditioner is a steady but unexplained rise in your electricity consumption. If your energy costs are climbing despite operating in the same-sized space and during similar periods, it could mean the compressor or coils are overheating, or the system is losing efficiency.
At AirGreen, we recently inspected a business in Laval where the monthly electricity bill had jumped by 18% compared to the previous year. After a thorough diagnostic, we discovered that the filter was clogged and the condenser was dirty—two issues causing the unit to work overtime.
Uneven or unstable indoor temperatures
Are your employees or customers complaining about hot or cold spots in your space? That might mean your commercial air conditioner is no longer able to distribute cool air effectively. This could be due to blocked ducts, a miscalibrated thermostat, or a failing blower motor.
In a retail store in Longueuil, our team solved an issue with uneven temperatures caused by a poorly located thermostat—it was placed directly in front of a heat source, which skewed the readings and triggered the system erratically.
Unusual, even faint, noises
A quiet commercial air conditioner is a healthy one. If you start to hear squeaks, whistles, clicking sounds, or strange vibrations—even faint ones—your unit is probably trying to warn you of an issue.
A beauty salon on the South Shore called us about a recurring low rumble. We quickly identified a misaligned condenser fan, which was causing premature wear on the motor. A simple adjustment restored proper function and prevented a costly breakdown.
Persistent and strange odors
A musty or burning smell lingering indoors is a sign of a serious air conditioning issue. This could mean mold in the ductwork, an electrical short, or even a refrigerant leak.
In a medical office in Montréal, we detected a strong odor of melting plastic. The culprit? An electrical overload in the system’s control board, which could have led to a fire without timely intervention.
Cycles that are too short or too long
An air conditioning cycle should run long enough to cool the space evenly, then shut off. If your unit keeps starting and stopping rapidly (short cycling), or runs without stopping at all, that’s usually a sign of an internal imbalance.
A restaurant in Terrebonne reported that their system was running nearly non-stop. Our inspection revealed a faulty temperature sensor that couldn’t send accurate readings to the system, overworking the compressor as a result.
A slow, hard-to-explain loss of cooling power
Lastly, if your commercial air conditioner just doesn’t seem to be cooling like it used to, even at full power, something in the system may be starting to fail. It could be anything from a refrigerant leak to an aging compressor or a faulty control board.
In an office space on the North Shore, the cooling effect was barely noticeable despite a thermostat set to 19°C. Our team discovered a slow refrigerant leak in the evaporator coil—completely invisible to the naked eye.
Why you shouldn’t ignore these signs
Even minor problems can escalate quickly. A struggling system works harder, wears out faster, and consumes more energy. A total breakdown in the peak of summer can result in high repair costs, loss of revenue, and even discomfort for staff and clients, potentially harming your brand’s reputation.
What we recommend
At AirGreen, we believe that a smart preventive maintenance strategy is the key to a long-lasting commercial air conditioner. That’s why we offer custom maintenance plans, tailored to the specific needs of each business.
Our experienced technicians operate across the Greater Montréal area, including Laval, Longueuil, the North Shore, and the South Shore. We have the expertise to detect even the most subtle issues before they turn into urgent and expensive emergencies.
When is it time to replace instead of repair?
Some warning signs indicate that it’s better to replace your commercial air conditioner than to repair it:
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The unit is over 12 to 15 years old.
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Repairs are becoming frequent and costly.
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The system’s energy efficiency is below today’s standards.
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It’s not compatible with eco-friendly refrigerants like R-32 or R-454B.
In these cases, we’ll guide you through selecting your new system—Fujitsu, Gree, Daikin, Lennox, Bosch, Goodman, and more—ensuring comfort, savings, and eligibility for local grants like Hydro-Québec’s LogisVert program.
AirGreen: your trusted HVAC partner in Montréal
With years of experience in commercial air conditioning, our mission is to deliver precise, fast, and fully tailored service to your business needs. From a simple check-up to a complete new installation, we handle every stage to ensure your commercial air conditioner remains an asset—not a liability.
Noticing one of these signs? Act now.
A preventive inspection could save you thousands of dollars. Contact us today for a free evaluation, and make sure your commercial air conditioning system is ready for the summer heat.