When a Simple Oversight in the HVAC System Can Trigger a Major Disaster
In the world of commercial real estate across Montréal, Laval, or the South Shore, a failing HVAC system isn’t just a comfort or energy waste issue. It can become a real safety hazard. At AirGreen, we were called to intervene at an office building in Longueuil that narrowly avoided a fire caused by a poorly installed air conditioning unit. This real-life case shows just how essential it is that the design, installation, and maintenance of HVAC systems are carried out by experienced professionals.
Case Study: Disaster Narrowly Avoided at a Commercial Building in Longueuil
Incident Overview
In the middle of July, with outdoor temperatures exceeding 30 °C, a short circuit occurred in the outdoor condenser unit of a 5-ton central air conditioner located on the roof of a 4-storey building housing a medical clinic, law offices, and a wellness center.
Flames were spotted by a nearby resident, and firefighters arrived just in time to prevent a full-blown fire. The unit was shut down, and our team was brought in to investigate the cause of the failure.
Technical Diagnosis
After a complete disassembly and inspection:
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The unit did not meet current electrical code standards
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The wiring was overloaded, with no proper protective fuses
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Leaves and debris were blocking ventilation, causing overheating
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The system had not been serviced in four years
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No safety devices (temperature sensors or circuit breakers) had been installed
How Poorly Managed Air Conditioning Systems Can Actually Cause Fires
Component Overheating
Without adequate ventilation, compressors and condensers overheat. This can cause insulation on wires to melt, lead to sparks, or even ignite flammable materials nearby.
Electrical Overload Risks
An undersized or incorrectly connected HVAC system can overload circuits. The lack of proper breakers or fuses makes this risk even worse.
Dust and Debris Accumulation
Leaves, insects, greasy dust, and various debris block heat dissipation. Blocked ventilation is a highly underestimated risk, especially for rooftop units.
The AirGreen Intervention: Full HVAC System Safety Upgrade
Technical Recommendations
We performed:
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Complete replacement of the unit with a Lennox ML14XC1 | 5 Ton central heat pump
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Rewiring of the electrical panel, adding dedicated breakers and code-compliant wiring
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Installation of thermal sensors to monitor temperature at critical components
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Protective mesh and weather guard to prevent future obstruction
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Signing of an annual maintenance contract to ensure ongoing performance
Results Achieved
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System now 100% compliant with CSA and ASHRAE standards
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18% drop in electricity usage thanks to the energy-efficient model
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Active protection against overheating risks
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Extended manufacturer warranty due to certified installation
Key Lessons for Commercial Property Owners
Don’t Overlook Rooftop Installations
Out of sight often means out of mind. Yet rooftop units are the most exposed to hazards (leaves, snow, rain, direct sun).
Only Hire Certified Professionals
HVAC installation is not a job for generalists. Only certified and qualified technicians should handle high-power units, especially in multi-tenant buildings.
Make HVAC Maintenance Contracts a Priority
With a structured maintenance plan that includes cleaning, electrical inspection, and safety checks, risks are drastically reduced.
Why AirGreen Is the Go-To Partner for Commercial Buildings
Proven Expertise in High-Risk Environments
We work in clinics, schools, office towers, and government buildings, always delivering custom HVAC solutions designed for safety and long-term reliability.
Access to Top Equipment and Grant Programs
Our partnerships with Lennox, Gree, Bosch, Fujitsu, and Zephyr allow us to offer highly secure central heat pumps and air conditioning systems, often eligible for LogisVert or ÉcoPerformance grants.
Full Support Every Step of the Way
From the initial audit to installation, through to annual maintenance and admin paperwork, our team handles it all.
Practical Tips to Keep Your HVAC Installations Safe
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Have your outdoor units inspected twice a year (spring and fall)
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Check electrical connections after any storm or power surge
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Install protective grilles to keep out leaves and birds
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Ensure clear airflow around the unit at all times
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Update your emergency plans in case of HVAC failure
At AirGreen, we know your building’s safety depends on a reliable, properly installed, and professionally maintained HVAC system. Count on our expertise to avoid costly—and potentially dangerous—mistakes.