A critical HVAC intervention that prevented disaster in a residential building in Plateau-Mont-Royal
Air exchangers are typically associated with indoor air quality and comfort, but in some situations, they can literally save lives. The story we’re sharing today shows just how crucial a well-designed and well-maintained system can be. At AirGreen, we were urgently called to intervene in an apartment building located in Plateau-Mont-Royal, in Montréal, after abnormal heat buildup was reported in the mechanical room. What could have been a major fire was averted thanks to a properly calibrated air exchanger installed just a few months earlier.
The context: rising heat in a technical room raises alarm
This 8-unit residential building, built in the 1960s, had undergone a full HVAC system renovation six months prior, which included the installation of a Venmar AVS N-Series air exchanger in the mechanical room that housed the heating equipment, ventilation ducts, and electrical panel.
On an exceptionally hot summer evening, one of the tenants noticed a burnt plastic smell in the hallway. He alerted the building owner, who contacted AirGreen immediately after spotting the system label near the control panel. Within an hour, our technical team was on site.
The diagnosis: ambient temperature exceeding 55°C
Upon arrival, our certified HVAC technicians discovered the mechanical room temperature had reached over 55°C. A secondary ventilation duct, blocked by leftover renovation debris, was preventing the hot air from escaping properly. Without functional ventilation, the electrical system could have overheated, leading to a breakdown or worse: a fire.
Thankfully, the Venmar air exchanger, equipped with smart temperature and pressure sensors, had automatically activated a high-ventilation emergency mode, helping stabilize the temperature until we arrived. This emergency feature, often overlooked, prevented the disaster.
The installed system: a decision that made all the difference
The original installation included:
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Model: Venmar AVS N-Series 240 CFM
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Airflow: up to 240 CFM, with automatic adjustment via onboard sensors
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Sensors: temperature, humidity, and differential pressure
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Control: programmable digital panel with built-in alerts
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Eligibility: HVI and ENERGY STAR certified unit, approved for Hydro-Québec’s LogisVert grant program
Our team had recommended this model during renovations to ensure constant air renewal in enclosed technical areas. The owner agreed to our suggestion of a premium model, even though it was slightly more expensive than basic alternatives.
Immediate impact, damage avoided
After cleaning the blocked duct and performing a full inspection of the mechanical room, the system resumed normal operation. No equipment was damaged. The relieved owner thanked us for insisting on the installation of this smart exchanger. He immediately decided to install the same model in two other buildings he owns in Outremont and Rosemont.
Why this story should be a model example
1. Proper HVAC sizing protects more than just comfort
An undersized system would never have evacuated enough heat. In this case, the high airflow and automatic sensors triggered a vital preventive response.
2. The importance of smart detection
Without alerts from the Venmar unit, the problem would have remained invisible until it was too late.
3. The crucial role of preventive HVAC maintenance
The blocked duct could have been avoided with an annual inspection. At AirGreen, we offer custom HVAC maintenance programs, including duct cleaning and sensor calibration.
Practical advice for building owners in Montréal
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Equip your mechanical rooms with smart air exchangers featuring built-in alarms
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Schedule a full annual inspection, covering ducts, sensors, and control units
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Contact AirGreen for a free risk assessment of your ventilation in critical areas
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Don’t overlook unoccupied rooms, which are often the most vulnerable to mechanical incidents
The AirGreen difference: beyond installation
We don’t just install machines. We anticipate risks, size systems for worst-case scenarios, and integrate the best technologies on the market. Our hands-on experience, paired with our HVAC engineering expertise, allows us to deliver robust, safe, and long-lasting solutions.
We serve all of Montréal, Laval, Longueuil, the North Shore and the South Shore, handling everything from light residential projects to complex commercial buildings.