A roof unit neglected for years: a typical case on a commercial building
At AirGreen , we were recently called in to service a commercial HVAC system installed on the roof of a building in Lachine , in the West Island of Montreal. The client, a warehouse owner, contacted us after noticing a significant drop in energy efficiency and an unpleasant odor coming from the ventilation system. A quick inspection revealed that the unit hadn't been thoroughly cleaned in over five years .
Initial diagnosis: corrosion, clogged filters and accumulated debris
Upon our arrival, we noticed several signs of inadequate maintenance :
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The bodywork is heavily oxidized on the upper part of the unit.
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Air filters saturated with dust and completely clogged.
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Accumulation of debris and insulating materials inside the access compartment.
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Clogged evaporator and condenser , reducing heat exchange.
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Traces of rust on the sheet metal, a sign of water infiltration through the hull.
These conditions resulted not only in excessive energy consumption , but also in premature wear of internal components .
Cleaning steps: a complete refurbishment
To restore the system's proper functioning, our team performed a complete, multi-step cleaning :
1. Securing and dismantling
We first disconnected the power and removed the access panels. The used filters were removed and discarded. The internal ducts were carefully inspected for mold or debris.
2. Cleaning the coils and the fan
The condenser and evaporator coils were treated with a biodegradable, enzyme-based cleaner , ideal for dissolving grease and dust without damaging the aluminum fins. We then performed a gentle rinse with clean water under low pressure to prevent any deformation.
3. Degreasing and antibacterial treatment
The internal walls and centrifugal fan were steam cleaned and then disinfected using a Health Canada approved antibacterial product , eliminating odor-causing germs and spores.
4. Check the drain and drainage system
The partially blocked condensation drain was cleared and flushed to ensure proper water drainage. This step is crucial to prevent mold growth in the collection tank.
5. Reassembly and testing
After complete drying, we installed new MERV 8 filters and reinstalled the panels. A start-up test confirmed that the airflow had returned to optimal levels and that the operating noise level had significantly decreased .
Result: restored energy efficiency and air quality
The benefits were immediate as soon as the procedure was completed:
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25% improvement in measured airflow.
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Significant reduction in fan noise.
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More stable temperature inside the warehouse.
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Complete elimination of stagnant odors.
The client noticed a decrease in electricity consumption and better uniformity of heating and cooling in their workspaces from the first week.
The importance of regular maintenance
This case perfectly illustrates why annual cleaning of rooftop units is essential:
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It preserves the lifespan of compressors and fans .
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It prevents costly breakdowns due to overheating or corrosion.
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It maintains indoor air quality , an important health issue for occupants.
At AirGreen, we recommend a preventive HVAC maintenance plan tailored to each building, including seasonal cleaning, drain checks, coil disinfection, and filter replacement at regular intervals.
By choosing AirGreen, you benefit from recognized expertise in Montreal, Laval, Longueuil, and on the North and South Shores . Our certified technicians use safe, environmentally friendly products that comply with manufacturers' recommendations to guarantee optimal and long-lasting operation of your commercial HVAC systems.