High-altitude maintenance to restore full performance to a rooftop heat pump
At AirGreen , we regularly service HVAC systems installed in demanding urban environments. This time, our team went to downtown Montreal , to the roof of a residential building, to perform a complete cleaning of a Goodman brand outdoor heat pump .
Exposed to the elements and urban pollution particles, this unit showed clear signs of fouling: fins clogged with dust, superficial rust stains and loss of efficiency felt by the building's occupants.
An accurate diagnosis before any intervention
Upon arriving on the roof, three units were lined up on a bed of gravel, including the one identified by the building manager as the most problematic. Our first steps were:
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Power was cut off to ensure safe maintenance .
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Visually inspected the fins, fan, and electrical connections .
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Checked the unit's airflow , clearly reduced by the accumulation of dust and pollutants.
The tenants had noticed that the heat pump struggled to maintain a stable temperature, especially on hot days. This symptom is typical of heat exchange hampered by a lack of maintenance.
Step 1: Thorough cleaning of the fins and the outdoor evaporator
Our technicians applied a specialized eco-friendly cleaner for HVAC exchangers , designed to dissolve dirt without damaging metal surfaces.
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Apply the product evenly using a low-pressure sprayer.
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Controlled contact time to maximize residue decomposition.
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Rinse thoroughly with clean water to remove all impurities.
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Visual inspection and careful straightening of damaged fins.
This step immediately improved airflow and reduced the thermal resistance of the coil.
Step 2: Degreasing the fan and checking the mechanical components
The fan blades had a thin film of dust mixed with greasy deposits, typical of urban environments. We have:
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Cleaned the blades with a microfiber cloth soaked in biodegradable solution.
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Checked the motor shaft and bearing to ensure smooth rotation.
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Greased minor friction points to prolong engine life .
Step 3: Checking connections and electrical operation
On roofs, electrical connections are often exposed to moisture and temperature variations. Therefore, we have:
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Inspected the electrical junction box and tightened the terminals.
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Cleaned the inside of the box and applied an anti-corrosion agent .
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Checked the supply voltage to ensure optimal operation.
Step 4: Performance tests after cleaning
Once the system was restarted, the measurements revealed:
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A 20% improvement in thermal efficiency .
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A significant reduction in ventilation-related noise .
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A more stable blowing temperature , a sign of restored heat exchange.
Why rooftop heat pump maintenance is crucial
Rooftop units, such as those installed in the city center, are particularly vulnerable to:
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The accumulation of dust particles and pollution .
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Thermal shocks caused by temperature variations.
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Water or moisture infiltration around electrical boxes.
An annual professional cleaning not only helps to preserve energy performance , but also prevents costly breakdowns due to overheating or a clogged motor.
Final result: restored efficiency and guaranteed comfort
At the end of our intervention, the building manager immediately noticed improved temperature regulation in the apartments connected to this unit. The Goodman heat pump, now clean and calibrated, operates quietly and with optimal efficiency.
At AirGreen , we combine technical expertise, ecological products and rigorous execution to offer Montrealers a complete and sustainable HVAC cleaning service — whether your unit is installed in a backyard, under a deck, or, as here, on a rooftop in the heart of the city.