An intervention under the terrace to restore the performance of an HVAC system
At AirGreen , we regularly encounter outdoor wall-mounted heat pump installations placed under structures such as balconies or terraces. While this configuration partially protects the unit from the elements, it also leads to an accelerated accumulation of dust, dirt, and debris . This is precisely the case with this installation in Boisbriand , on Montreal's North Shore .
Initial situation
The client contacted us after noticing that their wall-mounted heat pump was no longer effectively cooling their ground floor. The air blown inside was lukewarm, and the outdoor compressor seemed to be working harder than usual. Our team therefore went to the property for a complete cleaning and performance inspection .
The outdoor unit was installed under a wooden deck , against a brick wall. This positioning restricts airflow and increases the accumulation of dirt on the ventilation surfaces. Upon our visual inspection, we observed:
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A thick layer of dust and dried dirt on the bodywork.
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Traces of mold and damp soiling on the upper part.
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Pipe insulation that is dirty and slightly deteriorated .
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A clogged ventilation grille , greatly reducing airflow.
These combined factors explained the compressor overheating and the loss of energy efficiency in the system.
Cleaning steps
Step 1 — Securing and Logging Out
Before any intervention, we cut off the power supply and isolated the work area to avoid any risk of contact with the cables.
Step 2 — Disassembly and internal inspection
The rear cover of the heat pump was removed to access the identification plate and electrical connections. We thoroughly cleaned the cables and removed the accumulated dirt deposits near the control box.
Step 3 — Cleaning the condenser and fins
A biodegradable HVAC-specific cleaner was sprayed onto the surface of the fins. After a contact time, we used a low-pressure water jet to remove the embedded dust without damaging the aluminum fins. This step restored the condenser's heat exchange capacity .
Step 4 — Checking the insulation and refrigerant lines
The refrigeration pipes and their insulation sheaths were cleaned, then tightened and properly secured against the wall to prevent vibration or premature wear. The insulation was partially replaced to prevent heat loss.
Step 5 — Final rinse and drying
A final rinse with clean water removed any remaining cleaning product. After thorough drying, the device was reconnected and put back into service.
Results and benefits
The cleaning enabled:
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An immediate reduction in compressor noise .
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Faster and more stable cooling inside.
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Reduced electrical consumption , measured via the compressor amperage.
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A visible improvement in airflow through the condenser grille.
The customer noticed the following day a return to thermal comfort and a quieter operation of their system.
AirGreen Recommendations
For units installed under enclosed structures, we recommend a complete cleaning twice a year :
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In spring, to eliminate residues accumulated during the winter.
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At the end of summer, before the transition to heating mode.
This type of preventative maintenance helps to extend the life of the compressor , prevent overheating , and optimize seasonal performance.
AirGreen Expertise
Our specialized technicians service all types of residential and commercial HVAC systems : wall-mounted heat pumps, central units, multi-zone systems, and VRF systems. We use only environmentally friendly cleaning products that meet Canadian standards to maintain the performance and safety of your installations.
Each AirGreen service includes:
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A complete visual and mechanical inspection ,
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A documented intervention report ,
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Customized maintenance recommendations based on the installation environment.
Conclusion
Thanks to this service in Boisbriand, the client's outdoor wall-mounted heat pump is now operating at full capacity. Regular maintenance like this ensures lasting comfort while reducing energy consumption and the risk of breakdowns.
At AirGreen , we put our expertise at the service of the performance, comfort and durability of HVAC systems in Montreal, Laval, Longueuil, on the North Shore and the South Shore .