An intervention in an urban environment to restore the performance of a wall-mounted HVAC system
At AirGreen , we are regularly called upon to clean wall-mounted heat pumps installed in commercial or residential buildings in downtown Montreal. In this particular case, our team went to the Rosemont–La Petite-Patrie neighbourhood, where a homeowner contacted us for a cleaning service on a Daikin Inverter wall-mounted heat pump , installed on the rear façade of a brick building.
The urban environment, exposure to street dust, and ambient pollution often contribute to premature fouling of outdoor units. This cleaning was therefore essential to restore the system's efficiency and prevent unusual noises related to dirt buildup.
Initial diagnosis: visible fouling and signs of loss of efficiency
During our inspection, we quickly noticed several telltale signs of delayed maintenance:
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Accumulation of dust and black particles on the front grille of the condenser.
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Greasy and partially obstructed aluminum fins , limiting heat exchange.
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Condensation not properly drained , due to a partially blocked drain.
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The associated Fujitsu indoor unit also showed filters saturated with fine dust .
The customer had noticed for several weeks a significant decrease in the flow of cold air and an increase in his electricity consumption , typical symptoms of a system fouling.
Step 1 – Securing and accessing the outdoor wall unit
Since the installation was located more than two meters above the ground, our technician installed a secure, lightweight scaffold to comfortably reach the Daikin heat pump.
We proceeded to:
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The power outage .
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Checking the wall fixings (often weakened by vibrations and weight).
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Protecting refrigeration cables and sheaths with a temporary insulating film.
Step 2 – Deep cleaning of the Daikin heat pump
The cleaning was carried out in several specific phases:
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Application of AirGreen ProClean ecological cleaner to the coils to dissolve accumulated dust and grease.
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Gentle rinsing with clean water under low pressure , in order to preserve the integrity of the fins.
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Manual cleaning of the fan to remove deposits that were weighing down the motor.
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Suction of residues inside the crankcase , often responsible for odors or whistling.
This step allows air to circulate freely and the compressor to work under optimal conditions, thus reducing mechanical stress.
Step 3 – Drain clearing and additional interior cleaning
The condensation duct, slightly blocked by limescale deposits and micro-algae, was unblocked manually using a small drain snake and then rinsed with hot water.
Inside, the filters of the paired Fujitsu unit were:
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Removed and washed in lukewarm water .
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Dried completely before being put back in place .
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Then disinfected with a biodegradable antibacterial product.
We also cleaned the internal evaporator to remove any traces of dust and prevent musty odors.
Step 4 – Checks and recommissioning
Once the system was reassembled, we had:
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Checked the refrigerant pressure and the tightness of the connections.
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Controlled the blowing temperature .
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Listened to the fan running : no more rubbing noises were perceptible.
The customer immediately noticed a more powerful and even airflow , as well as a return to the desired temperature in just a few minutes.
Results: restored performance, comfort and durability
After this complete overhaul, the Daikin Inverter heat pump has been restored to:
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Increased energy efficiency , reducing compressor start-up cycles.
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Healthier indoor air , free from dust and contaminants.
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Quiet and smooth operation .
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And above all, a longer lifespan thanks to the regular preventative maintenance recommended by AirGreen.
We also reminded the client that annual cleaning not only ensures thermal comfort, but also prevents costly breakdowns often linked to compressor overheating.
The AirGreen approach: expertise and compliance with HVAC standards
Each AirGreen cleaning is carried out in compliance with professional HVAC industry standards and manufacturer recommendations.
Our certified technicians use biodegradable products, specialized equipment and safe methods, even in tight urban environments like here in the heart of Rosemont–La Petite-Patrie.
Because good maintenance is above all the promise of lasting comfort, a lower energy bill and cleaner indoor air .