A service call reveals a performance problem
At AirGreen , we regularly receive calls from customers in Sainte-Rose (Laval) regarding Mitsubishi wall units that seem to be losing efficiency over time. In this specific case, the customer contacted us after noticing that their wall-mounted air conditioner was no longer blowing cold air , even at full power.
Our technician quickly arrived on site to perform a complete system diagnosis . Armed with his infrared thermometer , he found that the air outlet temperature measured 25.7°C —a clear sign that the unit was working, but without any real cooling .
Diagnosis: loss of performance linked to fouling and lack of refrigerant
Once the cover was removed and the fins were visible, our specialist immediately noticed a buildup of dust on the evaporator and a clogged air filter , limiting air circulation. This type of clogging is common when annual maintenance has not been carried out.
After cleaning the filter and blowing out the coils, the technician continued the diagnosis by checking the refrigerant pressure . The readings confirmed a slightly insufficient R-410A charge , causing a noticeable decrease in cooling capacity.
Repair steps:
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Complete cleaning of the evaporator and condensate tray.
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Checking the refrigeration circuit and detecting any micro-leaks.
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Partial recharge with R-410A refrigerant to restore nominal pressure.
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Final performance test , with measurement of the air outlet temperature.
After recharging, the temperature dropped to 9.8°C , a result perfectly in line with expectations for a Mitsubishi wall-mounted air conditioner in good working order.
Restored comfort and optimized energy efficiency
As soon as the intervention was completed, the customer immediately noticed the difference: a powerful and stable flow of cold air , and a room temperature that had become comfortable again.
We took the opportunity to remind people of the importance of having your HVAC system cleaned and checked every spring , in order to avoid clogging of the coils, loss of performance and excessive energy consumption.
Care instructions:
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Clean air filters every 4 to 6 weeks during the summer season.
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Keep the outdoor unit clear (no obstructions within 60 cm).
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Schedule an annual professional maintenance for a complete inspection of the refrigeration circuit.
Why choose AirGreen in Laval and Greater Montreal?
Our certified technicians travel throughout Laval, Montreal, Longueuil, the North Shore and the South Shore , for all types of HVAC repairs — whether it's wall-mounted heat pumps, central air conditioners, or MultiZone systems .
Our approach is based on three pillars:
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Accurate diagnosis thanks to professional measuring instruments.
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Sustainable interventions with original parts and practices that comply with Canadian standards.
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Transparent and human service , always focused on customer satisfaction.
In Sainte-Rose, as elsewhere, each service call is an opportunity for us to restore the comfort and confidence of our customers.