When a simple maintenance brings your HVAC system back to life
At AirGreen , we know that a wall-mounted air conditioner can lose efficiency long before it breaks down completely. This is exactly what we found during a service call in Sainte-Dorothée, Laval , for a Midea wall-mounted heat pump that was suffering from a lack of cooling power and reduced airflow .
Initial diagnosis: a progressive loss of performance
Upon arrival, our technician immediately noticed that the indoor unit showed signs of advanced fouling . The filters were saturated with dust, and the evaporator coil showed a thin layer of accumulated dirt, limiting heat transfer.
The customer told us that the system seemed to be "blowing lukewarm" despite being set to 21°C and that an unusual noise was heard at low speed. These typical symptoms often indicate an internal obstruction, preventing proper airflow and causing a drop in energy efficiency .
Thorough inspection and intervention safety
Before starting the cleaning, we performed a complete electrical check : supply voltage, communication between the electronic boards, and temperature sensor continuity. No component issues were detected—excellent news, confirming that a complete cleaning would be enough to restore optimal performance .
We then removed the air filters , dismantled the front cover and isolated the turbine in order to carry out a thorough cleaning .
Using a specialized biodegradable AirGreen product helps remove greasy deposits and biofilms without attacking the coil's aluminum fins.
Cleaning the coil and turbine
The evaporator coil , which was dirty over nearly 60% of its surface area, was cleaned by gentle spraying, followed by a low-pressure rinse.
The turbine —often neglected—was completely disassembled, disinfected, and rebalanced. This step is crucial: an unbalanced or dirty turbine causes constant noise and a reduction in airflow of up to 40% .
Once the turbine was reassembled, we inspected the condensate drain . A slight deposit was partially obstructing the flow, which could have caused long-term water leaks . The pipe was purged and flushed to ensure free flow.
Post-intervention performance test
After complete reassembly, we restarted the unit in cooling mode to check the air inlet and outlet temperatures .
The result: a 10°C difference between the intake and exhaust air — a clear indicator of a system at full efficiency.
The noise level was also measured: 25 dB at low speed , which is in line with Midea specifications.
Results: comfort and healthy air restored
At the end of the intervention, the customer immediately noticed an improvement in airflow and ambient comfort . The system, now clean, operates quietly and without unpleasant odors.
Regular maintenance every 12 to 18 months is strongly recommended to prevent mold growth, reduce power consumption and extend the life of the compressor.
AirGreen Tips to Avoid Future Problems
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Clean the filters every 4 weeks during periods of heavy use.
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Watch for water leaking from under the indoor unit: a sign of a blocked drain.
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Never use abrasive products : use gentle, HVAC-certified cleaners.
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Schedule a complete professional maintenance before each summer season.
AirGreen expertise at your service
Every intervention we carry out, whether in Montreal, Laval, Longueuil, on the North Shore or the South Shore , is based on the same rigor:
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Accurate and transparent diagnosis
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Maintenance with professional products
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Checking electrical and mechanical components
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Full Satisfaction Guarantee
We believe a well-maintained HVAC system is a lasting investment . Our careful and equipment-friendly approach will restore your Midea heat pump to its original performance while improving indoor air quality.