Essential internal cleaning to restore optimal performance
At AirGreen , we are often called out for wall-mounted air conditioner breakdowns that, at first glance, seem serious, but whose real cause turns out to be advanced internal fouling . This is exactly what we found during this service call in Brossard , on the South Shore of Montreal .
The customer contacted us after noticing that their Sharp wall-mounted air conditioner was no longer blowing cold air, despite the outdoor unit seemingly operating normally. This type of symptom is typical of an internal airflow problem , often caused by a clogged heat exchanger or blocked drainage .
Step 1: Inspection and diagnosis of the wall-mounted air conditioner
Upon arrival, we dismantled the front panel and removed the air filters to directly observe the condition of the indoor unit.
Result: pronounced fouling of the evaporator fins (the coil visible in the photo), covered with a thin layer of dust and greasy particles.
This build-up significantly reduced the heat exchange capacity and forced the fan to run at high speed with no real effect on the ambient temperature.
To confirm our hypothesis, we carried out:
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A blowing temperature measurement , which showed only 19°C in cooling mode (instead of 12–14°C normally).
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An airflow check : the fan was spinning properly, ruling out a motor problem.
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An inspection of the condensate drain , slightly obstructed by deposits of damp dust.
Step 2: Thorough cleaning of the evaporator and ducts
We performed a complete cleaning of the Sharp indoor unit , a crucial step in restoring system performance.
This cleaning includes several specific actions:
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Application of a specialized biodegradable HVAC cleaner to the evaporator to dissolve organic and dusty deposits.
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Rinse under controlled pressure to remove all traces of dirt without damaging the thin aluminum fins.
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Cleaning the condensate tray and drainage pipe to prevent any water leaks or odors.
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Tangential fan dust removal , often overlooked, but essential for uniform airflow.
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Antibacterial disinfection to prevent mold growth—especially important in humid environments.
Step 3: Post-cleaning performance testing
Once the unit was reassembled, we restarted the system and immediately observed a noticeable difference in the blowing quality and outlet temperature .
The following measures were noted:
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Blowing temperature: 12.4°C .
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Inlet/outlet air difference: 9°C , indicating optimal thermal efficiency.
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No vibration or abnormal noise.
The customer immediately noticed improved comfort and fresher air, proof that the thermodynamics of the device had returned to its original efficiency.
Step 4: Prevention tips and regular maintenance
We explained to the customer that this type of fouling often develops after several seasons without professional cleaning , especially if the device is operated daily during the summer.
Even if the filters are cleaned regularly, dust still ends up infiltrating the coils and reducing the cooling capacity.
Our recommendations:
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Have the indoor unit cleaned once a year before the start of the hot season.
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Check the drain in the spring to prevent leaks.
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Replace filters if worn or damaged.
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Schedule a complete AirGreen service including checking the refrigerant gas and ensuring the outdoor unit is working properly.
Result: restored performance and satisfied customer
After the intervention, the Sharp wall-mounted air conditioner regained its full cooling power , providing clean and fresh air in the main room.
The customer was impressed that a simple professional cleaning could transform a “tired” appliance into a high-performance unit , without costly replacement.
This type of intervention perfectly illustrates AirGreen's philosophy:
accurately diagnose, rigorously maintain and extend the life of your HVAC systems.
Why South Shore Residents Trust AirGreen
Our customers in Brossard, Saint-Lambert, Sainte-Julie and Longueuil know they can count on:
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Certified technicians with in-depth knowledge of each brand of wall-mounted air conditioner.
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Professional cleaning procedures that comply with environmental standards.
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Fast and meticulous service , always focused on satisfaction and durability.
At AirGreen , we work on all brands — Sharp, Midea, Fujitsu, Gree, Lennox, Goodman, Zephyr — with the same precision and attention to detail.