Diagnosis and repair of a high-performance wall-mounted HVAC system, weakened by the heat of a solarium
In the charming Westmount neighborhood, the AirGreen team was called for a service call regarding a Fujitsu wall-mounted heat pump installed in a home office set up in a glass veranda . The client, who works daily in this light-filled space, had noticed a noticeable loss of efficiency in the past few days in his air conditioning system, which had been reliable for several years.
A demanding environment: the veranda as a thermal challenge
Conservatories and sunrooms offer exceptional light, but they also pose a challenge for wall-mounted HVAC systems . In summer, heat accumulated under windows and skylights puts a strain on indoor units, which are often in constant use.
In this specific case, the Fujitsu heat pump had difficulty maintaining a stable temperature, fluctuating between 26°C and 29°C , despite a setpoint of 22°C .
Our technician quickly noticed that airflow was reduced and the outdoor unit was struggling to keep up with demand. These symptoms suggested a partial loss of refrigerant or a problem with the indoor temperature sensor , both common causes in highly exposed environments.
Technical inspection: AirGreen methodology and precision
At AirGreen, every HVAC service call begins with a complete system analysis . For this intervention, our diagnosis was divided into four steps:
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Checking airflow and filters:
The filters were slightly clogged with accumulated dust, reducing airflow. A thorough cleaning immediately improved internal circulation. -
Measurement of refrigerant circuit pressures:
Slight underpressure detected on the low line, indicating a micro-leak of refrigerant . An inspection using an electronic detector confirmed a leak at the flare connection connecting the indoor unit to the copper pipe. -
Temperature sensor test:
The NTC air return sensor showed a reading drift of nearly 2.5°C , distorting compressor regulation. Its replacement was recommended. -
General condition of the outdoor condenser:
Well ventilated and in good condition. The fins have been cleaned to ensure optimal heat exchange.
Repair and recharging
After tightening the flare fitting and replacing the faulty temperature sensor , we proceeded to recharge the R-410A refrigerant according to the manufacturer's specifications. A complete vacuum of the circuit was carried out to eliminate all traces of humidity before recharging.
Once the system was restarted, the pressures and temperatures stabilized:
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Low pressure: 118 psi
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High pressure: 380 psi
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Blowing temperature: 19°C at the indoor unit outlet
These measurements confirm performance in line with Fujitsu standards.
Result: restored comfort and optimal performance
As soon as the intervention was completed, the home office returned to a pleasant and stable temperature, hovering around 22°C despite strong sunlight. The client was able to resume work in comfort, without the space overheating.
We also installed a remote room temperature sensor , allowing a more accurate reading of the actual temperature in the room. This small improvement optimizes regulation in cooling mode and reduces unnecessary stress on the compressor.
Our recommendations for verandas and glass spaces
At AirGreen, we always recommend a preventative approach for this type of environment:
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Clean filters every 4 to 6 weeks during the summer.
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Install thermal blinds or curtains to limit direct solar radiation.
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Have the refrigerant charge checked at the beginning of each warm season.
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Position a remote sensor in rooms with lots of glass to avoid reading errors.
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Schedule a complete annual maintenance with inspection of pressures, temperatures and connections.
These simple actions extend the life of the equipment and ensure optimal energy efficiency.
AirGreen expertise: more than a repair, lasting support
Our intervention in Westmount illustrates our approach: diagnose precisely, repair sustainably and advise intelligently .
Every service call at AirGreen is an opportunity to ensure the comfort of our customers while optimizing the energy performance of their HVAC system.
The customer's Fujitsu wall-mounted heat pump is now operating at full capacity, providing its occupant with a comfortable, quiet and energy-efficient working environment, even under a glass roof.
AirGreen — Your HVAC partner in Montreal, Laval, Longueuil, North Shore and South Shore.
Repair, installation and maintenance of residential and commercial heating, ventilation and air conditioning systems.