Complete restoration of a flat roof HVAC system
At AirGreen , we were recently called to Rosemère , on the North Shore of Montreal , to work on a Manuflow Inverter wall-mounted heat pump installed on the flat roof of a residential building . This type of installation, common in multi-unit buildings, requires special attention: direct exposure to the sun, significant thermal variations and possible infiltration of debris or water.
Symptoms observed before the intervention
The customer contacted us after noticing several anomalies:
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Loss of power in air conditioning mode : the unit was no longer able to maintain the desired interior temperature.
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Unusual vibrations when starting the compressor , audible from inside.
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Excessive condensation around refrigeration connections.
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Irregular forced air noises , a sign of an unbalanced outdoor fan.
These signals reflected mechanical misalignment combined with fouling of the condenser , two problems often linked to repeated thermal cycles on flat roofs.
Stages of diagnosis
Upon our arrival, our certified technicians undertook a series of technical checks:
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Visual inspection : slight corrosion on the exchanger fins, accumulated dust and plant moss around the base.
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Checking R410A refrigerant pressures : abnormally low reading, suggesting a slight leak.
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Fan Motor Check : Fluctuating electrical resistance, evidence of a tired motor or worn capacitor.
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Checking the unit's mounting : the treated wooden supports under the unit had a sag of a few millimeters, changing the alignment and causing the vibrations.
Intervention and repairs carried out
1. Straightening and stabilizing the base
We started by replacing the support blocks with high-density anti-vibration pads, ensuring better stability and reducing sound transfer to the structure.
2. Complete cleaning of the condenser
Using a pH-neutral, biodegradable product, we cleaned the heat exchanger fins and removed debris from the condenser base. This cleaning immediately improved airflow and reduced compressor discharge pressure.
3. Repair the leak and recharge the refrigerant
A micro-leak was detected at the service connection , caused by a worn seal. After replacing the seal and tightening it, we proceeded to completely evacuate the system before recharging with R410A refrigerant according to Manuflow's specifications.
4. Replacing the starting capacitor
The capacitor responsible for the initial pulse of the fan motor had a 15% imbalance, causing the irregular startup noise. It was replaced with an approved model of equivalent capacity (35 µF / 450 V).
5. Final calibration
Once the repairs were completed, the system was run through a full operating cycle in both cooling and heating mode . Temperature and pressure measurements were now stable and within manufacturer standards.
Results obtained
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Restored performance : the heat pump reaches the set temperature in 15% less time than before the intervention.
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Quiet operation : Vibrations have been eliminated by stabilizing the support and replacing the capacitor.
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Optimized energy efficiency : Compressor efficiency has improved, reducing estimated power consumption by 10 to 12%.
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Extended durability : Thanks to tilt correction and condenser maintenance, the unit is now protected against premature wear.
Advice given to the client
Our technicians recommended to the owner:
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Annual preventative maintenance before each summer to clean the fins and check the gas pressure.
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To avoid any accumulation of plant debris on the roof around the unit.
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Schedule an electrical wiring check every two years, especially in areas with high solar exposure.
AirGreen expertise at your service
Manuflow Inverter systems , while efficient, require careful calibration to maintain optimal performance. At AirGreen , we are trained to work on all models—from wall-mounted heat pumps to multi-zone systems—ensuring a clean, durable job that meets the highest HVAC industry standards.
Our interventions in Rosemère, Laval, Montreal, Longueuil, on the North Shore and the South Shore are carried out with the same level of requirement: transparency, expertise and respect for the environment .
AirGreen is the guarantee of lasting comfort and impeccable service, regardless of the brand or complexity of your HVAC system.