In an apartment in Ville-Marie , in the heart of Montreal, we performed a complete cleaning of a Gree wall-mounted heat pump . The type of service required was clear as soon as we opened the casing: the coil (evaporator) was exposed (as seen in the photo), indicating that we had reached the stage where a simple "quick" rinse was no longer sufficient. In this type of residential setting—drier air in winter, fine dust, humidity fluctuations, frequent cooking in a condo—a wall unit gradually accumulates deposits that eventually affect airflow , odors , and efficiency .
Our goal at AirGreen: to restore the machine to a clean and stable state, without compromising on the protection of surfaces, electronics and interior finishes.
The system: Gree wall-mounted heat pump (residential mini-split)
This is a Gree brand wall-mounted indoor unit (mini-split). The exact model is not visible in the photo, but the configuration is typical of Gree wall units installed in Greater Montreal: front cover, top filters, very dense finned coil, condensation tray and gravity drainage.
This type of system is excellent for condos, especially in Montreal, because it allows:
-
a stable temperature by zone;
-
an efficient auxiliary heater (depending on the configuration);
-
better control of comfort, without ductwork work.
But its weak point is known: if maintenance is neglected, dirt settles in critical areas (coil, turbine, tank, drain), and the machine “breathes” less well.
What the image reveals: the areas that warrant a thorough cleaning
The photo shows the unit open , with the evaporator coil clearly visible. Reaching this stage means you want to do a clean, accessible, and controlled job.
Important visual clues:
-
exposed coil : the fins can be treated and the deposits removed;
-
Internal access : we are in technical intervention mode, not just “filter cleaning”;
-
Accessible lower flap and deflector area : ideal for cleaning areas where dust often sticks together with moisture.
Why a thorough cleaning really changes performance
A wall-mounted heat pump works by passing a large volume of air through a coil. If this coil is filled with dust:
-
air passes less easily → loss of flow rate ;
-
heat exchange is less efficient → decrease in efficiency ;
-
moisture mixes with deposits → odors and risk of biofilm;
-
The machine can compensate by forcing itself → noise , more frequent cycles, discomfort.
In winter in Montreal, when the unit is working more in heating mode, a dirty wall unit can also give the impression of “heating less”, when the problem simply comes from heat transfer and airflow.
Our AirGreen method: structured, safe, and clean cleaning for the home
1) Protection of the premises (essential in a condo)
Before touching the coil, protect:
-
the wall and the baseboards;
-
the floor;
-
nearby furniture (in Ville-Marie, spaces are often compact);
-
the sensitive components of the unit (electrical areas, sensors, connectors).
Next, a suitable wash cover or a recovery device is installed, depending on the configuration, to control the flow.
2) Cleaning the filters (but not only that)
The filters are removed, dusted, and washed properly. Yes, that's essential, but it doesn't solve the problem:
-
the deposit stuck to the coil;
-
the dirt in the bin;
-
turbine fouling.
We still do it carefully, because filters that are not put back in properly or are not dried properly can bring back odors.
3) Coil treatment (evaporator) – the key component
Since the coil is accessible (photo attached), we proceed to:
-
controlled dust removal;
-
application of a foaming product designed for coils, which loosens contaminants without attacking the fins;
-
Controlled rinsing (appropriate pressure), to avoid crushing the fins and to protect the electronics.
If necessary, some areas of the fins are gently straightened (without forcing them) to preserve airflow.
Desired result: a coil that “breathes” again, and a more efficient heat exchange.
4) Condensation tray and drain: preventing damage and odors
A significant portion of the problems with wall construction stems from drainage :
-
A clogged bin = odors;
-
Partially blocked drain = drips, overflows, moisture in the wall.
We clean the drain pan, then we check the actual flow of the drain. We make sure the water drains properly and that the slope is functional. In a condo, this is a critical step: poor drainage can damage the finishes, and nobody wants that.
5) Blower turbine/wheel: where odors cling
Even though the photo doesn't show a close-up of the turbine, an open unit like this often indicates that the work also targets the inside of the air circuit. The turbine accumulates a mixture of dust and micro-humidity, and this is a common source of:
-
of odors at startup;
-
noise;
-
of reduced flow rate.
We clean this area in a way that is appropriate to the level of soiling (without “flooding” the unit), to restore a clean and regular airflow.
6) Targeted disinfection (when relevant)
When a unit has odors or a history of humidity, we perform a reasonable disinfection procedure compatible with the equipment. The goal is not to add fragrance, but to limit the rapid return of odors and to sanitize internal surfaces that remain damp during operation.
7) Reassembly and functional testing
After cleaning:
-
complete reassembly of the panels/shutters;
-
checking the movement of the blades;
-
test in ventilation mode then cooling (or heating depending on the season);
-
validation of throughput, noise, and stability.
We also check that the condensation flow is correct during operation.
What the customer notices as soon as the service is restored
In the majority of complete Gree mural cleanings in Montreal (and particularly in condos), the gains are immediate:
-
more neutral air (fewer odors at startup);
-
stronger airflow at the same speed;
-
more stable cycles and improved feeling of comfort;
-
The unit is often quieter because the air circulates better.
These are concrete effects, not theoretical ones: when the coil becomes clean again and the air flows properly, the machine works less “in resistance”.
How often should a wall-mounted heat pump be cleaned in Montreal?
For typical residential use:
-
Filters: check regularly (especially during intensive heating/cooling);
-
Complete internal cleaning: often once a year , sometimes more depending on:
-
presence of animals;
-
frequent cooking;
-
dust in the building;
-
symptoms (odours, reduced flow, abnormal condensation).
-
In Ville-Marie, you often see units with high turnover because the condos are well insulated but sensitive to heat gain (sun, appliances, cooking). Annual maintenance is generally an excellent compromise.
Our AirGreen approach: clean, measured, and results-oriented
A good cleaning isn't just a matter of "watering and leaving." It's:
-
access the correct areas;
-
protect the home;
-
clean without damaging the fins;
-
secure the drainage;
-
check the recommissioning.
That's exactly what we did on this Gree wall-mounted heat pump in Ville-Marie , with a cleaning focused on the coil , tray , drain , and internal surfaces related to air quality.