In the Rosemont–La Petite-Patrie borough, the outdoor units of wall-mounted heat pumps are often exposed to a very “Montreal” mix: urban dust, pollen in the spring, leaf debris in the fall, and salt/granule spray in the winter. As a result, even a reliable unit can lose efficiency if the outdoor unit (the condenser) gradually becomes clogged.
At AirGreen , we regularly perform complete cleanings of Gree wall-mounted heat pumps in this type of brick residential environment, typical of many central neighborhoods. Here, the cleaning focused primarily on the most critical exterior component: the coil and ventilation area, including the fan and grille.
Context: Why clean a Gree wall-mounted heat pump in the middle of an urban area?
A wall-mounted heat pump (mini-split) works hard all year round: air conditioning in the summer, heating during the shoulder seasons, and sometimes even in extended heating mode if the system is sized for Quebec's climate. The problem is that the outdoor unit acts like a "vacuum cleaner": it draws ambient air through the coil, and anything suspended in the air eventually settles.
Over time, we often observe:
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A decrease in airflow through the coil (heat exchange becomes less efficient)
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An increase in electricity consumption (the machine compensates)
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Noisier operation (turbulence, vibrations, slight imbalance)
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An increased risk of premature corrosion if residues remain trapped.
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Longer heating cycles, therefore less stable comfort
Proper preventative cleaning prolongs lifespan and stabilizes performance, especially on Inverter units like Gree.
Machine type and model (consistent with the brand provided)
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Machine type: Wall-mounted heat pump (mini-split / wall unit)
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Brand: Gree (brand name provided manually)
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Model: not reliably legible in the photo; therefore, we are sticking with a consistent designation: Gree Inverter wall-mounted heat pump (residential series)
What the photo reveals: concrete evidence of an ongoing cleanup
The image clearly shows:
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The Gree outdoor unit with the top cover open (access to internal components)
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The exposed propeller/fan , rinsed with foam : a sign of thorough degreasing and cleaning.
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The use of a controlled jet (hose nozzle) directed towards the ventilation area, typical of rinsing after applying a cleaning product
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Traces of foam on the blades: we are at the right moment in the process (removal of deposits before complete rinsing)
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A residential exterior setting (brick wall) that corresponds to a classic urban installation in Montreal
This type of cleaning aims for a simple objective: to restore the condenser's ability to exchange heat efficiently, without damaging the coil fins or unnecessarily wetting the electrical areas.
Our AirGreen approach: structured, safe and efficient exterior cleaning
A quick "clean" with a large amount of water is not a real cleaning. On a Gree unit, especially in an urban environment, we proceed step by step, with a focus on protecting the components and restoring airflow.
1) Securing and initial inspection
First and foremost, we ensure the safety of the intervention:
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Power off (safety procedure and checks)
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Visual inspection: condition of the coil, presence of debris, bent fins, corrosion, accumulation at the bottom of the frame
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Quick check of anchor points and stability (vibrations, supports, fixings)
This step also helps to confirm whether the dirt is mainly “surface” (dust/pollen) or whether it is a stickier mixture (urban grease + organic residues).
2) Preparation of the area and protection of sensitive components
We protect what needs to be protected:
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Control the direction of the flush to prevent seepage into electrical areas
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Moderate pressure rinsing method: enough to dislodge, not enough to crush the fins
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Flow management: we avoid unnecessarily "flooding" the inside of the chamber
3) Cleaning the propeller and ventilation area (a very visible element here)
The photo perfectly illustrates a step that many neglect: cleaning the propeller .
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Apply a suitable cleaner (foam) to the blades and soiled areas.
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Gentle brushing as needed (depending on the condition)
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Controlled rinsing until all residue is removed
Why is this important? A dirty propeller can cause:
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Slight imbalance → vibration
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Turbulence → noise
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Less consistent airflow → less stable heat exchange
4) Cleaning the coil (performance priority)
The coil is the "radiator" of the outdoor unit. If it is obstructed, the heat pump works harder.
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Rinse in the correct direction (to remove deposits rather than pushing them in further).
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Cleaning of areas with higher levels of pollen, dust, and micro-debris
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Fin inspection: if any are bent, we straighten them when appropriate
Objective: to restore uniform airflow across the entire surface.
5) Cleaning the chassis and grilles
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Remove the debris from the bottom of the container (leaves, small fragments)
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Clean the grid/structure without deforming it.
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Check the overall condition of the panels and screws, especially after freeze/thaw cycles.
6) Reinstallation, checks and restarting
Once the cleaning is complete:
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Safely reinstalling the hood
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Final visual inspection (no residue, no displaced parts)
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Power restored
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Functional checks: start-up, fan stability, abnormal noises, overall behavior
The tangible benefits after a good cleaning
When the outdoor unit regains a clean coil and normal airflow, the following is generally observed:
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Improved air conditioning efficiency (faster cooling)
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More stable consumption (less unnecessary effort)
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Quieter operation
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Improved tolerance to intense periods (heatwave, high humidity)
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A reduction in the risk of premature wear due to overheating or prolonged cycles
In winter, a clean outdoor unit manages its heat exchanges better, which can contribute to a more efficient defrosting process (without promising miracles: several factors come into play).
How often should a Gree wall-mounted heat pump be cleaned in Montreal?
In practice, for Greater Montreal:
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Exterior cleaning : ideally once a year (or every 18 months depending on the environment)
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More frequent maintenance is needed if: the alley is dusty, trees are very close, there is heavy pollen, or construction is taking place nearby.
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After autumn, if the unit is surrounded by leaves, it's often a good time.
And on the indoor side (wall head), cleaning the filters and periodic maintenance remain essential for air quality and to avoid odors.
Why entrust your cleaning to AirGreen?
Because a "poorly done" cleaning can:
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Bending the fins (loss of heat exchange surface area)
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Sending water where it shouldn't be
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Leaving critical areas still obstructed
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Giving an impression of cleanliness… without any real gains
We work with a clear method: protection, targeted cleaning, controlled rinsing, checks, and a clean restart. The goal is not just aesthetics: it's the performance , durability , and operational stability of your Gree wall-mounted heat pump .
Conclusion: A cleaning that protects your investment
In a neighbourhood like Rosemont–La Petite-Patrie , a well-executed exterior cleaning makes a real difference in the long run. The service shown here—with the propeller cleaned with foam, the hood open, and a controlled rinse—illustrates meticulous work focused on efficiency and reliability.
If you want to keep your system at the best level, preventative maintenance remains one of the most cost-effective things you can do for your residential comfort.