What happens after installation: the part no one talks about
At Saint-Mathieu-de-Beloeil, at the foot of Mount Saint-Hilaire, the residential housing stock consists largely of newer electrically heated homes without ductwork. These homes are well insulated and comfortable in winter, but the upper floors are often unbearable in July.
We installed a GREE FreeMatch R32 two-head configuration system. The installation itself proceeded without any particular obstacles. What makes this job interesting is what we spent forty-five minutes explaining to the client at the end of the day—because half of all dissatisfaction with heat pumps comes from improper use, not from a faulty unit.
First, the site constraint: installing a head unit in a corner
The room required a corner installation. The adjacent wall was covered with decorative wallpaper that the client did not want to have drilled or risk damaging.
Two decisions follow from this.
Choosing the wall
We installed the unit on the painted wall rather than the wallpapered wall. This is not merely aesthetic: quality wallpaper is difficult to repair, and even the smallest hole or trace of drywall dust leaves a permanent mark.
Our rule in a finished room: when two walls are technically equivalent, we work on the one that is easier to repair. Paint can be touched up. A mural cannot.
During the work, we systematically protect sensitive surfaces and vacuum at the source while drilling rather than cleaning up afterward.
The side clearance, which is not decorative
This is the technical challenge of corner installation, and it is almost always overlooked.
A wall-mounted head needs clear space on its sides, not just above it. Air is drawn in through the top of the casing and discharged from the bottom in a fan-shaped pattern. A perpendicular wall that is too close creates two effects:
- It cuts off the air stream on one side, which unbalances air distribution throughout the room. Half the room is treated while the other half stagnates.
- It encourages air short-circuiting: some of the air being blown out immediately rises along the wall toward the intake without passing through the room. The unit then measures its own air output rather than the actual room temperature and shuts off prematurely.
Each manufacturer publishes a minimum side clearance. This figure is not a suggestion. We respect it even when that means shifting the unit a few centimeters from what might look most symmetrical to the eye.
The mistake to avoid: asking the installer to “tuck the unit into the corner so it is less visible.” It will be less visible and it will work less well.
The installed equipment
The outdoor unit is the GREE FreeMatch R32, model GWHD(24)ND6MO, powering two indoor heads.
- Nominal capacity of 7,030 W (24,000 BTU/h), for both heating and cooling.
- Modulation from 7,500 to 31,400 BTU/h, G10 inverter compressor.
- Heating certified down to -30 °C, cooling up to 48 °C.
- SEER2 21 / HSPF2 10 / EER2 12, ENERGY STAR certified.
- R32 refrigerant (A2L) with an integrated leak detection sensor.
- Self-diagnostics, smart defrosting, automatic voltage adaptation.
- Heads powered by the outdoor unit: a single dedicated electrical circuit for the entire system.
- Standard 10-year warranty.
How to use your heat pump properly: the six settings that make all the difference
This is the section we explain in detail at every installation, in Saint-Mathieu-de-Beloeil as well as in Beloeil, Longueuil, Montréal, Laval, on the North Shore or the South Shore. It is worth more than any brochure.
1. Do not set a heat pump like a window air conditioner
This is mistake number one.
With an old air conditioner, lowering the setpoint to 16 °C made the unit run at full power, which cooled the room faster. The habit stuck.
That is not how an inverter system works. The unit continuously modulates to reach and maintain the setpoint. Setting it to 16 °C when you want 22 °C does not actually cool the room faster in any useful sense: it simply makes the machine run at high output for much longer, consumes more energy, and cools the room well below a comfortable temperature.
The right approach: set the temperature you actually want and let the unit do its job. An inverter system is designed to operate continuously at low speed. That is its most efficient operating mode.
2. Avoid constantly turning it off and on
The second habit inherited from older appliances: turn off the air conditioning when leaving in the morning and turn it back on when returning.
With a modulating system, this practice is generally counterproductive. Letting the house warm up by six degrees during the day then forces the unit to operate at full power for hours to catch up—and the moisture accumulated in the materials does not dissipate instantly.
A steady setpoint, possibly raised by one or two degrees when away, provides better comfort for comparable or lower consumption.
3. Understand what the display shows
A wall-mounted unit’s display generally shows the setpoint, not the room’s actual temperature. This is a constant source of confusion.
Two useful clarifications:
- Most units allow you to switch between °C and °F. Many come set to Fahrenheit by default, which is confusing when you see 61 or 72 and expect Celsius figures. The switch is made using the remote control.
- The unit’s temperature sensor is located inside the housing, at the top of the wall. It measures the air at that precise location, not at occupant level. In heating mode, the air there is warmer than at floor level. That is why a setpoint of 21 °C can feel like 19 °C around your feet.
This discrepancy is normal. Adjust it by finding, through a few days of trial and error, the setpoint that corresponds to the room’s actual comfort—not by concluding that the unit is “lying.”
4. Use sweeping rather than fixing the louvers in place
The natural instinct is to direct the louvers toward yourself. This is almost always the wrong idea.
A fixed louver creates a localized draft and leaves the rest of the room untreated. Automatic sweeping distributes the air throughout the entire space, which evens out the temperature and allows the sensor to measure something representative.
Two reasonable exceptions:
- In heating mode, directing the airflow downward helps counteract stratification.
- In cooling mode, directing the airflow upward prevents it from blowing directly on occupants.
5. Beware of automatic mode
“Auto” mode lets the unit decide between heating and cooling based on the difference from the setpoint.
During Quebec’s shoulder seasons—with cool nights and warm afternoons—this can cause the unit to switch back and forth between the two modes on the same day, resulting in unnecessary energy use.
We generally recommend explicitly choosing the mode according to the season, and using automatic mode only during clear transition periods, if you are satisfied with the observed behavior.
6. Dehumidification mode has a specific purpose
“Dry” or dehumidification mode runs the unit with reduced airflow over a cold coil, extracting more water per unit of cooling.
It is useful on humid but not very hot days—typically in June or September—when the house feels damp without being overheated.
It does not replace air-conditioning mode during a heat wave: its cooling capacity is deliberately limited.
The filter: the only maintenance you will do yourself
A clogged filter reduces airflow. Reduced airflow lowers the coil temperature. A coil that is too cold freezes. A frozen coil no longer transfers heat, and the compressor runs in a vacuum.
This chain of causes explains the majority of the service calls we receive in July saying, “my heat pump no longer cools.”
Clean the filters every 4 to 6 weeks during periods of heavy use. It takes five minutes: open the front panel, remove the two filters, rinse them with lukewarm water, and let them dry completely before putting them back.
What you cannot do yourself, however, is deep-clean the heat exchanger and blower wheel. The dust that sticks to them is invisible from the filter and accumulates over several years. We recommend this service every two to three years as part of professional HVAC maintenance.
What falls under the installation, and what you cannot correct afterward
It is useful to know what adjusting the settings can never make up for:
- Incorrect sizing. An oversized system dehumidifies poorly and cycles too frequently. No setting can fix that.
- An unsuitable head location. A unit placed in a dead corner or facing an obstacle will never treat the entire room.
- Insufficient clearances, both indoors and outdoors.
- An incorrect refrigerant charge. The GWHD(24) is precharged for 30 metres of total piping; beyond that, 20 g of R32 per metre must be added, weighed and recorded.
- A poorly performed vacuum pull. Residual moisture in the circuit attacks the compressor from the inside over several years.
That is why the technical assessment and workmanship matter more than the brand on the unit.
The A2L constraint
R32 is classified as mildly flammable. It requires a minimum room volume per indoor head, calculated based on the system charge. In a modest-sized enclosed bedroom, this check may influence the capacity selection. We perform it during the design phase, never afterward.
Financial assistance
GREE documentation indicates that these systems are eligible for local rebates, and ENERGY STAR certification is among the common criteria for Quebec programs. Eligibility depends on your specific situation and the programs in effect when the work is carried out. We validate the application before installation and provide the required documentation.
Have you just had a wall-mounted heat pump installed and aren't sure you're using it properly? Or are you considering a multi-zone system in Saint-Mathieu-de-Beloeil or elsewhere in the Vallée-du-Richelieu? Contact us. Commissioning and explanation are part of the job, not extras.