Installation of a MIDEA MIDEA35 wall-mounted heat pump in Saint-Rémi: commissioning and cooling test after installation
In Saint-Rémi, AirGreen installs and tests a MIDEA35 wall-mounted heat pump set to 20 °C. Commissioning, cooling check, performance down to -30 °C, and meticulous HVAC installation.
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The unit’s data sheet
The range as published on airgreen.ca: pick a size to see its capacity in deep cold.
| Size | Heating at −8 °C | Heating at −15 °C | Coldest certified point | COP at −15 °C | SEER | HSPF | Indicative LogisVert aid |
|---|---|---|---|---|---|---|---|
| Midea Série 35 9 000 | 11,000 | 13,500 | −30 °C: 7,500 | 2.0 | 33.3 | 14.6 | – |
| Midea Série 35 12 000 | 11,000 | 13,500 | −30 °C: 7,500 | 2.0 | 29.4 | 12.7 | $1,320 |
| Midea Série 35 18 000 | 19,300 | 22,600 | −30 °C: 11,900 | 2.34 | 25.6 | 16.2 | $2,316 |
According to NEEP, its certified maximum capacity at −30 °C (−22 °F) is 7,500 BTU/h, 83% of its nominal 9,000 BTU size.
At 8 °C, its certified maximum capacity reaches 17,200 BTU/h, 91% more than its nominal 9,000 BTU size.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 13,500 BTU/h, 150% of its nominal 9,000 BTU size. Its COP there is 2.00.
According to NEEP, its certified maximum capacity at −30 °C (−22 °F) is 7,500 BTU/h, 62% of its nominal 12,000 BTU size.
At 8 °C, its certified maximum capacity reaches 17,200 BTU/h, 43% more than its nominal 12,000 BTU size.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 13,500 BTU/h, 112% of its nominal 12,000 BTU size. Its COP there is 2.00.
According to NEEP, its COP at −15 °C is 2.34: the highest of the Série 35 line, which ranges from 2.00 to 2.00 at that temperature.
According to NEEP, its certified maximum capacity at −30 °C (−22 °F) is 11,900 BTU/h, 66% of its nominal 18,000 BTU size.
At 8 °C, its certified maximum capacity reaches 29,700 BTU/h, 65% more than its nominal 18,000 BTU size.
Data read live from the airgreen.ca page of each size (NEEP / AHRI certified performance). When the title names the installed size, it is highlighted; otherwise the whole range is shown. The aid shown is today’s, using Hydro-Québec’s rule ($120 per 1,000 BTU/h at −8 °C); amounts quoted in the article date from its publication. Only Hydro-Québec confirms the assistance granted.A dash in the aid column: amount to be confirmed for this model.
The article, chapter by chapter
In Saint-Rémi, a MIDEA35 set to 20 °C and then checked directly on site
For this installation completed by our AirGreen team in Saint-Rémi, the photo does not show only a MIDEA MIDEA35 wall-mounted heat pump installed on the wall. It primarily illustrates an essential step in our work: verifying the unit’s actual operation during commissioning.
The indoor unit is operating, its louvers are open, and its display indicates a setpoint of 20 °C. In front of the air outlet, our technician uses an infrared thermometer. The device displays a reading of approximately 8.3 °C, with a memorized maximum value of approximately 9.2 °C at the time the photograph was taken.
This check immediately confirms that the system is producing cold air. At AirGreen, however, we distinguish between a quick check and a complete HVAC performance analysis. An infrared thermometer primarily measures the temperature of the targeted surface; it does not replace a probe specifically designed to accurately measure the temperature of an air stream.
It is precisely this attention to detail that characterizes our wall-mounted heat pump installations in Saint-Rémi. We do not consider the work complete simply because the unit starts. We check its operation, airflow, cooling, drainage, and response to commands before leaving the site.
The MIDEA35 is part of Midea’s ductless wall-mounted system lineup, along with the MIDEA28, MIDEA25, and MIDEA22 series.
A commissioning process that confirms the heat pump is operating properly
After installing a MIDEA35 heat pump in Saint-Rémi, several checks must be carried out.
We specifically check:
- the start-up of the indoor unit;
- the fan response;
- the opening and positioning of the louvers;
- the response to temperature changes;
- switching between the different modes;
- cooling operation;
- condensate drainage;
- the absence of vibrations or unusual noises;
- the communication between the indoor and outdoor units.
For this installation, the unit is set to 20 °C and our technician checks the supply-air area. The reading of approximately 8.3 °C shows significant cooling at the time of the inspection.
However, the goal is not to obtain the lowest possible supply-air temperature. A modern variable-speed heat pump continuously adjusts its operation. The observed temperature can therefore vary depending on conditions inside the home, the outdoor temperature, the fan setting, and the compressor speed.
Why 8.3°C at the air outlet does not mean that the room is at 8.3°C
It is important to distinguish the setpoint temperature of the temperature observed near the air outlet.
In this Saint-Rémi installation, the MIDEA display shows 20 °C. This value corresponds to the requested temperature in the space.
The reading taken in front of the unit rather represents a local temperature observed while the indoor coil is cold and the heat pump is operating in cooling mode.
As the room approaches 20°C, the system can gradually reduce its speed. There is therefore no reason for it to constantly maintain the same supply-air conditions.
Why the MIDEA35 is well suited to the needs of a property in Saint-Rémi
The MIDEA35 is presented by Midea as a premium wall-mounted series designed for heating and cooling.
It uses the refrigerant R-454B, bears the Cold Climate V6.1 designation, and can operate in heating mode down to an outdoor temperature of -30°C.
The range includes three nominal cooling capacities:
- 9,000 BTU/h;
- 12,000 BTU/h;
- 18,000 BTU/h.
The corresponding nominal heating capacities are 12,000, 12,000, and 20,000 BTU/h.
Since the exact capacity of the unit visible in our photo cannot be identified with certainty, we do not arbitrarily assign it a BTU rating.
This is an important detail. For a heat pump installation in Saint-Rémi, we must size the equipment according to the building rather than simply choosing the largest available capacity.
Efficiency ratings of up to 33.3 SEER2
Efficiency ratings vary according to the capacity of the MIDEA35.
The manufacturer states:
- 33.3 SEER2 for the 9,000 BTU model;
- 29.4 SEER2 for the 12,000 BTU unit;
- 25.6 SEER2 for the 18,000 BTU unit.
The listed Region IV HSPF2 values are, respectively, 22.0, 14.5, and 16.2.
These figures show why it is important to consult the specifications for the actual combination installed. The “MIDEA35” designation does not correspond to a single efficiency rating.
Variable-speed technology for more stable comfort
Midea uses variable-speed technology that allows the compressor to adapt its operation to the home's actual needs.
Instead of constantly alternating between full power and complete shutdown, the compressor can gradually adjust its speed as the temperature changes.
Midea states that this technology helps reduce temperature fluctuations and maintain a more stable indoor environment.
In a Saint-Rémithis can provide several benefits:
- more consistent temperature maintenance;
- quieter operation at partial load;
- better adaptation to changes in outdoor temperature;
- reduced on-off cycling;
- more consistent comfort during long periods of cooling or heating.
The photo of our commissioning shows the unit during an active cooling phase. Once the setpoint is reached, the heat pump can reduce its output rather than continuing unnecessarily at the same rate.
Heating down to -30°C for Saint-Rémi winters
For a property located in Saint-Rémi, a heat pump's ability to operate throughout the winter is an important criterion.
The MIDEA35 range is rated for a heating operating range down to -30°C.
However, we always encourage our clients to look beyond this minimum temperature alone.
A heat pump does not necessarily produce the same amount of heat at -20°C as it does at 0°C. Its performance must therefore be examined at different temperatures.
At -15°C, Midea specifies the following nominal capacities:
- 13,500 BTU/h for the 9,000 BTU model;
- 13,500 BTU/h for the 12,000 BTU model;
- 22,600 BTU/h for the 18,000 BTU model.
The COPs specified at this temperature are, respectively, 3.60, 3.60, and 4.40.
This information allows us to better assess the role the heat pump can play in the actual heating of a Saint-Rémi home.
An installation in Saint-Rémi is not simply a matter of mounting the unit on the wall
A large part of the work that determines the reliability of a wall-mounted heat pump becomes invisible once the installation is complete.
The refrigerant lines, drainage, connections, wiring, and circuit preparation all play a role in the system's long-term operation.
Follow the copper diameters specified by Midea
The different capacities of the MIDEA35 do not all use the same lines.
For the 9,000 and 12,000 BTU, the specified liquid/gas dimensions are 1/4 in. and 3/8 in..
For the version 18,000 BTU, they increase to 3/8 in. and 5/8 in..
The manufacturer also specifies maximum lengths of:
- 82 feet for the 9,000 BTU model;
- 82 feet for the 12,000 BTU model;
- 164 feet for the 18,000 BTU model.
The maximum elevation difference also varies depending on the configuration.
When replacing an old heat pump in Saint-Rémi, we therefore do not automatically reuse the existing lines without verifying their compatibility.
An incorrect copper pipe size can affect the system's performance and reliability.
R-454B and A2L equipment
The MIDEA35 uses R-454B, a refrigerant belonging to the A2L category.
Midea's documentation specifically mentions an A2L refrigerant leak detection sensor and features designed for this new generation of systems.
The installation must therefore be carried out using the appropriate methods, procedures, and equipment.
For our AirGreen team, this involves paying particular attention to the refrigerant connections, circuit cleanliness, testing, drainage, and final commissioning.
Drainage: an essential check in air conditioning
When the heat pump cools indoor air, moisture condenses on the evaporator.
This water must be drained properly.
During an installation in Saint-Rémi, we therefore check:
- the drain slope;
- its drainage;
- the connections;
- the absence of back-pitches;
- the drain outlet;
- the absence of leaks near the indoor unit.
A heat pump can provide excellent cooling and still cause damage if its drainage has been improperly installed.
That is why the control visible in the photo is only one part of our commissioning procedure.
Up to 100 fan speeds
The Midea range allows particularly precise airflow adjustment. The manufacturer indicates up to 100 air volume levels as well as possible remote control using SmartHome and Wi-Fi, depending on the configuration.
The MIDEA35 also offers several useful features:
- fan speed from 1% to 100%;
- silent mode;
- sleep mode;
- timer;
- horizontal swing;
- vertical swing;
- Turbo function;
- Follow Me feature;
- 8°C heating;
- automatic cleaning;
- ECO mode;
- Wi-Fi control;
- smart sensor;
- humidity control.
These settings make it possible to adapt the operation of the MIDEA35 wall-mounted heat pump to the occupants’ habits rather than allowing the unit to operate constantly in the same way.
The Follow Me feature can improve temperature control
A wall-mounted unit is generally located near the ceiling, while occupants live much lower in the room.
The temperature measured near the heat pump may therefore differ slightly from that felt elsewhere.
The feature Follow Me uses the sensor built into the remote control to measure the temperature at its location and allow the system to adjust its operation accordingly.
In certain home configurations in Saint-Rémi, this feature can be useful for achieving regulation that better represents the actually occupied area.
A heat pump quiet enough to operate for long periods
A variable-speed heat pump is designed to operate for long periods at different speeds. The noise level of the indoor unit therefore becomes particularly important.
Depending on the model, Midea indicates indoor sound levels as low as 19 dB(A) for certain 9,000 and 12,000 BTU versions, and up to 16 dB(A) for the 18,000 BTU version at the quietest setting shown.
For a living room, bedroom, or open-concept area in Saint-Rémi, this quiet operation is a valuable advantage.
MIDEA35 AHRI numbers
The MIDEA35 combinations presented by the manufacturer have the following references:
- AHRI 215471386 for the 9,000 BTU version;
- AHRI 215471387 for the 12,000 BTU version;
- AHRI 215471388 for the 18,000 BTU version.
These numbers are important when a Saint-Rémi homeowner wants to verify their heat pump’s eligibility for a financial assistance program.
Eligibility and the amount available must always be determined based on the actual installed combination and the program conditions at the time of the application.
A warranty worth keeping all the documentation for
For residential applications, the Midea brochure presents a limited warranty of up to 12 years on the compressor, 12 years on parts, and 10 years on labor, according to the applicable terms.
After our installation in Saint-Rémi, we therefore always recommend keeping:
- the invoice;
- model numbers;
- serial numbers;
- the AHRI reference;
- registration documents;
- warranty information.
These documents can become essential several years after installation.
A MIDEA35 installation in Saint-Rémi checked before we left
This MIDEA MIDEA35 wall-mounted heat pump installation in Saint-Rémi perfectly illustrates how we work at AirGreen.
The machine was installed, connected, and started. We checked its operation in cooling mode and observed a reading of approximately 8.3 °C near the air discharge area while the unit was set to 20 °C.
For us, this inspection is not an optional step.
A heat pump may advertise excellent performance, operation down to -30 °C, and several smart features; however, these characteristics will only deliver their full value if the equipment is properly sized, properly installed, and properly commissioned.
That is why, for every heat pump installation in Saint-Rémiwe give as much attention to visible elements as to the technical details behind the unit: refrigerant lines, drainage, connections, control operation, and the machine’s behavior after startup.
The desired result is not simply a heat pump that turns on. We want to hand the homeowner a system ready to efficiently provide air conditioning and heating for their Saint-Rémi residence for many seasons.
The job tools
Two quick checks with real numbers: what heat costs, and what your current heaters add up to in BTU/h.
Baseboards and electric furnaces turn 1 kWh of electricity into 1 kWh of heat. A heat pump delivers more: that is its COP. At Hydro-Québec’s rate D (11.142¢/kWh above 40 kWh a day, since 1 April 2026):
Hydro-Québec: a heat pump can be up to three times more efficient than baseboards for heating in the colder months.
Estimate per kWh of heat, at the chosen temperature, using the certified COP from the product page. Taxes, access charge and backup heat not included.
Conversion: 1 W = 3.412 BTU/h. An indication, not a load calculation: baseboards and furnaces are often stronger than the real need, and they can stay as backup. AirGreen confirms the capacity on site.
How the job unfolds
The main steps of this kind of job at AirGreen. Every house has its quirks: the estimate brings them out.
We look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
Model, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
Floors and furniture protected, wall plate position marked level, wall opening located.
A single opening, with the slope the drain needs to flow outside.
Set on a stand raised above the snow, with the clearances the manufacturer requires.
Connected, insulated and protected. The opening is then sealed against water, cold air and insects.
A dedicated circuit and an accessible disconnect near the outdoor unit.
Leak test, vacuum, then start-up and a check of heating and cooling.
Remote, modes, filters: we show you the essentials before we leave.
- The on-site estimateWe look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
- The quoteModel, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
- Getting readyFloors and furniture protected, wall plate position marked level, wall opening located.
- The wall openingA single opening, with the slope the drain needs to flow outside.
- The outdoor unitSet on a stand raised above the snow, with the clearances the manufacturer requires.
- Lines, cable and drainConnected, insulated and protected. The opening is then sealed against water, cold air and insects.
- The electrical workA dedicated circuit and an accessible disconnect near the outdoor unit.
- Tests and start-upLeak test, vacuum, then start-up and a check of heating and cooling.
- The walkthroughRemote, modes, filters: we show you the essentials before we leave.
What we check on a job like this one
Each number is a point we check on site. Switch between summer and winter to watch air and heat move.
In summer, the outdoor unit rejects the house's heat outside.
Generic illustration of this type of installation, not a survey of this job site. Tap a number.
Mounted level on a wall plate, high enough for the air to reach the whole room, with enough space around it to slide the filters out easily.
The refrigerant lines, the communication cable and the drain go through the wall in a single opening, sealed against water, cold air and insects.
Two insulated copper pipes connect the two units. Outside, a line cover can protect them from sun, knocks and weather.
A shut-off switch near the outdoor unit isolates it safely for service. It must stay accessible at all times.
The compressor and the fan. In heating mode it captures heat from the outdoor air, even in winter, and moves it inside.
On the ground or on the wall, it keeps the unit above accumulated snow. The unit stays clear and defrost water can drain away.
The fan needs to blow freely. Storage, a fence or a wall too close, and efficiency drops while noise goes up.
Is your home ready?
Check what applies at your place. A "no" is not a refusal: it is what we sort out during the estimate.
Good habits, once the unit is in place
Six simple habits that keep the unit going. Your list stays on this device.
What to do, season by season
Three habits per season for this unit. They take a few minutes and prevent many calls.
- Clean the indoor unit's filters.
- Clear leaves and debris left on the outdoor unit by winter.
- Test cooling before the first hot days.
- Clean the filters more often when the unit runs a lot.
- Keep plants away from the outdoor unit.
- Check that no water drips from the indoor unit.
- Rake the leaves around the outdoor unit.
- Test heating before the first cold days.
- Book periodic maintenance before winter.
- Keep snow away from the stand and the front of the unit.
- Let the unit defrost: it is normal.
- Never hit the ice on the fins; call us if the unit stays iced up.
The right pages, at the right time
Four statements: true or false?
It all comes down to details you have just seen.
1. In heating mode, the outdoor unit can produce water.
During defrost cycles. That water must drain away without forming ice.
2. You pick the capacity with a simple square-footage rule.
Windows, insulation, orientation and how the room is used all count. Capacity is chosen on site.
3. A multi-zone connects several indoor heads to a single condenser.
One head per room, all on the same condenser. Each room keeps its own temperature.
4. The disconnect can sit behind the patio furniture.
It must stay accessible: it is what shuts the unit off for service.
0 / 4 right answers
What people ask us about this kind of work
Does a wall-mounted heat pump heat in winter?
Wall-mounted or multi-zone: how do I choose?
Where does the outdoor unit go?
Are there grants?
Do I need a permit?
How cold can it heat?
How much can I save?
How is the LogisVert assistance calculated?
Is it noisy?
The outdoor unit is covered in ice: is that normal?
Does AirGreen hold the required licences?
Is the estimate free?
No question matches. Write to us: we answer.
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Text and photo: a real AirGreen Climatisation & Chauffage job. The diagrams are generic illustrations of the type of installation, not a survey of this job site. Sources of the added figures: airgreen.ca product pages (NEEP / AHRI performance), Hydro-Québec (Heat pumps page, LogisVert, read on 13 October 2026), Régie de l’énergie (rate D as of 1 April 2026).