In Ormstown, the detail that draws attention is outside: an MIDEA35 installed well above the ground
On this installation completed by our AirGreen team in Ormstown, the photograph shows an essential aspect of a wall-mounted heat pump installation which is sometimes less noticeable than the indoor unit: how the outdoor unit is positioned, supported, and protected to operate in Quebec’s actual conditions.
We installed a MIDEA MIDEA35 wall-mounted heat pump, but this project stands out above all for its outdoor installation. The Midea unit rests on an four-legged elevated metal support, installed on a concrete surface. The compressor is therefore positioned well above ground level, with its coil and fan completely unobstructed.
On the right side of the photograph, we can also see the insulated refrigerant lines, the wiring and electrical enclosure arranged compactly near the equipment. The environment is relatively confined: the unit is positioned between the building and a nearby structure, which makes it essential to carefully consider accessibility and the clearance required around the heat pump.
This type of configuration is representative of the work of an experienced HVAC installer. It is not enough to find a place where the outdoor unit “fits.” We must consider snow removal, water drainage during defrost cycles, airflow, future service access, the route of the lines, and the mechanical stability of the support.
The MIDEA35 is part of Midea’s ductless wall-mounted systems, alongside the MIDEA28, MIDEA25, and MIDEA22 series.
Why elevate an outdoor heat pump in Ormstown?
In a region like Ormstown, a heat pump intended to operate in heating mode during the winter must be installed with snow, ice, and defrost cycles in mind.
When the unit operates in cold weather, the outdoor unit extracts heat from the air. Frost may form on the coil, and the system periodically enters defrost mode. The resulting water must then be able to drain beneath the unit.
This is precisely where an elevated support becomes useful.
For this installation, we maintained a significant space between the base of the MIDEA and the concrete slab. This helps keep an open area beneath the unit for water drainage and limits the risk of the base quickly becoming surrounded by accumulated snow.
A heat pump should not be enclosed in snow
A common mistake is to think that an outdoor unit can be installed almost at ground level simply because it rests on a solid slab.
The slab is important for stability, but in the case of a heat pump used for heating, height also matters.
When snow accumulates around the heat exchanger, several problems may arise:
- reduced air circulation;
- ice buildup beneath the unit;
- partial obstruction of the base;
- more difficult access for maintenance;
- less favorable defrosting if the water cannot drain freely.
The metal support visible at our Ormstown job site provides an additional safety margin between the heat pump and the ground.
A concrete installation that still requires a stable structure
The presence of a concrete slab is an excellent starting point, but it does not eliminate the need for careful mechanical installation.
The support shown in the photograph has four feet that distribute the heat pump’s weight across the slab. The unit itself rests on the support’s upper crossbars.
This type of mounting must be carried out in a way that keeps the appliance level and limits movement.
An outdoor unit contains, among other things:
- a compressor;
- a fan;
- a heat exchanger;
- motors;
- pressurized refrigerant lines.
It therefore produces some normal vibrations during operation. If its support is unstable or improperly positioned, these vibrations may be transmitted to the building or create noises that were not present during commissioning.
The challenge of a relatively narrow outdoor space
The photograph of this installation in Ormstown also reveals a very practical constraint: the space around the outdoor unit is not unlimited.
Yet we must allow the large front fan to move air properly through the heat exchanger.
The positioning of a heat pump should therefore never be decided solely based on aesthetics.
We check:
- the clearance in front of the fan;
- the space behind and on the sides;
- the proximity of walls and other equipment;
- the possibility of carrying out future repairs;
- the route of the refrigerant lines;
- the location of the electrical disconnect;
- water drainage;
- protection against accidental impacts.
The manufacturer also highlights the compact design of Midea side-discharge outdoor units and their ability to fit into various installation settings.
However, this does not mean that a unit can be squeezed in just anywhere. A professional HVAC installation must always preserve the operating conditions specified for the model used.
Visible piping on the job site: a small detail that conceals an important part of the work
On the right side of the unit, we can see the lines connecting the heat pump to the building.
The copper tubes carrying the refrigerant are, in a way, the circulatory system of the heat pump. Their installation requires much more than simply connecting two fittings.
We must, among other things, comply with:
- the diameter specified by Midea;
- the total run length;
- the height difference between the units;
- proper line insulation;
- the quality of the connections;
- mechanical protection;
- the refrigerant charge when the run requires it.
The copper dimensions change according to the MIDEA35 capacity
The MIDEA35 is available in several capacities, and the line dimensions are not identical for all of them.
The versions of 9,000 and 12,000 BTU/h versions use liquid/gas lines of 1/4 in. and 3/8 in., while the 18,000 BTU/h uses 3/8 in. and 5/8 in..
The maximum refrigerant line length indicated by Midea is 82 feet for the 9,000 and 12,000 BTU models, and 164 feet for the 18,000 BTU model.
The exact capacity of the equipment photographed in Ormstown is not legible in the image. We therefore do not arbitrarily assign it a BTU rating.
This point is important, especially when an old heat pump is being replaced: the existing lines must be checked before being reused. The fact that a pipe already reaches the right location does not mean that it has the correct diameter for the new unit.
A MIDEA35 designed for summer cooling and heating in extreme cold
The outdoor support catches the eye in our photo, but the installed unit also deserves a technical analysis.
Midea presents the MIDEA35 as its premium wall-mounted series, operating with the refrigerant R-454B and designed for heating down to -30 °C. The combinations presented in the brochure are identified as Cold Climate V6.1.
Three main capacities to adapt the system to the building
The MIDEA35 is available with rated cooling capacities of:
- 9,000 BTU/h;
- 12,000 BTU/h;
- 18,000 BTU/h.
The corresponding rated heating capacities are, respectively, 12,000, 12,000, and 20,000 BTU/h.
At AirGreen, we consider capacity selection to be a fundamental step.
Installing a heat pump that is larger than necessary is not automatically an improvement. Sizing must take into account the building's layout, insulation, windows, exposure, and how air can circulate between the different zones.
Up to 33.3 SEER2, depending on the selected capacity
The series' cooling efficiency varies by model.
Midea states:
- 33.3 SEER2 for the 9,000 BTU version;
- 29.4 SEER2 for the 12,000 BTU version;
- 25.6 SEER2 for the 18,000 BTU version.
The corresponding Region IV HSPF2 values are, respectively, 22.0, 14.5, and 16.2.
This is one reason why we always recommend comparing specific heat pump combinations rather than just series names.
Saying that a MIDEA35 offers “up to 33.3 SEER2” is accurate for the product line, but it does not mean that every capacity has a SEER2 of 33.3.
Variable-speed technology suited to long operating periods
Midea uses variable-speed compressor technology. The manufacturer states that the compressor can adjust its operation as demand changes rather than operating only in a complete on-off cycle.
This is particularly relevant in the context of an Ormstown winter.
A modern heat pump is often more comfortable when it runs longer at a moderate output rather than constantly alternating between maximum power and a complete shutdown.
This modulation can help maintain a more stable indoor temperature while reducing abrupt changes in operation.
The figure to look at in winter is not limited to “-30 °C”
A MIDEA35 can operate in heating mode down to -30 °C, but when evaluating a heat pump for a house in Ormstown, we also look at its low-temperature capacity.
At -15 °C, Midea states:
- 13,500 BTU/h for the 9,000 BTU version;
- 13,500 BTU/h for the 12,000 BTU version;
- 22,600 BTU/h for the 18,000 BTU version.
The corresponding COPs are respectively 3.60, 3.60, and 4.40.
These figures provide a better understanding of what the machine can actually deliver during a cold spell.
The minimum operating temperature is important, but it should never be used alone to size a building’s heating system.
R-454B and the new requirements related to A2L systems
The MIDEA35 uses R-454B, an A2L-category refrigerant.
The documentation also mentions an A2L refrigerant leak detection sensor, as well as a dispersion system specified in the characteristics of the MIDEA35, MIDEA28, and MIDEA25 family.
For our team, this means that installation and servicing must be carried out using the appropriate procedures and equipment.
An R-454B installation must not be treated as though the refrigerant type were irrelevant.
The disconnect switch and electrical connection must remain accessible
In the photo of our Ormstown installation, an electrical box is installed near the unit.
This type of arrangement is important for servicing. A technician must be able to isolate the electrical power supply before working on the machine.
Depending on capacity, the MIDEA35 has different electrical requirements. Midea specifically indicates a minimum allowable amperage of 16 A for the 9,000 and 12,000 BTU versions and 24.9 A for the 18,000 BTU version. The maximum protection ratings indicated are respectively 20 A, 20 A, and 25 A.
We therefore always verify the exact characteristics of the installed combination rather than using a standard electrical protection for all heat pumps.
Outdoor noise also matters when choosing the location.
The front-facing fan visible in the photo moves a significant volume of air through the coil.
Depending on the capacity, Midea indicates a high outdoor sound level of 57 dB(A) for the 9,000 and 12,000 BTU models and 61.5 dB(A) for the 18,000 BTU version.
We therefore take proximity into account to:
- a bedroom window;
- a deck;
- a neighboring property;
- a frequently used passage;
- a wall that could amplify certain vibrations.
An outdoor unit may be compact, but its location remains a technical decision.
The raised support also makes future maintenance easier.
The installation visible in Ormstown leaves the lower part of the heat pump accessible.
This facilitates several future tasks: inspecting the base, cleaning, checking drainage, accessing the connections, and verifying the support.
A unit installed too close to the ground can become much more difficult to maintain when surrounded by ice, debris, or vegetation.
We also recommend that the owner keep the area around the unit clear.
Do not allow objects to accumulate in front of the fan or let vegetation overgrow the coil during the summer. In winter, it is best to regularly clear snow from around the heat pump without damaging the fins.
An outdoor unit does not need to be sealed airtight.
Another mistake to avoid is adding a structure that is too enclosed around the unit to “protect it.”
The heat pump needs a large amount of air.
A poorly designed shelter can cause air discharged by the fan to recirculate and reduce performance.
Protection against the direct fall of a mass of snow or ice from a roof may sometimes be appropriate depending on the building, but it must be designed without blocking the required clearances.
The best approach is to plan this protection during installation rather than building a box around the equipment later.
AHRI numbers for the MIDEA35 series
For the three combinations presented by Midea, the AHRI references are:
- 215471386 for the 9,000 BTU model;
- 215471387 for the 12,000 BTU model;
- 215471388 for the 18,000 BTU model.
These references are important when we need to verify the characteristics of a combination or its potential eligibility for a financial assistance program.
For a heat pump rebate in Quebecthe AHRI number corresponding exactly to the installed indoor and outdoor units, as well as the program criteria in effect at the time of the application, must always be verified.
We therefore avoid promising a subsidy simply based on the commercial name “MIDEA35”.
Comfort features that complement the work of the outdoor unit
Although our photo mainly shows the outdoor equipment, the MIDEA35 also offers several functions at the indoor unit.
The brochure specifically mentions:
- airflow adjustable from 1% to 100%;
- ECO mode;
- Turbo mode;
- night mode;
- timer;
- function Follow Me;
- automatic cleaning;
- quiet mode;
- 8°C heating;
- horizontal and vertical swing;
- smart sensor;
- humidity control;
- Wi-Fi control.
Midea also indicates up to 100 airflow adjustment levels and the ability to control the system through SmartHome and Wi-Fi, depending on the configuration.
Residential warranty: keep the documents for the installed system
The brochure states, for the residential sector, a limited warranty of 12 years on the compressor, 12 years on parts, and 10 years on labor, according to the applicable conditions.
After an installation like the one in Ormstown, we therefore recommend carefully keeping:
- the invoice;
- the indoor and outdoor models;
- the serial numbers;
- the AHRI number;
- the registration documents;
- the warranty conditions.
In Ormstown, an installation designed for what happens in January as much as in July
This MIDEA MIDEA35 wall-mounted heat pump installation in Ormstown perfectly illustrates why we place as much importance on the outdoor unit as on the equipment visible inside the home.
The photograph summarizes several technical decisions: a unit installed on a solid surface, raised on a metal support, with its connections positioned nearby and access maintained around the equipment.
On a hot summer day, this height may seem like a minor detail.
In the middle of winter, when snow accumulates and the heat pump must regularly run defrost cycles, its value becomes clear.
At AirGreen, our goal is not simply to install a MIDEA heat pump in Ormstown. We aim to prepare the installation for the conditions it will actually face: heat, rain, freezing temperatures, snow, defrost cycles, and long heating periods.
It is this same attention to detail that we apply to ourHVAC installation in Montreal, Laval, Longueuil, the North Shore, and the South Shore : proper sizing, compliance with refrigerant piping requirements, appropriate electrical installation, adequate clearance, a stable support, and accessibility for future servicing.
A MIDEA35 has the features needed to deliver solid performance in our climate. The installer’s role is to create the conditions that allow it to perform properly, year after year.