Installation of a Midea28 wall-mounted heat pump in Griffintown (Le Sud-Ouest)
In Griffintown, we are installing a Midea28 ( wall-mounted heat pump , R-454B) on a flat roof : anti-vibration support, short run, HVAC compliance and maintenance . Four-season performance for Greater Montreal (Laval, Longueuil, North Shore, South Shore).
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.
A clean integration on a flat roof, designed for the city
In this building with its mixed brick-and-glass architecture, the outdoor unit sits on a galvanized frame attached to rubber bases to protect the membrane and dampen any vibrations. The elevation ensures perfect clearance for frost drainage in winter and free air circulation in summer, without recirculation against the parapets or railings.
The refrigeration path is short and clear : exit from the rear of the condenser, passage through a secure path on the gravel, then descent towards the technical column. The insulated lines and the communication cable are gathered in a UV conduit, with stainless steel fasteners. The condensate management of the internal head is gravity-driven , which eliminates the risk of noise and maintenance linked to a pump.
Why the Midea28 range for Griffintown?
The Midea28 is a recent wall-mounted unit operating on R-454B , a low GWP fluid, and designed for extreme cold (≈ −30 °C) . Its advantages in urban environments:
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Very fine inverter modulation : stable temperature without overheating or short cycles.
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Quiet on both the condenser and evaporator sides, ideal for roof terraces and near neighbors.
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High seasonal efficiencies : tangible savings in mid-season heating and summer cooling.
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Compactness : easily integrated into the roofs of buildings with restricted technical access.
Design: keep it simple, reliable, durable
Location and airflow
The condenser's orientation respects the manufacturing clearances and the opening of the grilles to avoid any air short circuit with the metal structure. We positioned the unit away from vents and chimneys to prevent the suction of effluents and limit dust accumulation in the exchanger.
Structure and anti-vibration
The support is a galvanized steel frame placed on high-density EPDM pads . This solution:
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distributes loads without puncturing the membrane;
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cuts off the solid transmission of vibrations;
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facilitates upgrade (we control at the electronic level with a tolerance < 1°).
Refrigeration and sealing
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Flares made with a calibrated cone, tightening torque controlled by a dynamometer.
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Nitrogen test at 450 psi, then deep vacuum (≤ 500 microns) with ascent control.
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Butyl sleeve on sensitive areas, anti-UV PVC tape, and stainless steel collars.
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Roof waterproofing ensured with a roof pass-through and membrane-compatible sealant, complying with the roofer's instructions.
Electricity and commissioning
A dedicated circuit is drawn from the housing panel: compliant circuit breaker rating, approved copper wiring, lockable external disconnect for maintenance. During commissioning, we validate overheating and subcooling , supply/return temperatures and intensities in hot/cold mode, then we configure the shutters of the interior head to uniformly cover the living area.
Result: controlled comfort, contained costs
Winter heating
The heat pump maintains stable comfort even during the coldest weather conditions. The 28 range's defrost logic limits cycle times; the unit quickly returns to full power, without any noticeable thermal shocks inside.
Summer air conditioning
In summer, the dehumidification mode makes a difference in glass lofts: better humidity control means a feeling of freshness with a higher setpoint — therefore energy savings .
Simplified HVAC Maintenance
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Recommended cleaning : washable filters on the inside (every 4 to 6 weeks during the high season), gentle chemical washing of the outside exchanger as needed.
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Annual inspection: tightening terminals, checking insulation and sealing, recording pressures/temperatures .
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On flat roofs, we check the condition of the pads and the proper drainage of water at each visit.
Challenges of an urban construction site and AirGreen responses
Vertical access and logistics
Limited service elevator, narrow technical staircase: we prepare the unit with its pre-assembled frame , then controlled lifting in two stages to limit handling on the membrane.
Neighborhood and nuisances
We schedule drilling and commissioning at times convenient to the condominium. Silent blocks and a suitable fan speed reduce noise levels; a dB reading is included in the completion file.
Climate protection
The condenser is positioned outside of snow accumulation and clear of wind blades channeled by the parapets. The wiring is UV-resistant ; the junctions are cased to withstand freezing/thawing.
Best practices for condominiums in Montreal, Laval and Longueuil
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Validate the co-ownership regulations before any addition to the roof (charges, fire breaks, drillings).
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Plan maintenance : safe route, accessible disconnect, clearances respected.
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Choose extreme cold : a wall-mounted heat pump rated for −25°C to −30°C reduces the need for electrical backups.
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Protect the membrane : EPDM pads, no unnecessary structural drilling, coordination with the roofer .
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Short trace : less thermal losses, better response, preserved aesthetics.
Grants and Eligibility
The latest generation of high-efficiency wall-mounted heat pumps ( R-454B and R-32 ) are generally eligible for Quebec/federal assistance programs when seasonal performance and installation criteria are met. We support our clients in:
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the choice of an approved model ;
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installation documentation (photos, serial numbers, detailed invoice);
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submission of requests and follow-ups.
What we deliver, beyond the device
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Measurable comfort (temperature and humidity readings),
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a clean integration that respects the architecture and the membrane,
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a clear HVAC maintenance plan ,
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and a service that covers all of Greater Montreal : Laval , Longueuil , North Shore and South Shore .
Conclusion
This installation of a Midea28 in Griffintown demonstrates our approach: rigorous technology, short trajectories, careful anti-vibration, electrical compliance, comprehensive testing and finishes adapted to the flat roof . At AirGreen, we transform urban constraints into four-season, sustainable and economical comfort .
Naturally integrated keywords : heat pump , wall-mounted heat pump , HVAC installation , HVAC maintenance , Montreal , Laval , Longueuil , North Shore , South Shore .
How it goes, from the first call to the end
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 the unit delivers when it is cold
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 28 9 000 | 12,000 | 11,500 | −30 °C: 5,100 | 1.8 | 27.4 | 12.5 | – |
| Midea Série 28 12 000 | 12,000 | 11,500 | −30 °C: 5,900 | 1.8 | 25.4 | 10.5 | $1,440 |
| Midea Série 28 18 000 | 18,000 | 18,000 | −30 °C: 8,000 | 1.92 | 21.4 | 11.0 | $2,160 |
| Midea Série 28 24 000 | 22,200 | 24,200 | −30 °C: 11,900 | 2.34 | 21.0 | 13.5 | $2,664 |
| Midea Série 28 33 000 | 32,000 | 35,000 | −30 °C: 20,700 | 1.98 | 19.5 | 10.5 | $3,840 |
According to NEEP, it delivers 12,000 BTU/h at −8 °C (17 °F), as much as at 8 °C. It heats as hard in moderate cold as in mild weather.
At 8 °C, its certified maximum capacity reaches 16,000 BTU/h, 78% more than its nominal 9,000 BTU size.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 11,500 BTU/h, 128% of its nominal 9,000 BTU size. Its COP there is 1.80.
According to NEEP, it delivers 12,000 BTU/h at −8 °C (17 °F), as much as at 8 °C. It heats as hard in moderate cold as in mild weather.
At 8 °C, its certified maximum capacity reaches 16,000 BTU/h, 33% more than its nominal 12,000 BTU size.
At −30 °C, its certified minimum capacity is 2,000 BTU/h (3,800 at 8 °C). It slows down instead of cycling on and off.
According to NEEP, it delivers 18,000 BTU/h at −8 °C (17 °F), as much as at 8 °C. It heats as hard in moderate cold as in mild weather.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 18,000 BTU/h, 100% of its nominal 18,000 BTU size. Its COP there is 1.92.
According to NEEP, its COP at −15 °C is 2.34: the highest of the Série 28 line, which ranges from 1.80 to 1.98 at that temperature.
At −30 °C, its certified minimum capacity is 2,400 BTU/h (11,800 at 8 °C). It slows down instead of cycling on and off.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 24,200 BTU/h, 101% of its nominal 24,000 BTU size. Its COP there is 2.34.
According to NEEP, its certified maximum capacity at −30 °C (−22 °F) is 20,700 BTU/h, 63% of its nominal 33,000 BTU size.
At −30 °C, its certified minimum capacity is 4,200 BTU/h (19,700 at 8 °C). It slows down instead of cycling on and off.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 35,000 BTU/h, 106% of its nominal 33,000 BTU size. Its COP there is 1.98.
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.
And at your place?
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.
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.
Which type of equipment for your project?
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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).