Project

Installation of a TOSOT wall-mounted heat pump in Rosemont–La Petite-Patrie

AirGreen installs a Gree R-32 wall-mounted heat pump in Rosemont–La Petite-Patrie: head above a door, rear outlet without interior cover, gravity drain , commissioning calibrated for Greater Montreal .

By AirGreen Climatisation & Chauffage Admin8 min read
Installation of a TOSOT wall-mounted heat pump in Rosemont–La Petite-Patrie
Installation of a TOSOT wall-mounted heat pump in Rosemont–La Petite-Patrie
–chapters in this story
8 minreading time
–type of installation
2025year published
The tour

Take a tour of the installation

Each number is a point we check on site. Switch between summer and winter to watch air and heat move.

Generic diagram: wall-mounted heat pump, indoor and outdoor units

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.

  1. 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.

  2. The refrigerant lines, the communication cable and the drain go through the wall in a single opening, sealed against water, cold air and insects.

  3. Two insulated copper pipes connect the two units. Outside, a line cover can protect them from sun, knocks and weather.

  4. A shut-off switch near the outdoor unit isolates it safely for service. It must stay accessible at all times.

  5. The compressor and the fan. In heating mode it captures heat from the outdoor air, even in winter, and moves it inside.

  6. On the ground or on the wall, it keeps the unit above accumulated snow. The unit stays clear and defrost water can drain away.

  7. The fan needs to blow freely. Storage, a fence or a wall too close, and efficiency drops while noise goes up.

The job

Installation of a TOSOT-GREE wall-mounted heat pump in Rosemont–La Petite-Patrie

Consistent comfort and discreet aesthetics: interior installation high above a door, invisible connections and precise calibration for a Montreal apartment

A demanding interior installation, carried out properly

In this Rosemont–La Petite-Patrie (Montreal) apartment, our team installed a Gree wall-mounted heat pump to provide four-season heating and cooling , with performance adapted to the local climate. The interior head is located above a circulation door , in a hallway that serves the kitchen and living room. This choice requires millimeter precision: respecting clearances, preserving the door's maneuverability, ensuring pleasant air diffusion to adjacent rooms, and maintaining a clean line on a white wall with no visible casing.

We opted for a rear outlet configuration: the refrigerant connections and the condensate drain leave the unit directly behind the rear panel, without internal capping , to join the front. This approach eliminates visual clutter, protects the pipes and facilitates maintenance. The high positioning (approximately 2.1–2.2 m) promotes air mixing and frees up space for everyday use in a passageway.

What we did, step by step

Technical visit and sizing

At AirGreen, the selection of capacity (BTU) is based on the surface area, orientation, thermal envelope, and occupancy habits. For a typical Rosemont apartment, the common range is between 9,000 and 18,000 BTU for the main head. We validate:

  • load losses and column heights linked to the route,

  • electrical compatibility for a dedicated 240 V circuit (15 A or 20 A depending on capacity),

  • location of the outdoor condenser with compliant clearances and snow-cleared access in winter.

Template, anchors and clearances

We install the wall bracket on a solid structure (uprights), anchored if necessary in the masonry. Clearances are respected: top, sides and in front of the unit to guarantee maintenance, access to the filter and performance measurement . Above a door, the horizontal alignment and the setback from the frame avoid turbulence directly on the opening.

Drilling and sealing

A single through-hole is made with a controlled slope (≈ 5–10 mm towards the outside) to ensure gravity drainage of condensates. We install a sheath and then carefully seal (closed-cell foam + exterior sealant) for a continuous air-water-vapor barrier. This detail improves comfort and energy performance by limiting infiltration.

Refrigeration connections and insulation

Annealed copper tubing (typically 1/4"–3/8" for 9–12 kBTU or 1/4"–1/2" for 15–18 kBTU) is smoothly rolled out and flared to Gree's recommended sizing. High-density insulation is joined and sealed at the connections to cut off any thermal bridges and prevent condensation . On the outside, the pipes are protected by a UV-protected cover that matches the facade when visible; here, the direct rear outlet makes the connections almost invisible from the inside.

Condensate drainage

Gravity drain is preferred: no pump, no additional noise, less maintenance. We check the slope up to the outside discharge and install an air trap if required by the configuration.

Power supply and protections

Connection to a dedicated circuit breaker with a compliant external disconnect. Grounding, sealing of penetrations, and length management to limit any voltage drop. Circuit labeling in the panel.

Pressurization, vacuuming and commissioning

  • Nitrogen test to check for leaks,

  • deep vacuum draw to the levels expected by the manufacturer,

  • opening of valves, functional tests in cooling and heating modes,

  • adjustments to the shutters to direct the airflow towards the kitchen and living room, not towards the door,

  • checking superheat/subcooling and currents.

Expected result

A silent system, gentle diffusion along the corridor axis and uniform comfort in the adjoining rooms. The high position clears the passage, reduces exposure to shocks and simplifies filter cleaning .


Why a Gree R-32 for Montreal?

New generation efficiency and refrigerant

The Gree R-32 wall-mounted series combines high seasonal efficiency with a reduced carbon footprint compared to R-410A. On our construction sites in Montreal, these units demonstrate:

  • reliable heating in cold weather , with extreme cold versions capable of maintaining useful power at −25 to −30°C depending on the series;

  • inverter modulation which precisely adapts the power to the needs, limiting the short cycle in mid-season;

  • low noise levels , appreciable in a corridor.

Eligibility for programs

Depending on the capacity and series selected (approved, high-efficiency, and extreme cold models), the installation may be eligible for grant programs in effect in Quebec. We support customers from start to finish: documentation, AHRI numbers , technical data sheets, and proof of compliant installation.


Salient installation details to remember

  • Head above a door : respect clearances and direction of the airflow to avoid turbulence on the opening and push the air towards the living areas.

  • Rear outlet without interior cover : clean aesthetics, protected pipes and minimized pressure loss .

  • Gravity drainage : increased reliability, no condensate pump and silence .

  • Sealed perforation : continuity of the air barrier and watertightness.

  • Fine adjustments during commissioning: shutters, anti-frost detection, calibration of modes for the Montreal climate .


Good practices and pitfalls to avoid

Best practices

  • Size capacity (BTU) based on a realistic heat load , not just surface area.

  • Place the head high up in a central area, with a clear view of the rooms to be served.

  • Promote a gravity drain and control the slope every meter.

  • Protect the exterior connections with UV cladding coordinated with the facade.

  • Document the installation: photos, AHRI number, commissioning parameters .

Pitfalls to avoid

  • Install too close to the ceiling or molding : risk of recirculation of hot/cold air and noise.

  • Blowing directly onto a narrow corridor without directing the shutters towards the rooms: discomfort and stratification .

  • Under-insulate pipes: condensation, leaks and stains on walls.

  • Forgetting the external disconnect or the dedicated circuit: non-compliance and difficult diagnostics.

  • Neglecting vacuum and nitrogen testing: performance and longevity suffer.


HVAC maintenance: simple and profitable

Annual maintenance ensures stable performance:

  • Cleaning the filters (every 4–8 weeks during peak usage),

  • inspection of the drain and external discharge,

  • control of intensities , fans and cleanliness of the exchanger,

  • checking the condenser supports , snow clearance and cowling.

We offer HVAC maintenance plans tailored to apartments and plexes in Montreal, Laval, Longueuil, North Shore and South Shore .


Frequently Asked Questions (selection)

Can it be installed above a door?
Yes, if the clearances are respected and the shutters are adjusted to direct air into the rooms. This is often an excellent aesthetic compromise in a hallway.

Condensate or gravity pump?
Gravity is preferred when the architecture allows it: silence , reliability and less maintenance.

What are the installation times?
After technical validation and procurement, we plan the intervention with a slot that minimizes the impact on the occupancy of the accommodation. The installation of a single-head wall is generally done during the day , commissioning included.


AirGreen, local HVAC partner

Based in Greater Montreal , we manage each project from design to commissioning , including grant documentation and maintenance . For a high-performance Gree wall-mounted heat pump , carefully integrated and designed for our winters, our team delivers a clean, durable and compliant installation.

Need an on-site estimate for a similar project in Rosemont, Laval , Longueuil , North Shore or South Shore ? We come, we measure, we advise, and we install.


Keywords: heat pump , wall-mounted air conditioner , HVAC installation , HVAC maintenance , Montreal , Laval , Longueuil , North Shore , South Shore , Gree , R-32 , extreme cold .

The steps

The big day, step by step

The main steps of this kind of job at AirGreen. Every house has its quirks: the estimate brings them out.

Step 1 of 9The on-site estimate

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.

  1. 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.
  2. The quoteModel, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
  3. Getting readyFloors and furniture protected, wall plate position marked level, wall opening located.
  4. The wall openingA single opening, with the slope the drain needs to flow outside.
  5. The outdoor unitSet on a stand raised above the snow, with the clearances the manufacturer requires.
  6. Lines, cable and drainConnected, insulated and protected. The opening is then sealed against water, cold air and insects.
  7. The electrical workA dedicated circuit and an accessible disconnect near the outdoor unit.
  8. Tests and start-upLeak test, vacuum, then start-up and a check of heating and cooling.
  9. The walkthroughRemote, modes, filters: we show you the essentials before we leave.
Your numbers

What would it look like at your place?

Two quick checks with real numbers: what heat costs, and what your current heaters add up to in BTU/h.

Size checkYour baseboards, in BTU/h
–BTU/h of installed electric heat

    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.

    Mistakes avoided

    Four mistakes we do not make

    Flip each card to see what we do instead.

    Going further

    Your own project, step by step

    Through the seasons

    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.
    At your place

    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.

    0 / 6 checked
    True or false

    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.

    2. You pick the capacity with a simple square-footage rule.

    3. A multi-zone connects several indoor heads to a single condenser.

    4. The disconnect can sit behind the patio furniture.

    Frequently asked questions

    What people ask us about this kind of work

    12 questions
    Does a wall-mounted heat pump heat in winter?
    Yes, it heats and cools. Its capacity drops in very cold weather; the operating range depends on the model and is listed on its spec sheet.
    Wall-mounted or multi-zone: how do I choose?
    One wall head and one condenser outside: the direct solution for a room or an open area. For two to five rooms, a multi-zone puts one head in each room on a single condenser.
    Where does the outdoor unit go?
    Where it stays above the snow, clear and accessible, away from walkways. We decide it with you during the estimate.
    Are there grants?
    Depending on the model and your situation, assistance programs may apply, including Hydro-Québec's LogisVert. AirGreen checks the model number before quoting an amount. See the grants.
    Do I need a permit?
    Rules vary from city to city: location, distances, noise. See permits and by-laws, and we check for your address.
    How cold can it heat?
    It depends on the model. According to Hydro-Québec, newer models work down to a temperature between −15 °C and −25 °C, and some cold-climate models are certified lower. The minimum temperature is on each unit's spec sheet.
    How much can I save?
    Hydro-Québec says a heat pump can be up to three times more efficient than baseboards for heating in the colder months. The result depends on the house, the climate and how it is used.
    How is the LogisVert assistance calculated?
    For ENERGY STAR cold-climate certified heat pumps, Hydro-Québec lists assistance of $120 per 1,000 BTU/h of heating capacity at −8 °C. AirGreen checks the exact model before quoting an amount; only Hydro-Québec confirms the assistance granted. See the grants.
    Is it noisy?
    The sound level depends on the model and is listed in decibels on each unit's spec sheet. Location matters too: when possible, we avoid putting the outdoor unit under a bedroom window.
    The outdoor unit is covered in ice: is that normal?
    Some frost is: the unit runs defrost cycles. Never hit the ice. If the unit stays iced up or stops heating, call us.
    Does AirGreen hold the required licences?
    Yes. AirGreen holds RBQ licence 5645-9605-01, subclasses 15.8 Ventilation, 15.10 Refrigeration and 16 Electricity.
    Is the estimate free?
    Yes. The on-site estimate is free and the quote follows within 24 hours. Book my free estimate.

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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).

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