Project

Installation of a Willis wall-mounted heat pump in Sainte-Julie

Installation of a Willis wall-mounted heat pump in Sainte-Julie , mounted on a wall bracket above the garage. A sustainable and energy-efficient HVAC solution, ideal for comfort and subsidies in Greater Montreal.

By AirGreen Climatisation & Chauffage Admin3 min read
Installation of a Willis wall-mounted heat pump in Sainte-Julie
Installation of a Willis wall-mounted heat pump in Sainte-Julie
–chapters in this story
3 minreading time
–type of installation
2026year 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

A custom installation for a modern South Shore home

At AirGreen , we understand that every HVAC installation project has its own unique characteristics. This is exactly what we found during this installation of a Willis wall-mounted heat pump in a residence in Sainte-Julie , on the South Shore of Montreal. The client wanted to optimize their comfort in both summer and winter while benefiting from a reliable, energy-efficient system that was eligible for available grant programs.


Why the Willis wall-mounted heat pump?

The Willis brand is renowned for its compact, high-performance units, ideal for residential properties in the greater Montreal area. In this case, the chosen model offered:

  • A capacity adapted to the needs of the house ( BTU sizing adjusted according to the surface area and insulation).

  • Stable operation in heating mode even at low temperatures.

  • Energy efficiency in accordance with the criteria of Quebec government programs .

  • Reliability adapted to the harsh winters of the South Shore .


Technical details of the installation

Our team installed the outdoor condenser on a galvanized steel wall bracket , securely fixed to the concrete facade adjacent to the garage. This configuration has several advantages:

  • Optimal ground clearance : protection against snow accumulation and debris.

  • Enhanced stability : robust mounting minimizes vibrations.

  • Easy accessibility for maintenance and periodic inspections.

The refrigerant lines and electrical wiring were carefully sheathed and connected to a sealed junction box, ensuring the safety and durability of the installation. The tubing length was optimized to reduce energy losses and maintain the machine's nominal performance.


The challenges encountered and our solutions

Every project presents its challenges. In this case, we were working on a decorative stone façade combined with a smooth concrete base. Our technicians used specialized anchors to ensure impeccable fixation without compromising the aesthetics or watertightness of the structure.

Another aspect concerned the working height. Since the unit was installed several meters above the ground, we used secure equipment to comply with workplace safety standards, while ensuring a precise and durable installation.


Results obtained

Upon completion, the client immediately noticed a difference in comfort and noise reduction. The Willis outdoor unit operates quietly, and the interior of the home benefits from even heating and cooling.

In addition to comfort, the owner now benefits from:

  • Significant energy savings on annual bills.

  • Eligibility for provincial and federal grants , which reduce the initial investment.

  • A scalable and sustainable system, capable of meeting seasonal needs efficiently.


AirGreen expertise in Sainte-Julie and throughout Greater Montreal

This project is a good example of our personalized approach: understanding the building's constraints, choosing the right machine, and executing a flawless installation. At AirGreen , we cover the entire Greater Montreal area, including Laval, Longueuil, the North Shore and the South Shore , with the same attention to detail and quality of service.

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.

    Could this job help a neighbour?

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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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