Plan, prepare, install: how to ensure your wall-mounted AC installation in Montreal is a total success
Installing a wall-mounted air conditioner in Montreal, whether in a Plateau apartment, a house in Ahuntsic, or a downtown condo, is far more than just mounting a unit on the wall. It’s a technical project that requires careful preparation, an in-depth understanding of the building and the unit itself, and proven expertise to avoid costly mistakes or disappointing results. At AirGreen, we’ve helped hundreds of clients in Montreal, Laval, Longueuil, on the North Shore and South Shore with wall-mounted AC installations that are reliable, high-performing, and free of surprises.
Here are our top 10 professional tips to guarantee an installation that’s smooth, cost-effective, and worry-free—based on real-world experience from our work in the field.
1. Choose a wall-mounted air conditioner suited to your actual needs
The choice of BTU capacity is critical. If the system is too powerful, it will consume more energy than needed and cost more upfront. If it’s too weak, it won’t cool the space efficiently.
➡️ Real example: In Villeray, we installed a 12,000 BTU Gree Lomo wall-mounted AC in a 650 sq. ft. condo with moderate insulation. A precise thermal evaluation showed this was the perfect size, avoiding unnecessary costs.
AirGreen tip: Have a thermal assessment done by a CVAC professional that takes into account sun exposure, insulation, number of occupants, and electronic devices in the space.
2. Check for eligibility for grants before making a purchase
Many grants, like the Hydro-Québec LogisVert program, can save you up to $1,860 when installing an eligible unit.
➡️ Client example: On the South Shore, a couple in Brossard received a $1,704 rebate for installing their 18,000 BTU Gree Extreme wall-mounted air conditioner.
AirGreen tip: Reach out to our team before buying—we’ll guide you toward certified models that qualify for current rebate programs.
3. Avoid improvised or non-compliant installations
We often see serious errors in installations performed by non-specialized contractors: crooked units, improper drainage slope, poorly insulated refrigerant lines…
➡️ Real-world case: In Montreal-North, we had to completely reinstall a Sharp ZU1 wall-mounted AC that had been poorly mounted, causing excessive vibration due to a non-reinforced drywall wall.
AirGreen tip: Always hire CVAC-certified professionals with experience working on buildings in the Montreal area.
4. Carefully select the indoor and outdoor unit placement
The indoor unit should allow for proper airflow and avoid blowing directly onto a bed or resting area. Outdoors, the unit must be protected from the elements and accessible for maintenance.
➡️ Client case: In Verdun, we moved the outdoor unit from a sun-exposed balcony to a shaded corner of the building, which reduced thermal load and extended the unit’s lifespan.
AirGreen tip: We always propose several placement scenarios, with clear explanations of the benefits of each.
5. Ensure electrical compliance before installation
Wall-mounted AC units often need a dedicated electrical line, especially models over 18,000 BTU. A certified electrician must check the setup beforehand.
➡️ Longueuil job site: During the installation of a 24,000 BTU Tosot wall-mounted AC, our electrician found that the panel was full. We added a sub-panel, preventing an unsafe overload.
6. Plan for future maintenance from the start
Ensure easy access to filters, coils, and connections from day one. This will make future maintenance easier, extend the unit’s lifespan, and ensure optimal efficiency.
➡️ Practical tip: In Laval, we installed a Fujitsu KZAH wall-mounted AC leaving 15 cm of space around the unit, ensuring optimal access for future cleaning.
7. Ask for a complete system test after installation
Every installation must end with pressure tests, leak detection, full startup, and checks of the remote control, drainage, and eco-mode.
➡️ At AirGreen, our technicians run through a 30-point verification checklist before signing off on the installation.
8. Protect your walls and building during the installation
Clean cable routing, careful drilling, and neat finishing are essential—especially in older Montreal buildings.
➡️ On the North Shore, in Sainte-Thérèse, our team installed a Zephyr wall-mounted AC in a century-old brick duplex without damaging the interior walls, using exterior conduits painted to match the brick.
9. Install a drain pan and heat cable if needed
In winter, outdoor drainage can freeze, causing water backups or breakdowns. A drain pan with heating cable prevents these issues.
➡️ Winter install: A project in Saint-Lambert included a heated pan for an Elios wall-mounted AC, preventing freezing problems during mild winter spells.
10. Get a clear, written, and comprehensive warranty
A properly installed wall-mounted AC can last over 12 years. Make sure the warranty covers parts, labor, and installation.
➡️ AirGreen guarantee: Our installations are covered by up to 12-year warranties, depending on the model, and we offer local, fast, and professional after-sales service.
Why choose AirGreen for your wall-mounted air conditioner installation in Montreal?
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Local expertise: We understand the buildings and climate realities specific to Montreal, Laval, Longueuil, North Shore, and South Shore.
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Safe, professional installation: All our technicians are certified and receive ongoing training.
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Maximized grants: We help you get the most out of available rebate programs.
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Personalized service: Every project is unique. We tailor our solutions to your space, needs, and budget.
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Proven customer satisfaction: Hundreds of satisfied clients across Greater Montreal.
Planning a wall-mounted AC installation in Montreal?
Get in touch with our team today for a free, fast, and detailed quote. At AirGreen, we guarantee a stress-free, no-surprise experience that delivers long-term comfort.