Discreet and efficient summer comfort, perfectly integrated into a Montreal apartment
At AirGreen , we design each HVAC installation to integrate with the lifestyle and architecture of Greater Montreal's housing. In this project in Côte-des-Neiges–Notre-Dame-de-Grâce , we are replacing an aging unit with a Danby through-the-wall air conditioner ( PTAC/through-the-wall family), chosen to provide reliable and quiet air conditioning in a bright living room with hardwood floors, an electric baseboard heater at the bottom of the wall, and a large side window.
Why choose a through-the-wall air conditioner (PTAC) in this context?
The through-the-wall air conditioner meets several requirements typical of Montreal apartments and condominiums:
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Compact and aesthetic footprint : the unit fits into a wall sleeve and a finishing frame ; no external condenser on the ground or on the balcony.
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Localized performance : ideal for efficiently air conditioning a large living room or bedroom, without complex refrigeration work.
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Reduced noise : vibrations are dampened by the sleeve and seals; the outer face directs airflow and noise to the outside.
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Easy maintenance : front access to the washable filter; easy cleaning of the coils during HVAC maintenance visits.
The Danby brand: practicality, availability and service
Danby is a well-known brand for through-the-wall air conditioners, which come in a variety of capacities (typically 8,000 to 14,000 BTU ). Key points that make us recommend them for this type of home:
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Precise electronic controls , timer and multiple fan speeds.
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Dry and Auto modes useful during humid inter-seasons.
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Electrical safety with plug incorporating a reset device.
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Parts and service available in the metropolitan area, which speeds up interventions.
Detailed description of the installation
Our team proceeds in stages to guarantee a clean, lasting and safe result.
1) Preparation of the wall and the sleeve
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Checking the existing wall sleeve : rigidity, peripheral sealing and outward slope (approximately 6–8 mm) to promote gravity flow of condensates.
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Re-sealing of the seals around the interior frame to eliminate any air gaps that could create hot infiltrations in summer or cold infiltrations in winter.
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Installation of a rigid finishing frame , flush with the painted wall for a clean finish around the appliance.
2) Electrical configuration
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Check the dedicated circuit (15 A or 20 A depending on the appliance's power) and the polarity of the socket. No extension cord should be used; the cable must go directly to the approved socket.
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Check the clearance of existing electric baseboards to prevent any overheating or recirculation of hot air towards the air conditioner inlet.
3) Setting up the Danby unit
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Sliding the device into the sleeve until it locks; installing anti-vibration pads to limit the transmission of structural noise.
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Alignment of the front panel to the frame; checking the firmness of the slats and the insufflation grid.
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Functional test: start in Cool mode, temperature differential control, verification of condensate flow and ventilation speeds.
4) Finishing and site cleanliness
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Straightening and discreet channeling of the power cable for a clean passage along the wall.
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Advice to the owner on the use of net curtains and blinds : leave the front grille clear and avoid any obstacles within 30 cm.
Constraints encountered and solutions provided
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Proximity to an electric baseboard : we have validated the minimum clearances and oriented the insufflation to prevent cold air from “recirculating” immediately towards the device.
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Wall adjacent to a large window : in order to avoid direct solar gain which distorts the temperature reading, we positioned the probe away from the rays and set the median speed during the day for stable regulation.
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Internal sealing : a small gap around the edge of the frame has been sealed to eliminate thermal bridges and prevent odors or dust from entering from the outside.
Sizing and comfort obtained
For a 20-30 m² living space in a well-maintained apartment, the typical capacity is between 9,000 and 12,000 BTU . The Danby selected comfortably covers these needs, with:
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Rapid cooling in the early afternoon when the solar energy is strong on the bay window;
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Effective dehumidification in Dry mode during humid episodes;
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Pleasantly contained interior noise level thanks to Low speed in the evening.
Good operating practices
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Leave at least 20–30 cm free in front of the grille to ensure even air distribution .
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Avoid extension cords or multiple sockets: the compressor requires a starting current; a dedicated socket is essential.
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In the event of a storm, activate the plug protection (“reset/test” button) if a power outage occurs.
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Keep the adjacent window closed during use; any entry of hot air deteriorates performance and increases consumption.
Maintenance recommended by AirGreen
Simple and regular HVAC maintenance maximizes the longevity of this type of device:
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Monthly filter cleaning during the warm season.
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Gently dust the evaporator battery (interior) and visual inspection of the condenser battery (exterior side) through the facade.
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Annual check of the slope of the sleeve and the condensate drainage hole .
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Checking the electronic controls (keyboard and remote control), the temperature sensor , and the silent blocks .
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At the end of the season, install an exterior winter hood compatible with the facade to prevent the infiltration of cold air and dust.
What to avoid
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Obstruct the exterior facade (bins, canvases, decorations): the machine must breathe freely.
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Block the condensation gutter : condensation water must drain outside; stagnation creates odors and can freeze in spring/autumn.
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Install above a heat source (radiator in operation) without sufficient clearance: this disrupts thermoregulation and the compressor works unnecessarily.
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Forget about sealing : small gaps around the frame result in significant energy losses and a feeling of draft.
Subsidies and alternatives
PTAC through-the-wall air conditioners are generally not eligible for grant programs focused on electrification and heating efficiency. If a customer is interested in financial assistance , we offer certified wall-mounted heat pumps (mini-splits) or central heat pumps , capable of heating efficiently down to -25°C/-30°C . In this case, our team performs a thermal analysis and compares the investment, annual consumption and maintenance to recommend the most cost-effective solution.
Security and Compliance
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Appliance plugged into an approved outlet corresponding to the required amperage, with an appropriate circuit breaker on the panel.
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Cabling runs neatly along the wall; no cables cross unprotected passageways.
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Respect the clearances around the exterior facade in accordance with the manufacturer's recommendations.
A careful project, a lasting result
The Danby unit installed in Côte-des-Neiges–Notre-Dame-de-Grâce now offers consistent summer comfort , without requiring any floor or balcony space, and with a sleek aesthetic thanks to the interior frame. The quality of the installation —controlled slope sleeve, resealed seals, secure power supply—guarantees long-lasting performance and simplified maintenance.
For co-owners and building managers in Greater Montreal who want to quickly modernize their homes without major renovations, the PTAC/through-the-wall solution remains a very relevant option. And when annual savings and grant objectives come into play, our team guides you toward the appropriate heat pump (wall-mounted, multi-zone, or central), always with a professionally installed HVAC system .
Our AirGreen support
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On-site assessment : BTU sizing, thermal load, noise and architectural constraints.
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Appliance selection : Danby or other brands available depending on capacity, voltage and required exterior facade.
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Turnkey installation : sleeve, joints, finishes, testing and commissioning.
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Preventive maintenance : scheduled visits at the start/end of the season to maintain the performance and cleanliness of the coils.
Do you want to replace an old wall-mounted unit, improve the comfort of a main room, or compare it with a wall-mounted heat pump ? We operate in Montreal, Laval, Longueuil, on the North Shore and the South Shore , with solutions adapted to the reality of each building.

3 comments
J’ai besoin d’un air conditionné throught the wall grandeur maximale 25 pouces largeur du trou par 15 pouces hauteur
J’ai besoin d’un air conditionné throught the wall grandeur maximale 25 pouces largeur du trou par 15 pouces hauteur
J’ai besoin d’un air conditionné throught the wall grandeur maximale du trou est de 25 pouces de large et 15 pouces de hauteur