Context: a rooftop condenser, zero compromise on waterproofing
At AirGreen , we were called in to equip a Rosemont–La Petite-Patrie home with a Sharp wall-mounted heat pump . The building has a flat gravel roof , typical of Montreal. The client wanted a quiet , economical , and reliable system in winter , without weighing down the facade or encroaching on the courtyard. The solution was obvious: installing the condenser on the roof , with supports that protect the membrane, and a clean, sealed refrigeration path to the interior wall header.
Why Sharp (ZU range) ?
Sharp 's Eco Inverter series is distinguished by:
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an inverter compressor that finely adjusts power, synonymous with energy savings and stable comfort ;
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Ion Plasmacluster technology (Sharp trademark) which improves indoor air quality ;
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a recent wall-mounted design operating with new refrigerants and adapted to the low temperatures of Greater Montreal .
In terms of usage, this means: efficient heating in the off-season and in winter , gentle and even cooling in summer, and low noise levels both indoors and outdoors — a crucial point in dense neighborhoods like Rosemont .
Visible installation details and key technical choices
We place the Sharp condenser on a raised aluminum support , itself resting on two treated wooden sleepers (beams) firmly fixed. This assembly:
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distributes the load on the gravel and prevents any perforation of the membrane ;
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provides sufficient ground clearance against snow accumulation and puddles;
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limits vibrations transmitted to the structure thanks to the wood/aluminum interposition.
The refrigeration path is protected by a white UV cover from the indoor unit to the roof (insulated copper connections + communication cable + power supply). In this type of building, we favor a short and straight path , with sealed passages at the crossings (walls/ceiling/roof). The total length is generally in a range of 7 to 12 m , perfectly compatible with the refrigerant charges of the range.
As for condensate drainage , we operate by gravity when the interior configuration allows it (natural slope), otherwise we integrate a silent mini-condensate pump that is accessible for maintenance.
Implementation steps — AirGreen method
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Preliminary checks
Analysis of the roof structure , the condition of the membrane , the surveys and flows . Survey of distances and heights from the future interior head. Identification of the electrical source and routing to the dedicated circuit breaker . -
Installation of supports
Assembly of the aluminum frame and wedging on treated beams . Installation of anti-vibration pads/spacers if required. Orientation of the condenser to free the blower and respect the clearances : free suction at the rear, clear blowing at the front. -
Drilling & sealing
Clean, small-diameter drilling for refrigeration connections, sheathing of the crossings, sealing with roof-compatible materials (mastic/flashing), then visual inspection and testing . -
Refrigeration connections
Flares compliant , tightening torque controlled, vacuum pumped to reach a deep vacuum level, leak test and commissioning according to the manufacturer's procedures. -
Electrical connection
Dedicated power supply with circuit breaker and proximity disconnect , grounding, polarity and cable section control. -
Calibration & testing
Power up, heating/cooling tests , checking currents , blowing temperatures , communication between units, control instructions and explanations to the customer.
Results: comfort, silence and aesthetics
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Immediate comfort : the temperature rise/fall is rapid and stable thanks to the inverter .
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Silence : the wall head operates at a low noise level in regulation, while the condenser, far from the facades and decoupled by the roof support, limits structural noise .
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Aesthetics : the white casing remains discreet on the facade; on the roof, the condenser is perfectly plumb and aligned for a professional look.
What we monitor on a Montreal flat roof
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Snow and wind : We plan the height of the support to avoid burial and ensure air intake . In very exposed areas, we may recommend a wind deflector or snow guard .
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Drainage : The condenser should never sit in an area of stagnant water .
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Maintenance access : clearances respected for cleaning batteries and diagnostics .
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Vibration : tightening, locknuts , and pads adapted to the wood/aluminum support.
Recommended maintenance (to maintain performance)
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Internal filters : regular cleaning to maintain air flow .
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Batteries (inside and outside): periodic dusting and gentle washing .
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Clearances : Keep the outdoor unit free of debris , especially after high winds.
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Annual inspection by our technicians: leak and charge check, electrical check, firmware update if applicable.
Regular maintenance ensures high yields , controlled energy bills and optimal longevity .
Energy performance & subsidies
Sharp 's latest wall-mounted heat pumps offer high efficiency in both heating and cooling. Depending on the selected BTU capacity and the low temperature operating range , the installation may be eligible for efficiency grants or programs (e.g., provincial and local initiatives). Our team systematically checks the eligibility of the selected model and supports the customer throughout the process (documents, proof of installation, certification numbers).
Sizing: the right BTU, no more
At AirGreen , we size the power (BTU) from:
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the surface area and insulation of the accommodation;
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from solar exposure and air infiltration ;
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occupation habits and possible support from other systems.
This approach avoids oversizing , which causes short cycles , noise and overconsumption , and guarantees constant comfort .
Pitfalls to Avoid (and How We Get Around Them)
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Leaky holes : on roofs, this is a no-go. We apply a proven roofing method (compatible materials, flashings, visual inspection and testing).
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Supports placed directly on the membrane : risk of abrasion . We interpose beams and frames and, depending on the membrane, suitable soles .
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Minimum clearances ignored : The Sharp condenser requires precise suction/discharge clearance . We check these dimensions before any final tightening.
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Oversized or poorly insulated refrigeration lines : performance losses, condensation. We adhere to the prescribed diameters and use UV-resistant closed insulation under the hood.
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Improvised condensate management **: we favor gravity ; failing that, a quality, silent pump , installed with anti-vibration and access .
Advice for owners in urban areas
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In co-ownership , notify the union : location, access route, work schedules . We provide you with technical sheets and implementation plans .
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For rented apartments , inform your tenants of the intervention periods . Our teams work with cleanliness and tight deadlines .
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In preparation for winter: Keep the perimeter around the condenser clear of snow, ice, and objects. Leave the unit in heat mode as instructed; avoid repeated power outages .
Why AirGreen ?
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HVAC specialists in Greater Montreal (Montreal, Laval , Longueuil , North Shore , South Shore );
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Controlled roof installations : waterproofing, supports, safety;
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Turnkey service : sizing, subsidies , installation, commissioning , HVAC maintenance .
The result: a Sharp wall-mounted heat pump that is well integrated into the urban life of Rosemont–La Petite-Patrie , ready to deliver efficient heating in winter and coolness in summer, with a durable installation that respects the building.
Quick Facts (Summary)
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Type : Sharp wall-mounted heat pump , Eco Inverter , Ion Plasmacluster
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Installation : flat gravel roof , aluminum support on wooden beams
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Route : connections under white cover , sealed crossings, typical length 7–12 m
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Objectives : 4-season comfort , silence , aesthetics and durability of the roof
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Maintenance : filters, batteries, clearances, annual AirGreen inspection
Need a similar installation?
We operate throughout Montreal , Laval , Longueuil , the North Shore and the South Shore . Our team guides you from the choice of machine to commissioning , with transparent support on performance , maintenance , and savings achievable.
Keywords : heat pump , wall-mounted air conditioner , HVAC installation , HVAC maintenance , Montreal , Laval , Longueuil , North Shore , South Shore , Sharp , Eco Inverter , Plasmacluster , flat roof , aluminum support .