A discreet and efficient HVAC system for an urban condo on the river
On a typical condo terrace in Nuns' Island , our team installed a Sharp ZU1 (R-32) wall-mounted heat pump designed to provide four-season comfort with a minimal visual footprint . The project showcases our approach to designing an elegant, robust HVAC system designed for the realities of a Greater Montreal condominium building.
Why the Sharp ZU1 for this project
The Sharp ZU1 is one of the new generation wall-mounted units using R-32 refrigerant , chosen for its heating efficiency in cold weather , its quiet operation and controlled consumption thanks to the Inverter compressor .
In a condo where outdoor space is limited and the peace and quiet of neighbors is paramount, this solution ticks all the boxes:
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Low temperature efficiency (stable heating even in the extreme cold of Montreal).
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Low noise level inside and outside.
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Reduced GWP compared to older R-410A systems.
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Compact design fits seamlessly into a narrow terrace.
Site context: constraints and objectives
The owner wanted:
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Replace an energy-consuming additional heater with a unique heating and air conditioning solution ;
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Preserve the aesthetics of the terrace;
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Avoid any transmission of vibrations to the structure.
The condo is located on a high rise, with patio door access and limited handling. Condominium regulations require specific clearances and the presence of an accessible electrical disconnect device .
Installation details visible on the site
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Raised aluminum support : anti-corrosion frame mechanically anchored to the tiled slab, raising the condenser to ~40 cm to promote drainage and protect against snow accumulation .
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Anti-vibration pads (blue plates) under the support points to isolate the structure and limit solid-borne noise towards the apartment and neighboring units.
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Very short refrigerant connections (≈ 2 m) passing through the exterior wall through a single hole with sealed sleeve and air barrier foam: reduced pressure losses, increased efficiency .
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Gravity drainage from the interior head: small PVC pipe exiting outside with a continuous slope and a safe termination to prevent splashing onto the coating.
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Dedicated power supply with sealed disconnect box in close proximity to the condenser for safe disconnection during maintenance.
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Clean routing : no unnecessary visible sheathing; the light color of the casing and accessories matches the facade.
AirGreen methodology: technical rigor from start to finish
To ensure long-term reliability, we systematically apply the following steps:
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Checking the clearances around the air intake and condenser exhaust, despite the proximity of the patio door and the guardrail.
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Crimping and brazing of fittings under nitrogen to prevent internal oxidation.
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Nitrogen leak test (high and stabilized) then deep vacuum < 500 microns until stabilization, proof of absence of humidity and leaks.
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Instrumented commissioning : temperature, pressure, current and subcooling/superheat readings to adjust operation to the actual profile of the condo .
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Remote control configuration and usage tips (shutters, Auto/Heat modes, anti-freeze management, programming).
Result obtained: comfort, silence and savings
The combination of short lines + detached support + R-32 results in:
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Rapid temperature rise in mid-season and stable heating during winter peaks;
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Minimal perceived noise on the terrace, conversation possible near the unit;
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Low power consumption , particularly in heating mode thanks to the high coefficient of performance of the ZU1;
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Easy maintenance (clear access, efficient defrosting, simple annual cleaning).
What we look for on this type of terrace
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Water management : slope and drain outlet away from traffic; prevention of frost in winter.
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Air discharge : avoid any recirculation towards the patio door open in summer; positioning respecting the side and rear clearances.
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Strength of anchors : torque-controlled tightening, sealing washers suitable for exterior tiling.
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Electrical routing : NEMA/CSA conduit and fittings resistant to UV and freeze-thaw cycles.
Recommended HVAC Maintenance for a Wall-Mounted Sharp
To maintain performance and lifespan:
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Cleaning of internal filters every 4–8 weeks of intensive use;
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Annual inspection by our technicians (exchanger, fans, tightening, leak test, refrigeration measurements);
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Clearance around the condenser at all times (leaves, snow);
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Check the drain in the spring to prevent overflows.
These simple actions prevent overconsumption and extend the reliability of the inverter compressor.
Grants and Eligibility
High-efficiency R-32 wall-mounted heat pumps like the Sharp ZU1 are generally eligible for Quebec energy efficiency programs when cold weather heating performance criteria are met. We assist our customers in Montreal, Laval, Longueuil, the North Shore and the South Shore in verifying criteria , preparing documents and submitting applications when applicable.
AirGreen support: from advice to commissioning
At AirGreen , we size and install the wall-mounted heat pump according to your envelope (orientation, glazing, sealing) and your use (night/day, teleworking, instructions). Our approach:
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Thermal load study and suitable BTU selection ;
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Implementation plan respecting co-ownership and RBQ/CCQ/CSA standards;
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Clean and fast installation with coordinated appointments;
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Documentation (photos of anchors, serial numbers, commissioning parameters) provided to the customer.
What if your project differs?
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Unique piece : an R-32 wall unit like the ZU1 is perfect.
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Multiple rooms : We offer Sharp Multi-Zone systems or GREE FreeMatch R-32 / Fujitsu Aquila R-32 alternatives.
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Ducted homes : Our R-454B central heat pumps (e.g., Midea EVOX G3) provide consistent comfort throughout the home.
Conclusion
This Sharp ZU1 installation on Nuns' Island exemplifies what we stand for: measurable performance , quietness , sleek aesthetics , and durability . In a demanding urban space, the combination of a raised, anti-vibration mount , a short, watertight connection , a well-designed gravity drain , and a secure power supply delivers a clean, efficient result—ready for many seasons of comfort.