Installation of a Gree wall-mounted heat pump (2 individual zones) in Rosemont–La Petite-Patrie

Two discreet outdoor units, a rigorous installation strategy: stable comfort and efficiency in urban environments

In a typical brick plex in Rosemont–La Petite-Patrie , we installed twoGree wall-mounted heat pumps, each supplying a separate indoor zone. The client's goal: to modernize summer and interseasonal comfort without transforming the building's architecture, while still allowing room for a possible third room to be air-conditioned later. Our approach: two independent single-zone systems to gain redundancy, ease of service, and room-by-room control.

Why two single-zone wall-mounted heat pumps rather than a multi-zone?

In many buildings in Greater Montreal, installing two individual wall-mounted heat pumps offers concrete advantages:

• Independence and redundancy : if one unit stops, the other continues to ensure the comfort of its area.

• Low temperature heating performance often superior at partial load compared to an undersized multizone.

• Simplified maintenance : clear diagnosis, less expensive parts, limited downtime.

• Scalability : possibility of adding a third unit later without disrupting the first two.

For this project, the client wanted to air condition a living room and a bedroom located on the same side of the building. We therefore positioned the two Gree condensers side by side on the rear facade, optimizing the passage of the refrigeration connection in a discreet vertical capping .

Brand and range selected

We selected Gree , a manufacturer renowned for its robust, quiet, and efficient residential wall-mounted heat pumps . The selected range covers summer air conditioning and interseasonal heating needs, with good energy efficiency and compact components adapted to the narrow facades of Montreal plexes.

Practical note: when the power required per room exceeds 9,000 BTU or when the envelope is poorly insulated, we size on a case-by-case basis (12,000/15,000 BTU) based on a thermal load calculation, in order to avoid oversizing which leads to cycling, noise and reduced efficiency.

Reading the site and preparing

• Brick rear facade overlooking a gravel roof terrace: perfect for working safely and limiting the visual impact from the street side.

• Controlled height : Condensers are mounted on wall brackets above the roof level to remain out of reach of water splashes, ice and snow accumulation.

• Electrical access : presence of a power supply nearby, allowing the addition of external disconnect boxes and compliant conduit wiring .

• Reversible path : a sand-colored vertical capping (harmonizing with the brick) centralizes the two refrigeration line paths and then separates them towards each unit — a clean and scalable solution.

Key steps of installation

1) Wall mounting and anti-vibration

Each condenser rests on a pair of galvanized brackets sized for weight and defrost thrust. We interpose silent blocks to limit the transmission of vibrations to the masonry. The base respects the lateral and rear clearances prescribed by the manufacturer, as well as the minimum center distance between the two machines to guarantee good air recirculation .

2) Drilling and sealing

We make targeted outward-sloping penetrations , sheathed and sealed with a brick/wood-compatible sealant. Inside, the penetrations are capped with rosettes for a clean finish. Outside, the capping protects the UV-insulated copper connections, the communication cable, and the power cable where permitted by code.

3) Refrigeration connections and brazing

The oxygen-free copper tubes are brazed under nitrogen to prevent internal oxidation. The Armaflex insulation is joined and sealed to the flare fittings with a UV-resistant sealant. Each circuit remains independent (single-zone), which facilitates subsequent vacuuming , leak testing and recharging if necessary.

4) Condensate management (interior)

The indoor units, installed above the living areas, are drained by gravity (prioritized whenever the layout allows). Slopes are checked at the level and the discharge is directed to a discreet and accessible point for maintenance. No condensate pump was required here, which reduces noise, consumption, and maintenance.

5) Electricity and protections

Each condenser is protected by its sealed disconnect box and connected according to the manufacturer's rated amperage. The circuit breakers in the panel have been sized according to the conductor gauge and starting/rated amperages. Grounding is tested. The assembly meets the requirements of the Canadian Electrical Code .

6) Vacuum drawing, testing and commissioning

We perform a deep vacuum (< 500 microns) and a strength test to verify the leak tightness. The factory refrigerant charges, sufficient given the installed lengths, are validated with the manufacturer's electronic scale and charts. Once in operation, we monitor the superheat/subcooling parameters and compressor current to confirm stability.

Integration details visible on the facade

• Two Gree condensers mounted on brackets, spaced to prevent recirculation of hot air.

• Unique vertical capping , neutral color, which receives two sets of lines.

• Rigid electrical conduits and watertight disconnect boxes in close proximity to the units for safe service .

• Management of shortest routes : compact horizontal connections to limit load losses and drops in efficiency.

• Installation height adapted to Montreal winters and roof snow removal operations.

Results obtained

• Zoned comfort : The bedroom can operate at a cooler temperature at night, while the living room is adjusted according to occupancy.

• Noise reduction : the anti-vibration installation and the orientation of the fans reduce the nuisance perceived by occupants and neighbors.

• Visual sobriety : capping and short paths preserve the aesthetics of the brick.

• Easy maintenance : two independent circuits, free access to service panels, clearances respected.

HVAC Operation and Maintenance Tips

• Internal filters : vacuum/rinse every 4 to 8 weeks during peak season.

• Outdoor heat exchangers : gently rinse the fins in spring/fall; avoid high-pressure jet.

• Defrost : When heating in humid/cold weather, a defrost cycle is normal; let the unit work.

• Clearances : Keep 60–90 cm free in front of the condensers; no objects or planting containers stuck to the grid.

• Maintenance Visits : Annual HVAC maintenance by our AirGreen technicians ensures stable performance and extends lifespan.

Grants and Compliance

Recent wall-mounted heat pumps , when they meet seasonal efficiency and cold weather performance criteria, may be eligible for current provincial/municipal grant programs . Our team assists clients in Montreal, Laval, Longueuil, the North Shore, and the South Shore in verifying criteria, preparing documents, and validating proof of installation.

Why AirGreen for your HVAC installation in Montreal?

• Rigorous sizing based on actual load, not assumptions.

• Clean finishes : harmonized cappings, controlled drilling, durable seals.

• Service : clear deadlines, follow-up after commissioning, availability of standard Gree parts.

• Warranty : device registration, documentation provided to the customer, usage instructions.

Whether you are considering a single wall-mounted heat pump for your condo, or a multi-zone configuration for a duplex, our team offers tailor-made, reliable solutions optimized for the architecture of Greater Montreal .

Express FAQ

What power should I choose per room?
We calculate it based on orientation, glass areas, insulation, floor, and number of occupants. A "standard" room might require ~9,000 BTUs, but a conservatory or cathedral-ceilinged living room will require more.

Two single zones or one multi-zone?
If rooms are far apart or you want redundancy , two single zones are often the best option. If you need to power 3–4 compact heads with a single external discharge, multi-zone becomes relevant.

Where to place the condensers?
Sheltered from snowdrifts, with sufficient clearance for ventilation and maintenance . Wall brackets above a roof terrace, as seen here, are an excellent compromise in a dense environment.

In summary

This installation in Rosemont–La Petite-Patrie illustrates a simple and efficient method: two independent Gree wall-mounted heat pumps , installed on wall brackets , with centralized capping , protected electricity and short cooling paths . The result: modular comfort, controlled aesthetics, simple maintenance and long-term investment.