A well-cleared wall-mounted condenser under the terrace: performance and longevity for a HoMa duplex
On the ground floor of a typical Montreal duplex, we installed a Zephyr wall-mounted heat pump with an outdoor condenser mounted on galvanized brackets , partially sheltered by a wooden deck. This HVAC installation was designed to combine winter reliability , silence and maintenance access in a narrow backyard—a common configuration in Mercier–Hochelaga-Maisonneuve .
Architectural context and client objectives
HoMa's backyards require short, clean, and robust paths. Here, the owner wanted:
-
efficient additional heating in winter, to reduce the use of baseboards;
-
discreet air conditioning in summer without encroaching on the terrace space;
-
assembly free from snow and thawing splashes ;
-
a simple system to maintain , with accessible parts .
The choice of wall mounting under the terrace meets these challenges: the unit remains clear of the ground, protected from falling ice, while maintaining good air flow .
Implementation details: what we optimized
Supports and decoupling
-
Condenser fixed on wall brackets adjusted by laser to ensure perfect horizontality .
-
High-density anti-vibration pads under the sole to reduce the transmission of vibrations to the masonry.
-
Center distance and anchors sized for dynamic load (de-icing, wind, icing).
Refrigerant path and drain management
-
Insulated copper connections running left in a UV-resistant white capping ; controlled bend radius to preserve oil return .
-
Joints brazed under nitrogen, then pressurized and drawn to a deep vacuum before opening the fluid.
-
Winter condensate drainage directed towards a permeable area of the yard to prevent the formation of ice slates .
Power supply and safety
-
External disconnect box installed within easy reach (maintenance plan).
-
Dedicated circuit from the main panel, gauge and cable conforming to RBQ/CSA requirements.
-
Grounding verified; mechanically protected path under the terrace.
Clearances and air circulation under the terrace
-
Respect side and front clearances to prevent the recycling of hot air during defrosting.
-
Terrace underside high enough not to disturb the plume; correction of two obstacles (twisted blade and movable slat) in order to free the blowing.
-
Provision for a removable deflector if future developments reduce spacing.
Why Zephyr for this project?
The Zephyr brand offers wall-mounted heat pumps that are popular for:
-
their silent operation on the rear panel;
-
stability in heating at low temperatures (optimized defrost mode);
-
a modulating inverter electronics which adjusts the power to actual demand ;
-
easy maintenance (easily accessible housings and filters).
In a Montreal duplex, these advantages translate into: uniform comfort , energy savings and low noise impact for neighbors in the yard.
Key steps in our HVAC installation
-
Taking measurements : measuring clearances under the terrace, checking the wall support (concrete block/brick), recording existing openings.
-
Installation of supports : mechanical sealing, anti-corrosion treatment of sensitive points.
-
Drilling and passage : single sealed drilling with sleeve and vapor barrier to prevent any infiltration of cold air.
-
Brazing and sealing : nitrogen brazing, prolonged pressure test , vacuum < 500 microns , strength control.
-
Wiring and powering up : functional tests, calibration of heating/air conditioning settings .
-
Commissioning : checking superheating/subcooling , checking the direction of fan rotation , validating the intensities .
Results: four-season comfort and preserved maintenance access
-
In wall-mounted air conditioner mode, the power is progressive and the air flow remains free under the terrace: the courtyard remains calm, without direct airflow on the relaxation area.
-
In heating , defrosting is done efficiently; water drainage is controlled to avoid slippery patches along the lower rail.
-
Access to the unit, disconnection and refrigeration connections is direct: annual maintenance is quick, therefore less expensive.
Best practices we recommend to the owner
-
Clear 30 to 45 cm around the condenser all year round (wood, objects, planters).
-
Do not close off the basement with a privacy screen that is too close together: ventilation is essential.
-
Clear snow from the air discharge area in winter and avoid piles of snow under the unit.
-
Seasonal cleaning of the inner head: vacuum the filters every 4–6 weeks during periods of use.
-
Spring inspection : tightening of fasteners, checking of silent blocks , purging of drain.
Grants and Eligibility
High-performance wall-mounted heat pumps may be eligible for financial assistance when efficiency and cold weather performance criteria are met. We support our customers in Montreal , Laval , Longueuil , North Shore and South Shore with: photos, serial numbers, certificates and proof of electrical compliance required for applications.
What AirGreen delivers, beyond installation
-
Precise sizing according to the surface area, orientation and envelope of the building.
-
Choosing the shortest and most aesthetic route to limit losses and simplify maintenance.
-
Complete documentation (pressurization, vacuum, commissioning) for manufacturer's warranty .
-
User training : seasonal adjustments, HVAC savings and maintenance tips.
-
Responsive after-sales service and parts available.
Why this under-terrace installation is a winner at HoMa
Montreal backyards face a multitude of challenges: snow , thaw , narrow passages , close neighbors . A Zephyr condenser mounted on brackets under the deck:
-
stays out of accumulations and does not eat up floor space;
-
benefits from natural protection against direct sun and showers;
-
limits sound propagation to the upper floor and neighbors;
-
maintains easy access for annual maintenance.
It is an optimal compromise between durability , aesthetics and thermal performance for the plexes of Mercier–Hochelaga-Maisonneuve and, more broadly, of Greater Montreal .
Quick to use fair
-
In heating: maintain a stable setting (21–22°C) to avoid short cycles.
-
In air conditioning: aim for 23–24°C , with the shutter swinging to homogenize the rooms in a row.
-
Prolonged absence: activate eco mode rather than turning off completely in winter.
-
Schedule annual maintenance : cleaning the evaporator, checking pressures and drain emptiness.
Balance sheet
This Zephyr wall-mounted heat pump installation on wall brackets under the terrace, in Mercier–Hochelaga-Maisonneuve , illustrates AirGreen's expertise: controlled route , respected ventilation , compliant electricity and clean finish . The customer now benefits from four-season comfort with optimized consumption , and a system ready for grant procedures when the chosen performance qualifies for it.