A precise exterior installation on a brick facade with a spiral staircase: performance, silence and durability in the heart of a Montreal plex
In this typical Plateau-Mont-Royal plex , our team installed aSharp wall-mounted heat pump ( ZU1 range, R-32 refrigerant) to ensure reliable heating and cooling all year round. The building, made of red brick with an exterior spiral staircase and white mullioned windows, imposes well-known implementation constraints in Montreal. Here we detail the routing of the connections , vibration management , facade fixing and best practices that guarantee high performance and simplified maintenance.
Project context and comfort objectives
The client was looking for:
-
4-season comfort for the main floor;
-
a discreet integration on the rear facade, courtyard side;
-
reduced operating costs compared to existing electric convectors;
-
a controlled noise level to preserve the peace and quiet of neighbors and the courtyard.
The solution chosen: a Sharp wall-mounted heat pump from the ZU1 (R-32) range , renowned for its heating capacity in cold weather and its efficient inverter . The unit serves an indoor head (day zone) in a single-zone configuration.
Installation details — brick facade and capped runs
Support and positioning
-
Condenser placed on galvanized wall brackets with anti-vibration pads .
-
Installation height : approximately 3.0 to 3.2 m from the finished ground — above the snow accumulation zone and away from projections.
-
Clearances respected around the exchanger to ensure free air intake and discharge , even near the metal staircase.
Refrigeration and electrical routing
-
Refrigerant lines covered in white PVC : a vertical segment from the interior head (inside, behind the upper window) then a horizontal segment to under the condenser.
-
Estimated total length : 3 to 4 m , ideal for limiting pressure losses and optimizing seasonal efficiency .
-
Dedicated power cable with gray rigid conduit and wall-mounted disconnect box in close proximity to the condenser, compliant with maintenance requirements.
-
Drainage from the interior head managed by gravity towards the exterior (controlled slope), which eliminates the risk of condensate pump failure and simplifies maintenance.
Drilling and sealing
-
Single drilling in the facade, with insulated sleeve and vapor barrier sealing to prevent any infiltration of air and humidity.
-
Fixing to brick with suitable mechanical anchors , tightening torque controlled to preserve the facing .
Why the Sharp ZU1 (R-32) range is a must here
-
R-32 refrigerant : lower global warming potential than R-410A and better volumetric capacity , for more efficient and compact appliances.
-
Cold weather heating : stable performance in Montreal climate , with capacity maintenance and optimized defrosting.
-
Quiet operation : crucial in an interior courtyard surrounded by dwellings, with a finely modulated inverter fan and compressor .
-
Smart Control : Wi-Fi and timer compatibility, convenient to adjust energy saving according to occupancy.
Recommended capacity : for a well-insulated living area of a plex, a configuration around 12,000 to 15,000 BTU (to be validated during load calculation) covers the majority of needs, while leaving a margin during heat peaks.
Specific challenges of a plex with an exterior staircase… and our solutions
-
Vibrations and resonance on the brick
-
Use of anti-vibration pads , spacers and calibrated fixing torque .
-
Checking the rigidity of the brackets to avoid any amplification under the effect of the compressor.
-
-
Shadows and air recycling near the spiral staircase
-
Condenser orientation to avoid recirculation of hot/cold air against the metal flight.
-
Front clearance preserved to maintain nominal airflow .
-
-
Aesthetics and maintenance in shared courtyard
-
White vertical and horizontal cladding perfectly aligned with the brick joints for clean integration .
-
Installation height designed to keep the unit out of reach , while remaining accessible for maintenance.
-
-
Montreal winter
-
Maintain clearance under the chassis so that ice from defrosting does not block ventilation.
-
Non-existent slope of the slab (wall) compensated by a slight angle of the bracket plate for natural drainage.
-
What this installation actually brings
-
Uniform comfort in the main room: gentle mixing and stable temperature.
-
Measurable reduction in heating costs compared to electric baseboards (continuous modulation).
-
Appreciable silence for the courtyard and the occupants (low-noise mode).
-
Easy maintenance : visible disconnection, accessible cover, washable filters on the inside.
AirGreen best practices on brick facades (useful checklist)
-
Choice of wall : favor a facade without an overhanging cornice which rejects the snow onto the unit.
-
Brackets : galvanized or stainless steel depending on exposure; anchoring lengths conform to the brick and the joint.
-
Hood : white color here to match the woodwork; black or brick color available on request.
-
Anti-vibration : under-chassis mounts + rear spacer to break the rigid axle.
-
Electricity : dedicated circuit , rating and circuit breaker according to the nameplate; accessible external circuit breaker .
-
Drainage/defrosting : Check water discharge to avoid icing walkways or stairs.
-
Maintenance : Provide sufficient front and side clearance for cleaning the batteries.
HVAC Maintenance: Keeping Performance at Its Best
Regular HVAC maintenance extends equipment life and maintains seasonal performance :
-
Clean the internal filters every 4 to 8 weeks during periods of use.
-
Annual inspection : pressure/freon, exchangers, electrical connections, tightening of anchors, condition of covers.
-
Winter clearance : ensure that snow does not accumulate against the unit (even when wall-mounted).
-
Gentle disinfection of indoor coils for air quality.
Grants and Eligibility
New generation R-32 wall-mounted heat pumps , capable of providing low-temperature heating , are generally eligible for assistance programs in Quebec. Eligibility depends on the exact model , performance (SEER/HSPF/SCOP) and the conditions of the current program. We support our clients to verify the criteria and prepare the file when the chosen device meets them.
What we measure after each commissioning
-
Superheating and subcooling in accordance with the manufacturer's specifications;
-
Absorbed intensity vs. setpoint;
-
Blowing temperature and room differential ;
-
Vibrations in the chassis and noise perceived on the stage side;
-
Waterproofing of drain crossings and slopes .
The end-of-construction surveys assure the owner that the contractual performance has been achieved and that the device is ready for demanding Montreal winters .
Result
The rear façade has a clean and functional design : a discreetly suspended Sharp condenser, aligned hoods and a secure power supply. Inside, the wall-mounted head provides immediate comfort , with fine modulation in both heating and air conditioning. This installation illustrates AirGreen's expertise in brick buildings in the Plateau-Mont-Royal region and, more broadly, throughout Greater Montreal .