A high-airflow central unit integrated into an especially tight technical space
Installing a central heat pump in Le Plateau-Mont-Royal often requires more than simply choosing equipment. Buildings are close together, side passages can be narrow, and the available areas around garages, foundations, and backyards impose very concrete constraints. For this Montreal installation, we integrated a Hitachi airCore 700 HeatForce into a technical area adjacent to the garage, where every clearance had to be used precisely.
The project photo shows a two-fan Hitachi outdoor unit installed on metal wall brackets above ground level. This configuration frees up the slab, reduces exposure to accumulated water, and keeps the unit at a favorable height during the winter. However, it requires very stable mounting, careful vibration management, and positioning that preserves sufficient space for airflow and future maintenance.
The result is a compact, accessible installation suited to a central system designed to provide heating and cooling throughout the property.
The main challenge: positioning a large unit without compromising its operation
An outdoor unit with two fans moves a significant volume of air. Its installation therefore cannot be improvised against a wall, beneath a structure, or near a garage door without checking several factors:
- clearance in front of the fans;
- the distance between the unit and nearby surfaces;
- access to the service panels;
- air circulation around the heat exchanger;
- drainage of the water produced during defrost cycles;
- the possible transmission of vibrations to the structure;
- protection against snow, ice, and splashes;
- the route of the refrigerant lines and wiring.
In this project in Le Plateau-Mont-Royal, the available space near the foundation was limited. A ground-level installation would have occupied part of the passage and placed the unit closer to accumulations of water, melting snow, and debris.
We therefore chose a wall-mounted installation with reinforced supports. The metal rails were anchored into a suitable structural section of the foundation and then fitted with supports to keep the unit level. A central heat pump of this size must remain perfectly stable: even a slight tilt can affect frame drainage, increase certain vibrations, or complicate defrosting operations.
Why Raise a Central Heat Pump in Montreal
Raising the outdoor unit is particularly important in the Greater Montreal climate. In heating mode, the outdoor coil may accumulate frost. The heat pump then initiates a defrost cycle that releases a sometimes considerable amount of water beneath the unit.
If the unit is placed too close to the ground, this water can freeze around the frame and form a mass of ice that blocks drainage or reaches the lower part of the coil. A wall-mounted installation offers several advantages:
- Better clearance beneath the unit, facilitating water drainage.
- Increased protection against snow accumulation.
- Simplified access to the unit’s base during inspections.
- More efficient use of the available space near the garage.
- Reduced contact with debris and ground moisture.
However, the height should not be chosen arbitrarily. A unit installed too high becomes difficult to service, while one installed too low may be exposed to ice. We always seek a balance between winter protection, accessibility, and architectural constraints.
A mounting system designed to limit vibrations
The weight of a central unit with two fans and the compressor’s speed variations require properly adapted supports. Using undersized or improperly anchored brackets can cause structural noise, movement of the unit, and premature deterioration of the fastening points.
In this installation, the supports are distributed beneath the unit’s feet, and the brackets remain separate from the fragile elements of the exterior cladding. The goal is to transfer the weight to a solid surface while limiting the transmission of vibrations to the garage and adjacent rooms.
This precaution is particularly important with a central heat pump featuring an Inverter compressor. Although modulation generally reduces abrupt starts, certain operating frequencies may become audible when the unit is mounted directly to a lightweight structure. The choice of hardware, tightening, leveling, and vibration-isolation components are therefore integral to the quality of the HVAC installation.
Line routing: protection, sealing, and maintenance
A protected vertical drop is visible below the unit, allowing the connections to be routed into the building. In a central installation, this area may include:
- refrigerant lines;
- electrical conductors;
- communication wiring;
- mechanical protection components;
- sealed penetrations through the building envelope.
The lines must be properly supported and protected against impacts, movement, and the elements. An improperly sealed wall penetration can let in water, cold air, or insects. A line that is too taut can transmit compressor vibrations indoors.
We also pay particular attention to the bend radii of the copper tubing. A crushed or overly sharply bent line can reduce refrigerant flow and affect system performance. Exterior appearance matters, but it should never take precedence over the quality of the refrigerant connection.
Commissioning as important as the mechanical installation
A central heat pump should not simply be connected and powered on. Before handing the system over to the owner, we carry out the necessary checks according to the installed configuration:
- inspection of refrigerant connections;
- leak test;
- evacuation of the circuit;
- electrical connection inspection;
- confirmation of communication between components;
- checking airflow in the ducts;
- verification of supply and return air temperatures;
- drainage inspection;
- heating and cooling test;
- thermostat or central control configuration.
Airflow deserves particular attention. A high-performance outdoor heat pump cannot compensate for a duct system that is too restrictive, an undersized filter, or an improperly configured fan. Actual performance depends on the system as a whole, not just on the outdoor unit.
Why the Hitachi airCore 700 HeatForce is suitable for demanding central-system projects
The Hitachi airCore 700 is a single-zone, direct-expansion packaged system offered with several categories of indoor units, including ducted units, cassettes, wall-mounted units, and central air handlers. The range is intended for residential applications as well as some light commercial spaces.
The HeatForce version uses an inverter compressor with R32 refrigerant. According to the manufacturer’s technical data, it can maintain a heating capacity ratio of 100% at -15 °C and over 70% at -25 °C under the specified test conditions. The HeatForce range is also ENERGY STAR certified for cold climates. These values represent the product family; the exact capacity of an installation must always be confirmed based on the model numbers and the selected AHRI combination.
Low-temperature heating
Winter performance is a major consideration for a central heat pump in Montreal. A conventional heat pump may experience a considerable reduction in capacity as the outdoor temperature drops. The HeatForce series is designed to limit this loss through several features:
- an R32 Inverter compressor;
- an optimized refrigerant path;
- a revised heat exchanger design;
- a fin design adapted to winter operation;
- a base heater intended to limit ice buildup in the chassis.
The manufacturer indicates a heating range that can extend down to approximately -25 °C for the series in question. This does not mean that auxiliary heating becomes unnecessary in every building. Requirements depend on the property's heat load, insulation, airtightness, selected capacity, and air distribution system.
In a central installation, we therefore assess the heat pump and backup heating as a single system. The controls must enable a logical transition between the heat pump and the auxiliary element, without excessive energy consumption or a drop in comfort.
R32 refrigerant and installation precautions
The Hitachi airCore 700 uses R32, an A2L-class refrigerant. It has a lower global warming potential than several refrigerants used in previous generations. However, its classification requires compatible practices, tools, and procedures.
In the central configuration with an air handler, Hitachi's documentation indicates that an R32 refrigerant detection sensor is factory-installed on the applicable modules. This device is part of the safety approach associated with A2L systems.
For the installer, this notably involves:
- compliance with applicable volume and clearance requirements;
- the use of tools compatible with R32;
- careful handling of the piping;
- a complete leak check;
- compliance with the manufacturer's instructions;
- proper configuration of safety devices.
Replacing only the outdoor unit without checking the compatibility of the indoor unit, coil, controls, and refrigerant piping is not an acceptable method.
An air handler designed for central systems
The airCore 700 series can be paired with air handlers available in several nominal capacities. The manufacturer's documentation notably lists sizes from 18,000 to 48,000 BTU/h for this category of indoor unit.
The air handler includes a five-speed ECM motor. Hitachi indicates that this design can reduce fan consumption by approximately 10% compared with certain reference configurations, while improving compatibility with different airflow requirements.
The 20.5-inch cabinet also facilitates installation in certain restricted spaces. This dimension can be useful in homes in Plateau-Mont-Royal, where mechanical rooms, basements, and clearances around existing ductwork are rarely generous.
The exact capacity should not be inferred from the cabinet size
The photo shows a two-fan outdoor unit, which generally corresponds to a higher-capacity category than smaller single-fan units. However, it would be incorrect to determine the tonnage solely from the appearance of the cabinet.
To confirm the exact capacity, we use:
- the complete outdoor unit model number;
- the air handler model number;
- the certified AHRI combination;
- low-temperature heating capacity;
- the building’s heating and cooling load;
- the capacity of the duct system;
- the available electrical supply.
An oversized heat pump may run for short periods, control humidity less effectively, and accentuate temperature variations. An undersized unit may frequently call on auxiliary heat. The right choice lies in balancing capacity, modulation, airflow, and the actual load.
The mistakes we seek to avoid when installing a central system
Choosing tonnage based solely on floor area
Two properties with the same floor area may have very different needs. The year of construction, number of exposed walls, windows, insulation, orientation, and air leakage all affect the heating load.
Reusing the ventilation settings from the old system
A new Inverter system may require different airflow rates and ventilation profiles. Fan speeds must be adjusted according to the capacity, static pressure, and ductwork.
Reducing clearances to save a few centimeters
A poorly ventilated outdoor unit can draw in its own air, lose efficiency, or become noisier. The panels must also remain accessible to technicians.
Neglecting defrost water
Water can form a dangerous sheet of ice or rise beneath the unit. The height, ground slope, and drainage area must be considered before securing the supports.
Assuming eligibility for financial assistance
The presence of an ENERGY STAR label or the reputation of a product range does not automatically confirm eligibility for a program. The exact combination, AHRI number, recognized capacity, and rules in effect at the time of the project must be verified.
Central control and connectivity options
The airCore 700 range offers different control options depending on the indoor unit and accessories selected. Hitachi notably offers an airPoint Room 700 wall controller, a five-wire thermostat adapter, as well as Wi-Fi, BACnet, and Modbus options.
The airCloud Go app may allow remote control when the compatible adapter is installed. This function must be planned from the design stage, as not all accessories work together in the same way.
For a residence, we prioritize a control that remains simple to use while allowing:
- selecting the mode;
- adjusting the temperature;
- fan control;
- scheduling;
- controlling auxiliary heating;
- checking operating alerts.
An installation designed for long-term maintenance
The photographed outdoor unit remains accessible from the front and the service side. This accessibility facilitates heat exchanger cleaning, wiring inspection, and refrigeration checks.
During HVAC maintenance, the technician must be able to remove the panels without dismantling the supports, moving heavy objects, or working in a dangerous position. A well-planned location therefore reduces service time and helps keep the system in good condition.
We also recommend keeping the area in front of the fans clear of boxes, bicycles, tools, bins, or stored materials. In a space adjacent to a garage, clutter can quickly change after installation. A unit that had the required clearance on the first day may become obstructed a few months later.
The result of this project on Le Plateau-Mont-Royal
This installation brings together several important elements: a Hitachi central heat pump, a HeatForce unit adapted for cold-weather heating, a stable wall-mounted installation, and the thoughtful use of a restricted space.
The chassis was raised to improve winter protection and free up floor space. Both fans have open front clearance, while the connections are grouped along a protected vertical route. The entire installation remains accessible for maintenance without unnecessarily dominating the space around the garage.
At AirGreen, we install central heat pumps, wall-mounted systems, and HVAC equipment in Montreal, Laval, Longueuil, the North Shore, and the South Shore. Each project is evaluated according to the building’s actual capacity, ductwork constraints, electrical supply, outdoor positioning, and the requirements specific to the selected equipment.
A successful installation is measured by more than the appearance of the new unit. It is recognized by stable operation, airflow quality, defrost management, accessibility for maintenance, and the comfort achieved in every room.