A central conversion completed in a tight mechanical space without compromising access to the system
In Lachine, in western Montreal, we installed a Hitachi airCore 700 central heat pump to provide heating and cooling through the property's duct network. The visible heart of this installation is a Hitachi air handler bearing reference JPE36B3XD2HS1A, a model in the 36,000 BTU class, or approximately 3 tons of nominal capacity.
The job-site photograph clearly shows the reality of many HVAC projects in Montreal homes: the equipment must be integrated into a compact mechanical room, between existing walls, piping, flexible ducts, and the main air distribution network. Such an installation requires more than simply replacing a unit. Each connection must be planned to preserve airflow, facilitate future maintenance, and ensure safe operation of the refrigerant system R32.
What we observe in this installation in Lachine
The indoor unit was positioned vertically in an upflow configuration. Return air enters the lower section of the unit, passes through the filter, coil, and fan, and is then directed into the metal plenum installed above.
Several technical details are visible:
- the cabinet is connected directly to the existing central duct network;
- the upper transition is carefully fitted to the rectangular plenum;
- the sheet metal joints are sealed with aluminum tape designed for HVAC installations;
- the insulated refrigerant line and copper liquid line run along the right side of the unit;
- the front remains accessible for diagnostics, fan maintenance, and servicing of the electronic controls;
- the control compartment is open during the connection and commissioning work;
- the refrigerant-related warnings A2L R32 are clearly indicated on the lower panel.
The mechanical room is narrow, but the selected layout preserves an access corridor at the front. This is essential. A central unit may operate properly at the time of installation yet become very costly to service if the panels, filter, coil, or electronic boards are blocked by a wall, tank, or another component.
A 36,000 BTU Hitachi air handler
The reference JPE36B3XD2HS1A corresponds to the 36,000 BTU air handler offered in the Hitachi airCore 700 range. This family includes central units from 18,000 to 48,000 BTU, designed for residential and light commercial applications. The air handler cabinet is approximately 20.5 inches wide, which facilitates its integration into restricted mechanical rooms such as the one in this project in Lachine.
The unit includes, among other features:
- a five-speed ECM fan motor;
- a design suited to vertical installation in a limited space;
- a rigid cabinet with smooth sides;
- a factory-installed R32 refrigerant detector;
- controls allowing different types of thermostat integration;
- compatibility with the control accessories provided by Hitachi.
According to the manufacturer’s documentation, the ECM motor reduces the fan’s electricity consumption while offering several airflow adjustment options. The airCore 700 range also uses R32 refrigerant, which has a stated global warming potential of 675.
Why the ECM Motor Matters So Much in a Central Installation
In a home equipped with ductwork, the heat pump’s capacity is only part of the equation. The indoor fan must move the right amount of air through the coil and throughout the duct system.
Airflow that is too low can cause:
- reduced heating or cooling capacity;
- inadequate supply-air temperature;
- a risk of ice formation in cooling mode;
- irregular operating cycles;
- increased energy consumption;
- uneven air distribution between rooms.
Airflow that is too high can, for its part, increase noise at the grilles, reduce summer dehumidification, and create unpleasant drafts.
The multi-speed ECM fan in this Hitachi central heat pump makes it possible to adapt operation more precisely to the system’s static pressure. During commissioning, we therefore do more than simply check whether the unit starts. We must also confirm that the airflow matches the system’s capacity and the actual duct configuration.
The three-ton capacity must match the building's actual needs
A 36,000 BTU unit, often called a three-ton heat pump, should never be selected solely based on living area. Two properties of similar size in Lachine can have very different heating and cooling loads depending on:
- year of construction;
- insulation quality;
- window area;
- the building's orientation;
- air infiltration;
- the number of floors;
- ceiling height;
- sun exposure;
- the capacity of the existing ducts;
- the heating requirements at Montreal's design temperatures.
An oversized unit can quickly reach the requested temperature and then stop before sufficiently dehumidifying the air. It can also lead to greater temperature fluctuations and increased wear caused by short cycling.
Conversely, an undersized heat pump may run continuously on the coldest or hottest days without achieving the desired comfort level. Before recommending a capacity, we therefore examine the building envelope, the existing system, air distribution, and the auxiliary heating source.
A clean integration with the existing ductwork
The upper part of the unit is connected to an existing sheet-metal plenum. This connection must be mechanical, airtight, and sufficiently robust to prevent vibration.
A poor transition can create:
- turbulence;
- pressure losses;
- whistling;
- air leaks in the mechanical room;
- insufficient airflow to certain rooms;
- a decrease in overall efficiency.
On this job, the transition fits into an environment already occupied by several ducts and accessories. The work therefore requires precise measurements to align the unit with the system without forcing the air to change direction abruptly.
Sealing the joints is also important. A leak in the supply plenum allows heated or conditioned air to escape before it reaches the rooms. When the mechanical room is located inside the building envelope, this loss may seem less significant, but it still reduces the available pressure in the ducts and unbalances the distribution.
The particular challenge of R32 refrigerant
The Hitachi airCore 700 uses R32, an A2L-classified refrigerant, meaning it has low flammability and requires appropriate installation methods. It must not be handled exactly like the older refrigerants commonly used in residential systems.
The photographed air handler has a factory-installed refrigerant detection sensor. This component is part of the measures предусмотрed for equipment using an A2L refrigerant.
For the installer, this means, among other things, that they must:
- use tools compatible with the specified refrigerant;
- follow brazing and nitrogen-purging procedures;
- carry out a rigorous leak test;
- perform a deep vacuum before releasing the refrigerant;
- keep the safety sensors and controls operational;
- comply with the applicable clearance and volume requirements;
- never bypass the detection devices.
The visible cables in the control compartment in the photo correspond to a connection or inspection stage. Once commissioning is complete, the wiring must be organized, secured, and protected so that it does not come into contact with moving parts or surfaces that could damage it.
Auxiliary heating and electrical power supply
In the climate of Montréal, a central heat pump is generally accompanied by an auxiliary heating strategy. Depending on the configuration, this may be an electric element installed in the air handler or another heating source integrated into the system.
The capacity of this element must not be chosen arbitrarily. It depends, among other things, on:
- of the electrical panel's capacity;
- of the building's heating load;
- of the heat pump's low-temperature capacity;
- of the conductor gauge;
- of circuit-breaker protection;
- of the thermostat's control sequence.
An oversized element can lead to unnecessary electrical work and significantly increase the power demand. An undersized element may be unable to maintain the temperature during a period of extreme cold or during a defrost cycle.
Controls and integration options
The Hitachi airCore 700 platform can be paired with various control solutions. The manufacturer offers, among other things, a wired wall controller and an adapter that enables the integration of a five-wire thermostat, Wi-Fi, and protocols used in building management, such as BACnet or Modbus.
These options do not mean that all accessories are present in every installation. The choice depends on the owner's needs, the thermostat selected, and the level of control desired.
In a residence in Lachine, the priorities are often:
- simple programming;
- clear selection of the heating and cooling modes;
- proper management of the auxiliary heating;
- fan control;
- a reliable temperature reading;
- remote access when the appropriate equipment is added.
In a rental or light-commercial building, integration with a centralized management system may become more relevant.
What a successful central installation should ensure after the technicians leave
Complete commissioning, not just startup
When the indoor unit, outdoor unit, refrigerant lines, and controls are connected, several checks remain necessary.
Our commissioning includes, among other things:
- checking the supply voltage;
- confirming the electrical protection devices;
- checking communication between the units;
- testing the safety devices related to R32;
- checking the condensate drainage;
- checking the airflow;
- measuring return-air and supply-air temperatures;
- validating the heating, cooling, and ventilation modes;
- observing the operation of the auxiliary heating when present;
- the closing and fastening of all service panels.
An installation may appear to be working while still having insufficient airflow, a minor leak, or an incorrect thermostat configuration. These problems sometimes appear several weeks later as noise, discomfort, high energy consumption, or error codes.
Mistakes to avoid when replacing a central system
Choosing the equipment based only on the previous tonnage
The previous equipment may have been oversized or installed before insulation work was carried out. The replacement should take the building’s current conditions into account.
Neglecting static pressure
Even an excellent heat pump cannot provide good comfort if the ductwork is too restrictive, the filter is undersized, or several grilles are blocked.
Blocking the service panels
The visible front clearance on this installation is essential. An appliance wedged against a wall can turn a simple service call into a major dismantling job.
Promising a rebate without verifying the pairing
Eligibility for financial assistance depends not only on the Hitachi airCore 700 name or the 36,000 BTU capacity. You must verify the exact outdoor unit reference, the indoor unit reference, the certified pairing number, and the program criteria in effect at the time of application.
Without the outdoor model and the certification reference for the complete system, it would be imprudent to guarantee a rebate amount.
Overlooking drainage
When cooling, the indoor coil produces condensation water. The drain line must be installed with an adequate slope, protected against backflow, and tested before the worksite is closed up.
The result for this Lachine property
This HVAC installation in Lachine makes it possible to use the home's central network to distribute heated or cooled air to multiple rooms. Unlike a wall-mounted solution, no indoor unit is added to the living spaces. Existing grilles distribute the air, while the air-handling unit remains consolidated in the mechanical room.
The Hitachi airCore 700 system offers several practical advantages:
- heating and cooling with a single central system;
- air distribution throughout the property;
- adjustable ECM motor;
- cabinet suited to tight spaces;
- technology compatible with R32 refrigerant;
- front access for maintenance;
- residential control or centralized management options.
However, the outcome depends on the quality of the entire installation: sizing, ductwork, electrical work, refrigeration, drainage, controls, and commissioning. A recognized brand cannot compensate for an unsuitable network or connections completed too hastily.
Our approach to central heat pumps in Greater Montreal
At AirGreen, we install and replace central systems in Montreal, Laval, Longueuil, the North Shore and the South Shore. Configurations vary considerably from one property to another: existing furnace, limited mechanical space, older ductwork, low ceilings, a limited electrical panel, or difficult access to refrigerant lines.
Our job is to propose a solution that truly works in the building, not just on a technical specification sheet. For a central heat pump such as the Hitachi airCore 700, we pay particular attention to sizing, airflow, service clearance, auxiliary heating management, and the requirements specific to R32.
This 36,000 BTU installation in Lachine clearly illustrates this method: integrating a modern central unit into existing infrastructure, maintaining access to components, and adapting each connection to the specific constraints of the mechanical room.