An installation on a ground-mounted support designed for winter heating and service access
In Senneville, we installed a HITACHI airHome Multi HeatForce triple-zone multi-zone heat pump to serve three distinct spaces from a single outdoor unit. The project presented a very practical constraint: the unit had to be placed in an already landscaped outdoor area, between the home’s siding, a brick wall, a concrete surface, and a composite deck.
The photo taken during the work shows a substantial outdoor unit installed on a freestanding metal base. It rests neither directly on the ground nor on the patio. This structure keeps the heat pump at a practical height for Quebec winters while leaving clear access beneath the unit for defrost water drainage and servicing.
The cabinet clearly displays the HITACHI, HeatForce, and airHome inscriptions. An EnerGuide label is visible on the front. The electrical disconnect is installed on the right, on the brick wall, in the immediate vicinity of the equipment. The tools temporarily placed on top indicate that the photo was taken before commissioning and site cleanup were fully completed.
This installation is a good example of our approach at AirGreen: we do not simply look for a location where the unit will fit. We must organize everything so that the heat pump can breathe, drain its water, withstand snow accumulation, and remain accessible for many years.
Why a triple-zone configuration made sense in Senneville
A triple-zone multi-zone heat pump allows three indoor units to be connected to a single outdoor unit. The three zones share the system’s overall capacity, but each indoor unit has its own temperature setting, fan speed, and operating schedule.
This configuration is well suited to several types of properties we encounter in Senneville and the western part of the Island of Montreal:
- a large open-concept area accompanied by two bedrooms;
- a multi-story home;
- one main area and two auxiliary areas;
- three rooms separated by long corridors;
- a residence with zones that differ significantly in terms of sun exposure;
- a home where the existing heating system does not distribute heat evenly.
In a large property, a single wall-mounted unit installed in the living room cannot always correct temperatures in the bedrooms or upstairs. Air does not move efficiently through several closed doors, and needs vary from room to room.
With the HITACHI airHome Multi system, some indoor units can remain off while the others continue to operate. Each occupant can adjust their setpoint and fan speed. However, the overall mode remains shared: in summer, the system operates in cooling, dehumidification, or fan mode; in winter, it operates in heating or fan mode. It cannot actively heat one zone while another is being cooled by the same outdoor unit.
This feature must be clearly explained to the owner. A multi-zone system offers excellent independence between rooms, but it is not a heat recovery system capable of producing heating and cooling simultaneously.
A metal base rather than direct installation on the terrace
The outdoor unit is installed on an aluminum or galvanized metal structure anchored to the ground. This solution protects several parts of the building.
First, it prevents the weight and vibrations from being transferred directly to the composite terrace. Terrace boards do not always provide a suitable base for an appliance of this size with multiple zones. They can shift with the seasons, expand, contract, or complicate maintenance.
Next, the support maintains clearance beneath the heat pump. In winter, a heat pump produces water when it performs a defrost cycle. This water must be able to fall beneath the unit and drain away without immediately encountering a closed platform.
The support also helps keep the equipment above:
- leaves;
- snow;
- ice;
- accumulated water;
- small debris carried by the wind;
- objects stored on the terrace.
However, the chosen height must remain reasonable. A unit that is too low is vulnerable to winter accumulation; a unit that is too high can be more difficult to stabilize and maintain.
An installation near a brick wall
The right side of the unit is near a brick wall where the electrical disconnect is installed. This proximity requires careful planning.
The service panels, connections, and wiring must remain accessible. Leaving a few centimeters around the cabinet is not enough. A technician must be able to remove the panels, connect instruments, check the connections, and perform work without dismantling the surrounding structure.
We must also prevent the discharge of hot or cold air from striking an obstruction that is too close. The photo shows that the front fan remains unobstructed. Air can therefore be expelled forward without being immediately redirected toward the heat exchanger.
In a semi-enclosed space, air circulation is essential. A heat pump that recirculates its own air operates under less favorable conditions and may lose efficiency.
The purpose of the clearance beneath a balcony or overhead structure
The upper part of the photo shows a structure partially covering the area. This protection may reduce direct exposure to rain or snow, but it must not enclose the unit.
The following must be checked:
- the clearance above the cabinet;
- the ability to discharge hot air;
- access to the top panel;
- the absence of obstructions in front of the fan;
- side ventilation;
- the possible accumulation of windblown snow.
Installation beneath an outdoor structure can be beneficial when it protects the unit without blocking airflow. It becomes problematic if the space is too enclosed or if objects are stored in front of the heat pump.
We therefore recommend that the owner keep this area clear. A table, tarp, storage box, or temporary panel placed in front of the unit could significantly affect its operation.
A HITACHI multi-zone platform suited to three spaces
The HITACHI airHome Multi line includes multi-zone systems with Inverter technology using R32 refrigerant. Depending on the outdoor model, it can power two to five indoor units and provide rated cooling capacities from 18,000 to 42,000 BTU/h.
For a triple-zone configuration, the documentation presents the outdoor model RAM-G24N3HAA, designed for three indoor connections. The photo does not make it possible to read the complete nameplate of the installed unit. The exact technical platform must therefore always be confirmed using the model number on site.
The triple-zone version presented in the brochure offers a rated cooling capacity of 24,000 BTU/h and a rated heating capacity of 24,000 BTU/h. Its modulation range can reach approximately 28,000 BTU/h in cooling with ductless units and 26,200 BTU/h in heating.
What a 24,000 BTU/h capacity with three zones really means
A 24,000 BTU/h outdoor unit can be connected to three indoor units whose combined nominal capacities sometimes exceed 24,000 BTU/h when this combination is authorized by the manufacturer.
This does not mean that each indoor unit simultaneously receives its full capacity. The compressor distributes the available power according to the demand from each zone.
For example, if only one room requires light heating, the system can operate at a low output. If all three rooms require a great deal of heat at the same time, the available capacity is distributed among them.
Sizing must therefore take into account:
- the load of each room;
- the likelihood of simultaneous demand;
- the most demanding zone;
- the insulation level;
- the glazed area;
- sun exposure;
- the ceiling height;
- the desired temperatures;
- the supplemental heating present in the house.
A poorly planned combination can create a situation in which the smaller zones are comfortable, but the largest room lacks capacity on very cold days.
Energy efficiency of the three-zone configuration
For the RAM-G24N3HAA model in a ductless configuration, the technical data sheet indicates, among other things:
- a TRÉ2 of 12.5;
- a TRÉS2 of 22.0;
- a CPSC2 of 9.5 in Region 4;
- a CPSC2 of 7.8 in Region 5;
- a COP of 3.5 at 8 °C.
The airHome Multi series can operate in heating mode down to -20 °C. For this three-zone platform, the stated maximum heating capacity is 18,500 BTU/h at -15 °C and 13,000 BTU/h at -20 °C.
These figures show why we always examine low-temperature performance. The nominal value of 24,000 BTU/h is not the capacity available during a night at -20 °C.
In Senneville, where some properties are more exposed to wind and have large glazed areas, this analysis becomes particularly important.
The HeatForce marking visible on the unit
The HeatForce marking on the cabinet clearly indicates a focus on heating performance. In the photo, this marking is positioned between the HITACHI and airHome logos.
However, we avoid attributing technical values to this designation that do not appear in the documentation provided. The brochure supplied describes the airHome Multi range, its capacities, operation down to -20 °C, and its general features, but it does not include a separate section providing data specific to the HeatForce designation.
The exact values for the installed unit must therefore be confirmed on its nameplate and in its official combination data sheet.
Inverter technology and capacity modulation
Inverter technology allows the compressor to adjust its speed according to demand. Instead of only starting and stopping at full capacity, the system can reduce its output as the zones approach their target temperature.
This modulation contributes to:
- stabilize the temperature;
- reduce fluctuations;
- limit short cycles;
- better distribute capacity among the three zones;
- improve acoustic comfort;
- maintain more consistent dehumidification.
In a three-zone installation, this adaptability is essential. The three spaces almost never require exactly the same amount of heating or cooling.
Several types of compatible indoor units
The airHome Multi lineup allows several indoor unit formats to be combined:
- airHome 400, wall-mounted;
- airHome 650, wall-mounted;
- airHome Floor, floor console;
- airHome Mini Cassette, compact cassette;
- airHome Ducted, concealed unit.
Available capacities generally range from 7,000 to 24,000 BTU/h, depending on the series and format.
This flexibility is useful in a Senneville property where the three zones may have very different layouts. A bedroom may receive a small wall-mounted unit, an open-concept area a higher-capacity unit, and a room without an available wall a floor console or mini cassette.
However, the choice should not be based solely on aesthetics. You must also consider:
- air distribution;
- noise;
- drainage;
- the piping route;
- access to the filters;
- compatibility with the outdoor unit;
- the permitted combination ratio.
Wall-mounted units capable of operating at a low noise level
The brochure indicates that some airHome 650 units can operate at approximately 27 dB(A), while some airHome 400 units can operate at approximately 29 dB(A), depending on the selected capacity and speed.
This low noise level is useful in bedrooms and offices. However, acoustic comfort also depends on the location.
A unit placed directly above a bed or aimed at a workstation may be felt more strongly, even at low speed. We therefore analyze the furniture layout and airflow direction before installing the equipment.
The EnerGuide label visible on the cabinet
The yellow label visible on the front confirms that the appliance belongs to an energy-rated category. Some values may be visible in the photo, but they are not clear enough to reliably associate all the data with a specific model.
For financial assistance programs, the presence of a label on the equipment alone is not sufficient. Eligibility generally depends on:
- the exact outdoor unit model;
- the combined indoor units;
- the AHRI reference;
- the current program criteria;
- the purchase and installation date;
- the type of building;
- the submitted documents.
The brochure states that the product line qualifies for most provincial heat pump incentives, but any rebate must be validated based on the exact combination installed.
The refrigerant lines of a triple-zone system
A triple-zone installation has three circuits between the outdoor unit and the indoor units. For the RAM-G24N3HAA platform, the documentation specifies three 1/4-inch liquid connections and three 3/8-inch gas connections.
The lines must be carefully prepared and identified. Each refrigerant circuit must correspond to the correct communication cable and the correct indoor unit.
A pairing error can cause:
- poor communication;
- error codes;
- inconsistent operation;
- activation of a zone different from the one selected;
- difficulties during commissioning.
We therefore label the circuits before completing the connections.
Length limits to observe
For the triple-zone model described in the brochure, the limits include:
- a maximum total length of 200 feet;
- a maximum length of 82 feet per indoor unit;
- a minimum length of 16 feet;
- a maximum total height of 66 feet;
- a maximum elevation difference of 16 feet between the indoor units.
These values allow some flexibility, but they must be calculated before work begins. On a large property, the three indoor units may be far apart, which quickly increases the total length.
An outdoor location that seems aesthetically ideal may become ineffective if it requires very long runs or runs that are difficult to protect.
The electrical disconnect located nearby
The gray disconnect visible on the brick wall allows the power supply to the outdoor unit to be shut off locally during maintenance or repairs.
Its location must remain:
- visible;
- accessible;
- near the equipment;
- protected against impacts;
- clear of the lines;
- installed to limit water infiltration.
The visible black wiring beneath the disconnect is secured along the wall and runs to the unit. Once the work is complete, all cables must be properly supported and protected against rubbing.
Triple-zone platform electrical data
The RAM-G24N3HAA model operates at 208-230 V, single-phase, 60 Hz. The documentation specifies a minimum circuit ampacity of 19 A and maximum overcurrent protection of 35 A.
These data are provided for reference only for the model indicated. The nameplate on the installed machine remains the final reference.
We always verify:
- conductor size;
- panel capacity;
- the circuit breaker;
- the disconnect switch;
- grounding;
- tightening of the connections;
- protection of the outdoor cables.
Essential steps before startup
The photo shows a worksite that is still active. Tools are on top of the unit, and some finishing work may not be complete.
Before commissioning, several operations must be completed.
Mechanical inspection
We confirm that the unit is level, the supports are tight, and the base is stable.
Leak test
The refrigerant connections for all three zones are checked to confirm that there are no leaks.
Evacuation
Air and moisture are removed from the lines. This step is essential for protecting the compressor and refrigerant oil.
Connection verification
Each circuit must be connected to the correct indoor unit and communication cable.
Drain inspection
All three indoor units must drain their condensate without backup.
Mode testing
We test the cooling, heating, fan speeds, and controls.
Final cleanup
Tools, materials, and debris are removed before the system is handed over to the owner.
Indoor unit air quality and maintenance
Depending on the selected indoor units, the range may offer:
- an activated carbon PM2.5 filter;
- a ViroSense S filter;
- FrostWash technology;
- the Mold Guard function;
- a refrigerant leak sensor.
FrostWash uses a freezing and thawing process to help clean the indoor coil. Mold Guard runs the fan for approximately 60 minutes after cooling or dehumidification to dry the internal components.
These features do not replace regular HVAC maintenance. Filters must be cleaned, and the fan wheel, condensate pan, and drain must be inspected periodically.
R32 leak sensor
Compatible indoor units include a sensor that can issue an alert in the event of an R32 refrigerant leak. Depending on the model and accessories, the alert may take the form of an indicator light, an audible alarm, or a signal transmitted to a compatible controller.
This feature improves monitoring, but it does not replace the quality of the refrigerant connections and tests performed at the time of installation.
Remote control with airCloud Go
An optional airCloud Go interface can enable remote control of compatible units. Occupants can adjust temperatures, schedule operating times, and monitor certain information from a connected device.
In a triple-zone home, this feature simplifies the management of rooms that are not used at the same times. A guest room can be maintained at a more moderate temperature while the main zones remain fully comfortable.
Mistakes to avoid in an installation like this
Installing the unit directly on the terrace
The terrace can transmit vibrations and complicate drainage. An independent structure is often preferable.
Placing the unit too close to the ground
A low height increases the risk of obstruction from snow and ice.
Blocking the front of the unit with furniture
The fan must maintain sufficient clearance at all times.
Forgetting access to the disconnect switch
The disconnect device must remain visible and accessible.
Underestimating defrost water
Water can refreeze beneath the unit and around the feet if drainage is not properly planned.
Choosing indoor capacities separately
The three zones share the outdoor unit’s capacity. The combination must be analyzed as a complete system.
Leaving the lines unprotected
Insulation exposed to UV rays and the elements deteriorates quickly.
Storing objects on the heat pump
The top of the cabinet is not a shelf. After installation, no tools, containers, or objects should be left there.
An installation suited to Senneville’s conditions
This HITACHI airHome Multi HeatForce triple-zone multi-zone heat pump installation in Senneville demonstrates the importance of properly integrating the outdoor unit into its immediate surroundings.
The ground-mounted structure protects the terrace and keeps the unit at a useful height. The fan remains unobstructed. The disconnect switch is installed nearby. The space beneath the unit remains accessible for defrost water and cleaning.
This configuration serves three zones with a single outdoor unit while limiting the equipment footprint around the property.
At AirGreen, we apply the same attention to multi-zone heat pump, wall-mounted air conditioner, central system, and HVAC installation projects in Senneville, Montreal, Laval, Longueuil, the North Shore, and the South Shore.
The final quality depends as much on the choice of equipment as on the base, clearances, sizing, refrigerant piping route, electrical work, and commissioning.