A multi-zone installation designed around a very practical constraint: placing a large outdoor unit without sacrificing access around the building
On this installation completed in Acton Vale, the outdoor unit of the 3-head GREE FreeMatch R32 heat pump had to find its place on a façade already occupied by several elements: brick masonry, a side window, a railing, a roof overhang, and relatively limited circulation space. The site photograph clearly shows the solution chosen by our team: a wall-mounted installation, with the outdoor unit secured above ground level rather than placed on a slab directly at the foot of the building.
This choice serves several purposes at once. It frees up the lower area, keeps the equipment away from debris and ground moisture, and makes it easier to accommodate the snow accumulation typical of Quebec winters. In the case of a multi-zone heat pump, this outdoor planning is particularly important, since the same unit must power three indoor units distributed throughout different parts of the property.
The visible result is a compact and orderly installation. The GREE unit is positioned against the masonry on metal brackets, while the refrigerant lines and wiring are grouped near the unit. The AirGreen logo affixed to the unit also makes it easy to identify the company responsible for the installation during future maintenance or service work.
Why install a heat pump on wall mounts in Acton Vale?
An outdoor heat pump can be installed on different types of supports depending on the building: a ground slab, an elevated base, or a wall mount. Here, the façade configuration made the wall-mounted solution particularly suitable.
In the photo, we can see that the unit is located near a railing and beneath a roof overhang. A ground-level installation would have occupied an additional portion of the available space and brought the base of the unit closer to snow, leaves, soil, and runoff.
By keeping the outdoor unit elevated, we gain several practical benefits:
- better protection against snow accumulation;
- clear space beneath the unit;
- easier access to the lines and connections;
- less contact with grass and debris;
- a reduced risk of the unit being surrounded by standing water;
- more efficient use of a limited outdoor area.
However, the wall mounting must be done correctly. A multi-zone unit is not a lightweight appliance that can simply be screwed into the exterior cladding.
Depending on the capacity selected, FreeMatch R32 outdoor units compatible with three indoor units weigh approximately 51 kg to 79 kg. Dimensions can range from approximately 964 × 660 × 402 mm to 1,020 × 826 × 427 mm for the models concerned.
The support, hardware, and anchors must therefore be selected according to the actual equipment and the wall structure.
The visible brick is not the only element to consider
A brick façade gives an impression of solidity, but we must always verify the wall's complete composition and the appropriate anchoring method before mounting the equipment.
Static weight is not the only factor. The compressor and fan also create slight vibrations during operation. Rigid, properly aligned, and correctly secured supports help prevent:
- movement of the outdoor unit;
- vibrations transmitted to the structure;
- resonance noises;
- unnecessary strain on the refrigerant lines;
- the gradual loosening of certain fastening points.
On this installation ofActon Vale, the two visible support arms beneath the unit distribute the load while keeping the lower section unobstructed.
A clearance that must remain sufficient despite the roof overhang
The outdoor unit is installed under part of the building that partially protects it from direct precipitation. However, this location must retain enough space for the unit to exchange heat properly with the outdoor air.
A heat pump should never be enclosed in a space that is too narrow. It must be able to draw in and discharge large volumes of air without that air immediately recirculating toward the heat exchanger.
In this photograph, the outdoor unit's large front face and fan are completely unobstructed. We must also respect the necessary clearances on the sides, rear, and above, according to the manufacturer's specifications and the building's actual configuration.
This check is even more important when a unit is located:
- under a porch;
- under a balcony;
- under a roof overhang;
- between two walls;
- behind a fence;
- near a guardrail.
A space that looks visually sufficient can cause air recirculation when the fan operates at full speed.
Winter operation is part of the design from day one
In Acton Vale, a heat pump must be installed to operate in July as well as January. The documentation for the product line GREE FreeMatch R32 indicates a heating range extending down to -30 °C and a cooling range extending down to -30 °C on the lower end, with an upper limit of 48 °C in cooling mode.
When a heat pump heats in cold weather, frost can form on its outdoor heat exchanger. The system must then periodically perform a defrost cycle. GREE also indicates the presence of a smart defrost in this product line.
During defrosting, water drains beneath the unit.
An elevated installation like the one in the photo helps preserve space beneath the outdoor unit for this water to drain. This does not mean the ice problem disappears: drainage must still be considered so that an ice sheet does not form in a traffic area.
We therefore pay attention to:
- the height of the unit;
- the slope of the ground;
- occupant traffic;
- the location of the stairs;
- areas where snow is cleared or blown;
- water from the roof.
The roof above the unit must also be inspected
The unit visible in the photo is located under an overhang. This type of location can offer some protection, but it is also necessary to ensure that water or ice from the roof does not fall directly onto the heat pump.
A significant buildup of ice on top of the cabinet or in the fan is never desirable. When an outdoor location presents this risk, we must adjust the position or plan a protective solution compatible with the required air clearances.
Three heads, one outdoor unit
Acton Vale’s project uses a GREE FreeMatch R32 three-head heat pump. In such a configuration, three separate indoor units are connected to the same outdoor unit.
This configuration makes it possible to treat several zones of a home or building separately without installing three outdoor condensers.
Each head can be positioned according to the room it serves. For example, an installation may include:
- one unit in the main living space;
- one unit in a bedroom or private area;
- a third unit on another floor, in an office, or in a remote room.
The setpoint temperature and ventilation can be adjusted by zone. However, the available capacity remains shared among the units simultaneously calling for heating or cooling.
This is one of the reasons we never size a system simply by adding three BTU values.
Which outdoor unit can power three indoor units?
The GREE FreeMatch R32 documentation presents several models. The smallest outdoor unit, GWHD(18)ND6MO, accepts two indoor units and is therefore unsuitable for a three-head system.
For a configuration like the one installed in Acton Vale, the models that can accommodate at least three indoor units are:
| Outdoor model | Number of connectable indoor units | Nominal cooling | Nominal heating |
|---|---|---|---|
| GWHD(24)ND6MO | 2 to 3 | 24,000 BTU/h | 24,000 BTU/h |
| GWHD(30)ND6MO | 2 to 4 | 28,400 BTU/h | 30,000 BTU/h |
| GWHD(36)ND6MO | 2 to 4 | 36,000 BTU/h | 36,000 BTU/h |
| GWHD(42)ND6MO | 2 to 5 | 42,000 BTU/h | 44,300 BTU/h |
These values come directly from the product line’s performance table.
The photograph does not allow us to read the outdoor unit’s nameplate with certainty. Therefore, we cannot honestly assign a precise capacity to this installation based solely on the cabinet size.
This is an important distinction for a homeowner comparing quotes. A three-head heat pump is not automatically a “24,000 BTU” or “36,000 BTU” system. The required capacity depends on the building and the three zones served.
How we determine the required BTUs
We analyze the heating and cooling demand of each zone and the expected behavior of the system as a whole.
The parameters that influence sizing include:
- area of each room;
- ceiling height;
- insulation quality;
- amount of glazing;
- solar orientation;
- air infiltration level;
- room location;
- air communication between zones;
- occupancy;
- heat-producing equipment.
A large south-facing open area may require significantly more cooling than a well-insulated bedroom. Conversely, a room above a garage or near a large glazed area may have a greater heating load.
We must then confirm that the combination of the three indoor units is compatible with the selected GREE outdoor unit.
Three heads do not mean three independent systems
Each head has its own controls, but all depend on the same outdoor refrigeration system.
Occupants can use different setpoint temperatures. However, the units should normally operate in a compatible general mode. The system cannot be used as though one head belonged to a completely separate heat pump from the other two.
We explain this particularity during commissioning to avoid operating conflicts between zones.
What the GREE FreeMatch R32 brings to this multi-zone installation
Up to 21 SEER2 and 10 HSPF2 according to the documentation
The product line’s technical data sheet states an efficiency of up to 21 SEER2, 12.5 EER2 and 10 HSPF2.
The technical table lists a rating of 21 SEER2 and 10 HSPF2 for the outdoor models listed, with an EER2 of 12 or 12.5 depending on the model.
These data are useful for comparing equipment, but they do not replace a proper HVAC installation.
The actual efficiency achieved in a property also depends on factors such as:
- the sizing;
- the quality of the vacuum;
- the refrigerant charge;
- the pipe length;
- the insulation of the lines;
- the airflow;
- the condition of the filters;
- the temperatures requested by the occupants.
A high-performance unit installed under poor conditions will not deliver the same results as a properly selected and commissioned system.
G10 Inverter technology: adjust output rather than operate only at full power
GREE documentation indicates the use of G10 Inverter, as well as self-diagnostics, automatic voltage adjustment, and quiet operation among the range's features.
In a three-zone system, compressor modulation truly comes into its own.
When only one room requires heating, the demand is not the same as when all three indoor units are operating at the same time. The system can adjust its operation according to demand, within its capacity range.
This modulation allows the system to respond better to load variations rather than operating only in on-off mode at maximum capacity.
Electrical requirements vary depending on the selected outdoor unit
FreeMatch R32 outdoor units operate at 208/230 volts.
For models capable of supporting three heads, the listed MCA and MOCP values are different:
- GWHD(24)ND6MO: MCA 19.5 A / MOCP 25 A;
- GWHD(30)ND6MO: MCA 23 A / MOCP 35 A;
- GWHD(36)ND6MO: MCA 30 A / MOCP 45 A;
- GWHD(42)ND6MO: MCA 30 A / MOCP 45 A.
This information illustrates why we always check the electrical panel and circuit before installation.
Two heat pumps from the same product family may require different electrical protection. The fact that an older unit used a particular circuit breaker does not automatically mean that the circuit is suitable for the new outdoor unit.
1/4 in and 3/8 in lines according to the FreeMatch R32 specifications
For the outdoor units shown, the documentation specifies a liquid line of 1/4 po and a gas line of 3/8 po.
In a three-head configuration, each indoor unit must be connected to the outdoor unit. Route management therefore becomes much more important than in a single-zone system.
The photo shows part of the piping grouped beneath the outdoor unit. Its arrangement must take several factors into account:
- avoid excessively tight bends;
- preserve the insulation;
- properly support the lines;
- prevent rubbing against brick or metal;
- protect exposed sections;
- clearly identify the circuits for the three indoor units.
A refrigeration line must not simply be “long enough.” Its length is part of the system calculations.
Up to 100 meters of total length depending on the model
For units compatible with three heads, the stated maximum total lengths vary according to capacity:
- 60 m for the 24,000 BTU/h model;
- 80 m for the 28,400 BTU/h model;
- 80 m for the 36,000 BTU/h model;
- 100 m for the 42,000 BTU/h model.
The maximum height difference is 15 m for the 24,000 BTU/h model and 25 m for the larger models on the list.
These limits make the FreeMatch R32 interesting when the three indoor units are distributed in different parts of the building, but they must be followed precisely.
The specification sheet also indicates the length of piping covered by the factory charge, as well as an additional charge of 20 g/m when required.
We therefore measure the actual lines rather than adding refrigerant “by approximation.”
Why evacuation is crucial
After the lines are assembled, the circuit must be prepared before the refrigerant is released.
Evacuation is used primarily to remove air and moisture from the refrigeration circuit. On a three-head heat pump, the combined lengths and number of connections make this step particularly important.
A professional installation includes, among other things:
- connection preparation;
- proper tightening;
- leak test;
- measured evacuation;
- vacuum stability verification;
- calculation of the additional charge if necessary;
- valve opening;
- startup;
- inspection of the three zones.
A beautiful outdoor installation is not enough if this invisible part of the work is neglected.
R32 and an A2L leak detection sensor
The range uses R32 refrigerant and the specification sheet mentions an A2L leak detection sensor included.
R32 requires practices, tools, and procedures compatible with this type of refrigerant. The presence of a sensor obviously does not replace a leak test or a properly executed refrigeration installation.
With three indoor circuits, we pay particular attention to identifying the connections. A mismatch between the wiring and the lines for a head can cause improper operation during commissioning.
Sound level: location matters as much as the value on the specification sheet
The outdoor sound pressure level indicated in the documentation varies by model. For units capable of accommodating three heads, it is between 58 and 63 dB(A) at the high setting indicated in the table.
This technical value does not fully indicate the actual perception of noise.
In this installation, the unit is located near a brick wall and beneath a roof overhang. Rigid surfaces can reflect some of the sound. The following must therefore be considered:
- of rooms located behind the wall;
- of nearby windows;
- of the rigidity of the supports;
- of vibrations;
- of proximity to adjacent properties;
- of the airflow around the unit.
A stable mounting and proper placement help reduce resonance problems.
AHRI, ENERGY STAR, and rebates: always verify the exact combination
The FreeMatch R32 sheet lists AHRI numbers distinct for ductless, ducted, and mixed configurations, along with an ENERGY STAR indication in the table.
It also states that the equipment is eligible for local rebates.
This statement does not mean that any combination of three heads automatically qualifies for the same amount of financial assistance.
For a subsidy or rebate application, the following must be confirmed in particular:
- the exact outdoor unit model;
- the references for the three indoor units;
- the corresponding AHRI combination;
- the program requirements at the time of installation;
- the requested supporting documents.
We always recommend that owners retain the detailed invoice and legible photos of the nameplates.
Warranty stated in the GREE FreeMatch R32 documentation
The supplied sheet mentions a 10-year standard warranty, as well as an additional two-year extension from Wolseley when the product is registered and/or proof of installation is provided, subject to the stated conditions.
Equipment registration should therefore not be treated as an unimportant administrative detail.
We recommend keeping the following together:
- invoice;
- outdoor model;
- indoor models;
- serial numbers;
- installation date;
- applicable AHRI reference;
- proof of registration when required.
Mistakes to avoid in an outdoor installation like this
Install the unit too close to the ground
A low-mounted unit quickly becomes vulnerable to accumulated snow and debris.
Neglect the space above the unit
A roof or balcony can protect the heat pump, but must not restrict airflow or create an area where rejected heat recirculates.
Secure the support without considering vibrations
Static weight is only part of the problem. The structure must remain stable during compressor speed variations.
Leave the piping unprotected
Exterior insulation can deteriorate when left exposed to UV rays, the elements, or mechanical damage.
Placing the unit in the snow-removal path
A heat pump installed at the proper height can still become buried if snow from a driveway is regularly pushed against it.
Forgetting about defrost water
The space beneath the unit must be able to receive and drain water without creating an ice hazard for occupants.
Order the system based solely on the number of heads
A three-zone system must be sized based on the needs of the spaces, not simply on the number “three.”
A final inspection of the outdoor unit and the three zones
Once the installation is complete, we carry out full commissioning.
The inspection includes, among other things:
- outdoor fan operation;
- the absence of abnormal vibration;
- communication with each indoor unit;
- the response of all three heads;
- operation when several zones are running simultaneously;
- checking the drains;
- discharge air temperatures;
- louver control;
- any error codes;
- explaining the controls to the homeowner.
We also verify that sufficient access to the outdoor unit remains for future HVAC maintenance. An installation that cannot be serviced without dismantling part of the building is poorly planned, even if it works properly on the first day.
What this Acton Vale installation illustrates particularly well
The final photograph shows an outdoor installation that makes efficient use of a brick façade without monopolizing the lower space. The unit is elevated, the fan remains unobstructed, and the lines are grouped close to the equipment.
For a homeowner, the result may seem simple: a heat pump on two supports.
For us, this image represents a series of decisions made before and during the work:
- choose the position in relation to the window and railing;
- determine the height;
- check the structure;
- plan the routes to three indoor units;
- manage R32;
- check electrical requirements;
- anticipate defrosting;
- maintain service access;
- test all three zones together.
This is precisely what distinguishes a simple equipment installation from a multizone heat pump installation truly suited to the building.
At AirGreen, we apply the same level of care to installations in Acton Vale, in Greater Montreal, in Montreal, Laval, Longueuil, in North Shore and the South Shore properly size the equipment, understand the building before choosing its location, and install each component in a way that facilitates both everyday comfort and future maintenance.