An elevated outdoor installation to protect the heat pump and optimize the space around the building
At this project carried out in Saint-Philippe, on Montreal’s South Shore, one of the most important decisions concerned the location of the outdoor unit for the GREE FreeMatch R32 three-head heat pump. The project photograph clearly shows the result: the outdoor unit was installed high up on two sturdy metal wall brackets rather than simply placed at ground level.
This choice addresses several practical constraints we regularly encounter when installing multi-zone heat pumps in Quebec. Among other things, it frees up floor space, keeps the unit above typical snow accumulation, and facilitates the drainage of water produced during defrost cycles.
The immediate surroundings made the planning particularly interesting. The unit is located against a finished exterior wall, in a relatively narrow space, with branches and vegetation nearby. Existing pipes also run along the building. The system therefore had to be installed without compromising airflow, obstructing existing infrastructure, or compromising sufficiently clear access for future HVAC maintenance.HVAC maintenance.
An outdoor unit on wall brackets: a detail that makes a big difference in winter
Installing an outdoor unit directly on a small slab may be suitable for some projects. In other situations, particularly with a a heat pump designed to operate during the Quebec winteran elevated installation becomes much more appealing.
In Saint-Philippe, we mounted the GREE outdoor unit on two triangulated metal supports anchored to the building. This type of structure must be sufficiently rigid to support the weight of the unit while limiting movement and vibration.
The most obvious advantage is the increased height.
During a storm, snow can quickly accumulate in front of the outdoor heat exchanger. If the unit becomes partially buried, its airflow decreases. It may then have more difficulty transferring heat, and its defrost cycles may be disrupted.
By elevating the unit, we reduce this risk while leaving space beneath the chassis for water drainage.
Defrosting actually produces water
When a heat pump heats a home in cold weather, the outdoor heat exchanger becomes cold enough for moisture in the air to form frost on it. The system must periodically reverse its operation to melt this buildup.
GREE also states that a intelligent defrosting among the features of the FreeMatch R32. The manufacturer also mentions G10 inverter technology, self-diagnosis, automatic voltage adjustment, and quiet operation.
After a defrost cycle, several liters of water may collect beneath the unit, depending on weather conditions. In the middle of winter, this water may then freeze.
Clearance beneath the unit is therefore essential. An installation that is too low can gradually lead to the formation of an ice block beneath the chassis. Over time, this accumulation can reach the bottom of the unit and interfere with its drainage.
Wall supports that must be installed precisely
The photograph also shows that the two supports are spaced apart to properly bear the load of the outdoor unit.
A wall-mounted installation does not simply consist of inserting a few screws into the cladding. We must identify a sufficiently strong structure behind the exterior finish and use anchors appropriate for the building.
Several elements must be checked:
- the strength of the support;
- the type of wall;
- the weight of the outdoor unit;
- the level of the unit;
- the depth of the anchors;
- the risk of vibration transmission;
- the recommended clearances;
- access to the service panel.
The outdoor unit must remain stable when its fan and compressor operate at different speeds. A structure that flexes or vibrates can produce noise that is perceptible inside the building.
We therefore pay particular attention to the contact points between the heat pump, the supports, and the wall.
A narrow outdoor space that requires attention to airflow
The visible unit is located in an area relatively enclosed by the building and vegetation. In this type of configuration, the fan must be able to draw in and expel a significant volume of air without excessive recirculation.
The air leaving the front of the unit must not immediately return toward the heat exchanger.
Poor placement can create a loop in which the unit reabsorbs some of the air it has just expelled. This situation can reduce efficiency and increase operating time.
Before choosing the location, we consider in particular:
- the distance to neighboring walls;
- the fences;
- the stairs;
- the balconies;
- the branches;
- the shrubs;
- the windows;
- the passageways;
- the other mechanical equipment.
In the Saint-Philippe project, the outdoor unit’s front remains well clear despite the relatively compact surroundings.
Vegetation must be monitored
The branches visible in front of and around the unit are not merely an aesthetic consideration. Vegetation changes with the seasons.
A branch that leaves sufficient space at the time of installation may move closer to the grille during the summer or under the weight of snow.
We therefore recommend keeping the area in front of and around the outdoor unit clear. Leaves, twigs, or climbing plants must not be allowed to come into contact with the fan or obstruct the heat exchanger.
Cela facilite également le nettoyage annuel.
This also makes annual cleaning easier.
A system designed to supply three indoor zones GREE FreeMatch R32 three-headThis installation is not limited to the outdoor unit visible in the photograph. It is a
, meaning that a single outdoor unit serves three indoor units installed in different areas of the building.
This architecture makes it possible to treat several spaces separately while avoiding three independent compressors outside.
- For homeowners, the benefits are tangible:
- fewer pieces of equipment around the house;
- three temperature zones;
- better adaptation to enclosed rooms;
- greater flexibility depending on occupancy;
- a more compact outdoor installation;
a single main mechanical platform to maintain.
FreeMatch is specifically designed as a multi-zone system. GREE documentation indicates that it can be paired with several types of indoor units and offers up to seven different indoor options depending on the desired configuration.
This makes it possible to adapt the emitters to each room’s architectural constraints rather than imposing exactly the same solution everywhere.
Which outdoor unit can actually supply three heads?
The exact nameplate on the outdoor unit visible in the photograph is not legible enough to identify its capacity with certainty. We therefore avoid arbitrarily assigning a BTU rating to this project.
The FreeMatch R32 range nevertheless includes several models capable of supplying three indoor units.
- The 36,000 BTU/h model accepts 2 to 4 units; According to the documentation: GWHD(24)ND6MO
- The 36,000 BTU/h model accepts 2 to 4 units; The 24,000 BTU/h model accepts 2 to 3 indoor units; GWHD(30)ND6MO
- The 36,000 BTU/h model accepts 2 to 4 units; The 28,400 BTU/h cooling model accepts 2 to 4 units; GWHD(36)ND6MO
- The 36,000 BTU/h model accepts 2 to 4 units; GWHD(42)ND6MO The 42,000 BTU/h model accepts 2 to 5 units.
The smallest 18,000 BTU/h model is limited to two indoor units.
In heating mode, the corresponding rated capacities are 24,000, 30,000, 36,000 and 44,300 BTU/h for the versions that can accommodate three heads.
The choice between these models depends on the thermal loads of the three spaces, not simply on the fact that there are three wall-mounted units.
Why we do not size a heat pump by counting only the square footage
Two homes of the same size can have very different requirements.
In Saint-Philippe, as in our facilities in Longueuil, Montréal, Laval, on the North Shore and elsewhere on the South Shore, we must consider several factors before choosing the capacity:
- quality of the insulation;
- age of the building;
- glazed area;
- window orientation;
- ceiling height;
- floor layout;
- wind exposure;
- air infiltration;
- use of each room;
- desired indoor temperature;
- presence of other heating systems.
An open living room that receives a lot of sunlight does not have the same load as a small north-facing bedroom.
In a three-head configuration, we must also check the balance between the indoor capacities and the outdoor unit's capacity.
Seasonal performance well suited to a multi-zone system
The documentation for GREE FreeMatch R32 indicates efficiencies of up to 21 SEER2, 12.5 EER2 and 10 HSPF2. It also specifies an operating range in cooling from -30 °C to 48 °C and in heating from -30 °C to 24 °C.
The SEER2 is used to represent seasonal cooling efficiency. The HSPF2 refers more specifically to seasonal heating performance.
These data are particularly relevant in Greater Montréal, where the same heat pump often has to handle hot summer days and very cold winter periods.
However, operation down to -30 °C does not mean that capacity remains identical to that advertised at milder temperatures. The building's heat loss increases as the outdoor temperature drops.
We therefore always assess the heat pump in relation to the entire building and, where required, the available backup heating.
What is not visible in the photo: piping, electrical work, evacuation, and commissioning
Three heads mean three circuits to organize properly.
A multi-zone system is more complex than a single-zone heat pump.
Each indoor unit must communicate with the outdoor unit and have its appropriate refrigerant connections. The lines must be identified to prevent errors between the different ports on the outdoor unit.
GREE documentation specifies connections of 1/4 in for the liquid line and 3/8 in for the gas line.
The maximum lengths also vary according to the outdoor model. The specified limit is:
- 40 m for the 18,000 BTU/h model;
- 60 m for the 24,000 BTU/h model;
- 80 m for the 30,000 and 36,000 BTU/h models;
- 100 m for the 42,000 BTU/h model.
The permitted height difference varies from 15 to 25 metres depending on the model.
These values are important in projects involving multiple floors or heads located far from the outdoor unit.
The refrigerant charge must correspond to the actual installed lengths.
The data sheet also indicates a different precharged length for each outdoor capacity and provides for adding refrigerant when the allowable precharged length is exceeded.
This step must not be estimated.
We calculate the actual length of the system and apply the manufacturer's specifications. Too little refrigerant or an incorrect charge can affect performance, operating temperatures, and compressor reliability.
A leak test before evacuation
After completing the refrigerant connections, we must check their tightness.
A three-head installation has more connections than a single-zone installation. This makes the work method even more important.
We carefully carry out the following steps:
- line preparation;
- flaring;
- proper tightening;
- leak test;
- evacuation;
- vacuum stability check;
- refrigerant release;
- commissioning.
Evacuation removes air and moisture from the refrigeration system. This step directly contributes to the heat pump's long-term reliability.
The electrical installation visible beneath the outdoor unit
In the photograph, an electrical component is installed directly beneath the outdoor unit. Coordinating the power supply is an integral part of designing a HVAC installation.
The FreeMatch R32 units in this range operate at 208/230 VTheir minimum circuit ampacity and maximum overcurrent protection vary according to capacity.
For example, the technical data sheet indicates:
- MCA of 19.5 A and MOCP of 25 A for the 24,000 BTU/h model;
- MCA of 23 A and MOCP of 35 A for the 30,000 BTU/h model;
- MCA of 30 A and MOCP of 45 A for the 36,000 and 42,000 BTU/h models.
These figures do not mean that you automatically choose the largest available circuit breaker. The circuit must be calculated based on the nameplate of the equipment actually installed, the wiring, and the applicable electrical requirements.
Outdoor noise depends greatly on the installation
The manufacturer specifies a high-speed sound pressure ranging from 58 to 63 dB(A) for models capable of powering three heads.
This figure represents only part of the actual sound experience.
An installation against a lightweight structure, on inadequate supports, or in a small alcove can transmit more vibrations.
In this Saint-Philippe project, the rigidity of the supports and the securing of the outdoor unit were therefore particularly important.
We also check that the lines are not under tension and cannot transmit compressor vibrations directly to the structure.
Three heads do not mean three opposing modes
Each indoor unit can be set independently for temperature and fan speed, but the three zones share the same outdoor unit.
Compatible modes must therefore be used.
In winter, all the units can operate in heating mode at different temperatures. In summer, they can all provide cooling according to the respective needs of the rooms.
However, you should avoid requesting heating in one zone and cooling in another at the same time.
Explaining this feature during system handover prevents a lot of confusion and allows occupants to use their GREE multi-zone heat pump.
The mistakes we want to avoid on an outdoor installation like this
Installing the unit too close to the ground
Snow and ice can reduce clearances and interfere with defrost drainage.
Mounting the unit on an insufficiently rigid structure
The vibrations may then be transferred to the wall or become audible indoors.
Allowing vegetation to overgrow the front of the fan
Branches, leaves, and plants can reduce airflow and make maintenance more difficult.
Neglecting service access
A technician must be able to reach the panels, connections, and components without having to dismantle part of the building.
Installing the lines without calculating the lengths
In a three-head system, the length of each branch and the total network length must be considered.
Mixing up the connections between zones
The communication cables must correspond to the correct refrigerant circuits.
Forgetting about defrost water
An outdoor unit regularly produces water while heating in winter. Its location must allow this water to drain without creating a problem beneath the unit.
Warranty, AHRI numbers, and available rebates
The technical data sheet provides separate AHRI numbers for ductless, ducted, and mixed configurations. It also identifies the equipment as ENERGY STAR in the technical table.
The manufacturer also indicates a 10-year standard warranty and mentions an additional two-year extension with Wolseley when the product is registered and proof of installation is provided. The documentation also specifies that the equipment may be eligible for local rebates.
For any financial assistance, however, the exact installed combination must be verified. The AHRI number for the complete system, the installation date, and the program conditions determine actual eligibility.
We recommend that owners keep:
- the final invoice;
- the indoor unit models;
- the outdoor model;
- serial numbers;
- the applicable AHRI reference;
- photographs of the rating plates;
- proof of warranty registration.
The result: a multi-zone installation designed to address outdoor constraints as well
This project in Saint-Philippe illustrates an often-underestimated aspect of heat pump installation: positioning the outdoor unit.
In the photograph, the equipment appears to be simply mounted on the wall. In reality, this location results from a series of decisions concerning snow, defrosting, airflow, vegetation, the structure, vibrations, connections, and future access.
The GREE FreeMatch R32 three-head then allows heating and air conditioning to be distributed across several areas of the building with a single outdoor unit.
At AirGreen, we carry out this type ofHVAC installation in Saint-Philippe and throughout Greater Montréal, particularly in Montréal, Laval, Longueuil, on the North Shore and the South ShoreOur work is not limited to connecting the equipment: we look for a location that remains functional in July as well as February, allows for proper maintenance, and respects the building’s practical constraints.