A multi-zone heat pump installed on a narrow deck where every inch mattered
This installation of a GREE FreeMatch R32 3-head heat pump in Saint-Joseph-de-Sorel perfectly illustrates a type of project where choosing the outdoor unit’s location requires almost as much consideration as sizing the indoor units. In the construction photo, the GREE outdoor unit is installed at the end of a relatively narrow wooden deck, between the railing and the home’s brick wall. A window, an outdoor light fixture, a downspout, and the route of the new lines further reduced the available options.
In this context, it would have been easy to install the unit in the most accessible location without considering its future use. Instead, we sought to preserve three essential elements: sufficient clearance for air circulation, reasonable access for maintenance, and keeping a usable passageway on the deck.
The outdoor unit rests on an independent metal structure that keeps it above the wooden floor. This elevation is particularly beneficial in Quebec because it keeps the heat pump’s base away from water, leaves, snow, and ice that can accumulate on a deck.
The photo appears to have been taken before the work was fully completed. Several lines are still temporarily grouped into loops near the wall, a ladder and equipment are visible on the ground, and some finishing sections have not yet been installed. This is precisely an important stage of an HVAC installation : before closing up and permanently protecting the lines, we must verify the lengths, connections, sealing, communications, and operation of all three zones.
The particular challenge of installing on a wooden deck
A multi-zone heat pump is not a small appliance. Its weight, vibrations, airflow, and the water produced during defrosting must all be taken into account.
In this project Saint-Joseph-de-Sorel, the outdoor unit could not simply be placed directly on the patio boards.
We therefore used a raised metal base. This setup notably allows:
- to distribute the weight of the unit more evenly;
- to limit direct contact between the frame and the wood;
- to allow air to circulate beneath the heat pump;
- to facilitate water drainage during defrost cycles;
- to reduce the risk of leaves accumulating beneath the cabinet;
- to maintain better access to the lower section;
- to keep the unit higher above snow accumulation.
The exact weight depends on the outdoor model selected. In the FreeMatch R32 range, the units capable of supporting three heads include models ranging from 112.5 lb for the 24,000 BTU model to approximately 174 lb for the larger 36,000 and 42,000 BTU units.
These data show why the structure beneath the unit must be selected based on the actual model, rather than simply because a support “seems sturdy enough.”
Wood transmits vibrations differently from a concrete foundation
Installing a heat pump on or near a terrace also requires particular attention to vibration.
A wood floor can amplify certain frequencies much more easily than a concrete slab. A vibration that would be almost imperceptible on a massive foundation can become audible indoors if it is transmitted to the patio structure and then to the building.
We must therefore take into account:
- the support points;
- the tightness of the fasteners;
- vibration-isolating components;
- the rigidity of the support;
- any potential contact between the lines and the masonry;
- sections of piping that could vibrate against the railing or wall.
The FreeMatch R32 documentation indicates an outdoor sound pressure level ranging from 54 to 63 dB(A) at high speed, depending on the condenser capacity.
This value reflects the operation of the unit itself. Poor mechanical isolation could generate additional noise that does not come directly from the compressor or fan.
Why positioning the unit at the end of the terrace made sense
The photo shows that the GREE unit was positioned near the end of the balcony, with its fan facing the open space.
This choice is important. The large front fan must be able to discharge air without immediately encountering a wall or obstacle.
In such a narrow passage, placing the heat pump in the other orientation could have reduced the space available in front of the fan or disrupted movement on the terrace.
We also took into account:
- of the railing on the left;
- of the brick wall on the right;
- of the window located immediately behind the technical area;
- of the downspout;
- of the outdoor light fixture;
- of the space required to route three sets of lines.
This arrangement makes it possible to concentrate the mechanical equipment at the rear of the terrace rather than installing it in the middle of the walkway.
Three indoor heads with a single outdoor condenser
The main benefit of a GREE FreeMatch R32 with 3 heads is precisely what is visible in this type of project: a single outdoor unit can supply several zones of the home.
With three single-zone systems, it would have been necessary to find three different outdoor locations or group three condensers on an already narrow terrace. The multi-zone system avoids this multiplication of equipment.
Depending on the selected FreeMatch outdoor unit, the manufacturer allows:
- 2 to 3 indoor units on the GWHD(24)ND6MO;
- 2 to 4 units on the GWHD(30)ND6MO;
- 2 to 4 units on the GWHD(36)ND6MO;
- 2 to 5 units on the GWHD(42)ND6MO.
The 18,000 BTU model can accommodate only two indoor units and therefore does not correspond to a three-zone project.
The photo does not make it possible to read the complete model number of the outdoor unit installed here clearly. We therefore do not assign it a specific capacity without the nameplate or the combination recorded in the project file.
How to properly size the three zones
A three-zone installation should never be sized solely according to the home’s total area.
Each room or area has a different heating and cooling load.
We examine, in particular:
- the area of each zone;
- ceiling height;
- the number of exterior walls;
- the number of windows;
- their orientation;
- the quality of the insulation;
- air infiltration;
- the floor;
- solar exposure;
- the number of occupants;
- the room’s use.
A small bedroom on the north side may require much less capacity than a living room with several south-facing windows.
That is why three units with identical capacities are not automatically the best solution.
A concrete example of a poor approach
Let’s suppose that a house requires three zones:
- a large open-plan area;
- a bedroom;
- a basement.
Arbitrarily installing three 12,000 BTU units because “12,000 BTU is a common capacity” can create an unbalanced system.
The large room could be inadequately served while the small bedroom would be oversized.
With a multizone heat pump, the right choice is to calculate the requirements of each zone, then verify that the complete combination is compatible with the selected outdoor unit.
The capacities available in the GREE FreeMatch R32 range
Page 2 of the GREE documentation presents several outdoor units.
For configurations that can accommodate three indoor units, the nominal cooling capacities are:
- 24,000 BTU/h for the GWHD(24)ND6MO;
- 28,400 BTU/h for the GWHD(30)ND6MO;
- 36,000 BTU/h for the GWHD(36)ND6MO;
- 42,000 BTU/h for the GWHD(42)ND6MO.
At nominal heating capacity, these same models are rated, respectively, at 24,000, 30,000, 36,000, and 44,300 BTU/h.
It is also important to look at modulation ranges rather than just nominal capacity. A variable-capacity compressor system can reduce or increase its output according to demand.
This modulation helps maintain a more stable temperature when the actual demand is below the system’s full capacity.
Efficiency of up to 21 SEER2
The technical documentation provided with the FreeMatch R32 lists values of up to:
- 21 SEER2;
- 12.5 EER2;
- 10 HSPF2.
For a homeowner comparing several multi-zone heat pumps in Quebec, these data provide a useful indication of the product line’s energy efficiency.
SEER2 mainly concerns seasonal cooling efficiency, while HSPF2 is used to compare seasonal heating performance.
However, the actual performance of an installation also depends on the quality of the work performed on site.
Even a unit with good technical specifications can lose some of its advantages if:
- it is oversized;
- the filters remain dirty;
- the lines are poorly insulated;
- the refrigerant charge is not appropriate;
- the outdoor unit lacks airflow;
- the vacuum pump-down was performed incorrectly;
- the setpoint temperatures are used inconsistently.
A heat pump designed to operate down to -30 °C
For heating, the documentation indicates an outdoor temperature range down to -30 °C, while the cooling range is stated as -30 °C to 48 °C.
This low-temperature operating capability is particularly relevant for a heat pump installation in Saint-Joseph-de-Sorel, where winter temperatures can become very low.
However, two concepts must be distinguished:
operation at -30 °C does not necessarily mean full rated capacity at -30 °C.
A heat pump’s heat output varies with the outdoor temperature. As the cold becomes more intense, the home’s heating demand increases simultaneously.
Proper sizing must therefore take into account the machine’s performance in cold weather, as well as whether or not a supplemental heating source is available.
Defrosting is particularly important on a deck
The FreeMatch documentation mentions a smart defrost.
When the heat pump operates in heating mode in cold weather, frost may form on the outdoor coil. The unit must periodically reverse its cycle to melt this accumulation.
This operation produces water.
On a wooden deck like the one shown in the photo, we must anticipate this phenomenon. Water must be able to fall and drain away without remaining trapped directly beneath the unit.
In winter, the owner must also monitor ice that could gradually form around the feet of the support.
It is recommended to:
- keep the area beneath the unit clear;
- remove significant snow accumulation;
- do not let snow extend below the cabinet;
- check that ice does not reach the lower openings;
- keep the entire fan face clear;
- avoid covering the heat pump while it is operating.
The loops of lines visible in the photo: a step before finishing
One of the most striking elements in the photo is the bundle of lines coiled against the brick wall.
These loops indicate that the image was taken while the installation was not yet completely finished or the routes were still being prepared.
For three indoor heads, we must manage several sets of refrigerant lines as well as communication cables.
A multi-zone installation requires each branch to be properly identified.
We must avoid any confusion between:
- indoor unit A and its pipes;
- unit B and its pipes;
- unit C and its pipes;
- the corresponding cables.
A branch reversal can cause a communication problem during startup.
Why we do not cut the lines too early
When a route passes around a window, wall corner, or floor, it is best to confirm the actual length before permanently cutting the copper.
A line that is too short would require adding an extra fitting, which we generally try to avoid when the route can be completed another way.
The final step is then to organize and protect the lines to achieve a neater, more weather-resistant route.
The length limits must be checked on a three-head system
The FreeMatch R32 offers significant piping flexibility.
Depending on the outdoor unit capacity, the stated maximum total length ranges from 40 to 100 meters, while the maximum height difference is 15 to 25 meters.
For models compatible with three heads, the total limits can reach:
- 60 m for the 24,000 BTU unit;
- 80 m for the 30,000 and 36,000 BTU units;
- 100 m for the 42,000 BTU model.
These values do not mean that using the full available length is desirable. We favor a logical, direct route whenever the building configuration allows it.
The additional refrigerant charge must also be checked when the length exceeds the amount covered by the factory pre-charge.
The documentation indicates an additional charge of 20 g/m according to the conditions specified by the manufacturer.
R32 requires meticulous refrigeration installation
The GREE FreeMatch uses R32 refrigerant.
The product sheet also mentions an A2L leak detection sensor included.
The R32 requires practices and tools compatible with A2L refrigerants.
In a three-head system, we must pay even more attention to the quality of the connections because there are more fittings than with a single-zone heat pump.
Commissioning includes, among other things:
- preparing the piping;
- checking the flares;
- tightening according to specifications;
- the leak test;
- pulling a vacuum;
- checking that the vacuum holds;
- opening the valves;
- checking the charge;
- starting the units;
- verifying the operation of each zone.
We never consider an installation complete simply because the compressor starts.
Drainage for the three indoor units
Each head produces condensation water in cooling mode.
Three indoor units therefore mean three drains that must function properly.
When the configuration allows, gravity drainage is generally preferable. It must maintain a continuous slope so that the water can flow naturally.
Poor drainage can cause:
- draining noises;
- odors;
- water in the condensate pan;
- an overflow;
- damage to the wall or ceiling.
During commissioning, each drain must be tested separately.
The power supply depends on the outdoor capacity
All outdoor units in this range operate at 208/230 V.
However, the minimum circuit ampacity and maximum protection vary by model.
For the entire range, the documentation indicates:
- MCA of 14.5 to 30 A;
- maximal protection of 20 to 45 A.
It would therefore be incorrect to say that a three-head heat pump automatically requires a breaker of a given capacity.
The electrical selection must always be based on the nameplate of the condenser actually installed.
From the deck to the three indoor rooms: an installation designed as a single system
The distinctive feature of this project in Saint-Joseph-de-Sorel is not found solely in the heat pump itself. It lies in how the system had to be integrated into an existing deck, between a railing and a brick wall, with several obstacles around the piping route.
The elevated outdoor unit occupies a relatively compact area at the end of the patio. This arrangement makes it possible to create three heating and cooling zones without having to install multiple condensers on the property.
How to use three heads effectively
The owner has separate control for each indoor unit, but this does not turn the system into three completely independent heat pumps.
The three heads share the same outdoor unit.
They can have:
- different setpoint temperatures;
- different fan speeds;
- different operating schedules.
However, their operating modes must be compatible.
It is not possible to request heating in one room and air conditioning simultaneously in another room connected to the same condenser.
This explanation is part of the system handover to the customer, because many service requests for multi-zone systems simply result from conflicting settings between the remote controls.
The features integrated into the FreeMatch R32
The manufacturer's technical data sheet presents several interesting features:
- self-diagnostics;
- indoor units powered by the outdoor unit;
- intelligent defrosting;
- automatic voltage adaptation;
- inverter technology G10;
- quiet operation;
- compact design;
- up to seven indoor unit options;
- integrated A2L sensor.
This variety makes it possible to adapt the indoor units to the building's configuration rather than necessarily using the same type of equipment in every zone.
ENERGY STAR and AHRI references
Page 2 of the technical data sheet lists separate AHRI references for ductless, ducted, and mixed combinations.
For ductless systems, the references indicated are 214931586 to 214931590, depending on the outdoor condenser. The table also lists the range's models as ENERGY STAR.
For a subsidy or rebate application, the exact AHRI number is essential.
Simply installing a GREE FreeMatch R32 does not automatically allow an incentive amount to be announced. Eligibility depends on the installed combination and the program conditions applicable at the time of the work.
Rebates must be confirmed before promising an amount
The documentation provided indicates that the range is eligible for local rebates, without specifying a single amount applicable to all configurations.
We must therefore verify:
- the exact outdoor unit;
- the three indoor units;
- the AHRI combination;
- the property type;
- the purchase date;
- the installation date;
- the rules of the relevant program.
This verification protects the owner from a situation in which a heat pump is selected solely based on an assumed subsidy that ultimately does not apply to the installed combination.
A warranty worth registering promptly
The manufacturer's documentation indicates a 10-year standard warranty, with two additional years offered by Wolseley when the product is registered and/or when proof of installation is provided, subject to the applicable terms.
After a three-head installation, it is important to keep the information for all equipment:
- outdoor unit model;
- outdoor serial number;
- model of the three heads;
- serial numbers of the indoor units;
- final invoice;
- installation date;
- AHRI number;
- proof of registration.
Mistakes to avoid in a similar project
Installing the condenser directly on the terrace
Wood can transmit vibrations and remains exposed to moisture. A suitable structure also facilitates drainage beneath the unit.
Blocking the passage with the heat pump
On a narrow terrace, the positioning must preserve reasonable airflow and service access.
Pointing the fan toward a nearby obstacle
The outdoor unit must be able to discharge its air without excessive recirculation.
Neglecting defrost water
A heat pump that heats in winter regularly produces water beneath its outdoor unit.
Leaving the lines without final protection
The loops and cables visible in a construction-site photo do not necessarily represent the final finish. The network must be organized and protected before final handover.
Choosing capacity solely by adding up the BTUs of the indoor units
A multi-zone system must be sized according to the heating and cooling loads and the combinations permitted by the manufacturer.
Confusing operation at -30 °C with full power at -30 °C
The operating range alone does not describe the available capacity at extreme temperatures.
Neglecting future accessibility
A technician may one day need to work on the valves, circuit boards, or compressor. The installation must remain accessible.
Our AirGreen method for complex multi-zone installations
At AirGreen, we approach a three-head heat pump installation as a complete project rather than simply adding an outdoor unit.
We analyze the following in turn:
- the needs of the three zones;
- the capacities of the indoor units;
- the authorized combination;
- the outdoor unit location;
- the support structure;
- air circulation;
- the line routing;
- the drains;
- the electrical supply;
- the refrigerant charge;
- vibrations;
- service access;
- the operation of the three indoor units;
- the warranty and eligibility documents.
We apply this approach in our HVAC in Montreal, Laval, Longueuil, on the North Shore, and the South Shore as well as in the surrounding municipalities where architectural configurations require tailored solutions.
This installation of GREE FreeMatch R32 in Saint-Joseph-de-Sorel shows that a narrow terrace does not necessarily prevent the installation of a multi-zone heat pump. However, the location, supports, defrosting, line routing, and future maintenance must all be treated as elements of the same project.
The desired outcome is simple: three better-controlled indoor zones, a single new outdoor unit, and an installation capable of operating in both summer and winter without unnecessarily sacrificing the available outdoor space.