Installation of a 3-ton GREE FLEXX ULTRA R32 central heat pump in Béthanie, in the Acton RCM

187 pounds hanging from a brick wall: the decision that shaped this entire Béthanie project

Béthanie has approximately 350 residents. It is a township municipality in the MRC d’Acton, in Montérégie, crossed by the Rivière Noire, well away from major centres. There is no natural gas, the lots are spacious, the winds are unobstructed, and snow accumulation is nothing like that on a residential street in Longueuil. It was in this context that we installed a 3-ton GREE FLEXX ULTRA R32 central heat pump, configured with GUD36AH2/G-D(U) indoors and GUD36W2/NhE-D(U) outdoors.

The final construction photo immediately shows what sets this installation apart: the outdoor unit is not resting on a slab. It is suspended from a wall bracket anchored to the home’s brick wall, approximately two feet above the stone bed. This is not an aesthetic choice. It is the choice that dictated half of the day’s technical decisions.

Why we raised the unit off the ground

Snow

A heat pump installed on low supports in a rural area of Montérégie is a machine that will spend part of February buried. An outdoor coil blocked by snow can no longer absorb heat: the defrost cycle starts more often, heating capacity drops, and the auxiliary heating takes over precisely when electricity costs the household the most. By raising the unit, we position the bottom of the cabinet clearly above the likely snow line, even after a windstorm pushes drifting snow against the wall.

Defrost water

In heating mode, a central heat pump produces water—a lot of water. Each defrost cycle drains melted ice through the bottom of the unit. On a slab attached to the house, this water freezes, builds up in layers, and eventually lifts the unit or traps the bottom of the coil in a block of ice. Here, the water falls directly into a draining stone bed, away from the pedestrian walkway. The drain elbow visible beneath the unit directs the flow toward this bed rather than along the wall.

The ground

Rural homes move. A wall bracket attached to the structure does not follow the ground’s freeze-thaw movements like a slab does. An appliance that tilts over the years operates less efficiently and vibrates more.

Hanging a 187 lb condenser on a wall: what it really requires

This is the part that many rushed installations overlook, and it is the one we pay the most attention to.

Brick is not structural. Residential brick veneer is a cladding attached to the framing with ties, with an air gap behind it. Screwing a bracket supporting 187 lb—the net weight of the GUD36W2/NhE-D(U)—into the veneer alone means loading an element that was never designed to support cantilevered weight. We anchor into the structure behind the veneer, or we use anchors rated for the combined load of the static weight and dynamic startup forces. Our internal rule is that a bracket must be rated for at least twice the weight of the unit.

Vibration. A wall is a sounding box. A compressor rigidly bolted to a wall bracket transmits its vibrations into the brick and then into the framing, and the customer hears a humming sound in the wall of a bedroom. On this job, the unit rests on anti-vibration pads placed between the feet and the support, and the tightening is checked—a bolt tightened down fully can completely negate the effect of the pad.

Level. A condenser mounted slightly askew does not drain its defrost water properly. We check the level along both axes before final tightening, not afterward.

Clearances. The unit is installed alongside an open ornamental iron fence, allowing the discharge air to pass through. A solid fence, dense cedar hedge, or shed wall placed in the same location would have recirculated hot air into the unit in summer and reduced its efficiency. The clearances specified by the manufacturer are checked with a tape measure, not by eye.

The unit: GREE FLEXX ULTRA R32, 3 tons

The FLEXX series, distributed in Quebec by Dettson, is a horizontal (side-discharge) airflow air handler powered by 24 VAC, compatible with a conventional thermostat. Configuration data for the installation in Béthanie:

• Indoor unit: GUD36AH2/G-D(U)
• Outdoor unit: GUD36W2/NhE-D(U)
• Nominal capacity: 34,000 BTU/h in cooling and 34,000 BTU/h in heating
• Modulation range: 18,000 to 37,000 BTU/h
• Efficiency: 18 SEER2, 12 EER2, 10 HSPF2, COP 3.2
• AHRI Number : 217120760
• ENERGY STAR Certification
• Heating range: down to -30 °C; cooling range: -15 °C to 54 °C
• R32 refrigerant, 2.9 lb factory charge, precharge covering 24.6 ft of piping
• Maximum piping length: 98.4 ft, maximum elevation difference 49.2 ft
• Diameters: 3/8 in. liquid, 3/4 in. gas
• Electrical: 208–230 V, MCA 5.3 A indoors, MCA 27.7 A and MOCP 30 A outdoors
• Indoor unit: 21 1/4 x 48 1/5 x 21 1/4 in., 163.1 lb
• Outdoor unit: 39 x 37 13/16 x 14 2/3 in., 187.5 lb, 1/6 HP fan motor
• Factory-installed Wi-Fi and included A2L leak detection sensor

The number that matters most in Bethany is not the 18 TRÉS2. It is the -30 °C. In a municipality in the Montérégie hinterland, where January nights regularly fall below -25 °C, a heat pump that gives up at -15 °C leaves the electric heating to work alone during the most expensive weeks of the year. The ability to continue producing heat at low temperatures is what turns a good specification sheet into real savings on the bill.

“Ultra Heat” and “Dual Fuel”: what these labels change

The FLEXX is advertised as compatible with Ultra Heat and Dual Fuel configurations. In practice:

• Ultra Heat is intended to maintain capacity in very cold weather, rather than merely being able to start.
• Dual Fuel means that the heat pump can operate alongside a combustion heating source—useful in rural areas where many homes retain a propane furnace or wood-burning appliance. The changeover logic must then be configured: above the balance point, the heat pump operates alone; below it, the other source takes over. If improperly adjusted, this logic runs both sources at the same time, which costs more than either one alone.

In Bethany, the house runs on electricity. The FLEXX provides the main heating and air conditioning, while the existing electric heating remains as backup for peak demand.

The refrigeration circuit and the A2L label

The R32 is classified A2Lslightly flammable. Two concrete consequences on this project:

1. The leak detection sensor integrated into the indoor unit must be positioned according to the air discharge direction. A horizontal-flow unit can be configured for left or right discharge; converting it without repositioning the sensor renders the protection ineffective. We verify the position and test the shutdown logic during commissioning.
2. A2L warning labels affixed to the outdoor unit are not decorative. They determine how a future technician will service the unit, and they must never be removed or covered.

The brazing was performed under nitrogen, followed by a deep vacuum with a pressure-rise test before the valves were opened. The actual line-set length was recorded in the file, because that is the information the manufacturer will request if a claim ever arises.

The wall penetration and power supply

The line set penetration through the brick wall was drilled, sleeved, and then sealed with mortar—not tape, not exposed foam. An improperly sealed penetration in an exterior wall lets in air, water, and rodents, and it is one of the few imperfections a customer sees every day when walking around the corner of their house.

On the electrical side, a disconnect has been installed within sight of the unit, mounted on the support structure, with a dedicated circuit compliant with the 30 A MOCP. The power cable and low-voltage control cable are routed separately and secured neatly along the support instead of being left looped against the brick.

What we validate before recommending a central heat pump in a rural area

Five checks that change the outcome

1. The ductwork. A central heat pump is only as good as the ductwork serving it. We measure the static pressure of the existing system before recommending a unit, because an overly restrictive system will undermine any claimed efficiency.
2. The electrical service. In rural areas, many homes have an electrical service already burdened by electric heating, the water heater, and sometimes a well pump. The electrical load calculation is done before the sale, not on the morning of installation.
3. The outdoor unit's orientation. Prevailing wind, snow falling from the roof, defrost-water drainage, and proximity to a bedroom window: four factors that determine where the unit should go, often contrary to the customer's first instinct.
4. The balance point. The heating load calculation determines the temperature at which the heat pump can no longer meet the demand on its own. That value—not intuition—is what governs the backup-heating logic.
5. Service access. A wall-mounted unit must remain accessible in winter. We verify that a technician can open the side panel without dismantling a fence.

Rebates: the current situation

The Chauffez vert program ended on March 31, 2026; in any case, it only covered conversions from heating oil and propane. Hydro-Québec's LogisVert program remains the main source of assistance for a central heat pump. The key requirements remain consistent: an ENERGY STAR unit with a valid AHRI number corresponding exactly to the installed indoor/outdoor combination, a contractor holding an RBQ licence and registered with the program, and submission of the application within the prescribed period after the invoice. The assistance is paid as a reimbursement afterward, and the amounts vary according to the unit and configuration.

The system installed here bears AHRI 217120760, listed in the file provided to the customer along with the commissioning report. This is the document that makes the difference between an approved application and one sent back.

Maintenance, in rural areas and in the city

There are two tasks we ask the homeowner to handle: clear fallen leaves from the stone bed beneath the outdoor unit in the fall, and clean the indoor filters according to the agreed schedule. Everything else—pressures, superheat, subcooling, airflow, electrical connections, and the condition of the support and pads—is covered by annual HVAC maintenance.

Why we travel as far as the Acton RCM

At AirGreen, we install central heat pumps, wall-mounted heat pumps, mini split systems, air conditioners, and air exchangers in Montreal, Laval, Longueuil, on the North Shore, on the South Shore, and in the rural municipalities of Montérégie that many contractors refuse to serve. Béthanie, Roxton Falls, Acton Vale, and the surrounding rural roads are among them.

This project summarizes how we work: the model was selected after assessing the building, the support was sized before being ordered, and the commissioning was documented. If you are considering a central heat pump, replacing a unit, or installing air conditioning for the first time in a home that has never had it, call us. We come to you, take measurements, and provide a clear proposal with the actual efficiencies, the AHRI number, and eligibility for rebates already verified.

AirGreen — Air Conditioning & Heating. RBQ 5645-9605-01. (514) 316-2973