Installation of a GREE FreeMatch R32 2-head wall-mounted heat pump (GWHD(24)ND6MO) in Saint-Simon, MRC des Maskoutains

R32 replaces R410A: what this changes for you, and what it does not

On the nameplate of the outdoor unit installed in Saint-Simon, there is an orange label, a diamond, and three characters: A2L R32. Most customers never look at it. Yet it is the most important difference between the unit we install today and the one we installed five years ago, and it has concrete consequences—for model selection, who can service it, and what will happen in fifteen years.

We have already written, for a project in Sorel-Tracy, about what to do with the old piping when replacing an R410A unit with an R32 unit. This page addresses the question upstream: why the change took place, and what it entails.

Why the industry changed refrigerants

R410A has never presented a performance problem. It presents a problem in terms of its global warming potential (GWP). Under the IPCC Fourth Assessment Report framework, commonly used in regulations, R410A is around 2,088 and R32 around 675—about one-third as high. International phase-down schedules for hydrofluorocarbons are making high-GWP refrigerants increasingly expensive and increasingly scarce, and manufacturers switched before they were required to.

Two technical differences matter more than the number:

1. R32 is a pure substance, while R410A is a blend. R410A consists of half R32 and half R125. A blend can separate—the more volatile component escapes preferentially during a vapor-phase leak—which makes the residual composition uncertain. R32, on the other hand, is a single molecule: what remains in the system is exactly what was there originally. This does not make a leak acceptable, and we do not “just add a little refrigerant”: a system that has lost refrigerant has a leak, and a leak must be found. But this simplifies diagnosis.

2. Less of it is needed for the same capacity. R32 has a higher volumetric capacity, so an R32 system operates with a lower refrigerant mass than an equivalent R410A system. On this job, the GWHD(24) has a factory charge of 1,700 g—for 24,000 BTU/h.

What “A2L” means—and what it does not mean

The A2L classification means: low toxicity, slightly flammable. It is not the same category as propane (A3), nor is it “nonflammable” like R410A (A1). R32 requires a strong ignition source and a high concentration in an enclosed volume.

The practical consequences are not merely symbolic:

• A minimum room area must be verified for each room served, based on the system charge. This is not a formality: it is a calculation we systematically redo, and using the final charge when refrigerant has been added—not just the factory charge.
• A minimum installation height for wall-mounted heads.
• An integrated A2L leak detector in the unit. We explained in detail on our Sainte-Anne-de-Bellevue page what it triggers and, above all, what it does not replace—neither the room-area calculation nor circuit tightness. And as we wrote in Montréal-Nord: it is not a smoke detector, and it does not protect anyone from carbon monoxide.

The consequence no one talks about: your contractor must be equipped

This is the most concrete point in this section, and it should be included in your comparison checklist.

The gauges, hoses, recovery cylinders, scales, and procedures are not interchangeable between refrigerants. A recovery cylinder that has contained R410A must not be used for R32. A contractor who primarily works with R410A is not automatically equipped, trained, and insured to work with R32, and this is rarely apparent from a quote.

Two questions to ask us, as well as anyone else:

1. “Does your team regularly work with A2L refrigerants, and what dedicated equipment do you use?”
2. “How do you verify the minimum room area, and based on what charge?”

And in fifteen years?

This is the question customers ask most often when we explain all this to them: if R410A has been phased out, will R32 be phased out too?

The honest answer is: probably, someday. Phase-downs are continuing, and refrigerants with even lower GWP are already available. What matters to a homeowner is not guessing the date, but learning the lesson of R22, which we explained on our Saint-Louis-de-Gonzague page: it is not the refrigerant disappearing that hurts; it is the parts disappearing. A well-documented, registered, maintained appliance serviced by a contractor who is still in business ages infinitely better than an orphaned appliance, regardless of its refrigerant.

The pool, spa, and wall-mounted heat pump: three appliances, one panel

In the municipalities of the Maskoutains RCM, lots are large, and above-ground pools are the rule rather than the exception. It is a question we routinely ask when preparing a quote, and it always surprises people: “Do you have a pool or spa, and when do you plan to run them?”

This is not mere curiosity. Three seasonal appliances may be connected to the same building, and they all reach their maximum at the same time of year.

July is the worst time of all.

• The filtration pump runs eight to twelve hours a day.
• The pool heat pump, if there is one, runs to maintain the water temperature.
• The wall-mounted heat pump is in cooling mode, at its highest load of the year.

Each of these units is properly sized individually. The issue is the total load at the electrical service, and that total is never the responsibility of just one contractor. Load calculations are the responsibility of the master electrician, and we do not improvise them: we provide our figures—for this system, MCA 19.5 A and MOCP 25 A—and ask that the verification be completed before signing, listing existing and planned pool equipment.

Two outdoor units cannot be positioned like one.

This is the most common mistake, and it is purely geometric.

A pool heat pump expels cold air: it takes heat from the surrounding air and transfers it to the water. A wall-mounted heat pump condenser in cooling mode expels hot air: it removes heat from the house.

Placing them facing each other, or in the same nook, amounts to asking each one to breathe what the other exhausts. In summer, the pool appliance receives the condenser's hot air — which helps it — but the condenser in turn receives depleted, confined air, and its condensing pressure rises. The result is an appliance that “lacks capacity” even though it is correctly sized, without the slightest error code.

What we apply:

1. Never place two appliances in the same enclosed nook. We documented this mechanism in Oka — two appliances in a box where the air is not renewed — and it applies here in exactly the same way.
2. The airflow axes do not cross. Each one blows toward an unobstructed area.
3. One slab per appliance, or one slab large enough for both with their actual clearances — not the slab that already existed for the filtration pump.
4. The pool environment is chemical. Chlorine or bromine vapors released by the water and the shed attack the aluminum fins. We covered this mechanism in detail for a spa in Côte-des-Neiges–Notre-Dame-de-Grâce, and it calls for distance and orientation, not just an annual rinse.

The October trap—and it is electrical

Here is the most concrete point in this entire section, and it costs nothing to address on the day of installation.

The pool system is winterized in October. The wall-mounted heat pump, on the other hand, heats the house all winter.

Every fall, someone goes down to the panel to shut off the pool. If the circuit breakers are not clearly identified — and in a house where two or three installations have been added over the years, they rarely are — there is a real chance that the wrong one will be switched off. The owner notices in November, when the house no longer heats, and calls a contractor.

Our rules, written in the handover file:

• No shared circuits between a pool appliance and the HVAC system. Ever.
• No shared disconnects, either.
• Each circuit breaker is identified by the appliance it powers, in full, and the panel directory is corrected — including circuits we did not install, when we find that it is inaccurate.
• The outdoor disconnect for the HVAC system is identified as well, because it allows the owner to cut the power before the annual coil rinse.

A panel whose labels are wrong is dangerous for the next electrician. More prosaically, it is also the cause of a service call in November that should never have existed.

The installed system

Why the smallest compressor that does the job

This configuration—two 12,000 BTU/h heads on a 24,000 BTU/h compressor—is not new in our projects, and we will not rewrite the selection rationale here. Only one reason needs to be added, and it follows directly from the first half of this article.

The minimum required room area due to the A2L classification of R32 depends on the system charge. A GWHD(24) contains 1,700 g. A GWHD(36) contains 2,700 g. In a village bungalow with modest-sized rooms, choosing the smallest compressor that actually does the job also means choosing the easiest room-area requirement to meet in the smallest room served.

The 17 m of total piping length remains well within the 30 m factory charge: nothing was added, so the calculation was based on the factory charge.

Moreover, two 12,000 BTU/h heads are above the system’s modulation floor (7,500 BTU/h), which means neither will cause the unit to cycle when operating alone during the shoulder season. And the larger head represents exactly half the compressor’s capacity, leaving each zone genuine reserve capacity.

The electric baseboard heaters were kept in the other rooms.

Saint-Simon, in the Les Maskoutains RCM

Saint-Simon is a municipality in the Les Maskoutains RCM, in Montérégie—an RCM covering 1,312 km² and comprising 17 municipalities, surrounding Saint-Hyacinthe, Quebec's agri-food capital and the first Canadian city to obtain technopole status, in 1993.

Saint-Simon is one of the area's founding parishes: the parish of Saint-Liboire was detached from Saint-Simon and Saint-Dominique in 1856. We have documented two projects in Saint-Liboire—a wall-mounted heat pump and a central system—as well as installations in Saint-Denis-sur-Richelieu, Saint-Damase, Saint-Bernard-de-Michaudville, Saint-Louis, La Présentation, and Sainte-Madeleine.

A practical note for our clients and dispatchers alike: “Saint-Simon” alone is not enough to identify a municipality in Quebec. Saint-Simon (Les Maskoutains), Saint-Simon-de-Rimouski, and Saint-Simon-les-Mines are different places, hundreds of kilometres apart. Always specify the RCM or region.

Rebates

The unit is ENERGY STAR and AHRI certified, a requirement for most Quebec programs, including Hydro-Québec's LogisVert and Rénoclimat. Eligibility depends on the heating system being replaced, the building's file, and the terms in effect when the work is carried out: we verify it in the file before promising it.

Contact us

At AirGreen, we offer sales, HVAC installation, and HVAC maintenance in Montreal, Laval, Longueuil, the North Shore, and the South Shore, including the entire Les Maskoutains RCM: Saint-Hyacinthe, Saint-Simon, Saint-Liboire, Saint-Damase, Saint-Louis, Saint-Bernard-de-Michaudville, Saint-Dominique, La Présentation, Sainte-Madeleine, Saint-Jude, and neighboring municipalities. Our teams hold the required RBQ licences and work daily with R32 systems.

For a detailed quote: sales@airgreen.ca.