Installation of a GREE FreeMatch R32 two-head heat pump in Saint-Jacques-le-Mineur (Jardins-de-Napierville RCM)

What is behind the unit: the basement window

Saint-Jacques-le-Mineur is a municipality of black earth. In its brief submitted to MAPAQ on May 16, 2023, it says so itself: “the agricultural zone occupies 98% of our territory, or 6,637 hectares out of 6,745 hectares”. The land is flat because it was once the bottom of the Champlain Sea, about eight thousand years ago—and that is where the dark soils come from that make Jardins-de-Napierville Quebec's vegetable garden.

The village itself covers 80.9 hectares. It is home to an 1889 wayside chapel, designated a heritage building since March 5, 1987—octagonal, made of wood, with an eight-sided conical roof, and the only chapel in Quebec built expressly to serve as a repose chapel for the Corpus Christi procession. The former church, rebuilt in 1938 after the November 1937 fire, became a community centre in 2010.

About 1,800 people live there, in a housing stock where, according to the municipality's urban plan, nearly 95% of homes are owner-occupied and where there are “very few two-family or three-family buildings.” Single-family homes, then. With basements. And basement windows.

In the photo of this project, the outdoor unit is installed on the ground, against a stucco wall, in a narrow side passage enclosed by a white PVC lattice and a wooden screen. And right behind it, at ground level, you can see a basement window.

It is a detail that almost nobody points out, and it changes four things.

The project at a glance

First thing: the water

A heat pump produces water outside, and not just a little. In heating mode, each defrost cycle releases the water accumulated on the coil; it falls beneath the cabinet, and in January it freezes in place.

A basement window is almost always set in a window well—a sheet-metal or concrete well dug below ground level, with a gravel bottom that is supposed to drain. In other words, the lowest point in the immediate vicinity, adjacent to the foundation.

Defrost water flowing toward this window well finds the perfect trap: it accumulates there, freezes, rises, and ends up just a few centimetres from an opening in the foundation wall. This is no longer an HVAC problem: it is water against a foundation, in the freeze-thaw cycle, precisely where the wall has been pierced.

The rule we apply is therefore simple, and it is decided before drilling: the water's path must start at the unit and lead away from the house, never toward a window well, never toward a foundation drain. And nothing—a pan or tray—should be placed under the casing to “catch” the water: it merely builds a column of ice somewhere else.

Second point: the noise, but not the kind you are thinking of

We will not reopen the acoustics discussion—our pages on Huntingdon (outdoor noise) and Saint-Chrysostome (noise perceived indoors) cover it in depth, and we have nothing to add.

One siting point deserves mention because it is specific to this configuration: a basement window is a thin wall, and what lies behind it is often a bedroom. A teenager's bedroom, an office, or a guest room. Placing an outdoor unit in front of this window puts the source within a metre of someone's ear, through a single pane of glass—whereas moving the same machine three metres along the same wall would disturb no one. It costs nothing to check this when choosing the location. It costs a lot to think about it afterward.

Third point: the air

A window well is an enclosed space with three sides, below ground level. Two effects occur there:

• It traps leaves, seeds, conifer needles, and powdery snow. A unit that draws air nearby also draws in whatever accumulates there—and an uncovered window well is a permanent debris reservoir.
• It does not ventilate well. The cold air expelled by the unit in heating mode is denser than the surrounding air, so it sinks. If it sinks into a window well, it stagnates there, and the unit eventually draws in air that is colder than the actual outdoor temperature. The frost threshold is reached sooner, defrost cycles become more frequent, and no error code appears.

It is the same mechanism we had demonstrated for a cabinet enclosed between three walls. Here, the third wall is below.

Fourth point, and this is the serious one: this window may be an exit

Here is the point we have never seen written in an HVAC contractor's article, and that nevertheless deserves to be.

A finished basement bedroom often has a window that serves as an emergency exit. This is a requirement of the Building Code, whose application depends on the building's year of construction, whether or not it has sprinklers, the configuration of the exits, and several other factors. We will cite no dimensions, articles, or thresholds here — this is not our profession, and the conditions vary from one case to another.

What falls within our profession is the practical consequence: if this window is a bedroom's emergency exit, whatever we install in front of it cannot obstruct it. A 964 mm-wide, 51 kg cabinet placed flush with the ground in front of a window well is not something a teenager can move through smoke.

Our practice, in three steps:

1. We ask what is behind the window before suggesting a location. A bedroom, a storage room, a mechanical room: the answer changes the decision.
2. If it is a bedroom, we move the unit. There is almost always another position on the same wall or an adjacent wall, and the additional piping cost is negligible compared with what is at stake.
3. If there is still any doubt, we put it in writing in the file and refer the question to the municipality or a building professional. AirGreen does not rule on whether an exit is compliant — we observe, report, and document.

The same is true of things that are not our work: the PVC lattice visible in the photo already closes off one side of the passage. A screen added afterward, a fence, a growing hedge: each of these elements can, alone or in combination, close off a clearance that was adequate on the day of installation. We therefore record the clearances and the reason for them in the final construction file, so that the person who comes afterward knows what they must not obstruct.

Article 4.2.22 exists, and we have not read it

We have gotten into the habit of writing about what we do not know. For Saint-Jacques-le-Mineur, the situation is unusual: we know exactly where the rule is, and we have not been able to read its text.

What is verified

The zoning bylaw no. 1200-2018 (codification 1212-2026) contains, in chapter 4, section 4.2, a section bearing precisely this title:

4.2.22—Air-conditioning units, heat pumps, heating and ventilation equipment, and other similar equipment

It appears on page 85. The title is confirmed, identically, in both codifications we consulted. The body of the section, however, could not be read: the document is truncated before reaching it, and direct downloading is refused.

The same bylaw contains, on page 68, section 4.1.3—“Accessory structures for all uses in yards and setbacks”, which presumably contains the table of permitted yards and distances. It could not be read any further.

We will therefore publish no list of permitted or prohibited yards, no setback, no maximum distance from the building, no screening requirement, and no height. We know the rule exists. We do not know what it says.

Regarding permits: the municipal page listing the permits and certificates issued—main building, accessory building of 9 m² or more, renovation, pool, well, antenna, tree cutting, change of use, and the rest—mentions neither heat pumps nor air conditioners. This is not an exemption; it is an omission from a list intended for the public, and the governing authority remains Bylaw 4200-2018, whose relevant sections have also been truncated. We will not write, “No permit is required in Saint-Jacques-le-Mineur.”

With respect to noise, however, we were able to read the bylaw in its entirety. Bylaw SE-902, adopted on July 18, 2023, defines excessive noise in section 1.4 as:

“a sound or set of sporadic, intermittent, or continuous sounds, perceptible to the ear, likely to disturb the peace, comfort, or peaceful enjoyment”

No decibel threshold. No prohibited time period. No mention of air conditioning or a heat pump. Fines range from $200 to $1,000 for an individual for a first offense, and double in the event of a repeat offense.

The practical consequence is more demanding than a number: the criterion is subjective, so the neighbor's comfort is what counts, and there is no sound-level-meter measurement to decide the matter for you.

The reliable way

Évelyne Dumas, urban planning and environmental inspector — 450 347-5446 extension 204, inspection@sjlm.ca, at 91 Principale Street. Office open Monday through Thursday from 9 a.m. to noon and 1 p.m. to 4 p.m., Friday from 9 a.m. to noon.

A five-minute call settles what neither this article nor any other can determine. And there is a good chance that the basement-window question interests her just as much as the setback question.

A very real local constraint—and it is not flooding

We found no documented disaster in Saint-Jacques-le-Mineur—neither flooding nor landslides. The vulnerability that the municipality itself documents lies elsewhere, and it is spelled out plainly in its 2023 brief:

“Any new construction within the urban area will always be impossible due to insufficient access to drinking water”

About five hundred residences are connected to the network. This explains why the hundred or so new homes built between 2016 and 2019 were not followed by further development, and why the local housing stock is aging rather than being renewed. For a homeowner, this means one thing: improving what already exists is the only path available, and that is precisely what a wall-mounted heat pump does in a ductless home.

The selected unit

Two wall-mounted heads, 12,000 and 9,000 BTU/h, for a total of 21,000 BTU/h on a 24,000 nominal rating—87.5%. We openly note that this pairing has already been published in this series: it is the suitable one, not a new development.

The reason for this choice lies at the bottom of the range, not the top. The GWHD(24)'s modulation floor is 7,500 BTU/h: the 9,000 BTU head, on its own, at night or in the shoulder seasons, maintains about 20% headroom above that floor. On a larger chassis—8,190 BTU/h on the GWHD(30), 8,870 on the GWHD(36) and the GWHD(42)—that same 9,000 BTU head would be just a few percent above the floor and would short-cycle. The floor belongs to the compressor, not the head.

These dimensions are not decorative in the context of this article: 964 mm wide and 402 mm deep is the actual footprint to compare with the width of the side passage and the position of the window well. A unit that “just fits” does not fit.

Errors to avoid

• Installing an outdoor unit in front of a basement window without asking what is behind it.
• Directing defrost water toward a window well or a foundation drain.
• Leaving a window well uncovered in the immediate vicinity of an intake face.
• Closing off the opening afterward—lattice, screen, hedge—without knowing which clearances were intentional.
• Concluding from the absence of “heat pump” in a permit list that no authorization is required.
• Accepting a margin quoted from memory for Saint-Jacques-le-Mineur: section 4.2.22 exists and must be read.

Rebates and service area

These units are eligible for local rebates, and the AHRI codes above are required by the programs. We support every application for LogisVert, Rénoclimat, and Chauffez vert, recording the codes in the project-completion file without promising amounts whose eligibility criteria are outside our control.

In the Jardins-de-Napierville RCM, we have documented installations in Napierville, Saint-Édouard, Saint-Cyprien-de-Napierville, Sainte-Clotilde, and Saint-Chrysostome. Our teams cover Montréal, Laval, Longueuil, the North Shore, and the South Shore, reaching the agricultural municipalities of southwestern Montérégie.

Why AirGreen

The location of an outdoor unit is not just a matter of piping and intake clearances. It is also a matter of knowing what is behind the wall, beneath the ground, and on the other side of the window. At AirGreen, we ask these questions before recommending a location, we quote regulations without interpreting them, and we write down what we were unable to verify—such as the wording of section 4.2.22—rather than filling in the gaps.

For an assessment in Saint-Jacques-le-Mineur, write to us: we measure before making recommendations.