Cooling a character home without damaging what gives it its value
Saint-Denis-sur-Richelieu is one of the villages where architecture is not a minor detail. Woodwork, chair rails, crown molding, original plaster: in these homes, every intervention leaves a trace, and poorly executed traces are difficult to erase.
The homeowner who contacted us therefore asked the question differently than usual. Not “how much does it cost,” but: “Will it be noticeable?”
It is a legitimate question, and it completely changes the installation method.
Why an older home is particularly well suited to a wall-mounted heat pump
The paradox is worth stating up front: character homes are often the best candidates for a ductless system.
A home built before the era of forced-air heating has no duct network. Installing central air conditioning would mean building vertical chases, lowering ceilings, sacrificing closets—in short, mutilating the space to make room for airflow.
A ductless multi-zone system needs only two copper lines, a cable, and a drain. The entire setup fits within a route just a few centimeters in diameter. It is the least invasive way to cool and heat a heritage home.
It still has to be done properly.
The five constraints of an interior with decorative woodwork, and how we addressed them
1. Finding an available wall when every wall has decorative woodwork
On this project, the room has panel molding across the entire lower section, crown molding around the perimeter, and solid walls between the two.
The possible installation area is therefore narrow: the strip of wall between the top of the chair rail and the crown molding.
Our method consists of evaluating each candidate wall according to three criteria, in this order:
- The distance to the outdoor unit. The shortest route provides the best efficiency and requires the fewest penetrations.
- Air circulation in the room. A head placed in a dead corner or facing an obstacle can only treat part of the volume.
- Visual discretion. A wall that is not often viewed from living areas is preferable to one in direct view from the entrance.
The third criterion never takes precedence over the first two. A perfectly concealed unit that heats poorly is a failure.
2. Maintain clearance above the unit
This is the technical point most often overlooked in the pursuit of being “discreet at all costs.”
A wall-mounted unit draws air in from above and discharges it below. Placing the cabinet against crown molding obstructs the intake. Airflow drops, discharge-air temperature deteriorates, and the unit eventually has to work harder for a poorer result.
Every manufacturer publishes a minimum clearance above and beside the cabinet. These values are not aesthetic recommendations: they are operating requirements.
In a room with crown molding, this sometimes means lowering the unit a few centimeters compared with where the client would have preferred it. We would rather explain this compromise in advance than deal with it during a service call two years later.
3. Make the lines disappear without opening the walls
This is where the difference between an ordinary installation and a carefully executed one becomes clear.
The default option in the industry is a white PVC line set cover installed on the wall. Functional, quick, and completely out of place in a room with wood trim.
The alternatives we systematically assess in old houses:
- Routing through the wall cavity, when the construction allows it.
- Routing through an adjacent cupboard, closet, or storage area, where the line set becomes invisible.
- Routing directly through the exterior wall, behind the unit, when the outdoor unit can be positioned on the right side. This is the cleanest solution: nothing runs indoors.
- Routing through the space beneath the floor or through the attic, depending on the floor being serviced.
The decision is made during the technical assessment, not on the morning of the installation. In an old house, improvisation is expensive when plaster repairs are involved.
4. Drill without cracking
An old-house wall is not the same as a wall in a recently built home. Depending on the period and region, you may encounter wood-lath plaster, solid masonry, irregular half-timbering, or several successive layers of renovations.
Drilling into this with a rotary hammer, as with a modern framed wall, produces cracks that radiate far beyond the hole.
Our precautions:
- Preliminary identification of the structure and utilities before any drilling.
- Core drilling rather than impact drilling in fragile materials.
- Drilling angled outward, with careful sealing. A horizontal hole or one angled inward directs rainwater into the structure—a defect we regularly correct, generally after a water stain has appeared on an interior wall.
- Floor and woodwork protection throughout the work.
5. The outdoor unit and the appearance of the façade
In older village centers, the appearance of buildings visible from public roads is often subject to municipal regulations, particularly when the area has heritage recognition.
We therefore systematically invite owners in these areas to check with their municipality whether installing a visible façade-mounted unit is regulated before deciding where to place the outdoor unit. This verification takes one phone call and avoids a costly correction.
Technically speaking, we favor side or rear façades anyway: less visibility, less exposure to snow falling from the front roof, and often a shorter route.
The equipment installed and why it is suitable here
The selected outdoor unit is the GREE FreeMatch R32, model GWHD(24)ND6MO, powering two indoor units.
Its defining features:
- Nominal capacity of 7,030 W (24,000 BTU/h), for both heating and cooling.
- Modulation from 7,500 to 31,400 BTU/h thanks to the G10 inverter compressor.
- Certified heating from -30 °C to 24 °C; cooling up to 48 °C.
- SEER2 21 / HSPF2 10 / EER2 12, ENERGY STAR certified.
- R32 refrigerant (A2L), 1,700 g precharged, integrated leak detection sensor.
- Quiet operation and intelligent defrosting.
- Indoor units powered by the outdoor unit.
- 10-year warranty standard.
Silence: a criterion that matters more in an older home
Character homes have high ceilings, hard surfaces, and few sound-absorbing materials. Sound travels and reverberates much more in them than in a recent construction with low ceilings and soft finishes.
An appliance that continuously modulates at low speed therefore offers a double advantage: it is quieter during normal operation and, above all, it avoids starting and stopping—these transitions, more than operating noise, are what attract attention in a quiet room.
Electrical service in an older building
The additional point to watch is the electrical panel. Many older homes have a panel with limited capacity, sometimes already heavily loaded.
For this model, the MCA is 19.5 A and the maximum overcurrent protection is 25 A, at 208/230 V. A single dedicated circuit is sufficient for the entire system, since the indoor heads are powered by the outdoor unit.
This is a real advantage: a conventional multi-zone system with two outdoor units would require two circuits, and therefore two available spaces in the electrical panel. We nevertheless verify the available capacity before confirming feasibility.
Load calculation in an older building envelope
A home more than a century old cannot be calculated like a 1985 bungalow.
The parameters that systematically skew quick estimates:
- Air infiltration, generally much higher and highly variable from one home to another depending on past renovations.
- Wall insulation, often partial, sometimes nonexistent, and sometimes added by blown-in insulation.
- Fenestration, whose performance varies greatly depending on the replacements that have been made.
- Ceiling heights, which increase the volume to be conditioned without increasing the floor area.
- The enclosed-room layout, typical of older architecture, limits air circulation between zones.
This last point is decisive when choosing the number of heads. A single head cannot condition a compartmentalized home, regardless of its capacity. Warm or cool air does not pass through closed doors.
We therefore measure room by room and position the heads according to how air actually circulates through the lived-in home—not as it appears on a floor plan.
The A2L constraint in enclosed rooms
R32 is classified as mildly flammable. This requires a minimum room volume for each indoor head, calculated based on the system charge.
In a compartmentalized older home, with small bedrooms and offices, this verification is not theoretical. It can guide the choice of capacity for each head, and even its position.
We perform this calculation during the design stage, before proposing a configuration—in Saint-Denis-sur-Richelieu as well as in Saint-Hyacinthe, Longueuil, Montréal, Laval, on the North Shore or the South Shore.
Financial assistance
GREE documentation indicates that these systems are eligible for local rebates, and ENERGY STAR certification is among the common criteria for Quebec energy-efficiency programs.
Eligibility depends on your situation: the heating source being replaced, the type of building, and the program in effect when the work is carried out. We validate the application before the work and provide the installation documentation required for applications, rather than announcing an amount that might not apply.
What the homeowner obtained
- Complete air conditioning in a home that had never had it, without ducts, lowered ceilings, or sacrificing a closet.
- Effective supplemental heating during the shoulder seasons and in moderate cold, reducing the demand on the existing system.
- No visible cable trunking in the living areas.
- Intact woodwork and mouldings.
- Two independently controlled zones.
Maintenance: a few particular considerations for older homes
In addition to the usual tasks—cleaning the filters every 4 to 6 weeks, annual HVAC maintenance, and clearing the outdoor unit—two points should be added:
- Older homes generate more fine dust, especially when original wood floors and poorly sealed attics remain. Filters become clogged faster than anticipated.
- The condensate drain should be inspected annually, particularly when it follows a long or diverted route to remain hidden.
Do you own a character home in Saint-Denis-sur-Richelieu or the Richelieu Valley and hesitate to install a heat pump because you are concerned about your décor? Contact us. The technical visit is specifically intended to determine what is possible without compromising the appearance—and to tell you honestly where a compromise would be necessary.