Running piping through a sprinkler-protected building: the project where we open before drilling
The photo from this Saint-Rémi project shows what the customer never sees in a brochure: two openings made in the building, one in the ceiling and the other in the wall beneath the head. In the first, you can see a sprinkler and its piping. In the second, the steel studs, insulation, and the new refrigerant line running vertically inside the partition.
These two holes tell the whole story about the difference between a planned HVAC installation and an improvised one.
Why we open before drilling
In a drywall partition with steel studs, no one knows what is behind it until they look. A partition may contain plumbing, electrical wiring, ventilation ducts, a drain, telecommunications cabling—and, in a sprinkler-protected building, sprinkler piping.
Drilling blindly with a long bit means accepting the risk of drilling into one of these elements. We therefore open an inspection window at the planned passage point, check what is there, and then route the piping downward along a clear path.
A small exploratory hole that needs to be patched takes fifteen minutes. A punctured sprinkler pipe means water damage and an emergency response.
Working in a sprinkler-equipped building
This is the major constraint of this project, and it completely changes the method. Our rules, without exception:
- Nothing is attached to the sprinkler piping. Not a refrigerant line, a drain, or a cable. This piping is fire safety equipment, not a support.
- No sprinkler is painted, obstructed, or covered. A painted sprinkler will not activate properly. The clearance around the head must remain unobstructed.
- We do not move any sprinkler heads. If the layout requires modifying the system, that must be handled by a fire protection contractor, with the required permits.
- Any penetration of a fire-rated separation is sealed with a certified firestop system, not ordinary expanding foam. Standard foam has no fire-resistance rating and voids the integrity of the separation—an issue inspectors flag and one that can have consequences in the event of a fire.
- The condo association or property manager is informed before work begins when the building is a condominium or rental property. Openings in common areas and separations between units are not solely the owner's responsibility.
Few heat pump contractors address these issues in their quotes. Yet this is what distinguishes a project that passes inspection from one that creates a dispute.
Routing the piping through the partition
The visible opening beneath the head shows the vertical routing inside the wall. This choice—concealing it rather than installing exposed trim—produces the cleanest result, but it imposes precise requirements.
The refrigerant line
It must run downward without tight bends or any crushing point. Copper pinched against a steel stud creates a permanent restriction that reduces performance for the system's entire service life. We also protect the piping where it passes through the studs so it does not rub against the steel—a constant vibration against a metal edge eventually wears through the insulation, and then the copper.
The condensate drain
This is the critical point of a concealed run. The drain operates by gravity and requires a continuous downward slope, without a single flat spot. A drain concealed in a partition is inaccessible: if it becomes clogged, we open the wall.
We therefore check the slope along the entire length before closing everything up, and we test the drainage by pouring water into the head pan. When a clear slope cannot be guaranteed along the entire route, we install a condensate pump equipped with a safety contact that shuts the unit off if the pan fills. It is an accepted cost rather than a gamble.
Insulation and airtightness
The insulation in place must be properly restored around the passage. A cavity left empty or a torn, unrepaired vapor barrier creates a thermal bridge and an air path. In an exterior wall, this produces condensation inside the wall assembly in winter—damage that can remain invisible for years.
What happens after the photo
A jobsite photo captures a moment, not a result. Here is what comes next in this type of installation:
- Closing the openings: drywall, joint compound, sanding, and primer. We always agree with the customer in advance on what is included—through the finished joint or through painting. A contractor who remains vague on this point will leave you with holes to have repaired at your own expense.
- Certified firestop sealing of the relevant penetrations before closing them up.
- Deep evacuation and a pressure-holding test on the refrigeration circuit. Residual moisture in an R32 circuit forms acids that attack the compressor windings.
- Documented commissioning: recording pressures and temperatures in cooling mode and then heating mode, for each zone. Without documented baseline readings, no technician will be able to determine in four years whether the system has drifted.
- Customer training: adjusting the louvers according to the season, maintaining a steady heating setpoint instead of making significant nighttime setbacks, and cleaning the filters every four to six weeks.
The installed system
The GREE FreeMatch R32 in a dual-zone configuration powers two indoor heads from a single outdoor unit, a single 208/230 V circuit, and a minimum number of penetrations—which, in a building with fire separations, is an advantage in itself.
What matters to a Québec homeowner:
- SEER2 21 / HSPF2 10 / EER2 12, certified by AHRI and ENERGY STAR Cold Climate;
- Heating maintained down to -30 °C, with intelligent defrosting and self-diagnostics;
- R32 refrigerant, A2L safety classification, with low global-warming potential;
- G10 inverter, enabling partial-load operation for most of the season;
- Quiet operation, a decisive factor in a semi-detached home;
- 10-year warranty on parts and the compressor, with 2 additional years upon registration.
Because R32 is classified as A2L, a minimum room area applies to each indoor head based on the served charge and mounting height. In a home with smaller rooms, this check may determine the permissible head capacity in a bedroom. It is performed during design, never after installation.
The mistakes we correct most often
- Drill without looking. This is the costliest and most common mistake.
- Seal a fire-rated penetration with ordinary foam. Fast, invisible, and worthless.
- Reuse existing piping. The mineral oils from older systems are not miscible with the POE oil used in R32 systems, and the diameters almost never match.
- Skip the vacuum evacuation. Invisible upon delivery, fatal to the compressor three years later.
- Leave the holes for the customer. Finishing is either part of the work or it is not, but this must be stated in the quote.
Rebates
The FreeMatch R32 is certified ENERGY STAR, Cold Climate, and AHRI, placing it in the categories targeted by Quebec assistance programs for efficient heating systems. The AHRI number applies to the combination of the outdoor unit and indoor heads, never to the outdoor unit alone. We validate the combination and eligibility before signing—the assistance cannot be claimed retroactively.
Our service area
At AirGreen, we handle the complete HVAC installation: load calculation, selection of the certified combination, routing and installation, sealing, documented commissioning, and annual HVAC maintenance. We serve Montreal, Laval, Longueuil, the North Shore, the South Shore, and Montérégie, including Saint-Rémi and Jardins-de-Napierville. In a sprinkler-protected building, the quality of an installation is first judged by what we did not touch.
