Ten inches deep: ventilating a condo without redoing the ceilings
The unit visible in the photo is recessed into the ceiling, behind an access panel. Its dark casing, side ports, and the balancing sticker affixed to its door are visible. This format is not merely a convenience: it is the only way to install a complete air exchanger in a condominium with no mechanical room, basement, or even an inch of vertical clearance.
At AirGreen, we installed a GREENTEK PROFILE 1.2E-D-EC in a condo in Westmount, inside an existing suspended corridor ceiling. Here is why we chose this unit, how it is installed, and what condominium owners should check before starting such a project.
The context: 1,250 sq. ft. on the sixth floor of a 1988 building
The unit has two bedrooms, an office, two bathrooms, an enclosed kitchen, and a south-facing living area. The building, constructed in the late 1980s, has a centralized ventilation system in the common corridors, but no mechanical fresh-air supply in the units themselves. Air renewal relied entirely on opening the windows—which was impractical from November to April.
The owners reported three issues: stale air in the primary bedroom late at night, cooking odors that lingered in the curtains, and humidity that rose above 55% in the bathroom without ever really going back down.
The requirement recalculated according to the logic of the CSA F326 standard:
- Primary bedroom: 10 L/s
- Second bedroom: 5 L/s
- Office: 5 L/s
- Living room and dining room: 10 L/s
- Kitchen: 5 L/s
- Two bathrooms: 10 L/s
Total: 45 L/s, or approximately 95 CFM.
An ERV rather than an HRV: the condominium reasoning
The PROFILE is an energy recovery ventilator (ERV). Its cross-flow core transfers heat and some of the moisture between the two air streams. A conventional HRV transfers heat only.
In a condo, this distinction carries significant weight for a reason that is rarely explained: a 1,250-square-foot dwelling ventilated continuously dries out quickly. The air volume is small, the relative air-change rate is high, and there are no moisture gains comparable to those in a home with a basement. In January, a properly adjusted HRV can bring relative humidity below 18% in a unit like this—wood movement, dry throat, static electricity.
The ERV retains some of that moisture as air passes through. In summer, the process reverses: it slows the entry of outdoor moisture, reducing the workload on the air-conditioning system.
We do not systematically recommend an ERV. In a home with a finished basement and multiple moisture sources, an HRV remains the right choice. In a condominium, it is almost always the opposite.
The GREENTEK PROFILE 1.2E-D-EC: the numbers that matter
- Airflow range of 40 to 129 CFM at 0.4 in. w.g., comfortably covering the required 95 CFM.
- Sensible recovery efficiency of 77% at 0°C, the best in the PROFILE series.
- Power consumption of 23 W at low speed and 74 W at high speed, thanks to the EC motor. In continuous operation, the unit draws less than a supplemental incandescent light bulb.
- Ventilation efficiency of 2.2 CFM/W, compared with 0.9 CFM/W for the conventional-motor version of the same size. On a unit that runs 8,760 hours per year, the difference is real.
- Installed depth of 10 inches. This is the feature that makes the project possible.
- 5-inch side connections, allowing the ducts to exit horizontally into the suspended ceiling without additional vertical clearance.
- Integrated motorized outdoor air damper on -D versions.
- Defrosting by stopping the supply fan.
- Original MERV 3 filter, replaceable with an MERV 8 or MERV 13.
- No drain required.
- CSA and HVI certifications, and ENERGY STAR certification for EC motor versions.
- Dimensions: 23 5/32 in × 25 1/16 in × 10 in, with a shipping weight of 35 lb.
Ceiling installation: the access hatch is the centerpiece
This is the point owners underestimate the most, and the one that determines whether the unit will be serviced or forgotten.
Size the opening for servicing, not for the unit
A hatch calibrated to the dimensions of the unit is an unusable hatch. The opening must allow:
- Filter removal without dismantling anything else.
- Removal of the cross-flow core, which slides out from the front.
- Access to the electrical connections and the junction box.
- Access for a pressure gauge to the balancing pressure taps.
We systematically size the access hatch according to the most cumbersome task, then add a margin. On this project, the opening was increased to 26 in × 28 in, with a metal frame and a removable panel aligned with the ceiling layout.
Choosing the location
The central hallway was the obvious choice: the ceiling was already lowered in one section, both bathrooms and the bedrooms were accessible via short runs, and the unit was kept away from sleeping areas for noise considerations. We systematically avoid recessing a unit above a bedroom, even when it is as quiet as a PROFILE at low speed.
The unit rests on vibration-isolating supports fastened to the structure, never on the suspension wires of the suspended ceiling itself.
No drain: what this changes in a condominium
A conventional HRV produces condensate and requires a connection to a drain. In a condo on the sixth floor, this means drilling through a concrete slab, obtaining authorization from the condominium owners' association, and assuming the risk of infiltration into the neighbor's unit below.
The PROFILE requires no drain. Its energy-recovery cross-flow core manages moisture through transfer rather than condensation. On its own, this is the argument that makes the project feasible in most Montreal condominiums.
The motorized damper, and why it resolves a common complaint
The -D versions include a motorized outdoor air damper that closes when the unit stops or enters defrost mode.
The complaint this damper eliminates is a common one: in very cold weather, a stopped air exchanger lets a stream of icy air in through the outdoor intake, and the owner feels a cold draft coming out of a ceiling grille. With a motorized damper, the passage closes mechanically. Supply fan shutdown defrosting works alongside it: during the cycle, only the exhaust airflow continues, and the damper blocks the entry of cold air.
What a condominium project requires in Westmount
Working in a Westmount building adds a layer of coordination that house projects do not:
- Written authorization from the co-ownership association before any modification affecting a common area, including drilling through an exterior wall.
- No drilling on an elevation visible from the street. The caps were moved to the rear facade, aligned with existing openings.
- Work-hours window, generally from 9 a.m. to 4 p.m. on weekdays, with no noisy work before 9 a.m.
- Protection for the elevator and shared corridors, with the freight elevator reserved.
- Proof of liability insurance submitted to the property manager before work begins.
We prepare this file before the first technical visit. A two-day project that waits three weeks for authorization costs the client more than a well-prepared project.
Balancing, measured and documented
The sticker visible on the unit's door converts the pressure read at ports A and B into actual airflow. We measure with a differential manometer, then adjust the branch dampers.
Final readings for this project:
- 88 CFM at the supply, 86 CFM at the exhaust at high speed.
- 42 CFM in continuous operation, low speed, at 23 W.
- Checked at both speeds, with the difference kept below 3 CFM.
A small difference matters twice as much in a condominium: a unit under negative pressure draws air from the shared corridor and neighboring units, along with the odors that come with it.
Filtration: moving from MERV 3 to MERV 13, and at what cost
The original filter is a MERV 3, designed to protect the core rather than purify the air. The owners chose a MERV 13, which is appropriate in an area exposed to traffic and summer smoke events.
Two honest clarifications:
- A MERV 13 increases pressure drop. It must be accounted for in the calculations, followed by rebalancing after installation, which we did.
- It needs to be replaced more often than a MERV 3 needs to be cleaned. In this context, we recommend replacing it every six months.
Mistakes to avoid with this type of installation
- Cut the access hatch to the unit's dimensions. Servicing then becomes impossible.
- Fasten the unit to the suspended-ceiling hangers rather than to the structure.
- Drill through an exterior wall before obtaining the co-ownership association's authorization.
- Install a MERV 13 without rebalancing.
- Install above a bedroom.
- Choose an HRV in a condominium out of habit, then look for a drain that does not exist.
- Omit the motorized damper to save money, then deal with complaints about cold drafts all winter.
Grants: the special case of condominiums
The Rénoclimat program provides $500 for the installation of an HRV or ERV listed in section 3 of the Home Ventilating Institute (HVI) certified product directory, provided that the EnerGuide rating improves between the initial and final assessments.
In a condominium, it is important to be clear: the application must be submitted through the condo association, which becomes the recipient of the assistance, and the energy assessment covers the entire building, not one unit. In practical terms, an individual owner who ventilates their condo cannot access this assistance. It becomes realistic when the condo association coordinates a building-wide ventilation program—a scenario we are seeing more and more often in buildings from the 1980s and 1990s.
Maintaining a built-in unit
The filter is removed through the access hatch without tools. The cross-flow core is removed once a year and rinsed with lukewarm water. The exterior caps can be checked in the spring from the rear balcony. And because a ceiling-mounted unit is easier to forget than a basement unit, we systematically schedule a reminder in the customer file.
What we bring to condominium ventilation projects
Westmount, Ville-Marie, Old Montréal, Griffintown, Brossard, and central Laval contain thousands of units where individual ventilation does not exist or relies on a bathroom fan and a window. Ceiling installation with a shallow unit solves a problem that conventional units cannot.
Our method remains the same everywhere: airflow calculations before the quote, equipment selection based on the actual space, an authorization file prepared for the condo association, pressure-gauge balancing, and a report provided. We carry out these HVAC installations in Greater Montréal, in Laval, in Longueuil, on the North Shore, and on the South Shore, in both single-family homes and condominiums.
For an assessment of your condo or building's ventilation, contact us at (514) 316-2973 or sales@airgreen.ca. RBQ 5645-9605-01.