Installation of a vänEE AI Series V160H80RT air exchanger in Elgin, in the Haut-Saint-Laurent region

A row house that became too airtight for its own comfort

Elgin has 440 residents, farmland stretching as far as the eye can see, and the U.S. border just a few minutes away by car. It is also a residential area with many homes built between 1950 and 1985 and renovated in successive waves: new windows, spray foam in the crawl space, blown-in insulation in the attic, and replacement doors. Each renovation improves the heating bill. Each renovation also quietly reduces the amount of fresh air that entered through building leaks.

The homeowners who called us in Elgin described exactly this scenario. Windows fogged up halfway on January mornings. A musty smell in the basement despite a dehumidifier running nonstop. The primary bedroom felt heavy upon waking. None of these signs is dramatic on its own. Together, they tell the same story: a house that produces moisture and contaminants but no longer has a mechanism to remove them.

This is the project we detail here—the installation of a vänEE AI Series V160H80RT air exchanger in the mechanical room of a home in Elgin—from airflow calculations through commissioning.

What an airtight house does to its air

A family of four releases between 8 and 15 liters of water into its home every day through showers, cooking, laundry, breathing, and plants. Added to this are CO₂, volatile organic compounds from furniture and household products, and—particularly in the Haut-Saint-Laurent—the radon levels measured in Montérégie, which warrant serious attention.

Without mechanical ventilation, this load builds up. Moisture migrates toward cold surfaces: exterior wall corners, window frames, and rim-joist joints. That is where mold takes hold, often behind the drywall, long before it becomes visible.

Opening the windows in February would solve the air problem, but by throwing out the heat you paid dearly for. A heat recovery ventilator (HRV) does exactly the opposite: it exhausts stale air and brings in fresh air while recovering most of the heat from the outgoing air.

Why an HRV rather than an ERV in this specific case

The question comes up on nearly all our projects, in Elgin as well as Longueuil and the North Shore. The two units look similar on the outside; their cores do not perform the same job.

• The HRV transfers heat only. Moisture from the stale air is exhausted outdoors with it.
• The ERV transfers heat and some of the moisture, returning it indoors in winter.

On paper, the ERV seems more sophisticated. In a home in Elgin where the main issue was excessive winter humidity—running windows, a damp basement, and a well and septic system nearby—returning moisture indoors would have been counterproductive. We therefore chose an HRV, and this is the recommendation we make for the vast majority of single-family homes in Greater Montreal, Laval, and the South Shore. An ERV has its place elsewhere: condos that are very dry in winter, buildings with central humidification, and properties where incoming air is already conditioned.

Airflow calculation: the step too many quotes skip

Before discussing a model, we measured. The Quebec Building Code method (Chapter I.1, Section 9.32) assigns an airflow rate to each room: primary bedroom, secondary bedrooms, living room, dining room, kitchen, bathrooms, mechanical room, and basement. For this three-bedroom home with a finished basement, the required total ventilation capacity was around 110 cu. ft./min, while the target continuous operating airflow was closer to between 55 and 65 cu. ft./min.

This two-number combination explains the entire purchasing rationale. A unit must be able to reach its full capacity during peak periods—morning showers, dinner for eight, laundry drying—while operating at a very low rate the rest of the time, without overventilating or drying out the house in January. Choosing “the biggest” is an expensive mistake: an oversized HRV that does not modulate dries the air to 20% relative humidity and drives up the heating bill.

The vänEE AI Series V160H80RT: what the unit really delivers

The vänEE AI Series V160H80RT covers exactly this range. Here are the figures that influenced the decision.

The numbers that matter

The 82% sensible recovery efficiency at 0°C places the unit at the top end of the residential range. However, the more important figure for Elgin remains the 67% at -25°C: that is the figure that applies on nights when the thermometer plummets in the Upper St. Lawrence, when the wind sweeps across the fields unobstructed.

The ECM PMSM motors also deserve a mention. Unlike the capacitor motors of previous generations, they maintain high efficiency even at low speed — precisely the operating range in which a properly tuned HRV spends 90% of its life.

Virtuo Air Technology: balancing that is no longer a gamble

This is the decisive technical argument for the AI Series.

An HRV must be balanced: the volume of supply air must equal the volume of exhaust air. If exhaust exceeds supply, the house becomes depressurized and draws air in through cracks, the septic tank, and the floor drain — and, in homes with combustion appliances, can cause combustion gases to backdraft. If supply exceeds exhaust, the house becomes pressurized and pushes moist air into the walls, where it condenses.

Traditionally, this balancing is done manually during commissioning, using a manometer and pressure taps on the ducts. When done properly, it is reliable on the day itself. Six months later, with half-loaded filters and a partially obstructed outdoor hood, the balance has drifted.

The Virtuo Air technology integrates an electronic airflow measurement device into the unit. You enter the desired airflow on the integrated LCD screen, and the unit automatically adjusts the speed of each of its two motors to maintain this balance — continuously, accounting for filter loading, the actual duct length, and outdoor conditions. The motorized dampers are also integrated, eliminating additional backdraft dampers and one more potential air-leak point.

In practical terms, for the Elgin customer: the unit stays balanced between service visits, not just on the day of installation.

The project process, step by step

Location. The unit was suspended in the mechanical room on chains anchored to the joists, above the existing plumbing network (red and blue PEX, copper hot-water line). Two requirements guided this choice: sufficient clearance to open the front door with its bottom hinges and remove the core, and a heated room. An HRV installed in a cold garage or unheated attic will freeze its core and drain—we systematically refuse this type of location.

Ducts. The two exterior runs—fresh-air intake and stale-air exhaust—were made with insulated ductwork, with the vapor barrier sealed at the ends. This is the detail most often botched: an uninsulated fresh-air duct running through a heated basement develops condensation along its entire length and drips onto the joists all winter. The interior ducts were kept as short and straight as possible, with generous bend radii. Each tight elbow adds pressure loss, which the unit compensates for by increasing its operating speed—therefore using more energy and making more noise.

Exterior hoods. The two hoods were installed more than 1.8 m apart to prevent exhaust air from being drawn back in, at a safe distance from the propane tank, dryer vent, and plumbing vent pipe, and high enough above ground level to remain above accumulated snow. In Elgin, where blowing snow accumulates against foundations exposed to open fields, this height is not merely cosmetic.

Condensate drain. The HRV produces water when it defrosts. The drain hose was connected with a trap, with a continuous slope toward the drain and no backfall. A 2 cm backfall is enough to create a water plug that backs up into the pan and overflows onto the floor.

Controls and commissioning. The unit was powered up, the automatic airflow test was started, the installation configuration was selected from the five layouts provided by the manufacturer (T1 to T5, depending on whether the HRV is completely independent or partially connected to the furnace network), and the minimum and maximum airflow rates were then programmed on the display. The homeowners were trained on standby, minimum, and maximum modes, as well as how the boost ventilation operates before a morning shower.

The mistakes we most often correct in other people's work

Every year, we redo dozens of poorly executed HRV installations, in Elgin as well as Huntingdon, Ormstown, Saint-Anicet, and also in Montréal, Laval, and on the North Shore. The same defects keep recurring:

1. Bathroom exhaust grille placed directly above the shower. Splashed water eventually ends up in the duct. The grille must capture ambient steam, not splashes.
2. Crushed flexible duct behind a stud or bent at 90 degrees. A flexible duct compressed by 50% loses far more than 50% of its airflow.
3. HRV connected to the furnace return without interlocking. Fresh air then remains trapped in the plenum until the furnace fan runs.
4. No balancing performed. On a unit without automatic adjustment, this is simply an incomplete installation.
5. Filters never replaced. A clogged filter makes the motors work harder, reduces airflow, and eliminates the unit's benefit.
6. Unit left in standby by the homeowner because no one explained that an HRV must run continuously at low speed, not intermittently.

Grants: $500 from Rénoclimat for this type of installation

The installation or replacement of a heat recovery ventilator (HRV) or an energy recovery ventilator (ERV) qualifies for a $500 grant under the provincial Rénoclimat program. Two conditions apply to this grant:

• The unit must be certified by the Home Ventilating Institute and listed in section 3 of the HVI certified products directory. This is the case with the AI Series, which bears the HVI 2100 certification visible on the unit's nameplate.
• An energy assessment must be carried out before the work, followed by a second one afterward. This is the most common sequencing error: a homeowner who has an HRV installed before the initial assessment loses eligibility.

We guide our clients in Elgin and throughout Montérégie through this process, and we provide the technical documentation required for the file.

The real maintenance of an HRV in a rural setting

A heat recovery ventilator requires little, but that little is non-negotiable:

• Every 3 months: remove and vacuum the MERV 8 indoor filters; replace them once a year.
• Once a year: remove the core and wash it with warm, soapy water.
• In spring: check the exterior hood screens. In June, poplar fluff in Haut-Saint-Laurent clogs them within a few weeks.
• In winter: make sure blown snow does not cover the fresh-air intake.
• After a haying or harvest season: inspect the intake, as airborne agricultural dust is significantly more abundant than in the city.

Why entrust your installation to AirGreen

At AirGreen, we have been installing air exchangers, heat pumps, and HVAC ventilation systems for more than twenty years, with over fifteen active field teams serving Montreal, Laval, Longueuil, the North Shore, the South Shore, and all of Montérégie, extending to rural municipalities such as Elgin, Franklin, Godmanchester, and Sainte-Barbe.

What this means in practical terms:

• We calculate airflow rates before recommending a model, rather than selling the same unit to every home.
• We document every installation with real photos from our job sites—not catalogue images.
• We test and record airflow rates during commissioning and provide the readings to the customer.
• We know the municipal regulations applicable in every borough and municipality within our service area, and our office team answers customers' questions on the subject.
• We hold an RBQ licence (5645-9605-01) and prepare rebate applications with the customer.

For an assessment of your residential ventilation needs, replacement of an aging HRV, or a new installation in Elgin, Haut-Saint-Laurent, or anywhere in Greater Montreal, email us at sales@airgreen.ca or call (514) 316-2973. We come to your property, take measurements, and provide you with a detailed, no-obligation quote.