Installation of a Broan-NuTone AI Series V130H65RT air exchanger in Coteau-du-Lac (Vaudreuil-Soulanges)

An airtight house, a stuffy basement, and 105 CFM to restore balance

At AirGreen, we see the same scenario recur every winter in homes built after 2005: the building envelope is airtight, the windows are high-performing, the furnace works perfectly, and yet the air becomes stuffy as early as November. At Coteau-du-Lac, in the Vaudreuil-Soulanges RCM, a homeowner contacted us describing exactly that: persistent condensation in the lower corners of the basement windows, cooking odors that lingered for the entire evening, and a feeling of stagnant air upon waking in the bedrooms upstairs.

Installing a Broan-NuTone AI Series V130H65RT air exchanger, set to 105 CFM, resolved the situation in a single day of work. Here is how we got there, and above all, why each technical decision was made.

The diagnosis before proposing anything

An improperly sized air exchanger is expensive to operate and unnecessarily dries out the house. An undersized air exchanger, on the other hand, does nothing to improve comfort. That is why we always start by measuring before making a recommendation.

On site, our readings showed:

• A relative humidity of 58% in the middle of December, while the comfortable target in a Quebec winter is between 30% and 40%.
• CO₂ concentrations exceeding 1,400 ppm in the primary bedroom early in the morning, with the doors closed, compared with a reasonable target below 1,000 ppm.
• Ventilation limited to bathroom fans and the kitchen range hood, with no controlled fresh-air intake.
• An already-installed Aprilaire humidifier on the furnace ductwork, adding humidity to a house that did not need it.

The picture was clear: the house was not lacking humidity; it was lacking air exchange. Adding a dehumidifier in the basement would have masked the symptom. Installing a heat recovery ventilator (HRV) addressed the cause.

Why 105 CFM instead of the unit's maximum airflow

The V130H65RT can modulate between 35 and 131 CFM (17 to 61 L/s). We could have left it running at maximum. That would have been a mistake.

The airflow calculation under the CSA F326 standard, which governs residential ventilation in Quebec, adds up the requirements room by room: the primary bedroom, each of the other bedrooms, the kitchen, bathrooms, and living areas. For this residence, the total came to approximately 50 L/s, or about 105 CFM of continuous airflow. This is precisely the value we programmed into the unit, and it is the number shown on the integrated LCD screen and repeated on the access-door label.

Ventilating beyond this requirement does not make the air “cleaner.” It exhausts paid-for heat, dries out the air at -20 °C, and makes the motors work for nothing.

Why we chose the Broan-NuTone AI Series V130H65RT

This model belongs to the AI Series from Broan-NuTone, built on the Virtuo Air Technology platform. The features that influenced our recommendation:

• Adjustable airflow from 35 to 131 CFM, leaving a comfortable margin on either side of the target of 105 CFM.
• Sensible recovery efficiency (SRE) of 68% at 0 °C and 60% at -25 °C, measured at 64 CFM. Apparent sensible efficiency of 72% at 0 °C.
• ENERGY STAR certification and HVI certification, two verifiable benchmarks rather than marketing claims.
• PMSM ECM motors with very low power consumption: the complete unit draws 110 W at 120 V / 60 Hz / 2.4 A.
• Five-inch top-mounted ports, a configuration that greatly simplifies connection when the unit is suspended between joists.
• Washable MERV 8 filter included, with the option to upgrade to a MERV 13 or HEPA filter for households sensitive to allergens.
• Compact dimensions of approximately 21 in × 21½ in × 16⅜ in and a weight of about 35 lb, which really matters in a mechanical room already occupied by a furnace and humidifier.

The decisive advantage, however, remains automatic balancing. An air exchanger only works properly when the fresh-air and stale-air flows are equal. Traditionally, this balancing is done during installation with measuring equipment and Pitot tubes, then drifts as the indoor filters become clogged, an exterior hood frosts over, or a duct collapses. The V130H65RT continuously measures its airflow and corrects itself, maintaining balance between HVAC maintenance visits.

What “105,” “STB,” and “T1” mean on the label

Homeowners often ask us about this when looking at their unit's label. The three displayed values correspond to the actual system configuration:

• 105 : the requested airflow, in CFM.
• STB: the mode displayed on the screen, here standby (standby), with the unit then switching to MIN or MAX according to the wall control and requirements.
• T1: the programmed installation type, namely a fully ducted system with recirculation capability. Configurations T2 to T5 cover setups in which the heat exchanger shares the furnace ductwork or operates in a simplified installation.

Programming the wrong type of installation is a common and silent mistake: the unit operates, but its defrost and recirculation sequences do not match the actual duct network.

The work process, step by step

The complete installation took one day with two technicians.

1. Mounting the unit. We secured a plywood panel to the basement joists, then installed the HRV on the supplied universal wall brackets. This approach prevents the weight and vibrations from being borne by a single anchor point.
2. Duct connections. Four insulated ducts connect the unit: stale-air intake, fresh-air distribution, exhaust to the outside, and fresh-air intake. Insulating the ducts that pass through cold areas is not optional: without it, condensation forms on the outer surface and eventually stains the ceilings.
3. Positioning the exterior hoods. We maintained a separation of at least 6 feet between the intake hood and the exhaust hood, a height of at least 18 inches above the expected snow level, and a distance of at least 10 feet from any dryer vent, chimney, or gas meter. In Coteau-du-Lac, where snow accumulation is a reality, hood height is not merely cosmetic.
4. Condensate drain. The drainpipe was installed with a trap-forming loop, keeping at least 2 inches between the unit and the loop. Without this trap, the unit draws odors from the drain.
5. Electrical supply. Dedicated 120 V outlet, within 6 feet of the unit, in a room whose temperature remains above 10 °C year-round.
6. Automatic calibration. With the doors and windows closed and the entire duct network sealed, we initiated the measurement sequence. The unit displays the maximum achievable airflow and indicates which side is limiting the system. We then locked the minimum and maximum values around the target of 105 CFM.
7. Commissioning with the customer. Demonstration of the wall control, operating modes, temporary boost ventilation, and removal of the interior filters.

The mistakes we most often correct in other contractors' work

A significant portion of our ventilation service calls involve properly functioning units that were installed incorrectly. Recurring cases include:

• Exterior hoods installed too close together, causing freshly exhausted air to be drawn back in. The HRV runs, but the house is not ventilated.
• Drain without a trap, a source of odours mistakenly attributed to the unit itself.
• Crushed or excessively long flexible ducts, which cause the actual airflow to fall well below the value displayed on a unit without built-in measurement.
• Unit never calibrated after installation, often because construction was completed before the windows were installed.
• Filters never washed. Washing them quarterly with warm, soapy water and allowing them to air-dry completely is sufficient. An HRV core should be soaked once a year.
• HRV installed in an unheated garage or a cold crawl space, below its operating temperature range.
• Confusion between an air exchanger and a humidifier. Both appliances were in this basement and serve opposite purposes. Running a humidifier at full capacity in an under-ventilated home worsens condensation on the windows.

Compliance, Novoclimat, and financial assistance: getting the facts straight

Since 2012, the Québec Construction Code has required a mechanical ventilation system in applicable homes, with at least 54% heat recovery at -25 °C and balanced airflow rates. With its 60% at -25 °C, the V130H65RT exceeds this requirement and also reaches the 60% threshold required by the Novoclimat program for new construction.

We prefer to be direct about subsidies: in Quebec, an air exchanger installed during a renovation is generally not eligible for direct financial assistance comparable to that offered for heat pumps. Its value lies elsewhere: Code compliance, measurable air quality, protection of the building envelope against moisture-related damage, and an improved rating during an ÉnerGuide-type energy assessment under Rénoclimat. When a contractor promises a subsidy for a simple air exchanger, it is worth asking for the exact name of the program and the stream number.

Have AirGreen install your air exchanger, from Coteau-du-Lac to Montreal

At AirGreen, ventilation is not an add-on module sold with a heating contract. It is a discipline in its own right, with its own calculations, standards, and measurements. We have installed and recommissioned HRVs and ERVs in bungalows in Vaudreuil-Soulanges, townhouses in Laval, plexes in Plateau-Mont-Royal, single-family homes in Longueuil and Brossard, as well as in recent construction projects on the North Shore, from Terrebonne to Saint-Eustache.

Our commitments on every HVAC ventilation installation:

• Airflow calculation documented according to CSA F326 and provided to the customer.
• Calibration completed and documented at the end of the project, never postponed.
• Exterior hood placement compliant with minimum clearances, with photos as proof.
• A complete explanation of routine HVAC maintenance, so the homeowner can wash their interior filters without relying on a service call.
• After-sales service provided by our own teams, distributed throughout Greater Montreal.

The owner in Coteau-du-Lac called us back six weeks later: relative humidity had stabilized at around 35%, there was no more condensation on the windows, and the heating bill remained comparable to the previous winter's despite continuous air exchange. That is exactly what a properly sized and properly calibrated air exchanger should deliver.

For an assessment of your ventilation system, an air exchanger replacement, or a new installation in Montreal, Laval, Longueuil, the North Shore, the South Shore, or Vaudreuil-Soulanges, contact us. We measure first, then make our recommendations.