Installation of a GREENTEK PREMIER 2.0H air exchanger in Laval

New construction in Laval: the 30-second test that tells you whether your air exchanger was actually connected correctly

Every year, we receive calls from homeowners of new houses in Laval — Sainte-Dorothée, Sainte-Rose, Vimont, Fabreville — who all describe roughly the same thing. The house is less than three years old. It has a brand-new air exchanger, supplied by the builder. And yet the windows run in January, the bedroom air feels heavy in the morning, and the smell of cooking takes all evening to dissipate.

The unit works. It runs, makes noise, and consumes electricity. But in a significant proportion of the cases we inspect, it has never been balanced, and in a non-negligible minority, it has been connected backwards.

The project described here is the opposite of this scenario. A new home in a developing area of Laval, where we worked during construction, with the basement still open and the joists exposed. We installed a GREENTEK PREMIER 2.0H, a side-port HRV, suspended by chains beneath the joists.

And here we will explain, using the actual numbers on the unit's label, how any homeowner can check the essentials themselves.

The four ports: exactly what the connection label says

On the front of the FIRST, a label illustrates the connection diagram for the four ducts. It is bilingual, positioned at eye level, and is the most useful thing on the entire unit for a homeowner.

It indicates, port by port:

Two ducts enter, two ducts exit. Two go outside, two go into the house. This logic seems obvious once written down. Yet it is reversed more often than you might think on fast-paced construction sites.

The two connection errors, and their symptoms

Error 1: the two exterior ducts are switched. The unit then draws fresh air through the hood intended for exhaust and exhausts through the hood intended for intake. Since both hoods are on the same façade, the unit partially draws back in what it has just expelled. Symptom: the house is ventilated, but air quality does not improve and humidity remains high. The recovery core itself continues to function—that is what makes the error invisible.

Error 2: the two interior ducts are switched. Fresh air is then delivered to the exhaust points—bathrooms, kitchen, and laundry room—and stale air is drawn from the bedrooms. Symptom: the bedrooms remain stuffy even though the unit is operating, and a cold draft can be felt near the bathroom grilles in winter.

The test you can do yourself, with the unit running and your hand open in front of each grille:

• At the bedroom and living room grilles, you should feel air coming out.
• At the bathroom, kitchen, and laundry room grilles, a sheet of lightweight paper should be drawn toward the grille.

If it is the other way around, the interior ducts are crossed. Thirty seconds, no tools.

The GREENTEK balancing table, read line by line

The other label on the unit is the balancing table. It converts a pressure measured at the unit's ports into actual airflow, in CFM and L/s, separately for fresh air and stale air.

Here is an excerpt of the values as listed on this unit:

Three observations that we systematically explain to our customers.

First: at GREENTEK, the relationship is direct. The higher the measured pressure, the higher the airflow. This is not universal—some manufacturers use an inverted convention on their own labels, where a lower pressure corresponds to a higher airflow. A technician who habitually applies another brand's convention will therefore balance in the wrong direction, and the result will be far from the target.

Second: the two columns do not show the same figures for the same pressure. At 0.40 in. w.c., the fresh-air side shows 136 CFM and the stale-air side 147 CFM. The two circuits of an HRV do not have the same internal geometry, so they do not have the same curve. That is exactly why the table has two columns, and why balancing by reading a single column for both sides creates a systematic imbalance.

Third: these values are measured at high speed. Balancing is performed at maximum output, then the lower speeds follow proportionally. Measuring at reduced speed produces low, unstable readings and an adjustment that does not hold.

Our target values for this project

After calculating the room-by-room airflow requirements for this house, the selected target was approximately 135 CFM at high speed, on both sides.

Converted into pressure readings, based on the table above:

• Fresh-air side: 0.40 in. w.g. → 136 CFM
• Stale-air side: 0.36 in. w.g. → 138 CFM

Final difference between supply and exhaust: approximately 2 CFM, or less than 2%. This is what defines balanced ventilation in the true sense of the term—the house is neither pressurized nor depressurized.

These two values, along with the date and technician's name, are recorded and provided to the owner. Five or ten years later, a technician taking over the file immediately knows what to compare their measurements against. Without this document, they have to start from scratch.

GREENTEK PREMIER 2.0H specifications

The 60 to 200 CFM range provides real headroom here. With a target airflow of 135 CFM, the unit operates at about two-thirds of its maximum capacity. This reserve accommodates the gradual buildup of dirt in the filters, allows for ventilation boosts during gatherings, and leaves room if the basement is finished later—which is almost always the case in new homes in Laval, where the basement is often left unfinished.

Defrosting deserves a note. It activates automatically when the outdoor temperature reaches –5 °C or below: the supply fan stops and the exhaust fan switches to high speed to maximize core defrosting. This is effective, but it temporarily increases depressurization. We therefore always check for naturally drafted combustion appliances — a gas fireplace, wood-burning fireplace, or naturally vented water heater — before selecting a unit with this strategy. In new homes in Laval equipped with a direct-vent, sealed gas fireplace, the issue does not arise; with a naturally drafted fireplace, it is a serious consideration.

The construction sequence: ventilation in a new house is determined before the drywall is installed

The four visits, and what is decided at each one

In new construction, a ventilation HVAC installation takes place over several visits spread across several months. This fragmentation explains why so many systems end up improperly adjusted: each stage is assigned to someone who assumes the previous one was done correctly.

Passage 1 — Rough-in, before insulation. Securing the unit, running the ducts through the walls and floors, positioning the collars where the future grilles will be installed, and drilling the two exterior openings. This is the only time when the routes are flexible. A decision postponed at this stage becomes a decorative bulkhead later.

Passage 2 — After insulation and the vapor barrier. Verification that penetrations are airtight, sealing of the vapor barrier penetrations around the ducts, and inspection of the insulation on the exterior ducts along their entire length.

Passage 3 — After finishing. Installation of the interior grilles, electrical connection, and installation of the wall control.

Passage 4 — Commissioning. Startup, documented balancing at both ports, control programming, verification of the direction of all ducts, and a demonstration for the homeowner.

Passage 4 is the one most often skipped. When the house is delivered late, the buyer is waiting for the keys, and three other units in the same development are scheduled for delivery that week, commissioning becomes a box to check rather than a task to be properly completed. That is where the calls we receive two years later originate.

Coordination with the central system

This house is heated and cooled by a central forced-air system with a heat pump. Two systems therefore coexist in the same basement, and their interaction needs to be carefully considered.

What we systematically check:

• The fresh-air injection point. When fresh air is delivered into the central system rather than through dedicated ducts, the connection point must be far enough downstream to prevent the fresh air from being immediately drawn back into the return.
• Fan interlocking. If fresh air travels through the central system, the system fan must run when the heat exchanger is at high speed; otherwise, fresh air stagnates in the ducts instead of reaching the bedrooms.
• The combined effect on building pressure. A high-volume kitchen range hood, dryer, bathroom fans, and the HRV in defrost mode: their simultaneous operation must be assessed, particularly in very airtight new homes.
• The shared condensate drain. The HRV and the heat pump coil both produce condensate. We connect them with separate, primed traps, never in series without precautions.

Novoclimat, Construction Code, and documents to require

For new homes covered by the Quebec Construction Code, balanced mechanical ventilation is required, and it is a condition of the Novoclimat program. A new-home buyer in Laval therefore has good reason to request supporting documents rather than rely on the physical presence of a unit.

What is worth requiring from your builder:

1. The balancing report with the measured supply and exhaust airflow rates, dated and signed.
2. The duct layout or, failing that, a list of the rooms served by the supply and exhaust systems.
3. The unit manual and the exact model installed.
4. A demonstration of how the wall control works, in person.

A reputable builder will provide these four items without hesitation. Refusal or vagueness regarding the balancing report is itself an answer.

Mistakes to avoid in a new home

1. Assuming that a new unit is a properly commissioned unit. These are two distinct things.
2. Not checking the direction of airflow in the ducts. The hand-and-paper test takes thirty seconds.
3. Turning off the unit because it “makes noise.” In a new home, the load of volatile organic compounds released by building materials is at its highest during the first few months.
4. Finishing the basement without adding an exhaust point. A finished basement playroom without a return becomes the most humid room in the house.
5. Confusing the standard MERV 3 filter with air-quality filtration. It protects the fans and the core. For actual filtration, you need the MERV 8 or MERV 13 options — and their pressure drop must be incorporated during balancing.
6. Ignore the required service clearance around the unit when finishing the basement. An air exchanger enclosed in a closet without front access will never be serviced.
7. Do not keep the balancing record. Without reference values, all future diagnostics start from scratch.

Maintaining a PREMIER 2.0H

• Every 3 months — rinse washable electrostatic filters, or replace MERV 8 or MERV 13 filters.
• Every 6 months — clean the cross-flow core, check the drain and the clamps at the collars.
• Annually — clear both exterior hoods, inspect the vapor barrier on insulated ducts, and revalidate airflow rates at the balancing ports against the commissioning record.

In new developments in Laval, where lots often remain under construction for several seasons, we add one recommendation: check the exterior grilles more frequently during the first year. Construction and landscaping dust accumulates on the screens much faster than in an established neighborhood.

For your project in Laval, on the North Shore, or elsewhere

At AirGreen, we work on both new construction and the correction of improperly adjusted systems. Our method remains the same: calculate airflow rates by room, plan the ductwork layout before selecting the unit, verify the direction of each connection, balance the system using measurements at both ports according to the manufacturer's table, provide the client with a record of values, and demonstrate operation to the occupants.

We carry out HVAC installations — air exchangers, wall-mounted and central heat pumps, air conditioners, and heating systems — in Laval (Chomedey, Sainte-Dorothée, Sainte-Rose, Vimont, Fabreville, Duvernay, Laval-des-Rapides), Montreal, Longueuil, throughout the North Shore and the South Shore. Licence RBQ # 5645-9605-01.

If you have doubts about the setup of the air exchanger in your new home, or if you are planning an HVAC installation, contact us at (514) 316-2973 or sales@airgreen.ca. We can check the connection directions and measure the actual airflow rates in your home.