A Charlemagne home that could no longer remove its humidity
The first call came one February morning. A homeowner from Charlemagne, in a 1970s bungalow located a few streets from the L’Assomption River, described windows frosted halfway up, a persistent odor in the finished basement, and a bathroom that remained humid for more than two hours after a shower. Yet a Lifebreath air exchanger had been installed in the basement when an addition was built about ten years earlier.
At AirGreen, we encounter this situation several times each season on the North Shore. The unit is working. The problem lies elsewhere: in the distribution system, the grilles, the balancing—and very often in a wall control that no one has ever explained to the customer.
The diagnosis: a healthy unit, a system that delivered nothing
Our technician started with measurements, not assumptions. A digital manometer, Pitot tubes, and balancing dampers at the doors: Lifebreath’s 99-BAL-KIT is part of the standard equipment on our trucks, and it was what revealed the real story of this home.
The results were clear:
- Measured supply airflow: approximately 38 CFM on high speed, even though the unit is designed to deliver considerably more at the system’s static pressure.
- Measured exhaust airflow: approximately 61 CFM. A difference of more than 35% between the two airflows.
- Clear imbalance: the home was under continuous negative pressure, drawing air from the crawl space into the living areas and perfectly explaining the basement odor.
- Original grilles: inexpensive fixed 4-in. grilles installed at the ends of 5-in. flexible ducts, with improvised adapters and a partially crushed flex duct behind a stud.
No setting on the unit itself would have corrected this. The bottleneck was at the home’s six supply outlets.
Why we specified the Techgrille 99-EAG5
The Techgrille 99-EAG5 is the 5-inch-diameter version in Lifebreath's Techgrille family, which also includes the 99-EAG4 (4 in.), 99-EAG6 (6 in.), and 99-EAG8 (8 in.). It may seem modest. Yet it solves three distinct problems at once.
A truly adjustable central cone
The center of the grille is a cone that you screw in or out to open and close the outlet ring. This allows the airflow to be adjusted vent by vent, by hand, once the system is powered on. On a fixed grille, the only available variable is the duct diameter—in other words, none. With a Techgrille 99-EAG5, each room receives exactly its share of fresh air.
In Charlemagne, this translated into the following:
- Primary bedroom: cone three-quarters open
- Secondary bedroom (occasionally occupied): cone half open
- Living room: cone fully open
- Finished basement: cone half open, to avoid over-supplying an already cool space
- Bathroom and kitchen: exhaust side, with reverse adjustment
Spring clips that actually hold in the duct
The 99-EAG5 clips directly into the round duct thanks to compression spring clips. No screws in the drywall, no visible collar, and no play that starts whistling after two winters. On a finished basement ceiling, this feature makes a tangible difference to the finish and ease of maintenance: the grille can be removed by hand for vacuuming and then put back at the same setting.
A white, non-corrosive material
Bathroom exhaust vents are constantly exposed to moisture-laden air. The Techgrille's non-corrosive body prevents the brown rust stains that eventually drip onto painted ceilings—a defect we regularly correct in homes in Repentigny, Terrebonne, and L'Assomption.
The project, step by step
Step 1 — Complete assessment and calculation of required airflow
Before drilling anything, we determine the total airflow required for the floor area and number of rooms, then distribute it accordingly. An improperly balanced air exchanger is not an air exchanger: it is a noisy fan that consumes electricity.
Step 2 — Reworking the ductwork and installing 5-inch Techgrilles
The crushed flexible ducts were replaced with straight, taut sections. Each outlet received a Terminator 99-TM5 fitting (5 in., wall or ceiling) where the structure required it, followed by a Techgrille 99-EAG5. Flexible duct lengths were shortened to the bare minimum: each unnecessary foot of corrugated duct adds pressure loss and takes airflow away from the room.
Step 3 — Wiring and integration of the wall control
This is what the job-site photo shows: a three-gang electrical box on the main floor, the plaster cut away around it, two existing Decora switches retained, and the Lifebreath 20/40/60-minute wall control integrated on the left.
This detail deserves attention. Lifebreath controls — whether the 99-DET01 timer, the 99-BC02, 99-BC03, and 99-BC04 basic controls, or the 99-DXPL02 digital control — connect using low-voltage, 20-gauge, 3-conductor wire, over a maximum length of 100 feet. This is not 120 V. The wire must therefore be run separately, which is precisely why we systematically take advantage of a renovation, an open wall, or a removed ceiling to install it properly.
The 20 / 40 / 60-minute sequence controls timed high-speed ventilation. One button, one duration, and an automatic return to normal operation. It is the most underused tool in the entire system: when properly explained to the client, it alone eliminates most complaints about humidity after showering or lingering cooking odors.
On this job, we completed the three-unit setup with a 99-107W decorative plate, compatible with the BC series controls and timers, to achieve a clean finish in an opening that had been hand-cut years earlier.
Step 4 — Documented balancing and commissioning
Balancing is performed at the unit's balancing dampers, then fine-tuned at the Techgrilles' cones. Final measurement at the end of the day:
- Supply: 64 ft³/min
- Exhaust: 66 ft³/min
- Difference: under 5%, well within the acceptable tolerance
The balancing report, with supporting figures, was provided to the client. A balanced system without written documentation is a system that has never been balanced.
The technical data to know before buying
For a project of this type, on the North Shore as well as the South Shore, here are the guidelines we use.
The diameter of the collars dictates the diameter of the grilles
- The RNC4-TPD and RNC4-TPF models use 4-inch ducts—therefore, Techgrilles 99-EAG4 grilles.
- The METRO 120D, METRO 120F, RNC5-TPD, RNC5-TPF, and RNC5-ES models use 5-inch ducts—therefore, 99-EAG5 grilles.
- Larger units, such as the RNC155, RNC200, and RNC205, serve larger homes and mixed 5- and 6-inch duct systems.
Reference performance
For comparison, the RNC5-TPD delivers 156 cfm at 0.2 in. w.g. with a sensible recovery efficiency (SRE) of 61% at 0°C, while the METRO 120D, only 9.75 in. thick, reaches 68% SRE and fits into a condo drop ceiling. The RNC5-HEX-TPF, with its counterflow HEX core, reaches 76% SRE. These differences show up on electricity bills throughout the Quebec winter.
Climate zone
Southern Quebec is located in Zone 2 of the North American climate map: cold winters and hot, humid summers. An HRV (heat recovery ventilator) is recommended there, or an ERV with a defrost system. An ERV without defrosting has no place in Charlemagne.
Warranty and certifications
Lifebreath units are covered by a lifetime warranty on the recovery core and a 5-year warranty on replacement parts. They are HVI-certified, comply with CSA and UL standards, and are manufactured under ISO 9001.
The mistakes we correct most often
- Installing the supply grille less than 3 feet from an exhaust outlet. The fresh air goes straight back outside without circulating through the room. It is a straightforward short circuit.
- Opening all the cones fully. The first instinct is to open everything “to get more air.” The result is the opposite: the outlets closest to the unit take all the airflow, and the back bedrooms receive nothing.
- Leaving excessive lengths of flexible duct. Three feet of properly stretched flexible duct is better than eight feet snaking through a joist space.
- Neglecting to insulate ducts in an unheated space. An uninsulated fresh-air duct in a Lanaudière attic causes condensation, followed by stains on the ceiling.
- Install the outdoor air intake in the wrong place. Keep it away from the dryer outlet, plumbing vent, garage door, and driveway. The 99-185 weather caps (5 in.) or the 99-190 dual cap allow for clean configurations, including when only one wall opening is possible.
- Never clean the filters. The supply and exhaust filters are washable. Twice a year is sufficient, and the difference in airflow can be measured immediately.
Subsidies and eligibility
In Quebec, installing or replacing an HRV may qualify for financial assistance under the Rénoclimat program, provided that an energy evaluation is completed before the work and a second evaluation follows its completion. The order of operations is crucial: an installation completed before the initial evaluation is not recognized. Distribution accessories such as the Techgrille 99-EAG5 are not eligible for a separate subsidy, but they determine the actual performance of the subsidized system.
Programs evolve, and so do the criteria. We systematically confirm eligibility with the client before scheduling the work, rather than promising an amount that might not materialize.
What this Charlemagne project reminds us
Three weeks after the work, the client called us back for an unusual reason: she wanted to know whether the system was still working because she could no longer hear it and her windows had remained dry during a cold snap at −24 °C. That is exactly the result we were looking for. A properly distributed and balanced air exchanger fades into the background.
The unit matters. The network that extends it matters just as much. A Techgrille 99-EAG5 costs a fraction of an HRV, yet it is what determines what actually reaches each room.
At AirGreen, we carry out this type of work in Charlemagne, Repentigny, L'Assomption, Terrebonne, Mascouche, and throughout the North Shore, as well as in Montreal, Laval, Longueuil, and across the entire South Shore. We measure before, we measure after, and we provide the figures.