Four buttons to control 218 CFM: why the simplest control was the right choice
On the hall wall of this Outremont home, there is no touchscreen, sensor, or volatile organic compound detection. Four buttons: MODE, AUTO, and two arrows. This is deliberate.
With their previous unit, the owners had inherited an interface they never used beyond the initial settings. When we replaced the system, the question of the wall control was treated as a technical decision in its own right, just like the unit capacity. At AirGreen, we installed a FANTECH HERO 200H with a multifunction digital EDF8 wall control, and the result is a system its occupants actually operate.
Here is the complete reasoning, in a 1928 home heated with hot water where no ductwork existed.
The house: 2,800 sq. ft., cast-iron radiators, and no air network
Located on one of Outremont's terraces, the house has four bedrooms, three bathrooms, an office, a double living room, a dining room, a rear kitchen, and a finished basement. Heating is provided by cast-iron radiators supplied by a natural gas boiler. A gas water heater completes the mechanical installation.
Three elements defined the project:
- No existing air network. As in most large prewar Montreal homes heated with hot water, there was no plenum, return, or duct to connect to. The entire system had to be designed and built.
- Two naturally vented combustion appliances. This is the point that changes everything in this type of building, and we will return to it below.
- A regulated exterior. The Outremont borough applies strict architectural integration criteria. The main façade and elevations visible from the street were off-limits for any drilling.
The occupants reported a second-floor bathroom that dried poorly, a persistent cellar smell in summer, and heavy air in the rear bedrooms upon waking. Nothing dramatic, but nothing normal either.
Airflow calculation before selecting the unit
The requirement was established room by room, according to the logic of the CSA F326 standard:
| Room | Airflow |
|---|---|
| Primary bedroom | 10 L/s |
| 3 other bedrooms | 15 L/s |
| Office | 5 L/s |
| Living room | 5 L/s |
| Dining room | 5 L/s |
| Kitchen | 5 L/s |
| 3 bathrooms | 15 L/s |
| Finished basement | 10 L/s |
| Laundry room | 5 L/s |
| Total | 75 L/s ≈ 159 CFM |
A requirement of this magnitude puts the house beyond the capacity of the compact 100-to-120 CFM units that are sufficient in a condo or duplex.
The FANTECH HERO 200H, in figures
- Net airflow of 218 CFM at 0.4 in. w.g., 233 CFM at 0.2 in. and 182 CFM at 0.8 in. The margin above the required 159 CFM allows the system to operate without ever becoming saturated, even with a MERV 8 filter installed on the supply side.
- Adjusted sensible recovery efficiency of 81% at 0 °C and 66% at -25 °C.
- Winterguard defrosting by internal recirculation, below -5 °C.
- Counterflow core made of thermoformed polymer plates, 14.4 in × 14.4 in × 14 in deep, washable.
- 6 in round connections on top, with rubber gaskets.
- 210 W, 2.0 A, 120 V, on a dedicated circuit.
- 56.9 lb with core; 27 7/8 in × 15 3/8 in × 24 7/8 in, with 16 in of front clearance required to remove the core.
- Standard washable electrostatic interior filters.
- HVI-certified, ENERGY STAR qualified, compliant with UL 1812 and CSA C22.2 No. 113.
Choosing the wall control: a trade-off rarely explained
FANTECH offers a complete range of interfaces, and price is not the right selection criterion. The right criterion is: who will use it, and how often.
The push-button timers (RTS 4, RTS-W)
They activate the unit at maximum speed for 20, 40, or 60 minutes, then return to the preset setting. The RTS-W version operates wirelessly, on battery power—a valuable feature in a 1928 house where running a low-voltage wire to the second-floor bathroom means opening up a lath-and-plaster wall. These are accessories, not primary controls.
The digital controls (EDF3, EDF8)
The EDF3 offers three modes: economical, 20 minutes per hour, and continuous. The EDF8, the one installed here, controls the unit using four speeds and three modes:
- Ventilation mode: outdoor air intake, the normal operating mode.
- Recirculation mode: the unit circulates indoor air without introducing outdoor air. Useful during smoke or smog episodes that regularly affect the island of Montreal in summer, or during peak pollen season in spring.
- Standby mode: controlled shutdown for an extended absence.
Sensor-based controls (ECO-Feel, ECO-Touch IAQ)
The ECO-Feel is preprogrammed to run continuously in ECO mode, with TVOC detection—designed for multi-unit buildings where no one ever touches the control. The touchscreen ECO-Touch IAQ automatically adjusts operation based on several measured parameters, including relative humidity. It is the control we install most often in newer single-family homes.
Why the EDF8 in this home
Three reasons, in order:
- The homeowners wanted direct control, not automation they would have to interpret. A sensor-based control that slows the unit down on an evening when guests are over produces exactly the opposite of the effect its occupants want.
- Recirculation mode was a requirement. Two consecutive summers of smoke changed the way many Montreal households think about ventilation. A mode that closes the outdoor dampers while maintaining indoor air circulation has practical value.
- Relative humidity is regulated here by airflow and by season, not by a sensor. In a hot-water-heated home without a central air-treatment unit, the air does not undergo the drying effect of a forced-air furnace. Winter behavior is different, and automatic settings calibrated for a forced-air home are poorly suited to it.
We set the unit to the second of four speeds for continuous operation, with manual switching to maximum speed during showers and cooking, supported by two wireless RTS-W timers on the second floor.
Network routing in a heritage home
Three days on site, with two technicians, plus the plasterer.
The unit was suspended in the basement mechanical room on chains and vibration isolators, away from the boiler, with the 16 inches of front clearance preserved and documented in the file.
Ventilation: five isolated 6-inch runs to the four bedrooms and the office, routed through the void of the former servants' stairwell, a vertical space that these houses almost always have and that we systematically look for before considering any ceiling bulkhead. The ornate ground-floor ceilings were left untouched.
The exhaust: three dedicated branches to the bathrooms, one to the laundry room, and one to the finished basement. No kitchen exhaust near the stove — the hood handles that role, and a core exposed to cooking vapors loses its effectiveness within one season.
The exterior caps were relocated to the side elevation, on the courtyard side, with 1.8 m of separation between the fresh-air intake and the exhaust, a height of 45 cm above the accumulated snow level, and deliberate separation from the dryer vents and the water-heater exhaust terminal.
The condensate drain connects to the mechanical-room floor drain, with a loop trap.
The step too many installers skip: the backdraft test
This is the technical heart of the project. With a gas boiler and a naturally vented gas water heater, a poorly balanced air exchanger becomes a real risk. If exhaust exceeds supply, the house becomes depressurized and air can flow back down the chimney instead of out of it, drawing combustion gases indoors.
Our commissioning sequence:
- Balometer balancing, outlet by outlet. Final results: 162 CFM supply, 160 CFM exhaust at maximum speed; 78 CFM in continuous mode, second speed.
- Depressurization test with all exhaust appliances running simultaneously — air exchanger at maximum, kitchen hood, dryer, bathroom fans.
- Draft verification on both gas appliances, with backdraft detection at the draft hoods.
- Written report provided to the owners with the measured airflow rates.
A system delivered without these measurements is not a delivered system.
The pitfalls we see most often
- Install without checking the combustion appliances. In the older buildings of Montreal, this is the most serious omission.
- Drill through a facade governed by borough regulations before checking what is permitted.
- Choose the most sophisticated control by default. An interface that no one understands ends up on a fixed speed, which defeats the purpose of paying for it.
- Extract air from the kitchen near the stove.
- Forgetting to include the MERV filter in the pressure-loss calculation.
- Leaving a 57 lb. unit on an improvised suspension.
- Not providing the client with any airflow report.
What qualifies on the grants side
The Rénoclimat program provides $500 for installing or replacing a heat recovery ventilator (HRV) or energy recovery ventilator (ERV). The unit must appear in section 3 of the Home Ventilating Institute (HVI) certified products directory—the HERO 200H is listed there—and the assistance depends on the improvement in the EnerGuide rating between the initial and final evaluations.
In a house like this, the winning strategy is to integrate ventilation into a broader package: attic insulation, sealing penetrations, and replacing the boiler. Installing an air exchanger on its own increases consumption and may compromise eligibility for the improvement condition. The initial assessment must precede the first penetration.
Keep the unit performing at its original efficiency
Washable indoor filters should be rinsed every three months and put back perfectly dry. The core is removed and rinsed once a year—the 16 inches of clearance provided during installation turn this ten-minute task into a ten-minute task rather than a complete teardown. Outdoor grilles should be checked in spring and fall. And every three to five years, an instrumented airflow check confirms that the system has not drifted.
Our approach in Montréal’s heritage neighbourhoods
Outremont, Westmount, Mile End, Ahuntsic-Cartierville, and Old Longueuil all require the same discipline: design the system on paper before opening anything, respect protected elevations, and treat existing combustion appliances as a design constraint, not an afterthought.
We provide this type of ventilation and HVAC installation throughout Greater Montréal, in Laval, Longueuil, on the North Shore and the South Shore: airflow calculations before the quote, a drawn layout, a backdraft test during commissioning, and a balancing report delivered in person.
To have your home’s ventilation evaluated, contact our team at (514) 316-2973 or sales@airgreen.ca. RBQ 5645-9605-01.