Can I use an ERV or HRV as my make-up air solution in a Toronto home?

An ERV or HRV can serve as a make-up air solution in limited circumstances, but most residential units do not have enough capacity to match a high-CFM range hood, so they typically work as a supplement rather than a complete replacement for a dedicated make-up air system. Understanding the limitations is critical before relying on an ERV or HRV for this purpose.

An HRV (Heat Recovery Ventilator) exchanges stale indoor air for fresh outdoor air while recovering 70 to 80 percent of the heat from the outgoing airstream, making it far more energy-efficient than a simple make-up air unit that heats cold outdoor air from scratch. An ERV (Energy Recovery Ventilator) does the same thing but also transfers moisture between the airstreams, which is beneficial in Toronto — it helps retain indoor humidity in winter and reduces incoming humidity in summer. Both are excellent ventilation appliances that improve indoor air quality year-round. The problem is capacity. Most residential ERV and HRV units are rated between 100 and 200 CFM. A typical large range hood is 600 CFM, and professional-style hoods go up to 1,200 CFM. Even the largest residential ERV or HRV running at full speed cannot replace the volume of air being exhausted by a 600 CFM range hood, leaving your home in significant negative pressure.

There are scenarios where an ERV or HRV can work as your primary make-up air solution. If your range hood is rated at 200 to 300 CFM — which covers most standard residential hoods — a properly sized HRV or ERV can provide enough replacement air to keep your home balanced. Some manufacturers offer higher-capacity residential units in the 200 to 350 CFM range that can match mid-range hoods. In these cases, the ERV or HRV must be interlocked with the range hood so it activates and runs at the appropriate speed whenever the hood is on. This approach is energy-efficient because you recover most of the heat instead of heating raw outdoor air, and it provides filtered, tempered air year-round.

For range hoods over 400 CFM, the practical approach in most GTA homes is a combination system: a dedicated tempered make-up air unit sized to handle the range hood's full exhaust capacity, plus an ERV or HRV running independently for continuous whole-house ventilation. The ERV or HRV handles your home's general ventilation needs (fresh air exchange, humidity management, stale air removal) at a steady low rate, while the make-up air unit kicks in only when the range hood operates. This dual approach is increasingly common in well-built Toronto homes and satisfies both the Ontario Building Code's make-up air requirement and the growing emphasis on continuous ventilation for indoor air quality.

Installation considerations matter in Toronto's climate. ERV and HRV units require their own dedicated ductwork — separate from your furnace supply and return ducts — with balanced intake and exhaust runs to the exterior. Duct runs through unconditioned attic spaces must be heavily insulated (R-12 minimum recommended for ERV/HRV ducts in GTA attics) and vapour-sealed to prevent condensation. The condensate drain from the unit must be routed to a drain and protected from freezing. HRV installation runs $2,500 to $5,000 and ERV installation $3,000 to $6,000 in the GTA. A qualified contractor can assess whether an ERV or HRV alone can meet your make-up air needs or whether you need a dedicated unit as well. Browse HVAC and ductwork contractors in the Toronto Construction Network directory to find a professional for your project.