What are the different types of make-up air systems available for Toronto homes?

There are four main types of make-up air systems used in GTA residential applications: passive air inlets, motorized damper systems, powered make-up air units with tempering, and integrated ERV or HRV solutions. Each has different capabilities, costs, and suitability depending on your home's construction, the size of your exhaust system, and how well sealed your building envelope is.

Passive air inlets are the simplest and least expensive option. These are essentially controlled openings in the exterior wall — a weather-resistant hood on the outside, a damper or grille on the inside, and sometimes a filter. They rely on the negative pressure created by the range hood to draw air in naturally. Passive inlets cost $100 to $400 installed and require no electricity or ductwork. The major drawback in Toronto is obvious — in January, a passive inlet brings in untreated -15 degree air directly into your home. There is no tempering whatsoever. For small exhaust loads (under 200 CFM), a passive inlet in a mild location may be acceptable, but for large range hoods in Toronto's climate, passive inlets create brutal cold drafts and are generally inadequate.

Motorized damper systems add a step of control. An electrically operated damper is interlocked with the range hood, opening automatically when the hood turns on and closing when it shuts off. This prevents air from entering when the hood is not running, but the incoming air is still untempered. These systems cost $300 to $800 installed. They are a step up from passive inlets but still have the cold air problem in winter. Some installations add a short section of insulated duct to slow the air velocity and reduce the perceived draft, but this does not actually warm the air.

Powered make-up air units with tempering are the proper solution for most GTA homes with high-CFM range hoods. These are self-contained units that include a fan, a filter, insulated duct connections, and an electric or gas-fired heating element that warms incoming air before it enters the living space. The unit is interlocked with the range hood and sized to match its CFM rating. In Toronto, electric tempering coils are most common for residential applications because they do not require a gas line to the unit. These systems cost $2,000 to $5,000 installed, including the tempering element and dedicated ductwork. This is the type of system that most contractors will recommend and most building inspectors expect to see for range hoods over 400 CFM.

ERV or HRV integration is sometimes proposed as a make-up air solution, and it can work in limited circumstances. An HRV (Heat Recovery Ventilator) or ERV (Energy Recovery Ventilator) exchanges stale indoor air for fresh outdoor air while recovering 70 to 80 percent of the heat from the outgoing air. However, most residential ERV and HRV units are rated at 100 to 200 CFM — far below the exhaust capacity of a 600 or 900 CFM range hood. An ERV or HRV can supplement a make-up air system or serve as the sole solution for modest exhaust loads, but it typically cannot keep up with a large range hood on its own. ERV/HRV units cost $2,500 to $6,000 installed with dedicated ductwork.

For most Toronto homeowners installing a serious kitchen range hood, a powered tempered make-up air unit is the right choice. Get quotes from qualified ductwork contractors through the Toronto Construction Network to find the right system for your home.