How does an HRV connect to existing ductwork in a Toronto home?

An HRV connects to your Toronto home's existing ductwork through one of two main configurations: integrated with your furnace duct system, or through a fully dedicated independent duct network. The approach that works best depends on your home's age, duct layout, and whether you want the HRV to operate independently of your heating and cooling system.

The most common installation method in GTA homes is the simplified integrated approach, where the HRV ties into your existing furnace ductwork. In this setup, the HRV's fresh air supply duct connects to your furnace's return air plenum, and the HRV's stale air exhaust picks up air from dedicated exhaust grilles in bathrooms and the kitchen. When fresh air enters the return plenum, it mixes with recirculated house air and gets distributed through your existing supply ducts to every room. This approach is cost-effective because it uses your furnace blower to distribute the fresh air, avoiding the need to run new supply ducts throughout the house. GTA installation cost for an integrated HRV setup typically runs $2,500-$4,500 including the unit, ductwork connections, and exterior wall or roof penetrations.

The key requirement for an integrated installation is that your furnace blower must run whenever the HRV is operating, even when neither heating nor cooling is called for. Most modern furnaces have a "fan on" or "continuous circulation" setting that runs the blower at low speed for this purpose. Without the furnace blower running, fresh air from the HRV simply sits in the return plenum and never reaches your living spaces. This does add a small amount to your electricity bill — roughly $10-$20 per month for continuous low-speed fan operation — but it is necessary for proper ventilation.

The fully dedicated duct system is the premium approach. The HRV gets its own supply and exhaust ducts completely independent of the furnace system. Fresh air supply ducts run to bedrooms and living areas, while stale air pickup ducts run to bathrooms, the kitchen, and the laundry room. This configuration delivers superior ventilation because it operates regardless of your furnace status and provides precise control over where fresh air enters and where stale air exits. However, running dedicated ducts through a finished Toronto home is significantly more expensive — typically $4,000-$6,000 installed — and involves opening walls and ceilings, which is why this approach is most practical during renovations or in new construction.

For older GTA homes — particularly pre-1975 homes in Scarborough, Etobicoke, or North York with undersized ductwork — an integrated installation requires careful assessment. If your existing return ductwork is already undersized (which is extremely common in post-war Toronto homes with single central returns), adding HRV airflow to the return plenum can worsen airflow problems. A qualified HVAC contractor should measure static pressure in your duct system before connecting an HRV to confirm the existing ductwork can handle the additional airflow.

Exterior penetrations are critical in a GTA installation. The HRV needs two openings through your exterior wall — one for fresh air intake and one for stale air exhaust. These must be at least six feet apart to prevent exhausted air from being pulled back into the intake. In Toronto's freeze-thaw climate, these penetrations must be properly flashed and sealed to prevent water infiltration, and the intake hood should be positioned away from driveways, garbage areas, and gas meter vents.