WHAT’S AN HRV/ERV?

In most cases, an HRV, or heat recovery ventilator, is required in a home to meet building code standards.  They improve the efficiency of the house as well as provide needed fresh air to buildings.  Essentially they allow the air that is leaving the house to be ducted close to the incoming air inside a heat exchanger.  This allows for the heat from the exhausted air to be passed to the incoming air so that your furnace won't have to work as hard to heat the incoming air in the winter.

Below is an infographic that shows how an HRV works and how it can be connected to a forced air system.  In the case where you do not have a forced air system, the fully ducted option is the only one that is possible:

How an HRV works?

An HRV (Heat Recovery Ventilator) is commonly referred to as an “Air Exchanger”. It is often a requirement in new construction as a means of providing continuous/intermittent fresh air to a home. In the ventilation process, 50-80% of the energy recovered from the exhaust air to the incoming fresh air. It reduces building heating/cooling energy bills.

Connection Types

Simplified

Exhaust air is taken from the return air trunk of the central furnace and the fresh air from the outside is supplied back into the same return air trunk after passing thorough the HRV.

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 Dedicated Exhaust/ Exhaust Ducted

Exhaust air is taken directly from ‘wet-rooms’ and fresh air is supplied back into the return trunk. 

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Fully Ducted

Exhaust air taken directly from ‘wet-rooms’ and fresh are is supplied directly to the living room, dinning room, bedrooms, etc. (no connection to the central furnace). 

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Bathrooms, kitchen and laundry exhausts are ducted to the HRV as “wet-rooms” if needed.

Applications

New buildings in Ontario with a forced air system when there are no wood burning appliances present. This is the least expensive connection type.

More advanced connection type. Suggested as the least expensive option when there is a wood burning appliance present.

The most advanced connection type. Usually used with non-forced air heating systems (ex. Radiant In-Floor Heating, Electric space Heating, etc.) or when a more advanced and expensive option is preferred over the exhaust Ducted one if there is a wood burning appliance present.