HRV vs ERV comes down to moisture. Both bring in fresh outdoor air and recover heat from the stale air going out. An HRV (heat recovery ventilator) moves heat only. An ERV (energy recovery ventilator) moves heat and some moisture too. In Greater Victoria's damp, mild winters, the usual problem is too much indoor humidity, not too little, so an HRV is the default choice for most homes. An ERV earns its place in a few specific situations, covered below.
What is the difference between an HRV and an ERV?
Natural Resources Canada defines an HRV as a packaged unit that transfers heat between two separate airstreams, and an ERV as an HRV designed to transfer both heat and moisture. Neither mixes the two airstreams. Both run continuously at low speed and boost when you shower or cook.
| HRV | ERV | |
|---|---|---|
| Recovers heat | Yes | Yes |
| Transfers moisture | No, moist indoor air is exhausted | Yes, returns part of the moisture to the incoming air |
| Winter effect indoors | Dries the house | Keeps more humidity in |
| Summer with air conditioning | Recovers some coolness | Also removes some humidity from incoming air |
| Core and drain | Condensation forms in the core; needs a drain | Condensation is less common; some units have no drain |
| Frost protection | Needed in cold climates | Core freezes at a lower temperature than an HRV's |
| Best fit in Victoria | Most homes, especially busy or damp ones | Homes that feel too dry in winter, or air-conditioned homes in humid stretches |
HRV or ERV for a Victoria home?
The BC Housing Heat Recovery Ventilation Guide for Houses, developed with BC Hydro, NRCan and CMHC funding, lists the factors that decide it:
- Moisture control. Where moisture control is the bigger concern, an HRV is often the better choice. Houses with a lot of moisture generation, such as densely occupied homes, may benefit more from an HRV because it does not hand moisture back to the supply air.
- Dry winters. An ERV returns moisture to the supply air, which helps comfort in climates with very dry winters. Victoria's winters are wet, so this rarely applies, but a lightly occupied, very airtight home can still feel dry.
- Hot, humid summers with air conditioning. An ERV in an air-conditioned house removes some humidity from incoming air and pre-cools it. Because a heat pump also cools, this is the main case for an ERV with a heat pump in Victoria. The guide notes the energy difference between HRV and ERV is minor in Canada's heating-dominant climate.
- Frost. An ERV core freezes at a lower temperature, which matters in cold interior climates. The guide says frost prevention is needed in most of Canada except BC's Lower Mainland (Climate Zone 4); Victoria's coastal climate is similarly mild, so frost is rarely the deciding factor here.
Do new homes in Victoria need an HRV?
The BC Building Code requires a mechanical ventilation system in every new house. Section 9.32 calls for a principal ventilation system that exhausts air from bathrooms and the kitchen and supplies fresh air to bedrooms and living areas, with one fan running continuously at a minimum rate. The code does not force that system to be an HRV, but in an airtight house an HRV or ERV is the practical way to meet it without throwing away heat.
Airtightness is the link. Newer homes built to the BC Energy Step Code are tested for air leakage, and the tighter the house, the less fresh air leaks in on its own. The BC Housing guide recommends a continuously operating HRV or ERV for coastal homes tested below 3 air changes per hour at 50 Pa, and for coastal homes between 3 and 5 as well. Homes leakier than that can use simpler central-fan strategies. If you are building, the HRV design should be settled at the same time as the heat pump sizing; see our guide to heat pumps for Westshore new builds.
Adding an HRV to an existing home with a heat pump
Retrofits work, but layout matters.
- Ducted heat pump or furnace: the HRV can supply fresh air through the existing duct system, with dedicated exhaust from bathrooms and the kitchen. The guide notes the furnace or air handler fan should then run continuously.
- Ductless heat pump: a fully ducted HRV needs its own small duct runs. Single-room or wall-mounted units can serve one or two spaces where running ducts is hard.
- Air sealing first: an HRV is only effective in a reasonably tight house. In a leaky house, more air bypasses the HRV through gaps.
Read our ducted vs ductless heat pump guide if you are choosing a heat pump at the same time.
Is there a rebate for an HRV or ERV in BC?
Only through the income-qualified CleanBC Energy Savings Program, which lists a ventilation rebate of up to $1,600 at Levels 1 and 2. Conditions from the program requirements:
- The HRV or ERV must be ENERGY STAR certified (qualifying bathroom fan systems are also covered).
- It must be installed together with an Energy Savings Program rebate-eligible heat pump, heat pump water heater, insulation, or windows and doors upgrade.
- The home must be ground-oriented: a detached house, a secondary suite in one, a mobile home, or a duplex, triplex, row home or side-by-side townhome. Condos are excluded.
- You must pre-register for the program before installing.
Our Energy Savings Program guide has the income limits, and the heat pump rebate checker shows which heat pump rebate the HRV can be paired with.
HRV and ERV maintenance schedule
An HRV that is never cleaned moves less air and recovers less heat. The BC Housing guide's example checklist:
| Task | How often |
|---|---|
| Clean and check the outdoor intake hood (leaves, nests) | Every 3 months |
| Check the outdoor exhaust hood | Every 3 months |
| Clean or replace the internal filters | Every 3 months |
| Inspect the drain tube (HRV) | Every 3 months |
| Clean the fan blades | Every 6 months |
| Clean the drain pan | Every 6 to 12 months |
| Clean supply and exhaust grilles | Every 12 months |
CMHC's own homeowner guidance is stricter on filters, at every two months, and suggests pouring about 2 litres of warm water into the drain pan to check it drains. Keep indoor relative humidity in the 30% to 60% range the guide gives; if windows fog in winter, run the unit higher rather than turning it off. Pair this with our heat pump maintenance checklist so both systems get looked at on the same visit.
Planning a heat pump and want ventilation designed in? Ask for a quote or see our services.