a heat recovery ventilation system exchanges fresh air from outside your property and uses the heat of the indoor air to heat the outside air as it comes in during winter, and during the summer it exchanges the heat the other way around.
benefits:
if you have internal thermal mass you need to allow cool air into the house & warm air out at night to remove the heat from the thermal mass. Without the HRV system, it relies on you opening & closing windows.
gives fresh air & removes humidity when you have the windows closed - like when you have heating/air-con on, or when you're out.
Sounds great in theory, but has anybody used it or looked into it, and can give an opinion on whether it's worthwhile?
Cost estimate $4000 to $8000.