To keep as much heat trapped as possible indoors and prevent cold drafts in winter, a house must have extensive insulation and air sealing. This may help with comfort and energy efficiency, but it also leads to a build-up of indoor contaminants and air that can be too humid or sometimes too dry.
What can you do about this? Open up the doors and windows for some fresh air? No, that just ruins the whole point of having a home insulated in the first place. All the energy used for the heating system simply goes to waste.
But what if you could recover that energy and use it to heat up fresh air coming from the outside? That’s just what an energy recovery ventilator (ERV) does, and it’s a great solution to unpleasant indoor air during winter.