> Ideal indoor air quality is equal to outdoor air quality. Ideal indoor air quality is (can be) better than outdoor air quality. This is because when the outs

> Ideal indoor air quality is equal to outdoor air quality. Ideal indoor air quality is (can be) better than outdoor air quality. This is because when the outside air is brought in it passes through filters to get rid of things like dust and pollen. > The air must be heated and costs some unit of energy to accomplish. Unless you use passive solar thermal, i.e., let the sun heat the home: * https://www.energy.gov/energysaver/passive-solar-home-design https://www.energy.gov/energysaver/passive-solar-home-design