3 ms·

One thing I'm curious about is how the CO2 levels in these "passive houses" look. If there's limited indoor to outdoor air exchange, wouldn't they build up? Is

• voisin 2y ago
  I answered elsewhere: They have heat recovery ventilation systems which bring in fresh air and send out stale air, capturing the heat in the process
  • anon7000 2y ago
    Yep. These make the air quality a lot better as well, since you have control over most incoming air.