A modern air-tight home needs mechanical fresh air ventilation to keep its occupants healthy. If you live in a climate like we do in Culver City, California, then you don’t really need an ERV or HRV system since it is almost perfectly 75 and sunny everyday. To keep it simple, we like the Panasonic WhisperFresh Select Fresh Air supply fan. It’s about $500 plus install and comes with built-in Merv 13 filter and controls for 50-150 CFM, temperature and humidity. So, on those occasional times when it’s hot or it rains, it will turn off automatically. This system is also on all the time unless one of the custom controls turns it off, but draws a max of 0.41 Amps when it’s on at 150 CFM.