Indeed, John, there is more than meets the eye in considering HVAC systems in a house. "Superinsulation" (almost akin to R2000 here in Canada) has proven to be a serious problem when the home owner doesn't know how to recognize problems inherent with such designs which MAY occur. I fought against the widespread use of much of the new "technology". The REAL problems on many of these houses built in the 80s and 90s were only recognized after the five year warranty (a program to boost sales) on such homes was over... rotting sill plates and worse. There IS such a thing as TOO energy efficient and it cannot be cured with a heat/air exchanger.

Simply, a house has to be able to breathe so the occupants can also breathe. It's a fine balance and the industry and government here went WAY too far one way.