First, thanks to the professionals for their advice about hydronic heating. Unfortunately, it just didn't fit the budget.
So back to forced air. I haven't met with the HVAC contractor yet; how important is it to insist on air returns both "high" and "low" on the walls to accomodate either heat or AC? I've heard that doing both, and shutting one level off depending on the season, helps to heat or cool.
Second, are a lot of you installing air-to-air heat exchangers in new homes? Are they as good as they claim at bringing fresh air into a home in the winter...and summer... without wasting energy?
For reference, I live in SE Wisconsin. Cold winters (except this year!) and warm-to-hot summer, often humid.