We need to replace our central air conditioner. What is the greenest way to go?

— Alice Martinez Hollywood, FL

Answered by Andrew Michler on September 29, 2010

Is fiberglass insulation or blown in insulation the best?

— Susan Franklin, TN

Answered by Randy Potter on July 1, 2010

Is three inches of batt insulation enough for my attic?

— Martin Bennett Bowie, MD

Answered by Steve Saunders on July 1, 2010