Two questions for the experts:
1. How can I measure the size of a flex duct? My house has two flex supply runs that have no indication of size. The branch lines clearly state its size but the supply runs do not. I'm trying to determine if my current ductwork is sized properly for my 3 tons of cooling.
2. I spoke with an HVAC contractor yesterday about potentially replacing my flex supply ducts with metal ducts. He mentioned that a round metal trunk would move air better than a rectangular metal trunk. What do you guys think? Any certain one you prefer?