Aug 26, 2016 · See part 2 of this article: More on Air Conditioner Sizing Rules of Thumb The duct system for my home (now rented out) was originally designed for a 5-ton condenser, but ended up with a 4-ton (long story). When I bought the home I replaced with a 3-ton system and it worked just fine, hooked to that huge duct system.
Designing Heat Pump duct systems with correct velocity and low restriction AHU Supply & Return connection - properly sized; minimize the System Effect, assure Static Regain and allow even airflow thru coils – Size the 1st supply fitting or duct to the dimensions of the blower outlet, not to the extents of the AHU or fan/coil cabinet.
DUCTWORK MYTH BUSTER. Before using your old Rule-of Thumb for sizing ducts, it might be good for you to read what Paul Wiebolt of Tradewinds Appropriate Technologies has to say about the subject. It's often said that to do something right, you have to get back to the basics. Sometimes, the basics involve putting aside what you think to be true.
How to size the supply duct rule Of thumb? How many square feet per 6" or 8" round duct? My house's kitchen and living - Answered by a verified HVAC Technician.