We are going to have our existing ducts sealed by contractor at same time as he installs new heat pump system. Ducts are in attic. Single return grille and 10 supply registers are in ceiling and walls.
If I had a way of measuring face velocity at each register and at return grille, would that give me an idea of how much leakage I have on existing system?
This would be a one time check, so I would need to use something like a low cost anemometer. Would that be accurate enough? Any suggestions for type?