This forum is very, very informative!!! My thanks to all the pros who participate.
Question to the pros--when doing a Manual J calculation, is it customary to round up or down when the final number of tons is calculated?
My HVAC contractor did a Manual J load calc on my home (two story colonial, about 3000 square feet--70 feet long x 20 wide, central new jersey, 23 year old home) and came up with a value of 4.2 tons, which then was rounded up to five tons. The rationale was that the two speed unit (Lennox XC21) would run at low speed most of the time anyway. Does this sound reasonable?
Thanks again all!