Cool Calc, a US home-heating calculator, is gaining about 150 new users a day; just over a third are homeowners rather than professionals, according to CEO Bill Fiore.
Its room-by-room heat-loss estimates help size heat pumps.
An unpublished study examined calculations for about 75 US homeowners.
Kevin Kircher says professionals’ calculations often overstated heating needs by at least 2×.
A wrong estimate can leave a home…