A colleague of ours (we'll call him Bill) once asked our
advice on choosing an air conditioner for his newly
renovated home. One of our recommendations was "Be sure
that the cooling load is calculated and that the air
conditioner is sized for that load."
That advice proved easier to give than to follow. Only one
of the four hvac contractors Bill talked to would submit a sizing
calculation (two others just wanted to know the home's
square footage). So Bill hired the contractor who did the calculation,
and installed a high-efficiency four-ton unit. The
local utility gave Bill a rebate for buying efficient equipment.
Unfortunately, this is not really a