80% are hardly known for "sucking every BTU".

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"RoyJ" wrote in message
m...
Echoing what Robert Nichols said:

I'm in the midst of optimizing a brand new, Bryant 80%
forced air, 2
stage, 110k Btu furnace. It sucks every BTU out of things
when running
in the low fire mode. On high fire it is just trying to get
you
comfortable enough to let it get back to the economy mode. I
doubt that
the difference is more than a few percent but I suspect it
is
measurable. If nothing else, the high fire mode requires the
high speed
fan and attendant increase in electrical use.