Jim Redelfs wrote:
Imagine all the added elbow room if the adjoining water heater was
GONE during a furnace retrofit. Well, that's what I'm going to be
doing (See Downsize Water Heater
) in a little
less than two weeks.

My contractor wants to DOWNSIZE to 75k from the 100k size of my
14-year-old, conventional (spec) gas furnace. Of course, this will
be done with a "90" (or better) model. He claims that the improved
efficiency of the new furnace will compensate for the difference. Do
you agree?

No one here can agree or disagree without doing measurements and
calculations for heat loss. You did not say how your contractor determined
you should downsize.

My guess is he is right, and did the calculations but I don't know.



He also mentioned, after taking measurements TWICE, that I need an
18-inch-frame unit and that a bigger unit would require a reducing
"boot", which he represents as a compromise. What's with that?

Then there's the PVC vent(s) outside. He claims that it is legit to
use only ONE - an exhaust line - that the furnace uses INTERIOR air
for combustion. He represents this as a DESIRABLE way to EXCHANGE
interior air with fresh.

While I would tend to put in a intake for outside air, with a higher
efficiency unit, your home is old enough (at least 14 years) to be loose
enough not to "need" it's own inlet.


I am old enough that this furnace may well be part a big part of the
resale value of our home. He wants to install a "Weathermaker"
furnace and a Rheem ac condensing unit outside. He says that the
Weathermaker FURNACE is virtually the same unit as a Rheem so this
would be an up-front cost-saving issue ONLY, assuming he's right.
What about resale then?

He further says that the condensing units are different and therefore,
recommends a Rheem unit outside.

--
Joseph Meehan

Dia duit