Four inch? Huh? i've seen two inch and three inch....

But it does need a drain.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"MLD" wrote in message
...
The 90+% efficient furnaces are condensing units as noted in another post.
Which means a pump and a way to get rid of the resulting water. However,
another big difference is that the 90+% combustion air comes from the
outside and then is subsequently discharged to the outside, both through 4
in. PVC piping. Built into the cost savings is the cost of using air
that you have already paid to heat (from within the house) for combustion
purposes (80% unit)? More uneven heat, more drafts as the air being sent up
the chimney has to be replaced by outside air. You could do the arithmetic
relative to the cost and considering the escalating cost of gas your payback
time frame may be shorter than you think. Check into your Utility company,
they often offer significant rebates for the more efficient furnaces with
the variable speed motors. I got a $450 rebate which was almost half the
cost difference between the two furnaces--and then I would estimate that I
saved approx $150 this winter in gas costs.
MLD
"Halvey" wrote in message
...
Hi. Getting bids for a new gas furnace in the house (don't need AC).
We got a couple bids, and they all gave them for the 80% efficient
furnaces, not the 90%+ efficient ones. They said that we wouldn't
recoup the cost of the more efficient one through utility savings over
the lifetime of the unit, and that the 80% efficient one has very few
moving parts, and thus has less need for repair and maintenance, whereas
the high efficiency ones (some claim 97%) are far more complicated, and
thus more susceptible to breakages/misalignments/etc. Furnace brands
were Bryant and Trane.

Can anybody speak to any of these issues, or share about their decision
in a similar situation? Also, the local gas company offers a $200
rebate and a $350 tax credit to get a 90% efficient unit.

Thanks,
h