In article m,
Justintime wrote:

Been doing some research and could use the help of the experts on a
couple of things. I had 5 HVAC companies come to my house for
estimates on replacing my 50 year old 90,000 btu furnace for my 1500
sq. ft. ranch in N.W. OH. The estimates where similar in terms of
cost for most, so I am going with the installer that I trust the most
and received good feedback on from references ( BTW - none of the
installers did a manual J calc, most where just concerned with how to
get the exhaust out). My questions for the group are these.
1) Do I go with a Trane or Armstrong, both are the 90 plus percent
efficient, but the Trane cost an extra $425. What does an extra 425
get me?
2) The contractor I am going with recommended a flue liner for $210
for the hot water heater exhaust. Is that necessary/recommended,
would it be better to skip the liner and route the water heater
exhaust throught the same PVC that is being run out the roof for the
furnace ( the furnace and water heater are next to one another)
3) Is it ok to run the PVC exhaust through an unheated garage to the
roof. It will be hugging the wall, but do I need to insulate the
pipe?
4) One installer recommended replacing the coil, while this guy said
to wait. Why would I replace the coil, is it recommended?
5) As far as sizing, all the contractors quoted something different.
The guy I trust the most said 60,000 btu but I had others that
recommended 90,000. What are the implications of undersizing/
oversizing. Is a manual J calc absolutely necessary or is a trained
eye who is familiar with the neighborhood construction able to tell
from experience.
Any feedback is appreciated.

You've had five experts come to your house. Now you want a bunch of
newsgroup junkies to tell you whether to trust them? Go with the guy you
trust the most, and trust him.

However, if you insist, I'm sure Monkey Boi and Putz will clarify things
for you.