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
CY: The Trane give you obscure parts which are expensive to replace. And
often only available through Trane dealers. You can expect to pay more for
service, and have fewer companies who can provide service.
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)
CY: I'd go with the flue liner. Please don't share a chimney if possible.
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
CY: By the time the 90+ gasses are sent out, they are pretty cool. I'd
suggest to run the pipe horizontal, and go out a side wall if at all
possible. Pumping cold air uphill isn't very effective.
4) One installer recommended replacing the coil, while this guy said
to wait. Why would I replace the coil, is it recommended?
CY: new coil less likely to leak freon. Also more energy efficient. If you
can afford the coil, please do.
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
CY: Oversized furnace won't run as often, you'll get temperature swings.
Under sized, and your house will be cold during the coldest days of winter.
You might need a space heater or a couple burners on the stove to help keep
the house warm. I'd go with the smaller furnace.
Any feedback is appreciated.
CY: I tend to give more credence to people who speak politely, using polite
terms. I have less confidence in people who curse and swear.