DIYbanter - View Single Post

wrote:
I was assuming that in North Carolina they would not be using much
heat. Obviously if they are very old and have a poorly insulated house
that might not be the case.

In the mountains of North Carolina or in the foothills, the number of
days where the high temp is below 50F is a non trivial number. There
may be 30-90 days a year depending on exactly where they live in NC when
supplemental heat will be required. Down on the coastline, they still
get 15-30 days a year when high temps are below 50F, and supplemental
heat is needed.

Unlike my application (cooling dominated), they have a more balanced
need for cooling and heating. The recommendations they are getting are
PREMIUM solutions, ones that will have LONG term payback with great
short term payback.

The customer needs to carefully consider 80% efficient vs 90+% efficient
furnaces. The ACEE has a useful calculator on its web site to show how
much difference in energy costs will be saved between the exiting 60-70%
efficient system and a new 80-90-95% efficient furnance. Up in the
mountains, DEFINITELY go with a 90+% efficient furnace, down at the
cost, maybe not. In between, its a good idea to run the model then
assume something about gas prices over the next 10 years. In may indeed
make sense to go with a condensing furnace in almost every case in NC.