OK,

Now as we started to talk about BTU... My current furnace takes about an
hour to raise 1 degree in the house. So it is really to small. I checked,
and I have 120,000BTU input furnace at 60% eficiency. that makes about
72000BTU out. Strangly, on the furnace it says max BTU out is 91800. So
maybe eficiency of my furnace is higher?
So now if I will get 100,000BTU in furnace at 94% eficiency, that means I
will have about 94000BTU out. That is much better, but I am not sure if it
is enough.
So, anyone know how much price different would be between 100,000 BTU
furnace and 120,000 BTU furnace?
Also, if I want to change variable fan speed from my thermostat - do I have
to request installers to add extra wire from furnace to thermostat or all
wiring is same as for old furnace?

Thanks,

"m Ransley" wrote in message
...
How well does your 120000 heat at the coldest point in winter and how is
its recovery if you set it back. Remember your old furnace may be 50-80
% efficient so a new 94.5% efficient 100000 btu furnace may put out
allot more heat than your 120000 of 80 %. I dought your old is 80 %
but if it is thats 96000 btu output. A new 100000 94.5% is outputting
94500 btu. Your old unit is probbly much less than 80 % in output
efficiency so you are lilely fine.