Furnace replacement

[eugpenn]

I have a 1986 Marlette home 60x28 and the original furnace an Inertherm 70,000 BTU furnace, needs to be replaced.

It has always been a little on the small side for it's ability to heat the square footage of the home it seems, maybe because I have 3 skylights,doorwall and bay window,

I have heard that the next size up is a 90,000 BTU and the choices seem to be Coleman,Inertherm, Nordyne and Miller.

I am thinking about the 80+ efficiency unit,not sure about the different stages, eventually I will probably add central air.

Any advice will be very much appreciated
Thanks!

[trmimo]

Intertherm, Nordyne and Miller are all the same furnace. Nordyne is the company that makes Miller and Intertherm. Today they are the same furnace sold under 2 different brands. My experience has been that the Coleman furnaces are more reliable, although repairs can be more expensive if needed.

[eugpenn]

Thanks for your help!