Axiom Home Page Forums General Discussion The Water Cooler Furnaces: High Efficiency vs......

I'm on my second super-duper-high-efficiency furnace. My impression is that you are better off spending the extra $$ on insulation and drapes, unless you want the super-quiet super-electricity-efficient servo fan that some of them come with.

My first was a Lennox which was too expensive but worked really well (even though I ended up getting one size larger than I needed, my fault, long story), the second was a (Bryant ? something starting with B) which has worked well but which seems to have a less efficient & louder fan.

My recollection is that there are basically 3 levels - 80% efficiency, ~90% efficiency, and ~95% efficiency. If that's still the case, the 90%'ers seemed like a good deal if your furnace runs a lot during winter, but I wouldn't bother with the 95%'er (despite buying 2 of them ;)).

If your winters are moderate then it's hard to justify spending a lot more money on efficiency. You're going to save maybe 12% of your annual heating bill going from an 80 to a 90, so saving 600/yr implies that your heating bill is 5000/yr (which sounds high to say the least).

One other obvious point -- smaller furnaces running longer tend to make for more comfortable houses and lower fuel bills. If you size the furnace to keep your house toasty on the "coldest day in 5 years" that's probably bigger than you need... next time I would go with something sized to "keep the house comfortable on the colder days running most of the time" and put on a sweater or light a fire on the occasional freeze-ups. I guess having the furnace burning relatively more of the time would translate into a shorter heat-exchanger life but I've never actually heard that discussed.