80 vs 95 percent new gas furnace

theoldhouseguy

Hi,



New Jersey

balloon frame house - no insulation in walls

large ducts in walls

converting from oil to gas

usually keep heat 65 day, 55 at night and close off some non used rooms

apx 1500 sq ft, 2 floors



Converting from oil to gas and confused about what % efficiency furnace to get. Furnace guy recommends Rheem 80 2 stage, ECM. Less repairs than 95%.



With 95, I need a chimney liner for my water heater which is an additional expense. Don't know how much yet.



Rebates end 12/31 supposedly. Not sure if worth the extra money. From what I hear only the 95% will be sold after May. Is the 80% cheaper because they need to get rid of them? Is it better to wait till May and maybe the 95% will cost less or will the problems be ironed out if I wait?



Don't want to spend more than I need but don't want to be left behind with a furnace that is not up to date. Advise appreciated - thanks.

John Mills_5

Well...

Drafty old house, I'd sure want the most efficient furnace I could get. The 95% furnaces are normally just the manufacturer's 80% furnace with a condensing heat exchanger and a drain system. They would have a plastic inducer not metal but otherwise, usually same board, ignitor, gas valve. They should be no more unreliable than a comparable 80% assuming proper installation and MAINTENANCE!!! Forced air furnaces are not like boilers where the 90+ models are very complex compared to the 80s.

With an 80% furnace, you would want a chimney liner for the furnace & water heater to avoid condensation. With a 95% furnace, the orphaned water heater would need a small liner to help it vent and also prevent condensation.

In the northern states, after May 1, 2013 it will be illegal to install an 80 but much of the country will still have them so the price of an 80 won't change.

Seems to me get that 95% in now and start saving.

drhvac

If you plan on

living in the house for awhile I would go for the 95% efficient furnace. If the 95 is installed properly, it will be just as reliable as the 80. Installation mistakes usually is the problem with 95's when there is a problem. I'm a contractor from freehold NJ. What part you from?

theoldhouseguy

80 vs 95 percent new gas furnace

Hi - I'm in the borough. Not sure how long I will be there. A big problem is that the rebates will expire before I can get the work done.