a/c failed, time to upgrade furnace too?
I've got a 1997 carrier weathermaker 58TUA speed / 2 stage furnace and a
2.5 TXA030 a/c unit. Compressor failed on condensor.
So.. had couple of companies out already.
Plenum above furnace where a/c coil is is 16"
Return air duct on side of furnace seems undersized for all
the return air going into it.
I understand that a/c and furnace dont need to be replaced together.
I dont need more than 14 SEER given that I use it about 1/4 time in
summer. So no need to replace both to get higher SEER for a/c.
Would you replace the furnace and a/c now? I'm considering buying
the manual J program Hvac-calc and running some figures as I
may build out a room. Contractors have little interest in doing it,
I think I can input all the data at least (I'm an engineer).
Replace furnace and a/c together now? Any ideas on life left in the
furnace, motor has been already replaced.
Thanks for any advice
How much are your summer electric bills?
Low in the summer $150 july/aug
I would replace the furnace with a 95% efficienct furnace
I'd also replace the furnace. At 15 years old there's not a lot of time left before you're dealing with a very expensive repair or two.
Having a load calculation done may not be a bad idea. At $150 ($100 for cooling only I'm guessing, $50 for "base load"), you may be closer to 2 tons than 2.5 tons, especially in yoru climate and with the hotter weather. If it's been maintining 75F in the late afternoon when it's be in the mid 90's and above, it's definitely not undersized.
Originally Posted by restar
For example, I'm right at 3.5-4 tons and and am projecting a $240 bill so about $190 for cooling with an average of about 14 SEER between both systems. But obvisouly every home is a little different.
You might as well replace the furnace and go vairable speed, 2 stage and 95%+. You'll spend 3/4 of the labor just to change the coil, you might as well swap out the furnace then, otherwise you have to remove the coil all over again when you do change your furnace.
THe load calculation should verify your furnace size too. You don't oversize just because it's 2 stage. In northern Iowa I think design temperature is around -2 to -5F so at those temps and lower it should be running almost continously in high stage and almost continously in low stagebelow about 10F.
Last edited by motoguy128; 07-23-2012 at 08:55 AM.