Questions about replacing furnace/AC

**grammyr** · 06-09-2005, 04:33 PM

We are looking to replace a 30-yr. old gas furnace and 17-yr. old A/C. We live in a split foyer type of house with app. 2000 sq. ft. So far we have had several estimates and are getting more and more confused. One company feels that the minimum BTUs for the furnace should be 100,000. Another gave us an estimate for 125,000. I had another guy come today who said we probably wouldn't need even 100,000 because the house was a split foyer. Of course, they are hard to heat and cool regardless of the unit. We have also been told conflicting opinions as to Seer and efficiency ratings. One told us that we needed a minimum 90% and 12 Seer A/C. The other told us that we would be fine with the 80% and 12 Seer. The recommended A/C unit is 3 ton. I don't know what we have at the present. One contractor did give us a price for the VS which is almost 2,000 more than the one speed 90%. I'm not sure that either of the two did a load calculation. The guy who came out today had pictures of the house and said that it would take at least a day to get an estimate. He seemed to be more knowledgeable in many ways and took more time to look at everything.
Can anyone give me any advice as to the efficiency ratings? We live in NC, thus have moderately cold winters and very hot, humid summers. I was also reading about the R-22 etc. so that is something I need to inquire about before purchasing.

**alben** · 06-09-2005, 07:13 PM

3 Tons will only cool 1200 sq. ft. And you be better off with the 90% because you will not have to be charge for a make up air, you do not need it if 90% efficincy. How many BTUH? Hope somebody can make a good recomendation.

**alben** · 06-09-2005, 07:17 PM

By the way you need 400 sq. ft per ton of cooling. So 5 Tons could be a possibility or you could go 5 1/2. Like you said your home may take longer to cool or heat. Hope is will insulated.

**beenthere** · 06-09-2005, 07:22 PM

Request a manual J be done.

That way you know for sure what size equipment you need.

As to seer, I think 12 seer or better would be good for NC.

How warm do you like to keep your house in the winter, the warmer you keep it, the more you should consider a 90+ furnace.

BUT, before you replace your system, you should look to improving your insulation, doors, and windows.

They may be already upgraded, if you only need 3 tons, or you may be able to improve alittle more and go with 2.5, and a 80,000 btu furnace.

The size of a/c, or furnace you need is not based on sf of house.

**dandyme** · 06-09-2005, 07:27 PM

Originally posted by alben
By the way you need 400 sq. ft per ton of cooling.

WHAT kind of CRAP is that!!!!!!!!!!!
I could cool a horse barn with that theory.

like beenthere said .......load calculation and go from there.

piedmont or mountains????????

had any rain this week?

**grammyr** · 06-09-2005, 08:55 PM

We live in central NC. We tend to keep the house rather cool in the winter. 68 in the daytime and 62 at night. But that's because we live mostly upstairs and it's warmer upstairs. That would probably not work if we stayed downstairs much. In the summer, the house never gets very cool upstairs. It also faces the south. I think we have adequate insulation, but I'm sure the windows aren't probably the best. We just can't afford to do all of this at one time. I think the guy that came out today is doing the load calculation. So far, no one else has. I have someone else coming tomorrow so I'll see what goes with him. It's just so much to learn and comprehend and we want to make the best decision. I might add that we might not stay here but about 10 more years. If and when we get to retire, we may leave this area. Should that be taken into consideration in the purchase?

**beenthere** · 06-09-2005, 09:59 PM

You should think about that while your deciding, but remmember, 10 years is along time when it comes to paying the utilities.

**klyons20** · 06-10-2005, 01:24 AM

He ment 400 cfm per ton.. Both guys sound about right..
100,000 afue with 3 tons of cooling..

regards,
Kelivn

**Irascible** · 06-10-2005, 02:00 AM

Ease off on Alben guys. I thought his shtick was hilarious. He's obviously practicing his stand up routine.

**alben** · 06-10-2005, 04:12 PM

Just to let you all know I type with one arm because that is all I have, I am amputee from my left arm, and if I make a typing error is nothing compared to some people with two. I am not an A/C expert, but I done work here and there and continue educating in this field. Like this guy said I mean 400 cfm per ton.
God Bless America.

**alben** · 06-10-2005, 04:13 PM

Just to let you all know I type with one arm because that is all I have, I am amputee from my left arm, and if I make a typing error is nothing compared to some people with two. I am not an A/C expert, but I done work here and there and continue educating in this field. Like this guy said I mean 400 cfm per ton.
God Bless America.

**grammyr** · 06-10-2005, 09:27 PM

So far I have gotten 3 estimates. One suggested a furnace with 100,000 BTU, 90%. Another 120,000 80%, another 80,000 80%. Boy am I getting confused! I don't know who to trust. That seems to be quite a variation. Also one of the estimates included a TX Valve and none of the others mentioned it. Can someone let me know what that is.

**grammyr** · 06-10-2005, 09:30 PM

I forgot to ask about something else. Would you suggest getting R-22 or the newer Puron? It will cost $175 more for the Puron. I know that eventually R-22 is supposed to be phased out.

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