School me on central air

[UTpowder]

Flipped on the central air the other day and the compressor didn't come on. Replaced fuses etc. and its still dead. Had the local HVAC guy out today and he says the capacitor is bad and so is the fan motor. Looking like about $500 to get it fixed. We have been in the house for 16 years and put in the AC right after we moved in. The house is about 20 years old now and has the original furnace. The HVAC guy says they start to see compressor problems at around the 15 year mark. They do not replace compressors and said we would need a new unit if it went out. One thing that we have noticed is that our current system has a very difficult time keeping up through out most of the summer. Is runs non stop from 10:00 am until 11:00 pm. Both the furnace and AC are Carrier brand. We haven't been extremely happy with either one. Lots of small problems that have been a pain to get fixed. A new AC unit similar to what we have was quoted at around $2300. Wondering about replacing furnace and AC. Have a couple questions. Has there been enough improvements in efficiency over the last 20 years to justify replacing the furnace? Its seems to be working just fine now. The AC seems to be over worked with it running all the time. We were told with our furnace this is the largest AC unit they can use. Its a 2 ton unit for a 1200 sq ft house with not a lot of natural shade. Looking for advice about replacing just the AC or doing both AC and furnace. Should we go with a bigger AC unit? If we do replace what brands should we be looking at? We want something reliable and efficient. If we replaced I would probably not stay with Carrier. Any help would be great since I know very little about HVAC. Thanks

[huckbucket]

Flipped on the central air the other day and the compressor didn't come on. Replaced fuses etc. and its still dead. Had the local HVAC guy out today and he says the capacitor is bad and so is the fan motor. Looking like about $500 to get it fixed. We have been in the house for 16 years and put in the AC right after we moved in. The house is about 20 years old now and has the original furnace. The HVAC guy says they start to see compressor problems at around the 15 year mark. They do not replace compressors and said we would need a new unit if it went out. One thing that we have noticed is that our current system has a very difficult time keeping up through out most of the summer. Is runs non stop from 10:00 am until 11:00 pm. Both the furnace and AC are Carrier brand. We haven't been extremely happy with either one. Lots of small problems that have been a pain to get fixed. A new AC unit similar to what we have was quoted at around $2300. Wondering about replacing furnace and AC. Have a couple questions. Has there been enough improvements in efficiency over the last 20 years to justify replacing the furnace? Its seems to be working just fine now. The AC seems to be over worked with it running all the time. We were told with our furnace this is the largest AC unit they can use. Its a 2 ton unit for a 1200 sq ft house with not a lot of natural shade. Looking for advice about replacing just the AC or doing both AC and furnace. Should we go with a bigger AC unit? If we do replace what brands should we be looking at? We want something reliable and efficient. If we replaced I would probably not stay with Carrier. Any help would be great since I know very little about HVAC. Thanks

I can't answer all of your questions, but CAN tell you that a replacement capacitor is ~$30-40 depending and a fan is ~$50 bucks. Could buy you some time. Labor on that isn't $400 but the electrical can be a little tricky. Maybe find an independent to do the install? When my AC crapped out last summer, I went through a cap and a fan only to discover that it was a fried circuit board that prevents fast cycling ON/OFF. Circuit board was $12.

[Captain Awesome]

This may or may not be relevant, but I had a similar problem a few years back: http://www.tetongravity.com/forums/s...pacitor-on-A-C

I replaced the part for about $20. If your fan motor is gone, that's a different matter, but once I got the cap replaced, things were ready to go.

Obviously, it doesn't deal with the bigger issue of the unit being potentially undersized or overworked, but it might be a cheap way to buy time to sort that out.

[El Chupacabra]

As an aside on your A/C issues --

If the unit runs non-stop all day long to try to cool your house, have you looked into other ways of making the house more energy efficient? e.g., more insulation, solar screens on windows exposed to direct sunlight for most of the day, close your blinds/curtains/whatever during the daytime... can you plant a fast-growing leafy tree and generate some shade?

From your user name, if you're in UT, a swamp cooler would work in that climate -- and be a lot cheaper to run than A/C.

[uglymoney]

I have a two ton Bryant A/C Seer 13 (made by Carrier) on a 1360 sq feet house with a 1360 sq foot full basement. It only runs half the time on the hottest days of the year. It is ten years old and has never given us a problem.

Attic insulation is @ R-60.

[Pow4Brains]

Yes, they have made significant energy improvements in the last 20 years. Most notably by the use of scroll compressors. Additionally, the condensing unit prolly has R-22 in it which will become quite expensive in the near future (it’s on the EPA phase out list and will sky rocket in price once they stop making it).

IMO if you’re going to do one, do the other. They have also made improvements in the heating sections in regards to efficiency, some of which can be as high as 98% if you’re willing to spend the money up front. Your existing is mostly likely 70% on a good day and has no means of modulation of the burner. I.e ON/OFF

The size of your condensing unit seems about right for the size of house, going any larger may cause short cycling and reduce the life of the compressor. I would recommend installing or closing your blinds during the day, and as others recommended, check your insulation and ensure you have proper roof ventilation.

Hope that helps.

[Garth Bimble]

I can't speak to the A/C issue but we put in a high-efficiency furnace 3 years ago and our therm usage has dropped by about 40%. Unfortunately for us this doesn't mean big $$$ but everything helps. My old furnace was almost 30 years old so I needed to replace it anyway. IIRC the new furnace with a new central a/c unit (we replaced both, although we rarely use the a/c) cost around $6000 but after all the tax credit/rebates we got from the fed, state, and utility company it was closer to $3500.

If you can afford it you should replace both at the same time...cheaper that way.

[splat]

Call your utility for an energy audit. Should be a free service they provide. Get that guy's opinion. He should know the latest greatest on energy consumption, can run a current use/cost analysis against projected use/costs of a new setup, clue you in on rebates and no cost financing (some companies will make the payments the same as the savings offset) and that utility person will generally be your third party advocate and storehouse of pertinent knowledge.

[schwerty]

Call your utility for an energy audit. Should be a free service they provide. Get that guy's opinion. He should know the latest greatest on energy consumption, can run a current use/cost analysis against projected use/costs of a new setup, clue you in on rebates and no cost financing (some companies will make the payments the same as the savings offset) and that utility person will generally be your third party advocate and storehouse of pertinent knowledge.

This is sound advice!

Outside of about 10 days a summer there is no real need for AC where I live but we sure as hell use heat in the winter. I've consulted our local utility co and had excellent results. Can't hurt. You probably get a slight discount on your bill just for have a guy do the audit.

[UTpowder]

Thanks for all the help. I called a local independent HVAC guy that had done some work for me at my office. He looked things over and said he could replace the capacitor and fan motor, recharge the AC and give the furnace a good cleaning and inspection for $225. We'll take the money saved from not getting a new furnace and AC and use it towards making the house more efficient. I checked the attic and found 7 inched of blown in cellulose. From what I can tell that only gives me an R value of 22-26. Sounds like that is not nearly enough??? We will get an energy audit done and see what they recommend. Personally I'm fine without the AC but the wife has some lung problems and needs to regulate temp closely.

[TWINS]

Good choice^ We upgraded 3 years ago to a 2 stage fau and 15 sear compressor.
Did not save a whole bunch of money on electricity though.
Would have been better off with insulating/sealing the house.Do that first and you might not have to upgrade your unit.