replacing AC

[trailer]

Our air conditioner unit is almost 20 years old now. It is a Trane unit and still works fine-SEER is 12.

The attic furnace, also a Trane, is natural gas and is about 13 years old. It still works OK.

We haven't had problems with any of the equipment since installation. I live in northern Texas-the summers can get pretty hot and humid.

I hear a lot of commercials recommending that I change out the old units with new, higher efficiency air conditioners and furnaces. Many of the commercials claim that the newer units will pay for themselves with savings in utility costs.

My house was built in 70s and I have added insulation in the attic. It has about 2200 sq ft living area. My highest electric bill this summer was $350 (electric only).

Is it worth replacing the AC and/or the furnace with new units? Depending on the costs, I would strongly consider upgrading the SEER.

Thanks.

[Ralph Mowery]

It is not worth it to replace the unit if it is working. It would take many years (like maybe 15 or 20 or more) to pay for it. a SEER of 12 is not really that bad if it is working and already installed. Even if you clould save $ 15 to $ 30 a month , it would be a very long payback and by then you would need a new unit.

I would just run what you have and if it breaks and costs more than say around $ 500 to repair, then replace it.

[Edwin Pawlowski]

Run the numbers. Since your house has additional insulation, it may be possible to get the same or more comfort with a smaller unit. You need to find a competent installer that can properly size (Manual J) the unit and figure operating cost comparisons. We don't know your climate or your electric rate so we can't decide for you.

OTOH, if it breaks it is probably not worth investing a lot of money in repairs. At least you'll be ready to make the right choice if it does.

[jmeehan]

I have to totally agree with Ed. I usually do. Any good installer will do the numbers (Manual J) and can give a an reasonable accurate answer. Local conditions mean a lot in this situation, so anyone outside the area is working at a disadvantage.

Good Luck.

[jmeehan]

On Sep 26, 6:07=A0pm, [e-mail] wrote: ..

I had to add one thing. If a contractor wants to give you an answer or do the work without doing the numbers, you should look for a different contractor. While an experienced contractor can usually hit close, the smart ones will do the numbers. If you had a standard home in a development with all the same homes and had not had additional insulation, then a local contractor who had recently worked on several homes in your area like yours might be able to give a good opinion without doing all the numbers.

[Jeff]

My take

Simple rough calculation. Assume $250 of the $350 is for AC. Compare your electric bill to April or October when you aren't doing much heating or cooling. Assume new system is SEER of 16.

Cost of new AC in worst month is $250*12/16 = $188, so you would save $62. So maybe about $200 to $250 over the year. You may wish to compare this to interest you could earn by putting the cost of replacing the AC in the bank. Something like 4% these days. This also assumes you are staying in your house for more than 10 years.

That being said with all the financial problems in this country there is going to be a lot of inflation. Both electric rates and the cost of a new AC will be rapidly increasing. So it probably is a good investment. This time of the year is probably a good time to shop around as folks aren't using their AC as much and installers/repairers are less busy.

[UDARRELL]

A 12-SEER is very efficient & a new higher SEER may not gain much in savings, if anything. A lot to be learned in respect to SEER & Return On Investment (ROT)! It is usually a better (ROT) investing on reducing the heat-gain of your home.

udarrell