Author Topic: Advice on Buying New Central A/C  (Read 2200 times)

FastStache

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Advice on Buying New Central A/C
« on: June 27, 2013, 10:32:39 PM »
Well, my A/C unit has been giving me issues ever since I got the house.

Tonight, when I get home the a/c is not tracking with the set temp, so I go and check out the air handler and I saw ice on the cooper lines outside the unit, and a ton of ice on the coils once I took the cover off.

Also, my drain line was clogged. After fixing both of these issues, I can tell my ac is not cooling as well as it should.

I will be considering buying a new unit for the first floor of my house which is about 2000 sq ft.

Does anyone have any advice? Any tax breaks I can get? How to negotiate a good price on an efficient unit?

Forcus

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Re: Advice on Buying New Central A/C
« Reply #1 on: June 28, 2013, 10:44:21 AM »
Couple things. A/C units are pretty simple in componentry so make sure it is working right before thinking about installing a new one.

Ice on the lines isn't hurting the unit but can be a sign of high humidity inside your house, which makes it feel warmer, and also makes it a little harder for your A/C to work.

Ice on the coils basically negates much of the work the A/C is trying to accomplish. Again, a sign of high humidity. You may need to shut the A/C off long enough to melt the ice and figure out a way to get the humidity down so that your A/C can run efficiently (without excessive humidity, A/C does remove some moisture from the air).

Make sure that the unit has the correct amount of refrigerant and pressure (this will obviously require a professional visit). An A/C unit will still work with much lower refrigerant levels than it should have, it will just be very inefficient until it stops working.

If after all this the A/C is determined to be working as well as it can then there are likely one of two issues: 1) inadequate insulation or 2) undersized unit.

If at this point I find that the unit is either not functioning correctly and needs replaced, or is undersized, is the point I would go get a new unit.

Goodman will sell to the homeowner. Their stuff is generally used on builder basic new construction. They have improved in quality such that they are generally comparable to the lower end name brand units. However, after pricing out their units, and figuring in my time to install, I called a local vendor and had them install a Carrier unit (only $100 more than Goodman) and warranty their work.

As far as tax breaks go, I'm not sure they still apply. However I know some utility companies are still offering rebates for A/C upgrades - mine was offering $500 or $750.

FastStache

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Re: Advice on Buying New Central A/C
« Reply #2 on: September 23, 2013, 03:10:23 PM »
Alright, so I'm thinking of replacing the whole unit due to all the issues I've had over the years.

How do you guys recommend sizing the unit? Do I look for a certain airflow and seer rating?

I plan on getting a carrier unit with a 10 year warranty.

chasesfish

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Re: Advice on Buying New Central A/C
« Reply #3 on: September 23, 2013, 07:40:35 PM »
I did this three years ago and have loved it.  I got a couple of quotes and did it in the early spring before the busy season. 

Do you get your AC serviced annually by an HVAC company?

mikefixac

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Re: Advice on Buying New Central A/C
« Reply #4 on: September 23, 2013, 09:44:01 PM »
Make sure to get a "Load calc" on your house to determine proper size of unit. Most AC units are oversized, meaning more money on electricity, less comfort and shorter life of system.

HVAC Talk is a good forum that might give you a few ideas.