13 SEER compatibility with 10 SEER coil

Hank99 · 08-06-2009, 10:57 PM

I have a 10 SEER central a/c, and the compressor needs replacing. Can I use a new 13 SEER compressor/condensor unit and connect it to the 10 seer coil inside unit? The coil is only a couple years old, and I don't want to replace it so soon. I was told by one a/c company that the mismatch could damage the new compressor, if the coil doesn't have an expansion valve. Another a/c guy said that the new compressor would work fine on the old 10 seer coil. Can anyone help answser if the new compressor will work alright with the old coil? Thanks.

Hank

hvaclover · 08-06-2009, 11:55 PM

The second ac guys is full of sh!t. The coil should be replaced. Even adding an expansion valve is no guarantee. You have to dick with the freon charge to even get close. That is not something somebody would do at no addtional cost. So you might as well spring for a couple hundred bucks more and get the coil. You will get a 30% reduction on your electric bill.

JohnH1 · 08-07-2009, 12:18 AM

The a/c unit will work. It just may not work as well as you want it to. Unless it is a matched system no one could say what the BTU output would be or efficiency. That is as long as the evaporator did not help in the death the previous unit by having a restricted metering device. In my opinion it is not worth the chance. Everytime I go cheep on something I end up kicking myself later.

**beenthere** · 08-08-2009, 06:25 AM

You probably won't get the capacity of the outdoor unit.

Some manufacturers, have ratings for their older coils, that are less then 5 years old, most don't.
Some manufacturers will void compressor warranty, if the indoor coil isn't an ARHI listed match.

mmitchell_1978 · 08-08-2009, 09:09 AM

If it were it a heat pump, there would be more of a concern on matching up to the older coil. One of the major manufacturers actually approves their condensing unit (a/c) with the addition of the correct expansion valve if the coil is 10 years old or less. It's not going to blow up your air conditioner by using the old coil, which is 2 years old. Check the temperature drop and pressures and you should be fine.

**beenthere** · 08-08-2009, 09:12 AM

Quote:

Originally Posted by mmitchell_1978

One of the major manufacturers actually approves their condensing unit (a/c) with the addition of the correct expansion valve if the coil is 10 years old or less.

Thats probably if its their indoor coil.
Not a different brand.