13 seer and 10 seer evaperator coils

[fourwinns16]

When changing out a 10 seer condensing unit with a new 13 seer condensing unit, should you also change out the old 10 seer evaperator coil or can you leave it in if it seems to be okay? I've been in the business for only two years, I've learned a lot, but I'm still learning everyday. I would appreciate if you could elaborate on this subject. Thanks.

[comfortdoc]

To get the rated efficiency you should have the indoor coil selected and matched to the outdoor unit. Some combinations require a TXV, some will use fixed restrictor. There may also be warranty issues if the coil is not matched.

[phinncraft]

change the coil to the matched one

[hvac hero]

you certainly cant go wrong changing the coil. Installing 13 seer is so new to me, I'm not real sure if its going to harm the compressor in a few years by leaving a 10 seer coil on it. We do so many condensers, that we're changing out the evaporators too. Mainly because in 2 years I'm not wanting a nightmare of dozens of units with bad compressors. IMO, it probly would work fine with the old evap, but that is just my opinion.

[RoBoTeq]

They are called "systems" because a specific indoor portion is designed to operate with a specific outdoor portion. Using an existing coil is asking for trouble. Using an existing indoor coil designed for 10 SEER while installing a 13 SEER outdoor unit is begging for trouble.