Replacing inside air control unit - have to replace outside as well?

yalej

Hey guys. I have a Crane unit, and the air control unit (the thing that sits up in the attic) needs to be replaced. This will be done under a home owner's warranty (we're the second owners of the house). The unit is 12 years old.

The guy who came to look at the unit also recommended that when the air controller is replaced, the outside unit also should be replaced. He stated that if you don't do this, they won't be matched/compatible, and it will result in significant cooling inefficiency leading to higher bills. He claimed that it would cost about $2000 ($5500 for a Trane unit) to do this, but I'm not sure if this includes labor charges. This latter option would not be covered by the home owner's warranty.

Is what he stated true? What would the relative inefficiency be if I didn't match the units. 60%? 90%?

yuri

It can be made to work with the existing outdoor unit but not perfectly. The new airhandler probably will have a higher SEER evaporator coil than the lower SEER outdoor unit. You may lose 5% efficiency and it may have unusual operating pressures which may shorten the life of the outdoor unit compressor in extreme cases. Sounds like he is trying to scare you and may be a bit shady. I would get 2 more complete quotes from well established reputable companies.

beenthere

There may or may no be a loss of efficiency.

The new coil should allow your older outdoor unit to work easier.
May even increase your systems capacity some.

If it was the other way around, you would definitely lose capacity and efficiency.