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