Swany, Thanks for the response. The CU is Lenox HP23-211-1P and the AHU is Lenox B2402-1P. Apparentely this is a 1 1/2 ton CU with a 2 ton AHU(with txv). It is my understanding that if a piston is used the CU & AHU must have the same piston size. Did the AHU txv need to be changed to match the CU when the system was installed? I am replacing the Lenox AHU with a trane with a piston. A 1 1/2 ton piston will need to be installed in the AHU(instead of the 2 ton that comes with the AHU). Am I correct on this? Thank You, Lee.
A Trane TWE024C air handler should work just fine with that HP23 heat pump. Use the piston size listed on the heat pumps name plate or get a TXV kit for it. There is also the TWE024P air handler that already has a TXV in it.
It will work just fine, just no way to tell what the actual capacity and efficiency are. What you end up with will likely have more sensable capacity, but less latent capacity than the origonal system. You could go with the TWE018C or TWE018P for more latent capacity. Its all just guesswork though.
While the ideal would be to change a system out with a complete ARI matched system, in the real world compromises often have to be made based on customers needs and budgets.
If more government is the answer, then it's a really stupid question.
I do like a matched system but in this case I will probably go back with a 2 ton Trane AHU as that is the airflow the homeowner is accustomed to getting. I will call Trane and get the correct piston size to match it with the 1 1/2 ton CU.