Need to have a 4 ton Carrier heat pump replaced. The contractor has proposed either a 19 seer 25HNA948A003 or a 16 seer 25HNA648A003. same coil with either outdoor unit, a CNPHP4821ATA. The existing furnace is about 10 years old and works fine, and is a 58mvp-100 weathermaker infinity variable speed furnace. Right now there are 4 zones controlled by a Comfort Zone 2 controller.
My question is this furnace compatible with communicating infinity components like the proposed new heat pumps, and should a zoning Infinity controller be installed (or is it necessary)? Any thoughts on the differences between the 16 and 19 seer heat pumps besides the efficiency?