I do not know of a NC code that forbids mixing a system although it is not advisable to do so. But as long as the system components are matched for BTU/hr and efficiency they should work OK. If the old unit is a Refrigerant 22 system and is unavailable and you are forced to use the new system with Refrigerant 410A, then yes you will need a new heat pump and (AH)air handler. Also the refrigerant lines may have to be replaced as well as the return duct to the system will need to be increased in size. If the evaporator coil is the cause of the failure and the rest of the air hander is ok, you can get a replacement coil rather than a new air handler. If the air handler has to be replaced I woud suggest you take the money from the home warranty and invest it in a Trane air handler. I highly recommend you get more than just one HVAC company to look at this. Those home warranty companies are not all they claim to be. I refuse to do work for them because of the shortcuts they force you to take. Also, be advised you need to verify that the contractor is reliable, do not rely on home warranty to tell you as they look for the cheapest price and not nessearily quality. NOTE: NC Code section 312 requires a heat and cooling load be preformed based on ACCA manual J and manual S and a permit be obtained prior to the installation and to be inspected and approved by the mechanical inspector. If you need any more info feel free to contact me. I would like to know the outcome also.
- Vote on answer
- posted
10 years ago