I live at the beach and outside heat pumps go fast. I want to replace my 4 ton Ruud 10 seer heat pump, model UPKA-049-jaz, and use my inside air handler for a few more years. I have found a UPKB-048-DAZ but can't find anybody who will tell me if it will work with my system. Everybody I talk to wants to sell me a new Trane with a higher seer for $10,000. Help!

If the second uses the same refrigerant as the one you have, it's a 4 ton unit like the one you have, unless I`m overlooking something it should work
If you are going from r-22 to 410a,, no it want, the evaporater needs to be changed

I live at the beach and outside heat pumps go fast. I want to replace my 4 ton Ruud 10 seer heat pump, model UPKA-049-jaz, and use my inside air handler for a few more years. I have found a UPKB-048-DAZ but can't find anybody who will tell me if it will work with my system. Everybody I talk to wants to sell me a new Trane with a higher seer for $10,000. Help!

Many manufactures make what is called a Costal unit. It is especially designed for use around salt water. When you talk to your contractor have him quote you on that type unit. They last a long time in the salt.

There is also a company that makes what is called a corrosion grenade that will also SLOW the corossion.

Corrosion Grenade Stocking Wholesalers (http://corrosiongrenade.com/wholesalers.htm#OH)