First, I have a place on the Beach. There are two heat-pumps, both are Coleman's. The Coleman with an all aluminum coil and fins is enduring the weather OK. The aluminum fins are getting thinner as they oxidize away. The other heat pump has a copper coil with aluminum fins. At just 4 years old, the fins are basically gone (very heavy corrosion) and they are loose on the copper tubing. The 4-year old unit (copper/aluminum) is also losing freon but no visible signs. (R-22).
I've called several local HVAC businesses and have demanded an all-aluminum coil/finned condenser or an E-coated coil. No one will provide a bid because they only sell copper coil/aluminum fins units. Also being told all-copper is not made for residential installs. It is "understood here" that your heat pump needs to be replaced every 4-5 years and that's what people are doing. I'm trying to get more life out of the unit.
Does anyone have a list of manufacturers that use all-aluminum coil/fins? I know Trane does (spine-fins). I'm frustrated as no one will bid and year-end it almost here. Was hoping to get a 15 seer+ 2.5 ton unit that would qualify for the rebate or just get another R-22 condenser unit and retain the current 19 year old American Standard Air Handler. Also very open to recommendations. Running the 15KW heat strips is VERY costly.