Hello, I'm a first-time poster. We have an inherited large log home in southern Indiana. My parents installed a Unico system central AC in 1999 - two separate units - 2 ton for upstairs, 2.5 ton for downstairs and basement. The system has worked very well until just recently the downstairs' unit's evaporator coil has developed pinhole freon leaks - the system used R22.
Since the building of the house in 1978, heating has been with electric baseboard (very inefficient).
We like the AC system and would like to continue with the Unico, but are considering options: 1) replace the leaking evaporator coil - HVAC repairman recommends against this - expensive and may be obsolete in several years due to lack or expense of R22 - plus likelihood of other components failing
2) update AC with non-R22 components - HVAC repairman's recommendation; 3) replace AC unit with air-to-air heat pump - thereby getting more efficient (?) heating, but retain existing electric baseboards for supplemental heat in the depths of winter - question is, do heat pumps work efficiently with high-velocity Unico ductwork? 4) replace AC unit with ground source (geothermal) heat pump - (we have lots of room for horiz. ground loop)
So, does anyone have any comments/recommendations/warnings, or otherwise good information to share on these options? Thanks!