I have a well insulated 700 cu ft basement (one wall against earth) area I want to use as a wine cellar. I would like to install a split cooling system to maintain the space at 55-57 deg F.
I have looked at commercial wine cellar cooling systems but their fan coil units do not fit aesthetically into the design of the cellar. Also, the cheaper ones have low customer ratings and the expensive ones are expensive ($4K).

The look and size of many of the high efficiency mini split room ac systems on the market (e.g Frigidaire) with 22 SEER ratings seem much more economical and aesthetically compatible. Based on the above information I have the following questions:

(1) The mini splits are sold to only go to about 62 deg F. If I understand correctly the coil temperature will be around 40 def F and should provide cooling (not optimal) at 55 deg F. If I modify the thermostat to control at 55-57 def F will this cause problems with the compressor or other components? If so why?

(2) If I can run the mini split at 57 deg F, will the SEER rating drop dramatically?

(3) I could also install a refrigeration compressor (e.g Danfoss 1/3 hp Model 114N2020). But then I would need to install a compatible fan/coil unit. Something around 30"x 11" x 9" is required. Could I use the Frigidaire fan coil (rated 9000 BTU) or is there something with similar dimensions on the market compatible with the Danfoss.

(4) Would the Danfoss be as efficient as the high efficiency mini split at 57 deg F?