Equipment for Wine Cellar

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?

Wine Cellars,

There are two different criteria you have to look after in a wine cellar, yes temperature is one but the other one is the humidity.
The proper units for the job has been designed to cool as much as possible whilst removing as little moisture as possible.
A/C units on the other hand has, as us humans feel better in drier conditions, been designed to remove as much moisture as possible.

You want to build it from parts, good luck (but it will become expensive and before you got it cooling your wine it would have been cheaper to buy the proper machine to start with)

:cool:

Yes, I agree with you about the criteria. I agree with you that A/C units are designed to remove humidity and lower the temperature in living spaces.
But lets look at the facts. When a room is at 75 deg F and 50% RH (Dew point 55 deg F) and cooled by an AC unit with an evaporator temperature of 40 deg F, moisture will be removed because the coil is BELOW the dew point. However, in a wine cellar where the air temperature is 55 deg F and 50% RH (ideal), the dew point is 38.5 Deg F. With an evaporator coil temperature of 40 deg F, the coil temperature is ABOVE the dew point, so no moisture will be removed until the RH rises in the cellar. So in this case the evaporator is regulating against high humidity and maintaining it around 50% Humidification can be added if the RH lowers. This is why I would like to use an AC system for cooling.

So getting back to my first question, is there any mechanical problem with running a room AC mini split system to cool the space to 55 deg F. If so, why?

With regard to your second point, I can get a mini split AC system for less than 25% of the cost of a "wine cooling system". These specialty units basically contain the same parts as an room AC system (compressor, condenser, evaporator, fans, etc.) They cost more because they are sold to affluent people with no appreciation for cost and are not mass produced.

No Luthie, of course there won't be any issues.

My 30+ years of experience that taught me that in rooms cooled by AC split units to around 55ºF the humidity levels drop to around 25-30% counts for nothing.

We all have to experiment, just don't expect it to be the cheapest option...
It isn't just the name of the kit; AC vs Wine cooler. Look at the evaporator; physical size, number of passes/rows and fin spacing. Also how the system react as the evaporator temperature nears freezing.
Also double check your delta T figures, a modern AC running a room at 70ºF I would expect to evaporate at no more than 50ºF, that is a delta T of 20ºF... Your example of running at 55ºF, less 20ºF is 35ºF...

:cool: