There are several manufacturers that are produce high quality cooling units in all three styles of units which are through the wall, ducted or split. WhisperKOOL (Vinotheque)
is probably the most recognized name in wine cellar cooling and produces units in all three styles and in various sizes. N'FINITY
produces a base version of the through the wall systems and is one of the best values on the market. EuroCave
makes the INOA
self-contained unit which can be used through the wall or in a ducted application. It is one of the quietest and most reliable available. Wine Guardian
is best known for their ducted air handler style units, but they also make a through the wall and split system and well. Lastly, there are custom ducted and ductless split cooling systems produced by WineZone
that are similar to a central AC system you may use in your home.