Is it possible to convert to thermo cool?

The "tower" humidors are not great candidates for conversion to temp control-if one plans to use peltier cooling units. They are only 17" deep & have a full glass door. I have found one has to use 1-2" of high R value foam to keep things efficient enough that it only requires a couple hundred watts of cooling power to get a 20 degree temp drop.

If you dont' use insulation, then it takes 6-8 times as much cooling capacity to get the same temp drop--that gets expensive & takes up a lot of cigar space.

There is a very high Rvalue custom vacuum panel available, but again it's very expensive & not cost effective. They also have not been around long enough for me to entirely trust the panels are going to maintain an effective vaccum for 20 years.

Net/net--A great many cabinets can easily be converted to humidity control, but not many are designed to retrofit with cost effective cooling/insulation and a good functional & elegant result.

cheers,
Bob Staebell