So a while back there was all this talk of chillers and coolers and A/C units for highland Neps and I think the end result of all that talk was that there just wasn't any easy way to cool them at night without spending huge amounts of money.
Well... Yesterday I was at Home Depot looking for some 3" square pots (which they do not have and I can not find!!! ) and I saw something that might work. It costs a bit but it was cheaper and less elaborate than alot of the stuff that got tossed around before -- A wine cabinet. These are designed to store wine in at a cool temp, add a couple lights and hook one up to a timer and viola - instant Nep grow chamber. The one I saw was about 4' x 2' x 2' and was only $119.
Just a thought