I helped my brother build his home with a low voltage lighting panel using GE 24V RR7 relays. This panel is located in a basement so it doesn't go through high temperature excursions. I might look into installing a peltier effect module if I ran into the situation you describe. I say this because I could use the module to reduce the inner panel temp below ambient in the summer, then warm it above ambient in the winter. The modules are becoming quite popular in coolers these days. It would be a simple matter to come up with a control scheme with upper and lower limits.
Joe
