For certain types of dogs and climates, an air conditioned dog house can make a lot of sense. Unlike us humans, dogs do not have a very efficient temperature control system, especially when it comes to body cooling.
Young dogs, old dogs that are no longer in peak physical condition, dark-haired dogs in the sun, and long-haired dogs whether in sun or not -- all face an increased risk of overheating. If your dog is in one of these categories, you live in a region with very hot summers, and you are unable to situate the dog house in an area with shade, an air-conditioned dog house might well be worth looking into.
Most air-conditioned dog houses are made from wood (it is an excellent insulator and relatively inexpensive) with insulation panels inside the walls. PETCool makes a very popular AC system for dog houses. It is actually a heat pump so it keeps the dog cool in the summer and warm in the winter. And because dog houses are comparatively small, the electrical power usage of this unit is quite reasonable - it's on par with that required to power 4 standard light bulbs.
