Designs for residential houses and appliances that ensure waste heat goes outdoors in the summer, and stays indoors in the winter. (And vice versa: refrigerators and freezers that take advantage of cold outdoor air in the winter, rather than using electricity to run compressors.)
The only common appliance that I can think of that produces a lot of unwanted heat would be a dryer. But instead of a gas dryer that sends all the waste heat outside, you could get a condenser dryer with a heat pump which consumes much less energy and hence produces much less heat.
From a residential standpoint it doesn't really make sense.