If you design your roof right you might never have to do any cooling at all
(The following post is slightly speculative engineering. It at least makes sense on paper. It hasn't been vetted by an expert and may have some fatal flaw I don't know about. But it's at least plausible and is what I came up with after spending some time thinking about the problem.) During the summer in warmer climates you need to expend energy for air conditioning to keep a house a livable temperature. But there's a loophole. The sky isn't all hot, only the sun part of it is hot. The rest of it is very cold. Polyethylene has the magical property that it's a thermal insulator while letting through radiant heat, allowing you to cool off by touching the sky. Let's say that you want to build a house in Los Angeles, which has constant need for cooling and where the sun is always due South (It roams…