 In other words, try using a fan, she says, or open a window to move a breeze through the room. Some of her colleagues at Berkeley have invented an office chair with a fan built into the seat. It keeps people comfortable without cranking the AC. But here's the problem. You've probably noticed the planet is getting hotter. And you, me, heck, just about everyone, we're going to use a lot of AC. It's an issue that Serene Grandma is trying to solve.