If you are alive in 2020 and are not extremely concerned about climate change, congratulations: you must have found one very comfortable rock under which to live. As for me, a recent dry, record-breaking hot spell that threatened to destroy the garden found me trying new tricks to stay cool.
I try to avoid using air-conditioning at night, but sometimes it seems necessary to use the fan, which might use even more energy than the central air. Solution: set up natural cross-ventilation from first to second floor. Exploiting bi-level cross-ventilation involves leaving doors open that normally remain closed for privacy, but other than that, is cool and efficient. You need a two-story home that allows air to travel through your (screened) bedroom windows from an entrance, and a locking-screen door on said entrance. (We hope that the danger of being burglarized is in your neighborhood is low.) Once you’ve locked the screen door, you can leave the main door open wide, fling open your bedroom windows, and leave the bedroom door open, too.
Do you feel a wonderful puff of cool air? Success! You’ve drawn the cool air across and up/down while its movement has pushed the hot air out and away. Tried this last night after a 95 degree evening and got chilled enough to consider adding a summer blanket. A free, natural fan that creates no carbon pollution? Yes! And to the neighbors: you’re welcome to the t.v., if you really want it! Good night!