We cool the house with window units, and two of them are on the north wall of the house. (No sun to speak of.) About 3 years ago I replaced all the ancient units with new Frigidaires, 8k in the front room where we have the computers and desks, 11k in the oversize bedroom...both of these in the north-facing wall.... and a huge one in the living room that cools the rest of the house.
First off, this cut about 30% off our electric bill the first full summer month with 'em. They're all slingers, though. I don't like the sound, sounds kinda like something fell into the fan. What I like even less is that, in our humidity, they start slinging water almost immediately after being turned on and splatter it everywhere like a shaggy dog coming out of a pool. This water gets all over the side of the house and started turning the area around the a/c green. Now, I like "different", but a furry house is NOT a good "different".
So I found a low spot and drilled 'em all with about a 1/4" hole. Be sure and use a cordless drill you don't like all that much because it's gonna get wet. Did not hurt the efficiency much, if at all. Over the last couple years, our electric usage has averaged that same 30% reduction, even after the drilling. And my house is staying the correct color now!
I have one more Frigidaire 8k that I'm going to mount in the trailer, it'll get drilled too. And I really like the flanged elbow solution to getting a drain line attached to it! I'd been constipating on how to do that

....Thanks for posting your solution, NO David!