I was washing off the sides of my heat pump, when I realized sand had collected around it, covering the pad and about an inch up the back of the unit. Partially covering the grills. I dug out the dirt and finished washing everything off.
I want to put a small retaining wall on the right of the unit, probably where the black drainage pipe is now. How much clearance should I have to the right of the unit? Connections are on the back right corner.
Here's a picture: