I picked up an older release from Taylor Deupree this weekend, this one Stil.. It's 4 tracks of nice, long, quiet pulsing drones and hums. There are a few clicks and hisses of course, it is Taylor Deupree after all, but in all it's nice stuff to stick on in the background and go about your business.
If you're looking for nice ambient work on the electronic end of the spectrum, you could do worse than just picking up anything Deupree's excellent 12k records produces. They don't disappoint.