The intake vent to the furnace is in the living room, ten feet up the wall. The cover has to be taken down at least yearly, the dust visible to anyone who studies it. Eight screws hold it in place. Taking it down and putting it back up is a bit dangerous and a pain in the kazoo.
I took it down yesterday. She cleaned it, then decided it was showing too much wear and tear, so she painted it. This afternoon, re-installing it, I had seven of the eight screws in place when she looked up and said, " The vent openings have to point down."
I responded, "No, if the vents point down, you'll be able to look into this hole from the living room."
"No, the vents HAVE to point down or the dust will fall into the intake and we'll have to clean it more quickly."
Seven screws back out, I turned the vent 180 degrees and started to re-install it. I had three screws started when she said, "WAIT! Were the vents up when you first took it down? 'Cause that's really ugly!"