The person renting our basement complained about the furnace / central ac unit making too much noise. I Also didn't like having the system with nothing around it to protect it. So.....I built a wall on wheels!
Here's what the furnace looks like without the wall:
And here's how it looks with the wall:
Much quieter, and it's more protected now. Also it looks a lot nicer than having a furnace out in the open. If we need to get at the furnace to fix something we can just wheel the right angle wall out of the way.