I live in an apartment complex. We have a room air conditioner. it is a Whirlpool. On the side are the letters and numbers CU124XAO, and underneath that the numbers 1164610. I have no idea as to how old it is; we've been living here for almost 5 years and it was here when we moved in. I need more information about it because I have to replace the filter. If anyone can give me any information I would appreciate it.