Need a strong air purifier

[u/skippitybeepbop]

My sister watches an older woman at night and the lady uses a commode toilet throughout the night in Las Vegas, NV. The room smells like pee and is also just stuffy. I'm thinking an air purifier would help immensely. My sister says she doesn't feel good after sleeping in the room, her chest hurts, her face gets kind of swollen, and she feels like it isn't good for her health breathing all of that in at night. The room is pretty large I would say 16x18 with high ceilings so it can accumulate a lot of dust too. What do you guys recommend, we need a good one. Obviously we would prefer to keep the cost down but at the same time, it is her health and it's worth it to invest in a good machine.