Ltpgtthe meacoclean ca hepa 47x5 can move up to 236mltsupgt3ltsupgt of air per hour the more often the air from your room goes through the air purifier each hour the cleaner the air will become if your symptoms are mild then three times an hour will be fine five times an hour will give better results and a factor of seven or eight times an hour should be used if your allergy is severe the table below gives you an indication of the room sizes that the meacoclean ca hepa 47x5 can