The FPK50UW with True HEPA filter is an excellent air purifier for 250 sq. ft. rooms. Sharp's patented Plasmacluster technology captures particles as small as 0.3 microns to generate the cleanest possible air for small rooms up to 259 sq. ft.   
 
The Sharp FPK50UW Plasmacluster Ion Air Purifier with True HEPA Filtration effectively reduces pollen dust pet dander smoke germs bacteria viruses odours mould and fungus in your living space. This air purifier for small rooms like 250 sq. ft. has a three-stage filter system including an activated carbon filter and long-life True HEPA filter which captures 99.97% of particles as small as 0.3 microns from the air that passes through it.