Hospitals spend hundreds of dollars on special machines that use UV to steralise whole rooms. The drawback to using these machines is that they are highly detrimental to human skin and eyes and to the environment in general. Plastic yellows, and other materials break down. A hospital will use such a machine as it is a cheap way to clean whole rooms. For the average person it is a dangerous and not recommended way of treating an environment. Studies and evidence collected has shown that 254 nm bulbs have next to no effect on mites. If anything it may help them as it provides a source of heat.