Hoverson states that when the steam is trapped, it allows both the heat to be concentrated at the surface and penetration by the steam into the surface''s pores. When the steam is not trapped and the heat is allowed to dissipate immediately, penetration is not as deep and cleaning is not as effective.
He notes that control offers more versatility and effectiveness; many lower-end units comprise only a boiler, a hose and a nozzle, with no way for the operator to assert control over the pressure being employed, resulting in uneven coverage and lowered efficacy.
According to Hoverson, while steam is an effective disinfectant — hospital autoclaves use steam to sterilize equipment and other objects — testing has shown that steam produced by this particular process kills microbes, including the notoriously resistant Clostridium difficile (C. diff).
He adds that the growing awareness and demand by consumers for cleaner, greener methods proven to eradicate microbes and remove soils can only serve to raise the profile of steam vapor technology.