Hot Water Extraction (HWE) is a method of

carpet cleaning Carpet cleaning is performed to remove stains, dirt, and allergens from carpets. Common methods include hot water extraction, dry-cleaning, and vacuuming. Hot water extraction Hot water extraction, sometimes mistakenly called "steam cleaning ...

. It involves a combination of hot water and cleaning agents being injected into the fibers of a

carpet A carpet is a textile floor covering typically consisting of an upper layer of pile attached to a backing. The pile was traditionally made from wool, but since the 20th century synthetic fibers such as polypropylene, nylon, or polyester hav ...

at high pressure and the lifted soil being removed by a powerful

vacuum A vacuum is a space devoid of matter. The word is derived from the Latin adjective ''vacuus'' for "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often dis ...

Process

Though commonly called "steam cleaning", no actual steam is involved in the HWE cleaning process apart from steam that may escape incidentally from hot water. When the cleaning solution comes in contact with the carpet, it is 50 to 120 degrees Celsius, depending on the heat available from the cleaning unit. In a modern truck-mounted carpet cleaning machine, water can be heated under pressure to over 150 degrees Celsius, but after passing through high-pressure steel braided hoses and several manifolds, the water loses much of its heat. HWE begins with preconditioning using a pre-spray cleaner (typically neutral or alkaline) being applied to the soiled surface, followed by light agitation with a grooming or pile brush. For heavily soiled areas a Counter-Rotating Brush (CRB) can be used after the appropriate dwell time. Next, the surface is passed over several times with a cleaning wand or rotary extractor to thoroughly rinse out the preconditioner, using an acidic solution to reduce the pH of the carpet fibers back to a neutral state. In the next stage, the carpet is dried using a fan or carpet dryer. The final stage is resetting the

carpet pile A knotted-pile carpet is a carpet containing raised surfaces, or piles, from the cut off ends of knots woven between the warp and weft. The Ghiordes/Turkish knot and the Senneh/Persian knot, typical of Anatolian carpets and Persian carpets, are ...

to remove any unsightly wand lines, commonly referred to as "shark teeth", with a carpet groom or brush.

Hot water extraction machines

Professional machines range from portable machines, which use electricity to heat the water and power the water pump and vacuum motors, to larger truck-mounted machines. Truck-mounted machines are normally either powered by a stationary engine or PTO powered machines installed in a van or truck. Portable machines are able to access difficult to reach buildings and higher floors, while truck-mounted machines are more powerful and can clean and dry faster. Bissell spot clean pro

Consumer-grade and rental machines use similar technology to professional systems, but with less power and usually without an element to heat water. These units are not typically labeled as HWE systems, but are called "extration

vacuum cleaner A vacuum cleaner, also known simply as a vacuum or a hoover, is a device that causes suction in order to remove dirt from floors, upholstery, draperies, and other surfaces. It is generally electrically driven. The dirt is collected by either a ...

s", and may have additional heads for cleaning non-fabric surfaces like hard floors. Alternatively, some consumer machines contain a heating element but no vacuum function, and are simply called "steam cleaners".

References

{{Reflist Cleaning methods Cleaning tools Rugs and carpets

Process

Hot water extraction machines

See also

References