Carpet Cleaning

Carpet Cleaning Also known by Professionals as Hot water extraction

Further information: Hot water extraction

Hot water extraction, sometimes mistakenly called "steam cleaning", uses equipment that sprays hot water and detergent into the carpet and extracts it along with any dislodged and dissolved dirt. Many experts recommend hot water extraction as the most effective carpet cleaning method.

Hot water extraction equipment may be a portable electrical units, or for large jobs truck mount carpet cleaner with long hoses may be used as this may be faster and more effective than portable equipment.

A common process of hot water extraction begins with preconditioning. Alkaline agents such as ammonia solution for synthetic carpets, or mild acidic solutions such as dilute acetic acid for woollen carpets, are sprayed into the carpet, then agitated with a grooming brush or an automatic scrubbing machine. Next, a pressurized manual or automatic cleaning tool known as a wand passes over the surface to rinse out all pre-conditioner, residue, and particulates. If an alkaline detergent is used on a woollen carpet, a mild acetic acid solution will neutralize the alkaline residues and restore neutral fibre pH.

Thorough extraction is important to avoid problems such as mold growth and browning of wool. Carpet cleaning specialists try to find a balance between rapid drying (using less fluid) and the need to remove the most soil (using more fluid). Drying time may also be decreased by fans, de-humidifiers or simply opening windows.

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 hose and several manifolds, the water loses much of its heat.

HWE begins with preconditioning using a pre-spray cleaner with a typical alkalinity of 7 pH or above 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 fibres 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 to remove any unsightly wand lines, commonly referred to as "shark teeth", with a carpet groom or brush.

Truck-mounted hot water extraction machine

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. Consumer-grade 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 labelled as HWE systems.