Most people have heard of carpet cleaning companies that claim to steam clean carpets. Even carpet cleaning rental equipment is often referred to as a steam cleaner. The truth is, there is no such thing as steam cleaning when it comes to carpet.
Many people also refer to this carpet cleaning method as hot water extraction. In fact, this has become the popular term for this process within the carpet cleaning industry. Some have speculated that this change in terminology came about because consumers have become more sophisticated and most now realize that there is no such thing as steam cleaning carpet.
So called steam cleaning or hot water extraction is a carpet cleaning process that involves thoroughly soaking carpet with a large volume of water, then extracting some of the water with a powerful commercial vacuum system. The theory is that this deep cleans the carpet. In truth, this process simply washes the soil deep into the carpet.
Sharp Drop in Temperature
The first problem with this carpet cleaning method is in the name itself. The terms steam cleaning and hot water extraction lead consumers to believe that this method kills bacteria in the carpet. This has proven to be false because the temperatures simply arent high enough to kill anything. This fact was proven in anindependent test performed by Aziz Ullah, Ph.D., MBA.
Dr. Ullah placed a piece of carpeting next to a carpet cleaning truck containing a truck mount hot water extraction unit. This was done next to the truck to shorten the hose length used in order to get the hottest water possible. This test was performed on a 90 degree summer day. The hot water coming from the truck mount was 230 degrees Fahrenheit. The water temperature at the tip of the cleaning wand was 114 degrees Fahrenheit. This on a hot day with a short hose. You can imagine how much cooler the water would be on a cold day with a long hose.
The primary reason for the dramatic drop in temperature can be explained by pressure. When a liquid goes from a high pressure to a low pressure, it expands and loses a tremendous amount of heat on expansion. The water loses more heat as it travels through the hose and still more when it is atomized by the cleaning nozzle. I would guess that, by the time the water reaches your carpet, the temperature is lukewarm at best. Since this is the reality, the most accurate name forthis carpet cleaning method is warm water extraction.
Another problem with this method of carpet cleaning is known as wicking. When the lukewarm water is extracted, some of the dirt does come out, but much of the water and the dirt stay in the carpet pad and backing. As the carpet dries, the fibers act as a wick, pulling the dirt back up to the top. This is a very common problem with the warm water extraction carpet cleaning method.
Yet another problem is all the water that this method leaves behind. Warm water extraction methods involve gallons and gallons of water thoroughly soaking your carpet. It is impossible to extract all of the water from the carpet. Your carpet backing and pad remain wet for days.
In summary, warm water extraction methods soak your carpet with warm water, and leave the backing and pad wet for days. If I were a bacteria, I would consider this warm, moist, dark environment heaven.
Alternatives to Steam Cleaning
There are better methods for carpet cleaning. Low moisture carpet cleaning methods are strongly preferred by people who understand the myth behind warm water extraction.
With low moisture carpet cleaning, carpets are dry vacuumed first then lightly sprayed with a very good cleaning solution. Low moisture carpet cleaners use agitation and absorption to remove moisture and dirt. This method results in cleaner carpet that is dry in a very short time, usually about one hour.
No matter what people tell you, dont fall for the myth of warm water extraction cleaning, or steam cleaning, as it has been known. Common sense says that this method simply couldnt work.