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Putting Heat in the Hot Seat - Comparing cold- and hot-water extractors

Written by  Joe Versluis

Hot Shower

Not everyone may be aware of a controversy that has been brewing in the professional carpet cleaning industry for nearly a decade. But as more and more BSCs begin offering carpet-cleaning services to their clients, this argument will likely involve them as well.

The gist of the debate surrounds whether to use hot- or cold-water carpet extractors. You may wonder why this is such a big issue, but it has caused advocates on both sides of the fence to bicker openly. In this article, we’ll look at each side’s points, and though I want to stay as objective as possible, I must say from the start that I’m an advocate for hot-water carpet extraction. I believe hot water is ultimately much healthier for building occupants, is more “green” than many who oppose it may realize, and helps the technician perform carpet cleaning quicker, more effectively, and more thoroughly.

A little history
After World War II, there was a home-building boom in the United States, and instead of hardwood flooring, which had been the trend for decades, wall-to-wall carpeting was installed. To clean these carpets, most technicians of the day either shampooed the carpets or used a bonnet system. Without going into details, these systems worked, but also had drawbacks. For instance, the chemicals used to clean the carpets often resulted in rapid resoiling. Plus, the systems tended to remove only the top levels of soiling and not reach deeply embedded soil, which is necessary in effective carpet cleaning. In some cases, these processes could even damage carpet fibers.

"If using hot water means the technician needs to make fewer passes over the carpet, the job may be completed considerably faster."

In the late 1960s, what were first known as “steam cleaners” were introduced. These were typically truck-mounted carpet extractors and cleaned much more thoroughly and effectively than the other systems. The drawback with truck mounts was that they could clean only as far as the hose would allow the technician to reach. In time, portable extractors were introduced that could travel just about anywhere. Some of these portables cleaned using cold water only, but more advanced systems were introduced that used heat. Heat was added for a simple reason: Heat enhances the molecular activity of chemicals—in this case the cleaning chemical being used, along with water. The result was more effective, and often faster, cleaning. The heated chemicals did more of the “heavy lifting” when it came to carpet cleaning, which could help make the carpet cleaning procedure much faster.

The start of the controversy
Into the early 2000s, the only issue carpet-cleaning technicians had when selecting a cold- or hot-water carpet extractor was whether they wanted to pay a little extra to get a more effective system. However, that changed in 2006 when the state of New York issued its Green Cleaning Guidelines, designed to help make the state’s schools more environmentally friendly. In time, more school systems and other types of facilities adopted variations of these guidelines. While most segments of the professional carpet cleaning industry welcomed many of the components of the Green Cleaning Guidelines, one section caused a lot of commotion—the guidelines insisted that only cold water be used when cleaning carpets. It is now believed that the authors of the guidelines made some incorrect assumptions. These errors were pointed out while the guidelines were still in the public discussion phase, but the authors maintained the position that cold water is necessary in order to make carpet cleaning more environmentally friendly.

Assumptions that need to be revisited
Green cleaning is often viewed as a journey, which implies we are learning more and more things as we go. While this journey often introduces us to new ways to be more protective of health and the environment, it should leave the door open for reexamining policies that may not be as green and environmentally friendly as originally believed. Here are a few such views as they relate to carpet extractors:

Heat sources use energy: One of the reasons the authors insisted on the use of cold water is because they assumed the building’s boilers provided the hot water. This is not the case. Whether using a portable hot-water extractor or a truckmount, the equipment produces its own heat. For instance, if the truckmount is a vehicle-powered system, the heat will be generated by the vehicle.

Worker safety is at risk: The authors were also concerned that using hot water, which reaches more than 200 degrees F. in portables, can cause burns and injuries. While it is true that water at this temperature could cause burns, the hot water is released through the wand applied to the carpet and doesn’t flow near the worker’s body. So although there certainly may be situations where a worker is somehow injured—we at least can’t rule it out completely—I have never heard of it happening.

Heat is just not needed: When the guidelines were first introduced, chemical manufacturers had developed detergents for carpet cleaning that did work well with cold water. There are even more of these today. However, just as with all chemicals, these cold-water detergents work even more effectively with hot water. This has been scientifically verified by the Argonne National Laboratory as well as by other studies and researchers.

Heat melts and spreads soils: Finally, a key reason for requiring the use of cold water was the authors’ argument that heat melts soils, which then spread, making them harder to remove. The guidelines are unclear whether they are referring to hard-surface floors or carpets, but when it comes to carpet cleaning, one of the goals of using a hot-water system is to help melt and loosen soils, which actually makes it easier for the machine to extract them from carpet fibers.

Is hot water green?
On the other side of the coin is the fact that using hot water may actually increase the environmental safety of the cleaning process. Earlier we mentioned the false argument that a hot-water carpet extractor uses more energy than a cold-water system. However, if using hot water means the technician needs to make fewer passes over the carpet, the job may be completed considerably faster. With the carpet cleaned more quickly, less energy may be in fact used, which certainly helps promote sustainability.

With heat enhancing the effectiveness of the cleaning chemicals, this not only helps speed up the cleaning process, it may also mean that less chemicals are necessary. As noted by Dr. Michael Berry, author of Protecting the Built Environment: Cleaning for Health, “even without soap, small amounts of grease will dissolve in water… [but] the amount increases in hot water sometimes ten-fold.” This can result in less chemical being necessary to clean the carpets, and the less chemical used to clean any type of surface, the healthier it is for the environment.

Whether the guidelines are adjusted or not, it is becoming common knowledge in the carpet cleaning industry that hot-water carpet extraction is the most effective way to clean carpets. BSCs and in-house cleaning professionals involved in carpet cleaning may have to educate their customers about this, because the facts appear to be on the side of heat. It is the healthier and more effective way to clean carpets.

Joe Versluis is national sales manager for U.S. Products. He can be reached through his company website at www.usproducts.com


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