Recent green movements, especially noteworthy in the state of New York, have cleaners up in arms on the cleaning with hot water issue. New York is contemplating accepting or (depending when you read this) has probably accepted a proposal that would force all schools, public and private, to do most cleaning with cold water. That includes carpet cleaning as well.
You can expect that other states will follow this movement, so be prepared for it to eventually be part of your professional life.
Part of the idea is that heating water costs money, so cleaning with cold water is based on a financial need.
Cold Water Cleaning
How many of us have really tried to clean with cold water on purpose?
As you know, most soils react better with hotter water. We don't need 300 degrees, but we do need something reasonable. And cleaning a school carpet with cold water? Just try it. Gum, Playdough and many other types of soils or spots/stains have a personal vendetta against carpet cleaners: Once they find their way into the carpet, they don't have any desire to leave. They have found their home.
Carpet cleaners need more weapons, and one great weapon is heated water. By taking that weapon away, you will see cleaners adding more chemicals in an attempt to achieve good results. The "glug glug" method of mixing chemicals will take on an entirely new meaning. That's not the way to clean for visible results, not to speak of cleaning for health reasons. Are there products out there that clean effectively in cold water? Yes. But it is not truly "real world" cleaning.
What's the truth about hot water?
Most cleaners state with strong opinion that hotter chemicals clean better. Cleaning solutions are more active when hot. That's the key.
When cleaning virtually any surface—from carpet to dishes to automobiles and more—adding heat to the cleaning solution makes the cleaning agent more active.
What that does to soils... your experience tells you the answer to that.
Yes, you can clean clothes at home in cold water and get great results, but think about how much dwell time those clothes have in a detergent solution. Think of how much agitation they receive in the washing machine.
With carpet, 10-15 minutes preconditioning dwell time is about all you can expect. And agitation is not often a big part of the cleaning system. Many cleaners depend on the high pressure of their cleaning machines and cleaning tool movement to be the "agitation". Of course, using a power cleaning tool with any type of cleaning system is an advantage. There's nothing wrong with that as long as they have good chemicals, time for them to work, and HEAT.
The carpet mills make the carpet. What do they say? Go to the Carpet and Rug Institute to access Manufacturer-Recommended Deep Cleaning Methods. Notice the type of water that the majority of manufacturers recommend?
It's not cold water.
Thinking beyond hot water extraction...
Most carpet cleaning is done via hot water extraction. That's the method in which heat is most important.
Other methods, including absorbent pad, absorbent compound, or encapsulation don't need or require the heat discussed in this technical bulletin. For some, it just isn't part of the cleaning system. They rely more on agitation and specific chemistry to be effective - agitation is an especially huge element.
But with hot water extraction, you need a hot water rinse to complete the job properly. And since that is the method most often used, even in the commercial setting, taking away heat isn't a smart move.
Heat and Some Cautions
It's important to use the appropriate amount of heat when cleaning carpet and furniture - but only to the point the weaves, fibers, and dyes permit.
There are normally three phases in cleaning to consider when increasing the temperature of your cleaning solution:
1. Preconditioning: Using a hotter preconditioning agent means the chemical gets to work faster and does a larger part of the cleaning job even before you begin cleaning.
2. Rinsing: Adding heat to your rinsing solution increases soil removal, and helps the rinse agent do its share of the cleaning.
3. Spot removal: Spots are soils; adding heat to your spotting solutions makes them work faster and better. Follow manufacturer directions or contact the formulator if in doubt. Many spot and stain removers work best with added heat, typically with a steamer or clothes iron.
Other benefits to using heat include increased productivity and faster drying.
You must consider not only the colorfastness of the fabric, but also how delicate it is. Some fibers and weaves weaken with heat, and a combination of heat and agitation may cause damage. Velvet weaves and flocked materials are prime examples. Many natural fibers need to be cleaned with a lower temperature. Cut pile fabrics are more sensitive to higher temperatures. If the simple movement of your cleaning tool leaves jet marks, heated water can increase the marks and be difficult to remove.