Carpet Care: Spotlighting Carpet Extraction

Carpet extraction is a hot-button topic that causes both confusion and debate among facility and cleaning managers. Techniques and frequencies often change and are largely impacted by facility type, location and desired level of clean.

To help clear up some of the confusion, Housekeeping Solutions asked equipment manufacturers to weigh in on the top questions asked by end users. The panel included:

• Bob Abrams, product manager for vacuums and carpet extractors at Plymouth, Minn.-based Nilfisk-Advance (manufacturer of the Advance, Clarke and Kent brands)
• Geoff Greeley, vice president market development and support at Racine Industries, Inc. in Racine, Wis.
• Fred Hekman, principal engineer, advanced product development at Holland, Mich.-based Tennant Company, Commercial Products Division
• Adam Schaffer, territory manager a Tornado Industries in Chicago

Q: Is hot or cold water better for extraction?

A: Schaffer: Chemicals are now formulated to work with cold or hot water, but typically, it is better to use hot water extraction. Heated water accelerates chemical reactions and reduces the surface tension of water, enabling it to clean faster. Chemical costs tend to be lower due to the speed and efficiency of cleaning, as heat increases the emulsification of soil and breaks down faster. Less water and chemical minimizes overwetting and the possibility of mold and allergens.

A: Abrams: The hotter the water, the more effective and efficient the extraction process. Water temperature is one of four factors that contribute to extraction effectiveness: temperature, agitation, chemical and solution dwell time.

Q: When should you use wet vs. dry extraction?

A: Abrams: Wet extraction is the least costly and most effective because it removes the widest range of soils, but it has longer dry times. With dry extraction, most areas can be opened to traffic about 20 minutes after cleaning.

A: Schaffer: Hot water extraction is used for deep restoration cleaning (once or twice per year) and is especially effective when cleaning heavy or greasy soils. Dry methods, such as encapsulation, are generally used for interim (monthly) or daily carpet maintenance and can be better for natural water-sensitive materials (non-synthetic carpets or fabrics).

A: Greeley: Wet extraction is useful when the carpet has been flooded and must be dried. If a carpet is heavily spotted and soiled, dry extraction avoids the wicking of spots and delays resoiling. With dry extraction, one can focus cleaning techniques and chemistry on the most highly trafficked areas, removing deep-down dry soil and oily, sticky soil.

A: Hekman: Dry extraction processes are really low-moisture processes and are best used when dry time is important. Some dry extraction processes leave residue behind, which can build up. For this reason, many cleaners will substitute a deep [wet] extraction every third or fourth time to remove soils and media that [might] have built up in the carpet.

Q: What are the advantages to using pre-spray or in-tank chemicals?

A: Hekman: Pre-spraying gives chemicals time to work on spots and stains and [reduces the amount of chemicals used during extraction]. But, it requires a separate step and might be seen as lowering productivity. The opposite is true if you measure productivity in terms of results, since every chemical we tested worked better as a pre-spray than as an in-tank chemical. Pre-spray also allows you to use clear tap water (perhaps with a slight amount of acid rinse) in the tank.

A: Greeley: Pre-spray or pre-conditioner is the better option. It reduces the residues of cleaning chemistry left behind in the carpet. The disadvantage is that applying the pre-spray directly to the carpet will loosen the soil quickly, causing it to run deeper into the carpet, making removal more difficult.

A: Abrams: Pre-spray is the best method because it allows some chemical dwell time. It also keeps chemicals from passing through the extractor pump, which can shorten the life of the pump. If you use in-tank chemicals, it helps to do a quick application of solutions to the carpet, and then come back with full extraction several minutes later.

Q: How often should you extract carpets?

A: Greeley: Cleaning should be driven by the soiling conditions in the facility. Studies show that the majority of the soil tracked into the building is dry — around 80 to 85 percent — and is best removed by simultaneous vacuuming and pile lifting. The remaining 15 to 20 percent of soil is greasy and sticky, requiring cleaning chemistry to remove it.

A: Schaffer: Carpet cleaning frequency depends on use, traffic and the environment inside and outside the facility. In most cases, carpets in office settings should be cleaned using extraction once or twice per year. In schools, frequency might actually increase to three or four times per year.

A: Abrams: This depends on traffic and desired cleanliness. Nursing facilities extract their carpet daily. Hotel rooms should be extracted monthly, but few hotels do it that frequently. In office buildings, the upper floors can be cleaned once or twice a year but street-level floors should be cleaned much more often.

Q: How does extraction frequency affect the life of the carpet?

A: Schaffer: Carpet and Rug Institute (CRI) studies state that extraction is necessary to maintain the life and appearance of carpeting. Without it, soils become embedded in carpet fibers. These soils can then grind down the fibers and backing, which eventually limit the life of the carpet.

A: Hekman: Carpet is usually replaced because it doesn't look good. To maximize carpet life, frequent vacuuming and less-frequent wet extraction should be built into budgets.

If the carpet in a medium-traffic facility is vacuumed once a week and extracted once a year, it will probably look dirty and be irreparably damaged within a year. That same carpet might last 10 years (and look better) if vacuumed everyday, spot cleaned as needed and wet extracted on a quarterly basis.

Q: Do techniques change when cleaning recycled carpets, carpet tiles or more traditional carpets?

A: Abrams: Manufacturers recommend different methods for cleaning their carpet. The method, type of chemical used, pH of the chemical, temperature of the water and carpet dry time may be factored in.

A: Schaffer: The most important factor to consider is the use a low-moisture machine or a machine with a powerful vacuum system, providing excellent recovery. Using too much solution during the cleaning process can weaken the carpet backings and the glue holding the carpet to the floor.

A: Hekman: Extraction techniques can vary depending on the carpet construction, so it is always good to consult the carpet supplier to make sure it can be maintained with your intended methods. Recycled carpet (usually carpet tile) can be cleaned with normal methods and, due to its construction, can tolerate a lot of water. It is actually much easier to clean and dries more quickly than residential jute-backed carpet.

Q: What new trends should end users watch for?

A: Schaffer: End users should look at improvements made to existing technologies rather than entirely new trends. One big innovation has been carpet extractors that incorporate "heat" systems, a technology that can improve the effectiveness of carpet extractors dramatically. Another is the new low moisture/enhanced vacuum systems, which are more effective at removing moisture from carpets after cleaning.

A: Hekman: The most significant trend is toward using less water and fewer chemicals. Cleaning with just hot water is also becoming more popular, especially when cleaning the latest carpets, which have effective stain and soil-repellant properties.

A: Greeley: An innovation in dry extraction is combining vacuuming and pile lifting into one machine. Pile lifting facilitates and improves vacuuming effectiveness. Typical commercial uprights do not have the brushing action needed to open and stand up the carpet yarns so that dry soil removal is effective. This technology reduces chemical cleaning frequencies and improves effectiveness.

A: Abrams: With the demand for shorter dry times, low-moisture extraction features on equipment have been introduced. For routine surface cleaning, one might use the extractor in its low moisture mode. For deeper restorative cleaning, one would use the extractor in its full moisture mode.

Q: What tips are essential to remember during carpet extraction?

A: Hekman: C.H.A.T. is important to remember. Chemical — the right amount and type of chemical, applied in the right place. Heat — Hot water cleans better than cold water. Agitation — mechanical agitation loosens soil and works the water and chemicals into where they are needed. Time — allowing time for chemicals to work is essential.

A: Greeley: Control moisture — too much, too quickly loses control of the soil, making removal difficult. The most effective [extraction], in our experience, uses one gallon or less of liquid flow per minute, while other systems spray at a rate of two to five gallons per minute. Efficient recovery of the water is also important to carpet performance.

A: Abrams: Use matting at doorways to minimize tracked-in soil and wear patterns, vacuum and use a chemical below 10 pH. Do not use chemicals with solvents as in-tank chemicals, only as pre-sprays. And for thorough cleaning and maximum recovery, move slowly with the extraction head. Finally, use blowers to cut dry times in half.

A: Schaffer: Vacuuming is one of the most important steps in a carpet cleaning process. Vacuuming removes dry soil from the carpet, preventing that soil from becoming "mud" when it gets wet in the cleaning process.

Q: How do extractors play into green initiatives and IAQ?

A: Hekman: Green initiatives often mandate the use of specified equipment and chemicals. This might mean phasing out older equipment in favor of new, efficient machines with lower dust emissions and a certified level of cleaning efficiency. This usually, but not always, translates into an improved level of indoor air quality (IAQ). Vacuums and carpet extractors are tools to keep a space attractive and healthy, but they have to be used regularly to get results. IAQ is not assured by a clean carpet, but the lack of carpet maintenance, or the use of the wrong equipment, can dramatically degrade it.

A: Greeley: Green initiatives encourage the conservation of natural resources. Minimizing water usage during extraction saves water, lowers water treatment costs and controls energy costs. Less water also is essential if concerned about mold and other biological growth in the indoor environment.