What is the actual difference?
| Hot water extraction ("steam") | Low-moisture ("dry") | |
|---|---|---|
| How it works | Pre-spray, then hot water rinsed into the pile and vacuumed straight back out | A small amount of solution or a damp compound worked into the surface, then vacuumed or buffed off |
| Reaches | Deep into the pile, where most embedded soil sits | Mostly the upper pile |
| Drying | Several hours, depending on airflow and humidity | Faster, often within an hour or two |
| Best suited to | Periodic deep cleaning of home carpet; what warranties name | Frequent maintenance of commercial carpet between deep cleans |
The descriptions and drying times are general, reasoned from how each method works; they vary with equipment and conditions.
What do the carpet makers require?
Mohawk's own carpet care and maintenance guide states: "Mohawk requires professional hot water extraction every 18 months using cleaning products, equipment or systems that carry the CRI Seal of Approval." Shaw's carpet care page says to "schedule a professional hot water extraction (steam cleaning) anywhere from 6-18 months, depending on traffic." The Carpet and Rug Institute runs the Seal of Approval programme that Mohawk refers to, and notes that its certified cleaners are "recommended and sometimes required by the manufacturer to ensure results and warranty protection."
Is it really steam?
No. "Steam cleaning" is the everyday name for hot water extraction; the water is hot, not boiling steam. Shaw uses both names side by side. When a quote says steam cleaning, ask whether it means hot water extraction, which is what the warranties mean.
When does a low-moisture method make sense?
Mainly in commercial settings, where a space has to be back in use within an hour and entrances need attention every few weeks. It keeps the surface presentable between the periodic deep cleans, rather than replacing them. See commercial carpet cleaning for scheduling by traffic zone.
What should you keep for the warranty?
The receipt from every professional cleaning, dated, naming the method. If your carpet is new enough to be under warranty, read its care section before booking anyone, and ask the cleaner whether their products or equipment carry the CRI Seal of Approval, since Mohawk's requirement names it.