The dry foam procedure is mostly rather than dry as the name infers, although the content of moisture is so low that it can actually be referred to as dry foam (90% air - 10% liquid). The dry foam machine is equipped with a pressure tank, which you will pour a solution of water and shampoo into.
A compressor will work to convert the solution into foam which is then dispensed all over the carpet using a revolving cylindrical brush. The brush will work to comb the foam through the piles of the carpet so that each individual fiber of the carpet is cleaned.
To achieve success, you must make sure that the bubbles being produced are of uniformed size so the foam can complete the cleaning process before it is dispersed. Once it has dried, the carpet is then thoroughly vacuumed to remove the dried crystals of dirt that have been left behind.