What I recon Martin is as you used a TM you are getting a retotational clean a bit of a sore subbject I know, no offence to the porty users they get an expetional clean too but just because youve got a TM with loads of suck doesnt mean your carpet will be dry in an hour as you know it's not down to suck its air flow and comparrisons on PSI also matter you may use the same PSI on a TM as a porty but its down too GPM not PSI it's how much water your putting down not at what pressure, deeper cleaning with more water will wet the carpet more from the backing up not just the surface.
Any 1 that can clean a carpet and have it dry in an hour with out a turbo drier after just finishing the last dry stroke has not acheived a restorational clean a maintance clean maybee and thats all thats needed to regular customers with light trafic if pre hovered well first.
So carpets that are still wet hours later doesnt mean youve done a bad job just a thorough job with unsuitable drying conditions some of the time.
Carpets dry in an hour mmm dont like it but it's good marketing as cheesy as it is, it works well and people love it
If your interested in Air flow go to the Hydramaster US web site and look it up, then explain it too me please he he