This thread is not to start a war, My buddy just bought a 870, I haven't seen it yet but it LOOKS AWESOME....shoot IT IS AWESOME. I can't wait to to go and do some CGD jobs with him...we are going to work together on some jobs, ZIPPER is going to love it!!!
The question about it is they set it I believe to 13"Hg, maybe 14"Hg even though the blower states 16" Hg. MHO is that 16 would be killer but as I have experienced that is a pretty big strain on belts,motor and mics parts.
So I am just curious if any of you out there have some time on Tm's that have been set to a lower spec.
My buddy brought over his Stanley van and it was a pretty big blower...I didn't dig in and find out what the size was but it was bigger than a 45 for sure.
We did cfm tests and lift tests and the lift came back at like 8" Hg if I recall this right.....That made total sense to me as why there carpet was so wet many times a complaint by customers that have used them.
It sounds like so far that it is pretty common to be sitting around 11"Hg or so while cleaning even with bigger blowers. I was not aware of this, this is why I am asking.
I got the vw fixed but I don't want to overdue again so just trying to get some honest feed back from some vets that have so input. Sounds like 13"Hg is a good target number to stay at.
The reason SS's carpets are left too wet is not their lift setting.
It is because they usually do not do any dry strokes as they are in a hurry to get to the next job, or if they do a dry stroke they do not over-lap properly, since they get paid only on a percentage of the ticket, and not by the hour, and their sales quotas have to be be met. I found this out how? Every time I would hire a former SS guy, we would get complaints from customers that the carpets were taking longer to dry than the last time we cleaned for them, using the same machine. The difference was the former SS Tech we had just hired. So I had to re-train them.
I have gotten great dry times with a setting of 9Hg, and even better dry times using a vac relief cuff at the wand so there is no lock-down occurring
ever when cleaning, and the air is ALWAYS flowing through the relief cuff and through the vacuum hose back to the recovery tank. Our wands are either set at a #6 or #8 flow, depending on which wand(s) we use, as we dual wand most every job.
Allowing a constant controlled "air leak" in the vacuum system also reduces fuel consumption, and will give all TM components a longer life due to less stress on the motor, blower, belts, etc. I have posted a few videos while we were cleaning, where you can hear the machine running, and if you listen, there is no up and down on the machine RPM while we are cleaning since there is no lock-down going on.
Just like the clear view tube on the Zipper, I have been using a clear tube on wands for years to determine when there is no more water that can be extracted from the carpet while cleaning to determine correct machine settings and wand techniques.
Larry C made some valid points about lift in his posts. Dan Gardner also makes some awesome posts here. He is one valuable individual to know.
I also understand where most carpet cleaners are coming from. They read about the development of sealing everything in the vacuum system off so it cannot possibly leak ANY of it's vacuum, but you actually want some controlled leakage in order to effect your best vacuum available given the parameters of your truckmount. If you watch a clear tube during extraction, you will see the flow stop when the wand is locked down, and then when the wand is lifted, you will see a rocket blast of water take off to catch up with all the water in the wand head.
Keep in mind that your wand stroke matters. If you don't pick up on the wand head at the end of a stroke, you are not introducing additional CFM into the mix.
If you have a controlled leak, the water has always been moving through the hose during the wand strokes, so instead of the "blast" to catch up, you have a more even flow of water back to the recovery tank all the time during cleaning.
You do not need 16 Hg in a truckmount. I agree it is impressive, but it is also not necessary, and it is actually a determent.
Remember - the inverse relationship between Lift and CFM - you can't get maximum "both" at the same time if you are locking the wand down to the carpet.