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Good article on CFM, Waterlift.

Printed From: Carpet Cleaning Forum
Category: Carpet Cleaners Discussion
Forum Name: Portable Carpet Steam Cleaning Machines
Forum Description: Discuss anything relating to portable carpet cleaning machines
URL: https://www.kleenkuip.com/forum/forum_posts.asp?TID=4533
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Topic: Good article on CFM, Waterlift.
Posted By: Johnsmith808
Subject: Good article on CFM, Waterlift.
Date Posted: 23/December/2007 at 5:20pm
This is a very informative article about the debate over cfm and waterlift:

http://www.hydramaster.com/inside/articles/articles2.asp

It's interesting to notice that truckmounts have lifts in the 13-15" Hg range, which is equivalent to around 175"-225" waterlifts, yet at cfm's around 300-500 or so. 

So when you consider running a portable with vacuums in a series, say 2-3 stage vacs, you will get upwards of 220" of waterlift, but the cfm will drop down to 90 or so.

When you run vacs in parallel, the waterlift will be around 140", which is around 10" Hg, but the cfm will then be at 200.

It would appear that running these vacuums in parallel would closer mimic the balance of cfm and waterlift that truckmounts use, but of course scaled back to portable levels.  When vacs are run in a series, the lift is as high as truckmounts, but the cfm is proportionately far lower, thus throwing the balance off.

As the article pointed to, only recently have more become aware of this balance.  Of course there have obviously been some who have been pioneering this understanding for many years, but the great majority haven't been listening, including your's truly I must admit.



Replies:
Posted By: FriendlyHammer
Date Posted: 23/December/2007 at 10:01pm
Imagine you made a machine with 1,000,000 inches of waterlift and only 1 cfm.  It would sell like hotcakes, but it wouldn't clean a darn thing.


Posted By: Ed Valentine
Date Posted: 24/December/2007 at 1:18pm
Wonder where they learned that??????????? (!!!!)


merry Christmas;
Ed Valentine
cross-american corp.


Posted By: Johnsmith808
Date Posted: 25/December/2007 at 5:53am
Would glides work better on a system running in a series or parallel?  


Posted By: John L
Date Posted: 25/December/2007 at 10:57pm
Buy something F A S T and make some loot..!LOL


Posted By: Johnsmith808
Date Posted: 26/December/2007 at 4:23am
Just when I think I understand this whole cfm and waterlift thing, I have another question.  Say you run a machine with dual 3 stage vacs in parallel or in a series.  Would running in parallel be better than running in a series for every hose length?

Say the numbers are Parallel= 140" waterlift and 200 cfm
                                  Series  = 220" waterlift and  95 cfm

Which would do better with 15 ft of hose? 25? 50?


Posted By: Johnsmith808
Date Posted: 26/December/2007 at 8:02pm
I just got an explanation of where vacs in series or parallel would be beneficial.  I'm sure you guys already know this, but please be patient.

I was told that vacs in a series would be better with low pile, commercial type carpet.  I would think that would be because the seal is pretty good at the wand, so lift would come more into play.

Vacs in parallel would better suite thicker, residential carpet, due to the seal not being as tight, thus airflow being better.

Does that sound about right?


Posted By: FriendlyHammer
Date Posted: 27/December/2007 at 12:14am
Originally posted by Johnsmith808 Johnsmith808 wrote:

Would glides work better on a system running in a series or parallel?  


Parallel.


Posted By: FriendlyHammer
Date Posted: 27/December/2007 at 12:23am
Originally posted by Johnsmith808 Johnsmith808 wrote:

I just got an explanation of where vacs in series or parallel would be beneficial.  I'm sure you guys already know this, but please be patient.

I was told that vacs in a series would be better with low pile, commercial type carpet.  I would think that would be because the seal is pretty good at the wand, so lift would come more into play.

Vacs in parallel would better suite thicker, residential carpet, due to the seal not being as tight, thus airflow being better.

Does that sound about right?


Perhaps, but if you've ever seen that carpet, I would think you would wonder what the difference is. That pile is so thin that "pile" is almost an oxymoron. Sure the seal is strong, but how much water can you get in 1/8 of an inch of carpet?




Posted By: FriendlyHammer
Date Posted: 27/December/2007 at 12:25am
Originally posted by Johnsmith808 Johnsmith808 wrote:

Just when I think I understand this whole cfm and waterlift thing, I have another question.  Say you run a machine with dual 3 stage vacs in parallel or in a series.  Would running in parallel be better than running in a series for every hose length?

Say the numbers are Parallel= 140" waterlift and 200 cfm
                                  Series  = 220" waterlift and  95 cfm

Which would do better with 15 ft of hose? 25? 50?
'

The shorter the better. Don't go above 50 feet with parallel. And 25 feet in series. I'm sure others have their opinions, but that's mine. Frankly, I would only use more than 20 feet if I were doing stairs or upholstery that couldn't be reached with a shorter hose.


Posted By: Johnsmith808
Date Posted: 27/December/2007 at 2:34am
Thanks Friendly.  I think I'm going to go ahead and turn my machine into parallel vacs.  I'm also going to make the intake on the recovery tank 2" instead of 1.5.  Shouldn't be too hard.  Of course I would then need to run 2" hose.

Yesterday I did a job using 15 feet of hose, and it dried faster than any job I've done recently.  It was actually easier to work with 15 feet of hose than 25 feet for the most part as well.

The only reason I use 50 feet sometimes is so I don't have to carry the machine upstairs on a two story house.  Now I plan on getting a continuous piece of 50 feet 2" hose and running the machine in parallel.   And for one story units, I'll stick with the 1.5 inch 15 foot house.  Would 2" on such a short hose even matter?


Posted By: Johnsmith808
Date Posted: 25/January/2008 at 6:48am
Would adding a 3rd 3 stage in parallel for 125" lift and 300 cfm be a good balance?  Or would the lift be a little low for that amount of cfm.  Should I just stick to 2 3 stage in parallel for  125" lift and 200 cfm?


Posted By: John L
Date Posted: 25/January/2008 at 12:39pm
Add it.. I did on my Recoil.. Faster dry times.. Bouncing%20Smileys


Posted By: Johnsmith808
Date Posted: 25/January/2008 at 1:34pm
Sounds good!  Thanks.


Posted By: Superglide Ken
Date Posted: 27/January/2008 at 1:08am
Originally posted by Johnsmith808 Johnsmith808 wrote:

Would adding a 3rd 3 stage in parallel for 125" lift and 300 cfm be a
good balance?  Or would the lift be a little low for that amount
of cfm.  Should I just stick to 2 3 stage in parallel for 
125" lift and 200 cfm?
You can get one or the other, but NOT BOTH at the same time.

-------------
Inventor of the Teflon Wand Glide and the Turboteck Rotary Air Duct Cleaners for TMs.



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