Mikey P
Administrator
Is that agitation is king.
All three of these blowers will be on the Sapphire Demo truck.
All of them will give different readings with the CFM meter I'm bringing, yet all of them will the 406 will clean exactly the same at the 410 at 150 ft.
All these theories and debates on inches of lift and cubic feet measures are based on Scrub Wand technology.
Remember this bullshit?
Lift determines how much CFM your wand will flow!
Most here do not understand the relationship that your TM's air flow(CFM's) and your wands ability to translate that into a clean and dry carpet have in the real world of cleaning. I will explain this in detail to make the subject more understandable.
First lets take a typical set-up as a good example of a real world situation. The 4M blower is probably the most common one out there so we will examine its air flow characteristics. This blower will usually put out about 320 cfm @ 14" HG(a typical setting) when turned at the usual 3000 rpm. This would be measured at the blower outlet. By the time system losses in the vacuum tank are deducted that number will be reduced to about 300 cfm or so. Add another 100 ft of 2" hose with a 1.5"- 10 ft whip hose and that flow is down to about 250 cfm. Still sounds pretty good,but what happens when a wand is added and the lips of that wand are put down on damp plush carpet. Your airflow is cut in half! The wand/carpet interface is such an obstacle to air flow that nothing else in the airflow system comes close. What you can do about it is what the rest of this article is about. After all, 125 cfm doesn't sound too impressive when you started off with 320, does it?
The role of Lift
What is lift in the context of carpet cleaning anyway? Well look at it this way; we all rely on the 30" HG of air pressure that surrounds us to force the air,water and soil into our wands when they are on the carpet cleaning. This is accomplished by dropping the pressure in the wand and hose to a low enough level that the higher air pressure outside the wand will cause air to move inside it. The greater the differential in those pressures the greater the lift that system has. As a simple example of this lets say that your system operates with the vacuum at 10"Hg. This means that the pressure inside the wand at the lips is really at 20"HG (30"HG - 20"HG= 10"HG) The gauge is really measuring the amount of pressure drop from the normal outside pressure (30"HG). Air always flows from high to low pressure and the greater that difference is the faster and more that volume (CFM) of air movement that will be.When the wand is on the carpet cleaning the Wand/Carpet interface is a very hard blockage to get by so maybe only 125 cfm from your original 250 cfm available to go into the wand can make it through there. If the lift of the system is increased to 15"HG instead of 10" HG what do you think will happen? Now there is 15" HG difference between the air pressure inside the wand and the air pressure outside. More air will now push past the wand carpet interface and in doing so the volume of the air(CFM) will increase too.The cfm may be up to 150 now which will increase your ability to clean that carpet better(especially heavily soiled ones),and the increase in usable cfm's will definitely dry that carpet better.By getting your system to operate at 15"HG you have improved your real cfm flow capability by 20% (150cfm/125 cfm).
This is why all 4M blowers are not created equal! Some will operate at higher levels of lift than others. The 4MP blower will operate at 16"HG all day long and allow you to run long hose runs when you need to while delivering excellent cleaning results because of its higher "real" cfm capability. A Roots 47 blower run at its normal lift setting of 12"HG wont be as effective at letting those extra CFM's through your wand. Bottom line here is this: The vacuum system that can create the greatest lift numbers at the wand/carpet interface is really the one that will move the greatest amount of air (CFM) into your vacuum system and dry the carpet the fastest; all other factors being equal.
© Ken Harris 4/11/2001
All three of these blowers will be on the Sapphire Demo truck.
All of them will give different readings with the CFM meter I'm bringing, yet all of them will the 406 will clean exactly the same at the 410 at 150 ft.
All these theories and debates on inches of lift and cubic feet measures are based on Scrub Wand technology.
Remember this bullshit?
Lift determines how much CFM your wand will flow!
Most here do not understand the relationship that your TM's air flow(CFM's) and your wands ability to translate that into a clean and dry carpet have in the real world of cleaning. I will explain this in detail to make the subject more understandable.
First lets take a typical set-up as a good example of a real world situation. The 4M blower is probably the most common one out there so we will examine its air flow characteristics. This blower will usually put out about 320 cfm @ 14" HG(a typical setting) when turned at the usual 3000 rpm. This would be measured at the blower outlet. By the time system losses in the vacuum tank are deducted that number will be reduced to about 300 cfm or so. Add another 100 ft of 2" hose with a 1.5"- 10 ft whip hose and that flow is down to about 250 cfm. Still sounds pretty good,but what happens when a wand is added and the lips of that wand are put down on damp plush carpet. Your airflow is cut in half! The wand/carpet interface is such an obstacle to air flow that nothing else in the airflow system comes close. What you can do about it is what the rest of this article is about. After all, 125 cfm doesn't sound too impressive when you started off with 320, does it?
The role of Lift
What is lift in the context of carpet cleaning anyway? Well look at it this way; we all rely on the 30" HG of air pressure that surrounds us to force the air,water and soil into our wands when they are on the carpet cleaning. This is accomplished by dropping the pressure in the wand and hose to a low enough level that the higher air pressure outside the wand will cause air to move inside it. The greater the differential in those pressures the greater the lift that system has. As a simple example of this lets say that your system operates with the vacuum at 10"Hg. This means that the pressure inside the wand at the lips is really at 20"HG (30"HG - 20"HG= 10"HG) The gauge is really measuring the amount of pressure drop from the normal outside pressure (30"HG). Air always flows from high to low pressure and the greater that difference is the faster and more that volume (CFM) of air movement that will be.When the wand is on the carpet cleaning the Wand/Carpet interface is a very hard blockage to get by so maybe only 125 cfm from your original 250 cfm available to go into the wand can make it through there. If the lift of the system is increased to 15"HG instead of 10" HG what do you think will happen? Now there is 15" HG difference between the air pressure inside the wand and the air pressure outside. More air will now push past the wand carpet interface and in doing so the volume of the air(CFM) will increase too.The cfm may be up to 150 now which will increase your ability to clean that carpet better(especially heavily soiled ones),and the increase in usable cfm's will definitely dry that carpet better.By getting your system to operate at 15"HG you have improved your real cfm flow capability by 20% (150cfm/125 cfm).
This is why all 4M blowers are not created equal! Some will operate at higher levels of lift than others. The 4MP blower will operate at 16"HG all day long and allow you to run long hose runs when you need to while delivering excellent cleaning results because of its higher "real" cfm capability. A Roots 47 blower run at its normal lift setting of 12"HG wont be as effective at letting those extra CFM's through your wand. Bottom line here is this: The vacuum system that can create the greatest lift numbers at the wand/carpet interface is really the one that will move the greatest amount of air (CFM) into your vacuum system and dry the carpet the fastest; all other factors being equal.
© Ken Harris 4/11/2001
