Vac Motor CFM Increase in Series Config | TruckMount Forums #1 Carpet Cleaning Forums

Vac Motor CFM Increase in Series Config

Jim Ellis

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As usual there is no exact formula's / specs / studies to follow on this subject available but here is what I've managed to put together based on limited observations and my own experiments:

  • The average cfm increase is about 15-20% when 2 vac motors are put into a series
  • Previous mis-information posted on the web used to indicate that you lose 10% of cfm from each additional motor added in a series - this doesn't appear to be true
  • CFM, I guess, increases even more with stronger lift motors in a series - case in point:
    If you go by Mytee's cfm ratings on the Escape the higher lift motors it uses - 145" must create a more dramatic increase on cfm since they are only 100 cfm - 2 x 2(series) would, based on 20% only produce about 240 cfm - however, Mytee rates the Escape at 325 cfm and has a video showing the cfm meter at 325. So with the higher lift motors the cfm increase is more like 60%?! Remember the Escape uses Mytee's c304 vac motors which only rate at 100 cfm each according to Mytee's own parts website - http://www.mytee.com/products/c304-vacuum-motor/#.Un6op3DIGzk
So what's the real formula for cfm increase here? I would imagine that the cfm increase is better with higher lift motors in a series vs lower lift due to the increased air velocity but I'm having a hard time believing that a Mytee Escape can put out 325 cfm from 100 cfm motors.
 

Jimsteam

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As usual there is no exact formula's / specs / studies to follow on this subject available but here is what I've managed to put together based on limited observations and my own experiments:

  • The average cfm increase is about 15-20% when 2 vac motors are put into a series
  • Previous mis-information posted on the web used to indicate that you lose 10% of cfm from each additional motor added in a series - this doesn't appear to be true
  • CFM, I guess, increases even more with stronger lift motors in a series - case in point:
    If you go by Mytee's cfm ratings on the Escape the higher lift motors it uses - 145" must create a more dramatic increase on cfm since they are only 100 cfm - 2 x 2(series) would, based on 20% only produce about 240 cfm - however, Mytee rates the Escape at 325 cfm and has a video showing the cfm meter at 325. So with the higher lift motors the cfm increase is more like 60%?! Remember the Escape uses Mytee's c304 vac motors which only rate at 100 cfm each according to Mytee's own parts website - http://www.mytee.com/products/c304-vacuum-motor/#.Un6op3DIGzk
So what's the real formula for cfm increase here? I would imagine that the cfm increase is better with higher lift motors in a series vs lower lift due to the increased air velocity but I'm having a hard time believing that a Mytee Escape can put out 325 cfm from 100 cfm motors.
CFM does increase as you say @ 15% with a series configuration. Throwing a single vac booster down line does not cause lift to drop to performance of the single vac booster less lift than the base unit yes but not drastically. Doing my own testing opened my eyes.
Jim,
If you can posts some videos of your testing.
 

Jim Ellis

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I'll do some more tests and post soon. Have to order another anemometer. Still does Mytee's 325 claim make any sense? 4 100 cfm motors paired up 2 in series... If their video and specs are accurate then they know something we don't about getting more cfm out of motors in a series.

Sent from my SGH-T679 using TMF Forums mobile app
 

Jimsteam

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Ever see a video of a CFM test with the 8.4 Breeze ? The claim of lift on the Eclipse ? End user and the Escape with a Anemometer? The list goes on and on.
No matter , I have found my "Niche" and has proven to be very reliable and profitable.
Carry on and prove thru videos what you have discovered, I'm done .
 

Jim Ellis

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Examples:

Goliath - 255 cfm in Steam Brite Video - 250 cfm in user videos - 4 97 cfm motors setup 2 x 2 (in series) - 25% cfm increase - appears valid

Mytee Escape - 325 cfm in Mytee's video - 4 100 cfm motors setup 2 x 2 (in series) - 60% increase?! Not likely.

Ametek 6.6 Motors in a series - 2 140 cfm motors in a series - 171 cfm - 22% increase - tested this

My conclusion is that a cfm increase somewhere between 20-25% is possible with motors in a series - However either the specs on Mytee's Escape vac motors are wrong or 325 cfm is not accurate.