Twin Fan Uprights - physics question for engineers out there

[eurekaprince]

In the 1950’s, Singer came out with their sleek revolutionary upright that offered a sideways-positioned motor with a fan on each side. This “twin-fan” upright design survived well into the 1970’s in the form of upright vacuums branded as Singer, Kenmore, Lewyt and Sunbeam. But these uprights never seemed to top Consumer Reports ratings for deep carpet cleaning….they were always outperformed by competitors’ uprights created by Eureka, Hoover and Panasonic.

Which brings me to a bit of a science question maybe someone could answer: is it possible that having two fans each creating a suction pull on each side of the brush chamber is actually counter-productive? In other words: is it possible that this design actually creates less effective air flow in the brush roll chamber because each fan is trying to pull air away from the other fan - thereby negating the suction pull on each side?

Thoughts?

 

[cheesewonton]

In the 1950’s, Singer came out with their sleek revolutionary upright that offered a sideways-positioned motor with a fan on each side. This “twin-fan” upright design survived well into the 1970’s in the form of upright vacuums branded as Singer, Kenmore, Lewyt and Sunbeam. But these uprights never seemed to top Consumer Reports ratings for deep carpet cleaning….they were always outperformed by competitors’ uprights created by Eureka, Hoover and Panasonic.

Which brings me to a bit of a science question maybe someone could answer: is it possible that having two fans each creating a suction pull on each side of the brush chamber is actually counter-productive? In other words: is it possible that this design actually creates less effective air flow in the brush roll chamber because each fan is trying to pull air away from the other fan - thereby negating the suction pull on each side?

Thoughts?

I suspect that other aspects of the vacuum's design led to it being less competitive. Without reading the tests however I can only speculate. Panasonic would be a clean air model with a higher amp motor than those old Singer's used and because it is clean air it would have more suction. Hoovers had especially aggressive brush rolls. Tacony makes a modern twin fan model of their own sold under the Carpet Pro brand name that I have been tempted to buy.

 

[centralsweeper63]

Good points. They got half of the equation, but not the other half.

 

[vacuumman]

In the 1950’s, Singer came out with their sleek revolutionary upright that offered a sideways-positioned motor with a fan on each side. This “twin-fan” upright design survived well into the 1970’s in the form of upright vacuums branded as Singer, Kenmore, Lewyt and Sunbeam. But these uprights never seemed to top Consumer Reports ratings for deep carpet cleaning….they were always outperformed by competitors’ uprights created by Eureka, Hoover and Panasonic.

Which brings me to a bit of a science question maybe someone could answer: is it possible that having two fans each creating a suction pull on each side of the brush chamber is actually counter-productive? In other words: is it possible that this design actually creates less effective air flow in the brush roll chamber because each fan is trying to pull air away from the other fan - thereby negating the suction pull on each side?

Thoughts?

Off the top of my head, I know that the Singer Magic Carpet series has a floating brushroll that doesn't make contact with the carpet super well, so that may put it at a disadvantage.

I feel like the air in a twin fan setup is more likely to take the path of least resistance through the nozzle rather than pull against the other motor, but I am not 100 percent sure.

 

[centralsweeper63]

It would work, as long as the pressure is the same from both motors, like on a parallel motor central vac.

 

[cheesewonton]

It would work, as long as the pressure is the same from both motors, like on a parallel motor central vac.

It is one motor laying on its side with a fan on either end of the armature shaft.

 

[blackheart]

I don't really know the physics behind it but I've tested at least 2 vacuum with a twin fan setup, that singer as seen above and a piranha upright which was made by tornado, based off of the bissell prolite design.
Usually in parallel settings the flow is boosted but this is a unique case where we have parallel airflow sources powered by one motor meaning that motor is getting all of the resistance in addition to that they also funnel all of the air into a single channel.
It's been my experience so far that there's not too significant a benefit to this design IF there even is one. The Singer I tested scored below many direct air single fan machines like the hoover convertible or Eurekas, The piranha though did slightly better than most if not all of the other lightweight direct air machines I've tested so far but only by about 5-6 cfm
The design *may* lead to better distribution of the airflow across the nozzle but that's speculation.

I'm not sure I'd say it's counter productive fluid will follow the path of least resistance and being powered by the same motor their suction should be equal I will say it definitely seems less efficient than just having one larger fan and a single airpath.