How Inlet Boxes Affect Fan Performance (System Effect Series 2 of 6)

[@efmiii8896]

Great video, Dave.

[@davidmaletich9392]

Thanks! Let us know if there are other topics you would like to see us cover.

[@efmiii8896]

@@davidmaletich9392 Initial restriction, expected service life, and noise attenuation for NYB pressure blower filter sizing options? Suggested by Jason Carpenter and Jeff Galinowski. Rob will reach out to you next week to discuss. Call us any time Dave.

[@user-fu9mz2de2x]

David This is interesting to me. What would happen if a wheel is added inside the box to work with the wheel in the blower. The same way a turbo charger works, but working with the air going in one direction.

[@lukedieleman6676]

assuming you mean running a second fan inside the inlet box connected to the same motor, you would gain some static pressure and cfm at the cost of more power consumption, so a similar effect to just running the first fan faster. This is unlikely to be worth it due to manufacturing complications, but as far as I know secondary fans like that are more effective at lower air pressures, so maybe a system like that could be useful in high altitude situations where the cost might be justified.

[@jeremiahchmielowiec2696]

How much of a improvement in fan cfm can be seen between the two inlet boxes?

[@NewYorkBlowerCompany]

Hey Jeremiah! Since we are measuring velocity pressure (VP) and the ductwork is 8” in diameter, cfm increases from approximately 1000 cfm to 1170 cfm.

[@HelloKittyFanMan]

What determines when a fan like this will sound like a vacuum cleaner fan (if this is a backwards-curved or radial-bladed fan)?

[@HelloKittyFanMan]

What's the supposed "difference" between changing and altering?

[@HelloKittyFanMan]

"Not bouncing up and down..." ...said as it still bounces a little.

[@aifrisyad7491]

does baseline pressure have the same number on any circumstances?

[@NewYorkBlowerCompany]

Hello! Thanks so much for watching and reaching out with this question. Baseline pressure is the same as long as configurations do not change. For all of the inlet configuration videos, the base line pressure is based on a fan with an open inlet, rectangular to round transition leading from the fan into a straight run of ductwork before heading into a damper with a preset position. Any changes to this configuration would establish a new baseline. For example, if the damper position changes, a new baseline is established. If the straight run of ductwork is removed, a new baseline is established.

[@aifrisyad7491]

@@NewYorkBlowerCompany i am wondering how many pressure do I need in order to have magnehelic to measure the standard pressure of in line pipe of my coffee roaster

[@NewYorkBlowerCompany]

@@aifrisyad7491 In order to better understand your question, can you clarify what you are trying to measure/accomplish? Are you looking for velocity pressure in order to calculate flow? Or are you looking for static pressure to calculate pressure drop? If Static Pressure (SP), one point should be good enough. If velocity pressure, it depends on the amount of straight duct available as well as how accurate the reading needs to be. Note that both readings are most accurate when taken in a straight run of ductwork (non-turbulent flow). Resources in include nyb’s Engineering Letter 7 - Field Testing of Fan Systems (www.nyb.com), AMCA’s publication 203-90 - Field Performance Measurement of Fan Systems, and AMCA's publication 201 - Fans and Systems. (www.amca.org)

[@HelloKittyFanMan]

"Enter into the box..." * "Enter _the_ box."

[@HelloKittyFanMan]

"Top region never sees any air." So you're saying that somehow there's a pocket of perfect vacuum right there?

[@NewYorkBlowerCompany]

Hi! To answer your question, there is never a “perfect” vacuum and this could have been stated as “sees very little to no air”. The pressure is near zero or a slight negative. Functionally this part of the wheel does little to no work.