Why Not Use Blower Fans Instead? Part 2

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6 ай бұрын

This video wraps up the differences between the two types of fans, briefly touching on some fundamental engineering mechanics: compressive force and shear force. Blower fans are designed from the ground up to move air by compressive force, which they do with a very high level of efficiency; axial fans are designed from the ground up to move air in a different way, akin to shear force (but with some compressive force as well... it's complicated!). I hope the video gives you a clearer understanding of the strengths and weaknesses of each type of fan, and I thought it would be interesting to wrap up with a comparison between two fans with near identical static pressure performance but not quite so when it comes to airflow!

Пікірлер: 32

@aldvelothi755

The pressure/volume tradeoff is why I use bellows to cool my computer. The static pressure and airflow is only limited by the work ethic of my children.

@hardrocklobsterroll395

You clearly really understand the underlying physics here I’m really loving this keep up the great work

@LogioTek

Ah! Pressure is Force per unit Area. Area is smaller in blower fan so pressure is higher in the part of manifold you obstruct at exhaust end. I guess shape of the blades on blower fan make it resistant to back-pressure and since there is no more flow, intake pressure (air resistance) becomes low and it can spin faster with less air resistance. Or maybe I'm talking from my behind.

@weirdmindofesh

I have seen blower fans used in SFF desktops as the CPU fan, using the large intake to draw air over the heat sink and discharge it right out the back of the system and of course they have made their home entirely in laptops. But as soon as space is available, back to the much quieter axial fan. Most of the my systems I play with use fans capable of reaching higher RPM's as needed but are often content to let the fan tick over around 1500 RPM.

@manchoiho

I wonder why they mostly use Centrifugal fan on Quadro series and Axial fan on GeForce series

@kyocreations7938

I’m now your biggest fan

@jennysquibb7440

Have you ever compared the behavior of a cross-flow fan to the axial and centrifugal blower fans?

@jasoneverett8491

Does the same hold true when looking at how much vacuum pressure each type of fan can produce? For example, shop dust collectors are usually blower fans but sucking in air instead of building pressure on the output. I think it'd be neat to see what the numbers say about that.

@mohammadmuzammil4848

Love your videos. Can you make a comparison between the blower and axial gpu cards because historically the blower gpus run hotter. I know there are other factors like heat sink design etc but this question is killing me

@gabrielv.4358

So how can laptops have blower fans and be cooled? I always thought blower fans would win because of their thin design and great flow on the exhaust part. if you compaire a normal cooler fan with a normal blower fan I mean. But I have seen on your first video that the blower fan generally makes more noise when the normal fan makes more wind and less noise. Cool videos!

@VitorFM

So, you are a Engineer too? Are you going to talk about laminar/turbulent flow and Reynolds number? I am a (bio) chemical engineer and, to be frank, air flow is hard but I found that gas exchange/reaction rate for a sphere and 'Thiele modulus' a much more wicked thing to understand the real thing underneath....

@Shocker99

I would have made the analogy of pulleys being the difference between these two fans because that is what i believe is happening.

@WillBurnham-qd3ne

@FanPhys, thank you for the informative mini series! I am building a small downdraft/suction table for working holding during an assembly process. The first version I built has two axial fans pulling through an array of holes, those holes are to provide suction on a thin sheet that is part of the assembly. The suction was inadequate and after some research I believed this was because of poor static pressure. Your demo would lead me to believe a blower fan would produce greater static pressure. My confusion comes because I would be using the fan to pull air through, not push. Would a blower fan have an equally great ability to generate high static pressure when pulling?