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Blowers vrs. fans?

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mccoyn

Senior Member
Joined
Nov 17, 2003
Location
Michigan, USA
I see a lot of blowers that are rated around 10 CFM, yet have high noise levels when compared to fans. Whats the advantage of a blower? Is it better at pushing through a heatsink? How much better?

I have a 30 CFM fan pushing through a rather constrictive heatsink. Would it cool better with a blower? Might it be quieter?
 

Yuriman

Member
Joined
Aug 27, 2002
Location
The OCFORUMS
Blowers normaly are less annoying, they buzz less. They also have a lot more pressure, and have no dead zone in the middle. With a 92mm tornado and an slk900, you may only get air over 20% of the sink, with a blow its 100%.
 

cstarritt

Member
Joined
Nov 7, 2003
you have to understand that CFM is a function of static pressure. the more resistance, the less flow. blowers move air agianst pressure alot better than axial fans do. with a 30cfm fan and a 20cfm blower, the static pressure might be near the max the fan will push air agianst, and you will get like 10 cfm actualy, whereas a 20cfm blower might give you 15 cfm agianst that pressure, even though its unresricted flow is 10 cfm lower. also, while the DB rating may be higher, the noise is more a sound of rushing air than a fan's high pitch annoying whine. blower noise is much more tollerable.
 

Valk

Member
Joined
Oct 31, 2002
I would be interested to see if there are blowers on the marktet right now that can match my smart fan 2. even thogh blower fans ARE more efficiant, thats 78 cfm to beat. although, if such a blower can beat it, im all over that. the dead spot on my sk7 is immense. somthing iwant to correct.
 

Robrules18

Member
Joined
Jul 20, 2003
Location
Peoria, IL
Valk, what ou should be aksing for is an 80mm blower that will beat a SF2 ive seen a 400 some CFM blower out of a furnace before and the one in my house is at least that probably.

IT would probably shoot the CPU out the back of the case :D
 

Valk

Member
Joined
Oct 31, 2002
:drool: wicked
I might jump into building my own blower. just rape an old smart fan 2 of its motor ;) I built a little injection molding machine a while back to make model airplane parts. i could potentially build a blower fan quite easily ;). oh well.

too lazy for that right now. I just want a more powerful aero fan if i can get it =\
 

archilochus

THE Senior FANMAN
Joined
Sep 26, 2003
Location
Houston,TX-USA
Like the guys were saying ,no dead spot in frt of the hub.This LINK will illustrate that point. THE FANMAN:cool:



FAN LINK

You may have to wait for page to load completely :D
 

vonkaar

Member
Joined
May 20, 2003
Location
Colleyville, TX
The blower on my heatercores pushes 770 CFM at 48v... I have it running at 36v. It's *much* quieter than a Thermaltake Smartfan 2.

IMO, the jet blower is hardly worth calling a 'blower'. Ya'll can get *real* blowers on Ebay for under $10. The main downside to using a blower over an axial (or tubeaxial) fan is size. My blower is 10"x7"x6.5"... not *enormous* but still a 'bit' bigger than a 120mm fan =p.
 

archilochus

THE Senior FANMAN
Joined
Sep 26, 2003
Location
Houston,TX-USA
This is what I found.The air pressure on the 2 fan types are as
follows.Thermaltake SF II: 8.43mm H2O @ 4800rpm / dBA 48.0
Aero Blower: 10.7mm H2O @ 3500rpm /dBA 37.5
80x80x70 mm. THE FANMAN:cool:
 

biyonic

Registered
Joined
Oct 21, 2003
Location
Cincinnati
A blower (but not the kind for sale for computer users) is overkill for any PC. It is by design used to overcome static pressure in an air handling system. There is little static pressure in a computer application. That is, unless you are ducting from a remote location through rough duct. Or, if you want to add one for visual effect - which is cool if that's your thing.
 

cstarritt

Member
Joined
Nov 7, 2003
well i got my blowers blowing into a duct, and i sit them on top of my psu. i also plan on ducting the 120mm fan hole they are feeding though down to ground level so its not sucking in hot exahust air form teh psu. they blow alot more air though my duct kit than a sf2 on high, and with less noise. and if i crank them up, they make alot of noise, but man do they move air.

one problem i have with them right now is the duct makes a very sharp turn at the HS, and the air all comes out one side of teh duct, so only one side of teh hs gets a good flow across it. i want to mod it so the air goes in at the side of the hs (tape off top) and comes out the other side.
 

vonkaar

Member
Joined
May 20, 2003
Location
Colleyville, TX
biyonic said:
A blower (but not the kind for sale for computer users) is overkill for any PC. It is by design used to overcome static pressure in an air handling system. There is little static pressure in a computer application. That is, unless you are ducting from a remote location through rough duct. Or, if you want to add one for visual effect - which is cool if that's your thing.

Dual heatercores. If I use even the 'best' of 120mm fans, I can still feel very little pass through the heatercores. If I crank that up and use a 178mm fan, I feel a lot more, but it still is very little in comparison to my blower, which is far quieter *and* more powerful than any axial fan I could use (within comparable dimensions).

Definitely not impractical. If you are talking about using a blower for case circulation, you are more correct, but I could still feasibly see a use or two ^_^.
 

biyonic

Registered
Joined
Oct 21, 2003
Location
Cincinnati
I'm trying to make it clear that there are PC-grade blowers and industrial blowers. I could be wrong but the blowers I think you have are light duty PC jobbies. Which are great for what you are using them for because they are quiet and low voltage DC - yes?

See the article database for a true industrial Granger catalog blower. Now that is a blower. With that kind of blower you are looking at $$$ and AC voltage which I would stay away from in a case modding application.
 

Robrules18

Member
Joined
Jul 20, 2003
Location
Peoria, IL
im sure they have blowers that put out several thousand CFM and are almost silent besides the massive whoosing of air... But they are probably as big as your case.... So Unless you get a small one made for PC youll have tyo mod it but it will give you excellent results.
 

vonkaar

Member
Joined
May 20, 2003
Location
Colleyville, TX
The blower I use is designed for cooling electronic test equipment. The only blowers that would be usable in a computer *would be* those that are designed for more than a light breeze. Heater-core blowers (as defined in a car-mechanics' vocabulary... ie, the real thing), rack-mount blowers and AC blowers all fit this description.

Like I said above, it's only 10"x7"x7". Very small... very quiet... very powerful. You could probably do just as well with an even smaller automotive blower.
 

NiTCOM

Member
Joined
May 17, 2003
Location
U.S.A. / Germany
mccoyn said:
I see a lot of blowers that are rated around 10 CFM, yet have high noise levels when compared to fans. Whats the advantage of a blower? Is it better at pushing through a heatsink? How much better?

I have a 30 CFM fan pushing through a rather constrictive heatsink. Would it cool better with a blower? Might it be quieter?

I bought a blower ones and have to say: stay away.
I make more air by farting than this blower can provide.
:D