AC cooling fan?? is it possible?

[noobuilder1]

Ok a friend just gave me a 120mm NMB 115v 50/60 Hz single phase 15/13 W AC fan. It moves HUGE, (right about 100cfm) amouts of air and is only slightly louder then my current 120 mm case fan, BUT its AC powered not DC... So here is my question, I know I can add a switch to the power line and make it manual on/off and plug it in to the wall, but is there any such thing as a DC molex inverter to 115v AC??? That way it could be powered on/off with the computer, and being that its only 15w my PSU should run it no problem, BUT could it handle the start up of the fan? (Some AC motors use a big draw to start but drop to low watts to remain running).... I REALLY want to use this thing but I dont know if it would work the way I want to.. Any help would be great...

 

[HugoStiglitz]

Short answer Yes, but totally not worth it.

your PSU is already a 115v to DV converter.
so your wanting to do the following

115v AC to DC then DC 12v to 115v AC
(Done by PSU)

the inefficiently your introducing by going from AC to DC then DC back to AC is not worth it. not to mention that to buy an inverter to do it would be MORE than it costs just to get a decent 120mm DC fan in the first place.

check out the Scythe GentleTyphoon (AP-15)

Pretty cheap fan and constantly gets great reviews, I have 6 of them covering radiators and all sorts

http://www.scythe-usa.com/product/acc/051/d1225c12b1ap_detail.html

 

[Someone Somewhere]

It would effectively be the same sort of inverter you plug into a cigarette lighter socket in a car. It's not just a rewire of the pins.

Not worth it, though powering it externally could be. AC powered fans can be FAST.

 

[noobuilder1]

Short answer Yes, but totally not worth it.

your PSU is already a 115v to DV converter.
so your wanting to do the following

115v AC to DC then DC 12v to 115v AC
(Done by PSU)

the inefficiently your introducing by going from AC to DC then DC back to AC is not worth it. not to mention that to buy an inverter to do it would be MORE than it costs just to get a decent 120mm DC fan in the first place.

check out the Scythe GentleTyphoon (AP-15)

Pretty cheap fan and constantly gets great reviews, I have 6 of them covering radiators and all sorts

http://www.scythe-usa.com/product/acc/051/d1225c12b1ap_detail.html

I agree with your answer, but damn if you saw this little beast in action you would want it in your system also... Its as quiet (there is noise, dont get me wrong) as a cheap 120 fan at max rpms, but its spinning at like 2900 rpm and putting out a torrent of smooth, smooth air, its amazing and best of all its free.... oh well just hoped that someone some where had the answer i really wanted to hear. I may just mount it to the exhaust port on my case and operate it manually but I dont know....

 

[noobuilder1]

Short answer Yes, but totally not worth it.

your PSU is already a 115v to DV converter.
so your wanting to do the following

115v AC to DC then DC 12v to 115v AC
(Done by PSU)

the inefficiently your introducing by going from AC to DC then DC back to AC is not worth it. not to mention that to buy an inverter to do it would be MORE than it costs just to get a decent 120mm DC fan in the first place.

check out the Scythe GentleTyphoon (AP-15)

Pretty cheap fan and constantly gets great reviews, I have 6 of them covering radiators and all sorts

http://www.scythe-usa.com/product/acc/051/d1225c12b1ap_detail.html

I agree with your answer, but damn if you saw this little beast in action you would want it in your system also... Its as quiet (there is noise, dont get me wrong) as a cheap 120 fan at max rpms, but its spinning at like 2900 rpm and putting out a torrent of smooth, smooth air, its amazing and best of all its free.... oh well just hoped that someone some where had the answer i really wanted to hear. I may just mount it to the exhaust port on my case and operate it manually but I dont know....

 

[noobuilder1]

It would effectively be the same sort of inverter you plug into a cigarette lighter socket in a car. It's not just a rewire of the pins.

Not worth it, though powering it externally could be. AC powered fans can be FAST.

2900 rpm's, and almost 100 CFM... Its a beast.

 

[Someone Somewhere]

That's like 50 L/s... A 0.5m*0.5m*0.2m cuboid per second. In other words, it would empty your case maybe every two seconds.

 

[HugoStiglitz]

what model / brand is the AC fan you have been given?

the Scythe GT AP-15 does 1850 rpm for 58.3 CFM for 28 dBA at max RPM
the info I could find on urs is 2750 RPM 95 CFM for 39 dBA at max RPM

so yes it moves more air but it's ALOT louder.

you could look at the Scythe GT AP-29, 30 or 31
AP-29 - 3000 RPM, 83 CFM at 36.5 dBA
AP-30 - 4250rpm, 116.5 CFM at 44 dBA
AP-31 - 5400rpm, 150.1 CFM at 50.5 dBA

and they are all 120mm 12v DC and each will cost less than an inverter will for your existing AC fan

take a look at most high end water cooled PC's and take note of the fans on their radiators. you will pick the Scythe's design a mile away.

http://www.frozencpu.com/products/1...Fan_-_1850_RPM_D1225C12B5AP-15_Hot_Item_.html
and for $17.50 pretty cheap

I tried quite a few fans, some 100+ cfm, some low noise / speed and they all sit in a box while my AP-15's cool my rig all day with no noise or fuss

 

[Someone Somewhere]

Difference. If he just wires it to a plug, it's free.

Plus the fan seems to fall roughly midway between the AP-29 and AP-30 in terms of both air flow and noise, and does so at a lower RPM (lower freq. noise? Good or bad?).

 

[noobuilder1]

Ok so like a little kid at xmas I got home from work and pulled the 3 5.25 bay covers and just sat the fan right there (computer off no fans spinning at all) and plugged her in. Holy crap I could pull the 2 120's and the sidedraft 80 and just run the ac fan.... there was noticeable air flowing out of every vent hole in the fron and side of the case and the rear was blowing harder then the 120 exhaust ever could.... noise was higher but really not by much.... I may just wire up a potentiometer and a power switch and just mount it in that triple 5.25 bay and call it a day... I am impressed to say the least. Although I did see on the manufacturer website that they have equal but 12volt fans... that would be much cleaner install but probably a waste of money. .... thanks for your input. ...

 

[Someone Somewhere]

Not sure how well a pot would work - it's AC, though I'd expect it to be a rectifier then just a brushless DC fan. If it's synchronous you're screwed...

You'd want a relatively low value pot.

Like I said, emptying your case about every two seconds, and if it's that long it's a big case.

 

[noobuilder1]

Not sure how well a pot would work - it's AC, though I'd expect it to be a rectifier then just a brushless DC fan. If it's synchronous you're screwed...

You'd want a relatively low value pot.

Like I said, emptying your case about every two seconds, and if it's that long it's a big case.

I was thinking of something like a dimmer switch for a light switch... but I may have a better use for my little beauty of cooling fan... and the power issue ac/dc will be irrelevant. ... I had planned to use a couple of larger fans to cool the inside of my component cabinet (cable box, receiver and htpc) but pop this little beauty in there and all my issues are solved.... I was going to cut up and old psu to run the dc fans but dont have to with this one.. thanks again for your help...

 

[Someone Somewhere]

Other option is extractor fan controllers - they should work.

Dimmer might, not sure.

Be careful around mains; 12V can't do anything more than tingle (unless you short out a high-current PS), but mains can be dangerous.