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Tales from a Ventilation Enthusiast
Here is a picture of my interior air circulation fan, on a gooseneck with a 2" spring clamp.

The 5 amp voltage bucker/speed controller  is attached to the fan itself.

The gooseneck is from an old clip on light, from the early 90's if not sooner. 

The fan is 175 CFM 92x92x38 MM Fan Delta PFB0912DHE.  It is the most powerful 92mm computer fan available.

It draws 3.1 amps at 12v and is extremely loud, a start up surge of 3.72 amps.

It draws 0.06 amps as slow/quiet as I can get it.  It is nearly silent at this speed, and very light amount of air is moved.

I can dial in any speed between these two, turning the 10 turn Bourns 10k ohm potentiometer which is attached to the fan hub.  At Super slow speeds, dialing in slightly more or less airflow require a fine touch on the potentiometer. There is a slight delay before it responds.

Generally bigger fans move more air for less noise and amp draw.  I have had a 120mm fan installed on this gooseneck.  The extra size was annoying inside my Van, so I went back to 92mm. Likewise I have had a powerful 80mm fan attached to it as well.  I prefer the higher flow of the 92mm fan.

On the back of the fan is an activated carbon air filter.  I hold it together with paper staples. It sticks to velcro I added to the fan perimeter.  I vaccuum it every two weeks or so, or more often when it is loaded with dust and lint. In this picture it is at least a week since I last vaccuumed it. It does not significantly limit airflow until it is caked with lint and dust.

This fan's flow is a fairly compact cone.  at 3 feet the dense column of air has spread from ~4 inches at the fan, to 12 inches 3 feet from it. I do not have an anemometer, but at high speed I would estimate that its airflow is moving 30 mph at 3 feet.

The only time I have turned this fan off since I built it is for taking this picture, and when I vacuum the filter, or when i move it to somewhere else.  I have used it outside to blow on a piece of plywood to blow the dust away so I could see the line better, or to blow fresh air at my face to keep dust away from my lungs.  The anderson powerpoles are my universal DC connector, I have 30+ feet of 12v 16awg extension cords.

I have another one of these fans attached to my engine cover, but without an airfilter and spring clamp.  It is so much better than the flow out of my vents.  My AC does not work so this fan aimed at me when I get in the driver's seat on a warm day is much appreciated.  I often aim it at some nearby exhaust fans.  In winter with the heater on I aim the  center dash vents at this fan and send it to the back.

I don't know how I managed to be comfortable inside on a hot day before I had this interior fan.  

The immediate predecessor to this 175cfm Delta fan, was a 154 cfm Delta fan.  It failed due to corrosion on the circuit board.  I have taken precautions with this fan, spraying Deoxit Shield S5 on the circuit board,  and using 'Amazing Goop' to cover the wires where they enter the hub and attach to circuit board.

Time will tell how long this one lasts, but if it fails tomorrow I'd get another one ASAP.

Noctua apparently wants the failed fan(s) back for inspection before they send another warranty replacement, to figure out hy they are failing in my application.

I have already sent the 3 previous failed fans back, only one left to send. I guess the new guy did not read the previous ticket very closely or his english is lacking.

My thought on failure are related to the occassional reverse firing up on startup. I think this might be related to the other fan in the shroud causing a high pressure area and putting the impeller on teh nearby noctua backwards instead of neutral.

But one time i returned from some errands to find one fan spinning slowly backwards after it had been going near full speed in the correct orientation.

I find it hard to believe they are not swamped with failed versions of this specific fan. yet that is what they are claiming.

No other fan in this location has failed as prematurely, no other fan has fired up backwards ever. Co-incidence? unlikely.

They sent me a UPS shipping label for doing so.

I'm pretty much over it, i intend to add the 120MM 200 cfm jaro fan on its own speed controller where the last Noctua fan resided and failed and where another fan now resides.

I mean I hope they'll send a warranty replacement 140mm 3k rpm fan, but using that fan would include modifying my acrylic fan shroud to the point it might become quite weak.

The Jaro fans are poorly balanced and above a certain speed vibrates badly, and draw 2 amps at 200cfm where the 140mm fan is something like 0.6 amps for 165cfm, So the 140 noctua would be better from an amp draw perspective, but I would also0 require a 140mm fan grille for it, whereas I already have a plethora of 120mm fan grilles.
The Silverstone FM181 in my intake shroud stopped responding to speed control yesterday, and just ran on its slowest speed. Which was not tolerable when its 91 degrees.

  I was thinking it might be a goner and was ready to fit a 24v Papst fan to its location, but I found one of the pins of the connector for the  SS fm181 fan's potentiometer, had either broken off or dissolved into copper sulfate.

No real need for a connector here. 
It came with one, I used it. 
I now eliminated this connector, and used a new 10K potentiometer as well..

Back to full range of speeds on 2 of 3 fans in my intake shroud. Yehaw.

I rebuilt an adjusto goose neck clamp fan, using the 24v Papst fan instead of the 120mm 252cfm delta fan,   The Papst has got 3 screw receptacles onto which something flat can be bolted on the circumference of the fan body. 

 I shaped some 2 inch wide aluminum flat bar to rest flat on these screw receptacles, and then bent it into a C shape, with the lower leg of the "C" attached to the fan body,  and the top part of the 'C' attached to a 16" Microphone gooseneck with the power cable running inside, This gooseneck attaches to a 2" spring clamp and I have a few feet of 18awg ( former Dremel power cable)  leading from clamp to an Anderson powerpole connector.

Inside of the 'C', will rest my 80 watt Drok Buck/Boost converter, but for now it is temporarily  clamped to its exterior with the remote pot loose as well, as I am awaiting 10 turn bourn's  50k ohm potentiometers to arrive

I have removed the Drok's voltage adjustment 50K ohm potentiometer, soldered wires in its place to a remote 270 degree 50K potentiometer.

This new 24v papst fan is balanced better than the first one I ordered, and it is also quieter at very low speeds Have not yet checked the third.

The Drok 80w Buck boost converter  can go as high as 36 or 37 volts with a 50K ohm pot.
 I really would like to prevent voltages above 30,  and tried a 20K ohm pot, but it would only allow 14.7v maximum.

 I then tested all my 50K ohm pots and found one which maxed out at 44K ohm, so I used that one and now it only goes to 33.2 volts instead of 37v.  Still a bit too high, but that amount of airflow is also rather extreme. 
    I'll try to keep it under 28vdc. 
It's like the last 15 degrees of that 270 degree sweep to go from 28v to 33.2v, so its not hard to back it off into safer voltages without looking at voltmeter. 
The amp draw goes up so much from 28 to 32 it is not worth the extra speed and flow anyway.

The Drok buck boost converter has a voltmeter on it, showing input or output and which can also  be turned off.

This New Fan is intended to be the new workshop fan blowing across me and the table, easily adjusted, and I intend to run a large dust filter on its intake side, to filter of course, but to also prevent things from getting sucked into or falling into the fan impeller and breaking a blade. 
This fan has excellent airflow for noise it generates.  I am really very happy with its function. Once I get to use it a bit more I will wire it up a bit more permanently and get the converter mounted inside the Aluminum 'C'. and post pictures.  It can easily be put in the Van anywhere I can put a 2 inch spring clamp.

I also attached a  5 amp voltage pot modified buck converter, to a JARO 120MM 200 cfm fan, the one which vibrates the least.  I am impressed with just how slow and quiet this fan can go.  At Minimum speed through the converter it is only drawing 0.05 amps as super slow speed, and is basically inaudible with the lightest of breezes at minimum speed.   It moves a lot of air at all speeds below 8 volts and 8 to 12 volts is quite powerful, way beyond the Silverstone fm121's 110 cfm.

The silverstone fan at high speed has 4 hotspots of airflow at fairly wide angles from the fan. This Jaro does not have steering vanes like my delta fans to concentrate the flow in a dense column with a lot of reach, but it remains fairly column like, unlike the silverstones 4 hotspot.
I was bummed with the vibrations of these 6$ Jaro fans at first at high rpms,  but in all likelyhood will not use them at those speeds for long anyway.  I can mount them semi isolated from the shrouds too to dampen those vibrations and any potential droning or harmonics.

When I peeled up the sticker to add some Amazing goop to the circuit board where the wires attach, I saw they had already added something similar in production. This is the only fan that I have noticed that took steps to coat/seal/reinforce this known weak spot/failure point.  I was impressed.  This is a heck of a fan for 6$ even with the vibrations at 10+ volts.

Once the Amazing Goop has lost its stink, The JARO fan is going on my intake shroud and should add another 100CFM max to the total rating of these three intake fans. 
 Restriction behind of, and in front of the fans obviously knocks down the theoretical maximum CFMs But:
 150cfm of the Silverstone FM-181
158.5cfm of the  NF-A14 industrialPPC 3K rpm[url=][/url]
200 cfm of the JARO fan model AD1212HB-F92GP

That's 508.5 CFM, will  all of 'em cranked as high as they can go at about 12.4vdc.

If the Silverstone were to be replaced with a 24v Papst, fan that would add another 133 cfm to that total.

I got some of these rotatable 120mm fan grilles. They spread the fan's output flow wider and flatter and at an ~35 degree angle.

[Image: 91wXlprwWcL._SL1500_.jpg]

The leading and trailing edges of this rotatable grill are just flat 1/16" thick slats,  and might get some streamlining for lesser noise and restriction.  Kind of neat that they come with really strong magnets to attach to the regular mounting screw holes, and can be easily removed and returned.
The 24v Papst Clamp gooseneck fan is awesome.  Used it today all day, in the workshop and could not have handled being in there without it.

 Being able to easily aim it and change the fan speed and have 283cfm available is freaking awesome. My 92Mm in Van gooseneck clamp fans go upto 175 cfm, but that much speed is loud and draws 3 amps.  Where the papst fan moves more air for less noise and similar or less amp draw through much of the speed range.

2 more Jaro 200 cfm 120mm fans grew a voltage bucker speed controller  on their sides today.

My 11 T10 LED BUlb  inline light housing is getting some 40MM x 10mm fans in a push pull configuration, So I can run the light at max brightness indefinitely  and not worry about frying the bulbs. This ventilation also opens the door for even brighter bulbs, which I know would not be able to handle their heat without forced ventilation.  The Light just wound up being 40x40mm, unintentionally.  Probably going to make an airfliter on the intake side to keep from pumping workshop dust through it.

I spent some time with a rotary rasp and dremel to reduce restriction to the 40mm fan flow, which will split in half when going through the light, Half over the wiring above and half below around the LED chipsets.


The voltage bucker/dimmer will reside inside this light with airflow over it, and it will have an on off switch on the light, and an additional Anderson powerpole for having another DC outlet handy right at the light itself

There is potential for using a Buck/boost unit inside of this light housing to add some more brightness to the LEDS with higher voltage.  With 6 to 8 cubic feet per minute  being forced through the light housing,  it should keep things from getting too hot.

Think the buck boost units yet to arrive,  will go on the remaining two 24v Papst fans though.
The 16 inch microphone gooseneck is fine for standing the 24v Papst fan straight up, or nearly so, and hanging it, but not to support its weight sideways.  That length does seem a bit unwieldy too, so some shorter goose necks are bookmarked.
I've yet to do anything more to it, other than simply use it, at this point.

My new acrylic fan shroud is coming along, clear Acrylic hinges, and 4 cutouts around the openings on each of the JARO fan's hub supports. The Jigsaw blade was set on a 97 degree angle, instead of 90, for less restriction to air flow whether on high or low pressure side. It still has the protective paper on it. It is smoked plexiglass/ cast acrylic 1/4 inch thick.


The rearward fan, I intend to have blowing inwards and down on Fiona's perch through the rotatable grille,  and those center supports will cause restriction and more fan noise on the suction side, but I/she might not like this fan blowing inwards, and I could instead put both of them as exhaust,  like my current plywood shroud with its 105 cfm 'stinger' fans. 

I've also found a way to use my digital scale that  I use for precisely mixing epoxy, to perhaps balance the fan's impellers so they do not vibrate badly at 10.12 + volts & ~2600+ rpm.  The imprecise hypothesis testing method revealed more than 0.5 grams difference from the heaviest side to the lightest side of the impeller.  I should be able to get solid improvements in this regard lightening the heaviest side.

I do not expect to often run these fans at such a rpm anyway, but better to have too much power with a throttle, than too little, especially as these seem quite efficient at lower speeds.  Pretty sure when I  dial the Jaro's down  to draw the same amperage as  the 'stinger' fans at their max speed, they will move more air and make less noise, but that is a guess, not a side by side comparison, but the latter will occur, it just hasn't yet.

The stingers are currently both controlled by a single LM2596 3 amp voltage bucker, which is not as efficient as the newer 5 amp XL4015 chip of my newer model buckers, and each Jaro fan will have its own speed control.
[-] The following 2 users say Thank You to sternwake for this post:
  • Gapper2 (09-09-2019), Scott7022 (09-10-2019)
I put one JARO fan on my intake fan shroud. Perhaps prematurely as i can still detect the amazing goop tolulene stank.

This shroud has the 180mm fm181 at ~150.cfm and the 140mm noctua at 160ish cfm And now.the 120mm JARO. With 200 cfm.

Tha balanced. Above speed 7.5 out.of ten the whole shroud starts vibrating. But at 7.5 out of ten, ten being max speed, the air flow of the jaro seems more than that of the other two larger fans combined.

I am impressed.

The, the screaming banshee, which i cannot adequately control speed/noise nor ampdraw wise, Is rated at 5400.rpm @12v. Of its 38mm.width perhaps.12mm is steering vane hub support and 26mm is the impeller width.

The jaro fan is also 38mm thick. But the hub supports are.perhaps 4mm thick, leaving ~34 mm for impeller thickness. More impeller thickness.. More air moved .

The restriction behind my intake fan shroud..... A screen and some fine mesh chicken wire for security.... Affects the other 2 larger fan's flow, much more.
Its not just rpm. The 140mm noctua is 3k rpm. The 120mm jaro is 3100rpm , and the jaro wins easily airflow wise, at 75% of max.power

Amp a different story. Ive not recorded amp.draw .data with shroud in place. The jaro is rated at 1.95amps, basically 3x the Noctua.

I Hardly need all three fans on max speed for long, but the JARO fan by itself at 75% speed, really seems to exceed the combined flow of the other 2 larger fans at their highest speed.

Once i balance the impeller.........

This jaro fan at only 75% of its max.speed is the most effective fan in my van in terms of intake or exhaust.

And.i have 3 more.

Did you just hear some manicial laughing in The distance?

Noctua just gave me the UPS tracking # to the 4th warranty replacement. They are sending, as requested, an Ippc 140mm 3k rpm after.i sent back the 4th failed ippc nf- f12 120mm.

Not sure how ill when it arrives. The unbalanced 6$ jaro fan on the voltage bucker speed control is winning all but amp.draw. yet dialed down to slow.amp.draw is likely nearly as low as the others as is noise, yet airflow is still superior.

The silverstone fm121 is an awesome 120mm 25mm with a built in speed controlller. Almost plug and play.
The 120mm x 38mm jaro fan on a v bucker is so much better. But not.plug and play. Even poorly balanced with a nearly vibration. Still the most.impressive 120mm fan ive yet employed.
[-] The following 1 user says Thank You to sternwake for this post:
  • rvpopeye (09-13-2019)
Awoke this morning and found the Noctua ippc 3k rpm 140mm fan did not want to respond to its speed control when i asked for some more flow from it. Great. It later did, once it warmed up and dried out, But an IP52 rated fan should be more resistant to humidity than this.

The new 120mm JARO fan on the same intake shroud, is kind of hard to dial in the speed precisely when down low, and a small twist of the 270 degree pot has huge effects on speed and flow. Still deciding where best to mount the bourns 10 turn 10k ohm potentiometer near it.
This fan's flow continues to impress me. Woke up overblanketed and overheated, and cranked all three fans up and it was like the warm air was nearly instantly purged from the area of my bed.

My last order from I ordered four, 60mm, 1.89$ fans as their picture indicated it was a high amp draw fan, and thus powerful loud fan worthy of a speed controller.
My bad for not reading the specs which clearly stated 17cfm and 0.08 amps. meaning not powerful.

I emailed them, informing them about the incorrect picture, that I did not want a refund or to return them or anything, but indicated I would have ordered differently had I been aware the picture did not match the specs.

They never responded to the email, but I just looked at my bank statement, and saw a nearly 8$ credit in my account from them. I thought they deserve a shout out for that. They have also fixed the picture on their website so that it says 0.08 amps on the sticker on the fan's hub instead of 0.24 amps.

They'll definitely get more of my business.

While the first 24v Papst fan I ordered from them was louder than I liked turned way down to 7.5 volts or so , the second 24v Papst fan I've wired up on same buck boost converter, is almost dead silent slowed all the way down.

4 new style 3 to 4 amp buck/boost voltage manipulation devices have arrived from Asia, and the one tested so far, maxes out at 30.4v with a light load. This 30.4v would be better for preventing the 24v fan seeing 33+ volts that the other B/B device allows. But this newly arrived particular B/B device is small enough that it will fit inside a light housing that I am making, instead of a 5 amp buck only converter I was intending to use.

This light shroud will have two 40mm fans in a push pull orientation on opposite sides of the light, flowing air across all 11 inline T10 LED bulbs, their receptacles, and the B/B device. There is a rather profound difference in light output in between 12 and 17 volts with these particular LED bulbs when I briefly tested the device under their load, and I have decided I want that extra light as an option.

I am going to wire in another potentiometer inline to limit max voltage to 17 or so, and perhaps to keep it from going under 8.2v where the LEDS shut completely off. The temperature the bulbs achieve and the total amperage will be the determining factor as to how much voltage I will ultimately allow them to receive. The buck boost device is less efficient than a buck only converter, but this light is not about max efficiency, but max function, and sometimes a 2200+ lumen light over the worktable yet below eye height, is just about right.
I have a powerful headlamp I use a lot to put light precisely were needed, but at night with the door open this headlamp draws winged creatures into my face, and almost always during a delicate task.

The Two 40mm fans I am using on this light housing are the least powerful ones I have, and I can always increase the airflow with my other more powerful 40mm's, and perhaps then the voltage and light output too. One of these same LED bulbs briefly endured 32+ volts before the solder on a resistor liquefied and the resistor then drifted downhill off the circuit board. The other half of the bulb still works though.

One of the buck/boost devices I got says it is good for 10 amps. One of its Diodes is poorly soldered though. I need to rectify that before testing it. It might be controlling two 24v Papst fans, and perhaps 3, if I order more. I want to eliminate a 120vac 20 inch box fan in the workshop that I use as an exhaust fan. There might be a new shroud with many fans on it soon where the 20 inch box fan now resides.
I Bet I can get more effective exhaust flow, for significantly less wattage consumed. I really prefer to take devices off the grid, run them off battery directly, when possible, even when the workshop is capably attached to the grid. The 20 inch box fan on high through an inverter, is well over 400 watts and low is still something like 185. The 20 inch box fans on high are around 2500 cfm though, unrestricted.

On an unrelated project, I had a friend order two 200mm Noctua 12v fans. I specify 12v as they have 5v versions too and these could then be powered from almost any USB port as they draw so little amperage.

These fans were designed to be super low amp draw and silent with low/medium airflow, which is what this particular project requires. I hope Noctua decides to make a higher rpm industrial version of it at some point. and I hope my relatively young 140mm Noctua not responding to speed control this damp AM, is not a sign of its imminent failure.
Noctua's UPS shipping bill for warranty returns and warranty replacements has got to be double that what I paid for the original IPPC nf-12 fans.

Newest warranty replacement is scheduled to arrive tomorrow.


Before and after of a questionable solder joint on a diode on underside of the circuit board of a recent arrival from Asia.  My 140 watt Weller solder gun was a bit overkill for this task.

I tested this supposed 10 amp  boost/buck, step up/step down voltage converter/module/device with a 194 incandescent bulb as the load.
Unfortunately, The product which arrived is just a buck converter, not a buck/boost.  Obvious visual differences between what I ordered and what arrived.  Seller is contacted, I asked for what I ordered rather than a refund.

As a Buck converter, I was feeding  it 12.00v, and it was outputting 12.00v too! 
Usually output voltage is lower than input by considerable margin.

When I manipulated the input voltage via different  loads on the battery, it was obvious that it was more like 12.002 in and 11.997 out, but I did not have my voltmeter with that much resolution handy.

In comparison to the much smaller sized 5 amp voltage buckers I employ elsewhere with teh XL4015 chip, well those are close to 0.3 volts lower output voltage compared to input voltage.
 I'll likely be able to put this unit to use even without the voltage boost feature.  But I want a unit with the ability to raise output voltage well above input voltage and handle 10 amps and hope the seller comes through. Pronto like and all.


A 50mm fan can bridge the heatsinks perfectly, and the unit has receptacles on the Circuitboard for powering a fan.  whether the fan is 5 v or 12v  or  on/off only  or various speed depending on temperature, is unknown.

If I ordered a 10 amp voltage bucker only, I would be pretty happy enough with the product.

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