Tales from a Ventilation Lunatic

[sternwake]

The BDS 140mm Delta clone fan and the three 5 amp xl4015 based voltage buckers arrived.

It comes with a grille/fingerguard and long machine screws to hold it in place, as opposed to the short self tapping screws that come with most fans for mounting.

The good, it works, with little to no vibration at max speed, and is pretty quiet at max speed, more a whoosh of air rather than a whirring of high rpm fan motor. it moves a very respectable amount of air at max speed, which on the LM2596 bucker I wired up last night for testing the Fm181, was still well below 12v.

The bad, it exhibits the same behavior as the 120mm 252cfm Delta screaming banshee. Below a certain voltage it just shuts off. I tried a different voltage bucker, an XL4005 with a current control pot. Same behavior on the current trimpot as the voltage trimpot, it just shuts off below a certain speed, but the voltage trimpot is easier to tune in that minimum speed.

The good...the voltage just above at point it shuts off, ~5.35v, it only draws ~ 0.26 amps whereas the screaming banshee is still over 1.6 amps and way too loud and powerful at the point just above where it shuts off, making it essentially useless for in van duties.

The bad, it is still moving a lot of air at this voltage, likely in the 100+ cfm range.

The good, is it moves a lot of air, for 0.26 amps. The 120mm silverstone fm121 and its 110 cfm rating occur at about 0.42 amps, and is much louder with air exiting at 4 hotspots at much wider angles. The steering vanes on these Delta and similar fans keep the airflow straight out from fan in narrow column which makes such fans much more effective as intake fans or interior circulation fan. The silverstone has a nice built in speed control, but if one wants ~110cfm this fan at 5.35 volts is quieter and uses less juice.

The bad, is of course that one does not always need 100cfm+ of air movement or want a 0.26 amp draw. The silverstone fm121 and fm 181 slow to 0.09 amps.

The good, the minimum speed is tolerable in noise and amp draw, but likely not at night when sleeping, and that much flow is way more then needed, usually, at night. The failed 140mm Noctua could be speed reduced to silent and barely measurable amp draw with barely detectable airflow, but of course it only lasted 8 months.

The bad, my intake fan shroud, the 140mm hole is in the middle of my intake shroud in front of the sliding window.
180mm/ 140mm /120mm and window slides opens from left to right..

The good, is that I can close off the window so only the 180mm fan has exposure to outside air, and shut off the other two.
The bad is I am lazy and prefer to just shut all three fans to their minimum speed and leave the window fully open. If I just shut off the other 2 then a significant portion of the air the 180mm fan moves simply exits the other two fans and reenters the first.

The whole purpose of a tight fitting fan shroud, is to exchange outside air for inside air, and not allow the higher pressure air in front of the fan, to seek the lowest pressure pathway, to the back of the fan that just moved it, recycling a lot of it. Blocking off the turned off fan apertures is more labor intensive than sliding the window shut.

The good is that I have further increased the intake fan shroud's ability to force fresh air inside, the bad is that more switch flicking, and window sliding is required when much less than full flow is required.



I hope the other 140mm delta fans on order, the 12 and 24v fans, will slow to much slower speeds via a voltage bucker, but I suspect not, and they will be relegated to workshop exhaust duty.

The Noctua NA fc-1 speed controller is rated for 3 amps and will soon be in the spare parts bin. I've not seen whether it will control the 4 wire 190 cfm deltas properly. I was scared to try it, but now that i have written off the 140mm Noctua's and all industrial noctua fans, I could try it and perhaps smoke it in the experiment without too much regret. The PWm signal generator I made for hte 120mm screaming banshee did not work on it, but might on the 140mms now in transit from China.

The Experiments and learning with fans and their speed controlling methods, will continue.
For now, time to melt some solder and add some switches and then perhaps sit in my windtunnel and laugh like the maniac I am.

[sternwake]

The newest 5a xl4015 based voltage buckers i recently ordered, come with 50K ohm trimpots. These tiny blue trimpots are something like 20 turns to go through their full resistance range. meaning that dialing in voltage to a hundredth of a volt requires half the amount of turning as a ten turn potentiometer.

This precision is only really helpful at very low fan speeds, and I was and still am using 10 turn pots on a few fans for dialing in these very low speeds.noise/ampdraw.

I have cheapo 3/4 turn 50K ohm pots and in multiple other values, as well as 10 turn pots in 5 10 and 50K ohm.

Most buckers when fed battery to battery charging voltages, half the upper range of the potentometers does not add any more speed.

So I have been wiring up the new buckers to all three intake fans, the SSfm181 whose internal speed controller failed, the new 140mm fan that does not slow enough, and the 1212 Delta EHE. The 140mm fan is quite difficult to its minimum speed before it shuts off. I am still doing the trick of the tiny trimpot inline with larger finger twist potentiometer which keeps the fan from stopping. i was using 10K ohm trimpots inline with a 50k ohm pot, I noticed that I could get the fan to slow way way down before it shut off completely, with the 20 turn trimpot inline and the other pot turned all the way down. However it made a rhythmic clicking noise down this low.

The 10 turn 10K ohm trimpot, seemed to be at the upper end of its range with fan dialed to enough speed it did not make the clicking sound. The cheapo 50k ohm 270 degree pot still had much of its range unused, the fan speed was already maxed out with perhaps 100 degrees of that 270 degree sweep left in the knob. I tried a 20K ohm pot and it still has the full speed range and perhaps 30 degrees of sweep left when getting about 12.17v reaching the bucker over my test leads from my 18Ah agm battery. With a nearly 14.7v input reaching the bucker, when charging, perhaps the full sweep of the 270 degree trimpot will be used for the full range of fan speed. No 10 turn pots needed anymore, and i can use well under the 10K or 50K ohm pots the buckers themselves came with at these voltages for this duty. Perhaps if I were running 24v system and fans I would need the full 10K or 50K ohm pots for full speed range.

I am a bit perplexed with the max ouput voltage leaving the bucker, Ipreviously measured just under 0.3v, 12.0v in max and 11.71 out max, but tonight with more direct wiring with 12.17v reaching the bucker I was getting 11.98v out for a 0.19 overhead loss. Seems the higher the input voltage, the more efficient the buckers are in terms of voltage loss across the unit.

The new 140mm fan was drawing 1.47 amps when bucker was delivering 11.98v. It and the 120mm Delta fan move an extremely impressive amount of air, even well below their maximum speed/noise/ampdraw. I though the Noctuas at full speed were impressive but the new fans dwarf their airflow. The single Jaro in this shroud seemed to double the flow of the 140mm noctua df ss fm181 combined, andthe delta is as powerful if not more so and the 140mm fan seems to move 2x as much as the 140mm Noctua.

I wonder how much longer the Silverstone fm181 will last. When it goes, a 24v Papst fan will likely replace it, even though it is not quite as Quiet at minimum speed, which is a factor.

I've not yet wired up the individual switches for each bucker/fan as I am not sure the most ergonomic location to mount them or the potentiometers. I've just just using test clips hooked to the buckers to power them whcih can be a bit dangerous if they slide off the solder pads and dig though the insulation and short out the bucker.

[sternwake]

There are two different 5 amp voltage buckers that I've been employing, those with the XL4005 chip, and those with the XL4015 chip. It seems the 4015 chip only drops 0.18v across it, whereas the xl4005 drops 0.27v. Compare this to the older LM2593 3 amp chips drop of 0.71v!.

I think the XL4005 chip will buck to a lower voltage, but that is not a factor in my intended usage.

While I was in Florida 6 inexpensive xl4005 buckers arrived slow boat from China. As of yet, I have no use for them.
------------------------------... the 12v and 24v 140Mm delta fans also arrived.

I returned to California last night, and tested the new 140mm Delta fans today.

The 140mmx 38mm '7.5 amp' Delta fan does indeed respond nicely to voltage as speed control, all the way down to 4.33v, but it makes some clicking type noises down this low, and while balanced better than the best of 4 Jaro fans, it is far from perfect. It is quite powerful, easily beating the 140mm Delta clone fan, as expected. It does not draw near 7.5 amps. more like a 4.2 amp start up surge and 3 amps at 12.8v, through a 10 amp bucker. This fan has more scythe like blades than regular Delta fans which oftentranslates to better static pressure ratings, meaning better performance agains restriction, whether an obstacle before or behind the impeller, or if fighting air pressure.

The 24v Delta 140mm fan, is 50mm thick, as thick as the venerable 10$ 24v Papst fan.
At 12.8v this fan is impressively powerful and draws about 0.8 amps. One could use this with a 5 amp bucker and have plenty of airflow and good speed control. It is not all that loud at this voltage, especially considering how much air it moves.

Fed 24volts, this fan is insanely powerful, and draws ~40 watts through the buck/boost converter. The volume of air moved, and its velocity are simply beastly, blowing away the 283 cfm 24v Papst fan in volume and velocity and also beating the 92 and 120mm high rpm deltas at 175 and 252 cfm respectively, in velocity.

The 383 cfm rating is certainly believable.

Its start up surge at 24v is barely above its continuous draw at 24v. I took it upto 26v, and that territory is so ridiculously overkill, that I will not take it there again. This fan is well balanced and does not vibrate, and is not as loud as the screaming banshee 120mm delta 252 cfm fan, or the 175cfm 92mm deltas, but it is loud.

This 24v delta fan's minimum speed occurs about 9.33 volts, and it is quieter than the 12v 140mm delta fan at its 4.33 volts, and draws about 0.14 amps through the buck/boost converter, but it is not as quiet as the SS fm181 near its minimum speed through the V bucker. There is some clicking, but not nearly as loudly as the 12v 140mm Delta, or the 140mm Delta clone.

Both of these new 140mm delta fans are 4 wire PWM fans. I need to see how well it responds to a PWM signal on the 4th PWM wire. Perhaps that low speed clicking will disappear.

As my current intake fan shroud stands, with the 140mm Delta clone fan, the ss fm181 and the Delta 120mm fan, I have way more airflow than I can use. One Night in Florida I had all three on half speed, as well as the ceiling exhaust 120mm Delta at slightly less than half speed from mid afternoon, and late at night when I stuck my key in the door air gushed out of the keyhole, and when I opened the door air pressure moved it another 2 inches against gravity, as I was parked facing uphill.

If I crack the two front door windows 2 inches, and have the 3 intake fans on high, and the ceiling exhaust fan on high, air gushes out the windows. There is no Need for the acrylic fan shroud I made for up there, but to make it visibly obvious to the most demented of self important doo gooders. that Fiona is in no Danger of overheating. The 3 intake fans by themselves even well below their full speed, can purge all the interior air quickly, and the 24v 50mm thick delta fan just increased that potential ability by a good amount once I employ it there.

This new 24v Delta fan has another potential 160cfm on top of the Delta clone 140mm fan, and it can be slowed way down better via voltage. PWM slowing via the 4th wire is still untested.
The SS Fm181 can be replaced with a Papst fan for another potential 120cfm and a lot more static pressure ability.

Really the ceiling 120mm delta exhaust, by itself, with all windows closed, is amazingly effective. When there is danger of rain, this fan on 1/2 to 3/4 speed was keeping my van within 3 degrees of ambient in direct Florida sun with intake fan window closed and all those fans off..

The two new 140mm Delta fans actually spin opposite directions in comparison to each other. Counter rotating fans inline, might, or might not vastly increase airflow. I might have to attach them to my skateboard, with my 18Ah Agm as the power source, and see how fast it can propel itself.

Ventilation 'Enthusiast' might not be accurate anymore. Perhaps 'Lunatic' is more fitting, as I've definitely achieved more than good enough, long ago, and cant seem to stop exploring potentially more powerful options.

[sternwake]

I used the Noctua nafc1 speed controller's blue output PWM wire, to speed control the 24v Delta fan, and it did slow nicely to very low speeds and about 4 watts of draw.
But at max speed it was drawing nearly 0.2 amps more than if I removed the PWM wire feeding the same voltage, and at minimum speed via voltage (~9.22v) the fan spun slower and was using ~3 watts.

in general the fan used more electricity and would not slow down as much, if I used that 4th PWM wire to control its speed.

Then somehow i managed to smoke the noctua speed controller.

BUt my success rate with PWM fans controlled by the 4th PWM wire, is exactly ZERO. 4 Nf-f12s failed being powered by the Noctua nafc-1 speed controller, one of those failures only fed the blue pwm wire, powered separately. One other Noctua fan also committted suicide on the Nafc-1 controller the industrial 140.
My homemade pwm signal generator is hiding somewhere , but I recall it not being worth it, power wise when I was testing it way back when.

My ONLY success to this point, with a PWM Motor Speed Controller powering a fan, has been the unit I use to power my HVAC blower motor under the hood. My PWM LED dimmers, all but one have been replaced with voltage buckers instead. Some of the PWM controllers degraded to making the LEDs flicker. Not one Bucker has, yet. Some of the PWm MSCs were only 14 or 18KHZ and would make the fan whine at reduced speeds.

So from here on out, I am going to control 12v LED brightness and 12v fan speeds, via VOltage buckers modified with better potentiometers for speed/brightness adjustment, and on 24v fans I will use buck/boost converters that have current limiting potentiometers to reduce or raise battery voltage reaching fan's power leads, from its minimum spin voltage to the fan's max rated voltage.

And that beastly 140x50mm 24v delta fan levitates the beast to a new height, at 26 volts, its maximum rating.

My electronics guru contact has acquired a top model Maxairr fan, that is rated/marketed at 900 cfm, he subjectively claims is no more powerful than The 24v Papst fan, which the seller rates at 283 cfm and Mouser rates at 243. The 24v delta's airflow @ 26 volts, exceeds that of the 24 Papst fan at 30v, by about 25%, in my subjective opinion.

4 of these 140mm 24v delta fans can fit in a standard 14x14 hatch opening.
16 amps of exhausting fury and a true 1000 cfm+ potential.

Yeeeeeeehaaaaaaaaawwwwwwwww!

Send me a thick cardboard cut out, which you have trimmed to fit tightly into your 14x14' roof vent @ 50Mm deep.
Starting at 300$, shipping not included... and some diy skills necessary on your end for feeding it 12vDC, and to secure it in place.

[tx2sturgis]

Not to be confused with vehicle ventilation, but I was looking to get rid of that very noisy bathroom fan in the place I bought, and came across these Panasonic WhisperValue DC ceiling or wall vents.

These are 120v AC powered fans but have a power supply that provides DC to the internal blower motor. Typical bathroom fans are very cheap 120v shaded-pole motors with a cheap, noisy, plastic agitator style fan. This high quality Panasonic fan uses a centrifugal blower, and it is smooth and quiet.

On the two lowest speeds, 50 and 80 CFM, it is barely audible. Set for 100 CFM, yeah, you can hear it but its not loud. It does seem to be very well made, and good quality.

I have no idea what the DC voltages are inside the unit, it might be interesting to tear into one but at about $95...nah...

https://na.panasonic.com/us/home-and-bui...-dctm-pick


           

[sternwake]

I was at my sister's house recently, and she complained of her bathroom fan doing nothing, while being noisy.

I removed the suspiciously dust free lid from the ceiling and had a peek, then peeked in the attic as the access was nearby.
There was no where for the air to go, no ducting, it was all closed off.

An invisible task skipped is a buck earned..... freaking contractors.

So essentially the bathroom fan was/is just a noise maker and electricity waster.

Its worse than kitchen fans which exhaust cooking gases back into the kitchen, noisily.

Its a rental whose lease might not be renewed and a douchy landlord, and I wasn't going to climb in the attic to do anything about it .

I hate the agitator style of fan, and a centrifugal/cage blower is much better if intake and exhaust are designed properly, but it is not as efficient as an Axial fan can be.

[tx2sturgis]

One very interesting feature that I suspect will not be needed by me, is that the fan detects higher levels of static pressure, or back pressure, and compensates by ramping up the blower speed. I tested this by obstructing the output with my hand and sure enough, after about 2 seconds, the fan speeds up and made more airflow, although the noise level also increased, obviously.

In the installation instructions they explain that it will try to keep the 50, 80, or 100 CFM even if there is restricted or complicated ductwork.

I wonder what one of these whisper fans would sound like in that fully enclosed fan bay at your sisters house....probably like a small but loud, turbine engine!

[sternwake]

I got a free  accellerometer app for my phone, and rigged up a method to secure my phone to the best of the vibrating120mm 6$ JARO fans.

After cleaning surfaces with rubbing alcohol to insure proper  adhesion of tape,
I put some masking tape on the hub and cut it with a razor with fan spinning, then labelled each fan blade 1 to 9.

I use a small washer and some gaff tape and moved it around, trial and error, until the peaks and valleys got narrower and narrower.  Turns out arbitrary blade number 7 was too light, and a piece of gaff tape on the lower portion of blade 4 tamed the worst of the vibrations.
Before:
   

After, the spike is from me grabbing phone to take this screen shot.  Impossible to see in the before pic.
   

I could probably spend more time and get it even better, but the difference is already night and day.

The horrid vibration at 10.5v+ is mostly gone, but not eliminated entirely. Above a certain rpm I believe the impeller  shape changes from centrifugal force, changing the balance., but again these voltages and rpms are so loud and powerful one would not be able to stand them for long anyway, but its nice to have that power on tap.

I got a decibel app too, and tried to get before and after measurements at the same amp draw, but at the same amp draw the after balancing, the fan was spinning so much faster making more noise.  Would need to measure noise at same rpm as opposed to amp draw or voltage.

Anyway it makes the Jaro fan more than tolerable at fairly high rpms, and much quieter at lower rpms and likely moves more air for the same amp draw or uses less amperage for the same air flow while making less noise

I just started to experiment with the new 12v 140mm x 36 delta fan that is the worst balanced of any of my Delta fans. 

 It's certainly a learning process of how to approach the trial and error of weight adding, and the accellerometer app makes the otherwise impossible, possible.

Shame I wasted so much time previously, by  trying to weigh 2 fan blades at once on a digital scale.

[sternwake]

The accellerometer app for the phone is amazingly useful for balancing the fans, though the perfect technique for fast and reliable balancing is still not yet honed. Vast improvements can be made relatively quickly with just one washer glued to the hub over the lightest portion, but seeking perfect balance is time consuming trial and error, and has not yet been achieved. I think there will always be some vibration as the fan blades cross the stator vanes and apply air pressure in pulses, but basically like tires, weights need to go on both sides of the rim, and so far I have only been effectively been getting small weights added on one side of that rim. The other side is hard to access, and get something to stick at 4K rpm+ just for the trial and error process to start has been at issue.

A long time ago, i ran a pair of 10 AWG wires from my rear fuse block to the dashboard to power the stereo and many other things that I wanted to remove from Key in/ Ignition on/accessory on Duty. All added at different times since 2001. its kind of a semi organized rats nest of mismatched wiring, that's been amazingly reliable considering how short it falls of my current wiring standards. I was last in there when I ran wires to power the passenger window acrylic fan shroud, using some 18 AWG. I was using this 18AWg fed anderson powerpole to power the 60 amp PWM motor speed controller that powers my Stock Hvac Blower. Needless to say lots of voltage drop was occurring on that particular circuit, preventing full potential airflow, but now there is ~ 16 feet of 8AWG direct to it from My 250 amp Load switch, and nothing else on it to reduce that voltage. It sounds like I am getting at least 20% more rpms from it, but I have not put a wattmeter inline at the powerpoles at the blower motor for actual data. Years ago I had run 8awg from teh speed selector switch to the motor, eliminated a few connections and 14awg and was amazed at how much faster the motor spun. This latest circuit bypasses all that old problem prone OEM originally undersized wiring.
Voltage baby, deliver it, Yeeeeeeehawwwwwww. I can stil luse the resistor packsna dn speed switch just move the powerpole back, but there is no reason to, unless the PWM Motor speed controller fails, and i am assured it is built like a tank.

I actually want to remove the blowermotor again and balance its cage fan. Its amazing how much more rpm is achievable when impellers ares better balanced, and how much less noise they makes, at least the computer fans. The cage motor is a different animal, but it does vibrate and that, has to be able to be improved upon.



I acquired 25 feet of 8AWG 2 conductor tinned sheathed marine wire, and ran a new dashboard always on Circuit from rear power distribution to the PWM motor speed controller, and another offshoot to the other things powered by that old 10awg I might wish to remove.. I extended the trimpot wires and mounted the pot next to the existing 4 position Hvac blower speed switch on the dash . I've not collected any true data yet, but a LOT more voltage must be reaching the motor when cranked to highest speed, and bypassing the wasteful resistors at reduced speeds is likely much more efficient, freeing up some alternator amps for battery charging. More Voltage will also be reaching my acrylic shroud 120mm Delta's too, but honestly They never need to spin more than half speed so having them go to 11, is mostly a very loud novelty, but dimmable power is great. It induces fits of maniacal laughing, keeps people from wanting to converse with me.
Win win.

Its awesome just turning the pot without the key in the ignition, to start forcing air inside through the defrost and foot vents, but not very efficient compared to the same wattage of computer fans. It is loud enough to easily hear from a distance, and should easily let halfwitted, self righeous, social justice doogooders from believing Fiona to be in danger of overtemperature. We are supposed to get a lot of rain this week, and this motor spinning can Keep fresh air flowing when my other intake shroud has to be turned off and closed.
--------
The passenger window acrylic fan shroud now has two Delta 190CFM fans instead of the Jaro's, and a crude but effective method to retain it tightly to the top of the window channel, with the window open. Upto 50MPH, so far, driving with this shroud in place, window open or closed, is very pleasant, I can't hear fans speeding up nor slowing down against changing/buffetting air pressure at speed, and the intake fan blows a nice steady breeze at me over Fiona's head on her Perch. Saves significant amount of time running errands as opposed to installing then removing and storing the shroud at each location, and is Quite secure. I painted some chromed metal 120mm finger guard grilles black, and its not really all that noticeable from a distance. Usually the sound of the fans is what makes people look at it, at which point Fiona, nearly invisible behind the removable vinyl mirror tint, barks at them.

The new 140Mm Delta fans are still getting some slow attention regarding trying to improve the balance/ vibration/ noise. The 24v 140 x 51mm Delta is the Beast among beasts. I did not even think it was poorly balanced until i put the accellerometer app on, and one small washer on the hub seemed to turbocharge that which was already supercharged. The velocity and amount of air moved in the 24 volt range is next level, seemingly dwarfing the flow of the Papst fan which is claimed to be 283 cfm.

The 12v 38mm thick version uses these forward jutting scythe like blades, that are generally designed for high pressure restrictive applications as opposed to high flow/ unrestricted. I notice it does not have the velocity of other 140mm or 120mm delta fans with their shorter more angled blades, and the flow spreads a bit wider, not as column like. Hard to actually measure how much airflow it has. Its a lot, but the 24v fan is what the King and queen of fans together worship and idolize.

Either of these new 140Mm Delta fans will vastly increase the rear intake fan shrouds ability to pump air inside, over the 140mm delta clone fan that resides there currently.

With All potential fans in place, running flat out top speed, I Bet the entire contents of the van can be purged several to a dozen time a minute and draw over 20 amps, ~14 of those just from the HVAC blower when it gets 14+ volts. So far I have never run all of them at once, not with the Hvac blower, and when I did run all of them in Florida on a hot day, the inside remained a cool windtunnel, with them all at about half their potential speed.

I'm still completely impressed with the ceiling exhaust 120mm Delta's efficacy, all by itself. If I have my sarongs hanging inbetween front seats and the back, and crank the ceiling delta exhaust fan to high, the sarongs's bottoms pull inward over two inches nearly instantly. When it is hot and there is no rain potential, I can easily remove the mushroom vent, and halve the restriction in front of that ceiilng Delta, and get a small skylight to boot. This mushroom removal was always a huge improvemnt in flow with the peasly 110cfm silverstone fm121 and its counterrotating feeder fan I use to think were so effective, and the Delta is capable of at least doubling their combined flow.

These Delta fans have increased my ability to ventilate several fold over what the industrial Noctua's and Silverstones that I once thought were more than effective enough at keeping the interior cool.

I bet with all the extra voltage that can now reach my Hvac blower motor on command, the heater can be more effective as well. I back flushed the heater core before I drove to Florida in December and gained 25f more temperature at the vents same engine temperature and fan speed, and it was greatly appreciated up at elevation at night. I think it could do even better perhaps with a CLR fill and back flush, rather than just cool hose water running backwards through it.

The heater in this Van used to be much more effective, the backflush helped return only a portion of that previously impressive heating ability. Rarely needed where i'm at but nice to have lots of, on tap. There could be blend door issues as well. I've never been inside the Hvac box before, but the foam seals at the blend door are known to get shredded, and for the door itself rust out badly.

[sternwake]

RIP Silverstone FM181.

I had it running all night at minimum run voltage via the bucker, and this morning cranked it up to max voltage, and the acrid ultra stinky magic smoke genie escaped, and I can't get that dang smell out of my nostrils,. I was walking Fiona a half mile away, and still smelling it.

I Guess A 24v Papst fan will be replacing it by tonight. Might replace the BDStime 140mm delta clone too, with an Actual Delta while I have the shroud on the workbench.
Now, will it be the mother of all fans, the 24v Delta, or just the second most powerful fan I own, the 12v 140mm version. Hmmmmm.