Tales from a Ventilation Lunatic

[sternwake]

While the Jaro fans are very powerful and very effective.... Their poor balance and bad vibration above 10.5v, is in addition to general fragility. I had a minor incident and sheared off three impeller blades where perhaps 1 was expected to shear. Before this incident at higher speeds it sounded like one blade had cracked and was hitting fan body at higher rpms.

Delta does have a 200cfm 120mm fan. Hopefully it arrives next week and responds nicely to voltage based speed cOntrol. IF it does ALL JAROS WILL BE PHASED OUT.

[sternwake]

Looks like It sheared off more than 3 impeller blades, and The Jaro fan also broke at the hub. 

I tried to snap off the remaining fan blades with fingers assuming fragility, and none came off easily.  I guess the fan was spinning much faster than I thought when it fell, sheared off 3 plexiglass finger guard louvers, and ingested them. I don't think any fan impeller  spinning more than 450 rpm would have been undamaged in the same instance. 

But the hub breaking, and the fact that the fan frame is not perfectly flat, but rocks a little bit on the plexiglass points to some lacking  of structure, the bad vibrations is another reason to not buy these fans to run them more than ~10.5v, granted it is still extremely powerful at 10.5v and a heck of a lot of air movement for 6$.

I removed the impeller and installed the one impeller I tried to balance, yet made it worse.  I only noticed the broken hub support afterwards.

  Its supposed to get hot the next few days and this new fan shroud is way more effective at keeping front of Van cool than previous plywood model which has 2 fans stinger fans exhausting.

Here's how I fix broken plastic and other things. Simple superglue would likely be more than adequate, but I use a cut off wheel on the dremel and cut a groove across the break. I fill that groove with superglue then drop two pieces of carbon fiber roving into the groove and push them into the middle of the superglue pool, and they turn wet and black and shiny and I push them flaround anf flat to spread the strength out over a wider area  I leave it to cure many hours without seeing any stress.  Superglue when used like this takes many hours to turn hard and strong.

   
   
   

The last photo shows some drilled holes on the hub of the fan where I tried to lighten one side of it.
Still irritated i failed so badly trying to balance this impeller.
Looks like I got a backup Jaro fan body, but hoping the Delta FFB1212EHE Delta fan is as good as I hope.

[sternwake]

With the louvered rotatable grille of the Jaro fan on the right directing fresh cold air at Fiona, and the tinted windows, she can hang out comfortably in direct sun on a warm to hot day.

   

[sternwake]

My intentions on improving an already well ventilated Van, are to protect Fiona to a higher degree, not only from heat, but from half witted dipshitted doo gooders who might not have enough brain matter to read a thermometer, and instead see themselves as future indignant heroes, while they dial 911 practically orgasming in their fabricated outrage.

Hmmmmm, seems my attempt to attenuate my general contempt for modern humans, is failing.
So it goes.

Loud powerful fans that send a column of dense air out at a high velocity several feet away, makes it much more obvious to those without logic centers in their skulls, that it is not steaming hot inside that my invisible, but not silent, dog is not in danger.
I'll sacrifice the battery state of charge, or some solar wattage, to insure she is safe from both these dangers.

Regarding invisible, I have mirror tint on the windows she is perched behind and reflectix on the other front windows. all back windows cannot be seen through in daytime. She has a great view west to northeast, but cannot be seen.
----

The broken but repaired Jaro fan in the new acrylic shroud is back fully operational, yet still needs some hardware fastening it to the top of the window track to keep it falling out when I lower the window. It fell out again today, but broke nothing.

In comparison to the two 105cfm 'stinger' fans exhausting the front passenger side window at their max speed, it is pretty amazing at just how much cooler the front of the van remains with one Jaro fan as intake and one exhausting, when parked facing the sun with reflectix window shades in place. With Stinger exhaust fans the back of the van is significantly cooler than the front when parked facing SW. Not with the JARO's. Fiona always opts for staying in the front while I am out surfing, usually on her passenger side perch but often on drivers seat.

I was not running them anywhere near their full speed either, easily still a volt or two below the point they start vibrating badly.

Today was nearly 87f outside while I was surfing, noonish till 2:30, and it remained 87F inside near the windshield reflectix, the hottest part of the van when parked at this spot facing SW. Fiona's mouth remained closed, she was not panting even in the slightest when I returned, and had drank none of her water bowl, and was eager to chase her ball in the parking lot, as always.




The new 120mm x 38mm Delta FFB1212EHE fan arrived.



Looks like this spec sheet says it is 190 cfm, not 200. Oh well, No biggie.

When I spun the impeller with a finger, there was a noise and something was rubbing inside the hub.
Vile Curses ensued.

It came with a standard 4 wire computer fan connector, the other two wires are rpm sensor and PWM for speed control from a computer motherboard, or perhaps a Noctua NA-fc1 speed controller. I was not going to cut off the connector as I envisioned having to potentially return it for the rubbing noise.

I hooked the new fan upto an extra powered, but unused 4 pin connector on my ceiling, which powers a 0.15 amp pusher fan , just to test to see if it spun on its own. It did, and seemed way less powerful than the Jaro, and there was still that pesky rubbing noise coming from inside the hub as it ran.

Curses continued.

It also seemed to draw no more than 1.3 amps, where it is rated to pull 3 amps on start up and I assumed about 2 amps running at 12v. I was thinking counterfeit POS fan and unscrupulous Asian Ebay sellers. More vile Curses.

After a while, I tested it again in same plug, and the internal rubbing noise had disappeared. Ok...good, but how the hell, and wtf?? Nothing fell out that I saw that could have been rubbing.

I brought it into workshop and hooked it to a 5 amp voltage bucker speed controller, and it slowed smoothly and perfectly down to 0.15 amps as I lowered voltage I was feeding it, and the fan blade was spinning so slow I could follow an individual blade with my eyes, and it was nearly completely silent.
Almost a Homer Simpson 'Whohoo!! 'moment.

Ok, not almost.
It happened.

Granted, the 110cfm silverstone fm121 fan draws 0.09 amps at minimum speed (~33cfm, iirc)and makes the same amount of noise and moves more air, but I am not so concerned about minimizing absolute amp draw. I want a huge airflow potential, and the ability to slow it way way down when that much flow is not needed. If it still drew 0.5 amps at minimum speed through the bucker, that would not be acceptable, but 0.15 amps is.



The new Delta fan when on my workbench, with a 4 pin receptacle soldered to my 5 amp tester bucker's output, also seemed more powerful than in the Van, and I recalled the undersized wiring to the one existing ceiling fan with the extra 4 pin connector receptacle was 22 or 24 gauge zipwire perhaps even aluminum instead of copper, intended to spin a 0.15 amp fan, not a 2 or 3 amp fan. Voltage drop was the reason it seemed to be weaker than expected when i tested it in the van.

The 5amp bucker drops no less than 0.3v. 12.0 in, 11.7 out, max.

I busted out the Jaro fan shroud on the workbench, and side by side with the Delta it was hard to tell any difference in the total amount of airflow between the two. The Jaro fan has four hotspots of higher velocity air exiting at wider angles around the 4 hub supports, while the Delta's 13 steering vanes/hub supports have a narrow even column exiting the fan face with no hotspots, and no wide spread. The delta fan's even column flow pushing through the rotatable grille angled louvers will likely work better than on the JARO fan too, but I have not checked that assumption, yet.

The Delta fan impeller seems perfectly balanced. Holding it when spinning at 12v in my hands, I can feel no vibration, and if not for the noise and airflow, I would not be able to tell it is running, whereas the Jaro fans will have ones fingers go tingly numb with time, from the vibrations.

This newest Delta fan might be the best balanced powerful fan I have owned!

The minimum speed is somewhere around 6.5 volts, whereas the Jaro fan still spins quite fast and moves a lot of air at 5 volts. The Jaro fan hooked up to a USB port would be a great air mover for very little current consumed, and at 5v one cannot detect the badly balanced impellers.

That might be the endgame for my JAROs, I'll cut up some USB wires and hook them directly to the fan and gift them, and even a weak outdated 0.5 amp 5v USB port should be able to power them, and more modern 2.1 amp USB ports will have zero issues doing so.

I had some issues with the cheap 270 degree 10k ohm potentiometer on my testing bucker, and perhaps issues with the bucker itself. more testing needed. I shelved it for now. I have many more, and other options for controlling voltage for quick testing purposes.

I put the new delta fan on the 80 watt Drok buck/boost converter that was formerly powering the 24v Papst fan as it has easy peazy screw terminals for stripped wire, and ran it as high as 15.5v, where it was drawing nearly 5.5 amps and seemed basically as powerful as the 252 cfm screaming banshee Delta fan, whose speed I could not adequately control to tolerable levels, much to my previous chagrin.

I did not actually power the 252 banshee side by side at the same time, yet, so 'seems' is obviously biased opinion. At 15.5v it was a monster air mover, but equal to or more than the 252cfm screaming banshee?...... It 'seemed' to be in that range.

The 200 cfm of the Jaro and newest Delta fan is way more than needed 95% of the time, so 252cfm, now seems to be even more ridiculous.

So, the JARO fans at surplus center dot com for 6$(no free shipping) are an incredible deal, but the impellers are badly balanced and the frame is perhaps not as strong and stable and unwarped as it needs to be. Perhaps these are seconds, perhaps they are discontinued for the balance/ strength reasons, perhaps both.

Running the Jaros under 10.5v, and they seem quite efficient and still very powerful, but above 10.5v( or 11.4v on the best of the 4 I ordered) and the vibrations become bad and will start shaking whatever the fan is attached to, and it has to be attached to something immobile, as it will pull itself backwards across the table at these voltages.

I spent 14$ on this latest Delta fan, free shipping. I thought it was shipping from Asia, but there is Illinois stickers on the packaging and the tracking and usually E bay packages from china do not send e mail notifications when they are delivered.. Not sure what is up with that, but I am likely to order 3 more of them if I can still get them at this price.

This newest Delta fan 'might' not be as efficient as the Jaros, but the fact that it is so well balanced, and needs no fingerguard on the front/output side, has way stronger hubs supports, make these much more desirable for me and my intentions, even with the higher price tag and perhaps higher average amp draw too.

I did not control the variables for really accurate comparisons regarding airflow and amp draw, and the buck/booster power supply is nowhere near as efficient as the bucker only power supply, yet when powering the Papst fan the amp draw is only 2.37 amps at 30 volts. I dont know at what voltage the 24v Papst fan earns its 283cfm rating, but it is quieter and moves more air than the deltas and for less amp draw through teh less efficient buck boost modules. The 24v papst fan is just round, 2 inches thick and nearly 2 inches more in diameter, and as such is less desirable to stick in a door window shroud. However if ultimate airflow was desired then the papst fans beat all the others..

The 24v papst fans for 10$ is the best bang for the buck, even with shipping one fan costing 15$, and requiring a 5 to 15$ speed controller/buck boost module.

These buck boost power suppliesI use are mainly intended for the impressive 24v papst fans which have a range of 7 to 30 volts.

The Newest delta fan at 15 volts basically doubled the amp draw compared to 12 volts, so there is little reason to run it on a buck/boost converter instead of just a buck for speed control.

My worklight in which I use a buck boost module/power supply to power 11 t10 LEDs and 2 40mm fans, I cant allow over 14.1 volts or the LEDs draw more than the rating of the b/b power supply, but 14v is significantly brighter than 12v so I traded some efficiency for that extra light. 3 more volts reaching the delta fans doubles the amp draw for perhaps 20% more flow, so I feel it is nt worth it, and it is only rated for 13.2v, though I have many fans that see a lot of time well over their max voltage rating without issue.




Anyway it appears that this latest 120mm 190cfm delta fan, will eventually be replacing all the JARO fans, once I order some more and transfer the buckers from Jaro to Delta, or perhaps just add new buckers and ten turn pots.

My current ceiling exhaust fans are two inline counter rotating 120mm fans pushgng through as mushroom vent. One fan is a silverstone fm121(110 cfm and 0.4 amps) that has its own speed control. the counter rotating fan below it( 0.15 amps 53 cfm) increases its airflow and reduces its noise and together they can draw 0.55 amps. The new Delta fan voltage controlled to 0.55 amps of draw, 'may' not move quite as much air as those together, but if I can get 12.8 to the bucker I can get 12.5 to the fan and at 12.5v it can move more than 190 cfm unrestricted whereas the two inline fans are not going to move 163 cfm together. I might be giving up a little efficiency at some fan speeds, for way more potential airflow on the ceiling exhaust.

The CFM rating of fans is achieved with no restrictions in front of or behind fan, The static pressure rating of a fan is usually directly related to its rpm and fan blade shape, and the delta fan static pressure rating is huge, so it should be able to force air through restriction of the mushroom vent above way better. It should be way more effective at exhausting air even well below its maximum speed compared to the existing inline fans.

While I saw this newest Delta fan drawing 2.35 amps at 12.0v, that was through the buck boost module. if I was feeding the bucker 12.3, and it was outputting 12.0, the amperage consumed should be considerable less as the buck boost module is much less efficient than the bucker. And both are less efficient than no voltage manipulation device between battery and fan. The B/B module was only getting 11.2v over the wiring I was using for the test, and stepping it up to 12.0, passing 2.35 amps. The lower the input voltage, the less efficient the boost/bucker, when boosting, becomes.

I am impressed with the degree of airflow improvement that these more powerful fans have allowed. The 110cfm silverstone fm121 used to be my favorite fan, as it came with speed control, but these 38mm thick high rpm fans can move so much more air. Their issue was speed control, and I got that completely sorted out.

Cooling below ambient in high temperature high humidity is the only remaining issue, if I were located in such an area. That's Pretty much the realm of air conditioner and an generator though.

I can now park in direct sun and keep it the same temp inside as out, and I should probably stop trying to improve performance, but I am an addict doing what an addict does and justify it by sharing what I learn with you good people.

But really, cut a 14x14 inch square hole in your roof and get a maxxair fan instead. But then you need one is a side window, in a shroud, and one for interior air circulation, and one for the front area, and ...................

[Cammalu]

You should sell little vandweller kits with the fan, vents, instructions and whatever else is needed. You’ve done all the research and it would be a great benefit to the community (I don’t you don’t give a shit about that ) but you could certainly make some $ for all your efforts.

[tx2sturgis]

Dang....you burned up one of my pabst fans....

[Matlock]

My 2¢ on out of balance fan blades. Assuming they are made with at least a bit of QC to a spec that requires a balanced product, if the blade looks ok it may be a short shot in the injection cycle. I'd try adding a small weight rather than drilling.

Personally, me finding that sweet spot would end quickly with a heavy flat-faced object and flying debris. (usually around the 4th beverage).

[rvpopeye]

Heya Matlock !

[B and C]

Easier to remove weight than add it and have it stick at higher RPM's. A dremel tool on the heaviest blade if that can be determined. Shave a small amount at a time.

[sternwake]

I was doing the dremel thing on the heaviest 2 blades and somewhat less so on their nearest neighbors, and the weight was changing so little, i went more drastic with the drill, still with little effect, then added weight to the lighter side's hub. Holding them on with superglue.
I went from 0.5 grams difference to 0.15 grams difference heaviest to lightest, reassembled fan, and it vibrated at a even lower voltage than before.

It was lucky not to meet a sledgehammer at that point.

I tried again to weigh it and could not get any repeat-ability when doing so. The same two blades resting on edge of scale would vary 0.5 grams in subsequent tests. The magnet in the impeller messes with the scale, which is why I was resting two impeller blades on the edge of it initially, for some more distance, but after running the fan perhaps the magnet was more magnetic or something, and the scale did not offer any repeatability.

I shelved it at that point, not worth the effort for a 6$ fan.

That impeller is spinning right now though, since I broke the other one.
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Regarding the smoked 24v Papst fan, it could have been a dud, or the voltage buck booster I was testing it with was a dud as it too failed, which took out which I know not, and I have not contacted either seller hoping for a refund or replacement as i feel it would be dishonest to lay blame on either when i know not, which caused it.

The other 2 24v papst fans I have work insanely well at 7 to 30 volts and I am having difficulty not ordering more of them at 10$ each. While they move a lot of air at battery voltage, I Have issues not being easily able to control their speed. One of them in my workshop I have to bust out the jeweler's screwdriver to change speeds but wind up doing it no less than twice a day.

Most of The 3 to 5 amp rated buck/boosters voltage manipulators that I've ordered have largely been failures, I think the only one still viable is inside my worklight. I have an 8 amp and a 10 amp one which work very well, and these have current limiting potentiometers, so I can limit them to say 2.42 amps, and then they cannot go over 30 volts twisting the pot all the way up.

Unfortunately these 2 buck boost modules employ 200K ohm potentiometers/trim pots, and Bourns and its clone counterfeiters does not make a 150 or 200K ohm ten turn potentiometer, and seemingly nobody else does either, so I've ordered 3/4 and 1 turn 150K ohm pots and will use a 50k ohm tiny trimpot inline to achieve 200, and perhaps 50k ohms will keep the fan from stopping completely when the bigger finger twist pot is turned all the way down.

The original drok 80 watt buckboost module still works well, but has no current control potentiometer and I can easily exceed 30 volts with it. The fan did not seem to mind a half hour at 33 volts, but amp draw increases exponentially after 29 volts with not all that much increase in rpm, so it is wasteful of battery juice, if not instantly damaging to the fan.

As far as selling kits, I'm not sure what is really a viable option. most of my posts in this thread as a record of progress as memory is so unreliable, and are intended for DIY minded who have some soldering and mechanical skills. I am weening out the available voltage manipulation products which work well as speed controllers, and powerful fans which respond nicely to them.
If I were to sell my interior air circulation fan, with
Clamp
Gooseneck and mating hardware
wiring and connectors
voltage bucker
10 turn potentiometer
Fan itself.
fingerguards
were looking at close to 50 bucks in parts.

Assembling all of them takes quite a while, its not like I can hire workers and form an assembly line or buy products in bulk.
I'd not sell my interior circulation clamp fan for less than 150$, as the time spent making it and the parts alone would be in that range, and honestly if I were offered that much cash for it right now, I'd say take a hike. Its 90f and low humidity right now and it is blowing at my chest and I am perfectly comfortable yet anxious wasting my afternoon typing inside as there be waves and work and projects I should be doing instead.

Even if I were willing to sell it for that price, nobody would pay that much and I would not expect them to, as I wouldn't.

I'd much rather share the exact parts and give instructions on how DIY'ers could do it themselves. A lot of my typing in this thread is just a 'journal entry' into my refinement/experimentation process and it always helps to understand things better writing them down for another person to understand. So many new ideas form as I lay out those plans already considered and tested, experimented with. I've a couple of similarly minded people who share with me, but really i can see they are doing the same thing, in their recording of their process, new ideas form.

Many readers with interest in keeping cool, and who could DIY it, will likely be smugly 'just fine' with a wally world purchased plug and play endless breeze fan stuck in a shroudless window for les$ than I am spending in parts, even if such a fan is a fraction as efficient/effective at exchanging inside air for outside.

I tend to want things outside what is available, and thus figure out how to make what I want instead.

My clamp fan is compact, and extremely effective at keeping me cool and providing enough white noise to blow out even the whiniest of screaming kids if I turn it up high enough. My Papst clamp fan needs some sort of blade/finger protection, and is of course much larger, but one cannot argue with its 283 cfm airflow. It's not really loud enough to drown out screaming kids having a meltdown either.

Nobody makes a tight fitting secure shrouded powerful fan to stick in front windows, or my rear conversion van windows, or my ceiling's mushroom vent, so i have made them, going through prototypes and different fans seeking more flow, more efficacy. Having a dog has made their performance and reliability more important. I now have more airflow than I need at the twist of a potentiometer, so mission accomplished, yet I still refine.

Nobody sells surfboard fins with a super high aspect ratio that have lot of grip, yet significantly less drag, so I make those too, and still experiment with shape design and construction method and the joy of being able to choose different lines on the wave is reward enough. Every other surfer knows exactly what a surfboard fin should look like, and mine are well outside this expectation, yet I can easily outsurf most of their opinions and triple their wavecount even using regular fins, yet my fins are faster and looser and will not catch on for many years, if ever, as surfers are ignorant self important sheeple, like most of the general public, if not more so.


No way to profit off any of my almost autistic weirdness, and if there were, I'd likely not follow through anyway.