Tales from a Ventilation Lunatic

[sternwake]

The cedar step down ring/manifold got a porting and a polishing to better align with the steering vanes of the delta fan and reduce resistance to airflow. 
Accomplished with a rotary rasp  with fan in place, then followed by barrel sanders on the Dremel  with fan removed.

   

Anyone with a Dremel, should get the sub 25$ right angle attachment for it.  The level of control and the comfort level is night and day compared to without it. I basically never remove it.

I didn't have any polyurethane and didn't want to mix epoxy, but had some Tung Oil thinned with citrus solvent on the shelf and let it soak up all it wanted.

It does seem quieter, and is likely moving even more air, but I can't prove it.
The Pic is before the Tung oil.


I did another side by side Delta next to Jaro fan, since One delta has now replaced the worst Balanced Jaro fan. 
. With both at max speed  and at the same voltage, the Delta was drawing ~0.3a  less amperage an@ 1.67amps.  Really hard to compare airflow with the rotatable grille screwed onto  the Delta, but the column of air it sends out does not spread very much at all even several feet away, and has a lot of velocity behind it. 
    The Jaro's 4 wider hot spots of flow are nowhere near as impressive. 

I need more voltage buckers.  I have a few more that have the current limiting pots and are slightly bigger.  I guess I could transfer those to the Yaro's and limit current to pre vibrate levels and use the buckers on the Jaros on the Deltas.  I think the workshop is going to get a 20x20" plywood shroud  panel filled with all sorts of 120 mm fans, and perhaps a Papst fan or three as well to replace, or assist, The 120vAC box fan exhaust.

[sternwake]

On a speed Controlling fan topic, My electronic's guru friend ordered a 40 amp 21khz PWM motor speed controller, took it apart and declared it to be well designed and well built with robust components.

While I hardly needed it, for 17$ I though it would be a neat product to have, and that I might consider powering my Dodge's dash blower (~18 amps) on it, with the engine off. 
 Will the airflow will be worth the amperage used at slow speeds?  I do not know, yet. I suspect a Delta fan can do much more air moving  at 1.7 amps.
  I have one Anderson powerpole feeding the blower motor already, but need to put one on the ground too.  Then I can put a wattmeter inline and feed it with either the stock Fan switch or the PWM motor speed controller and then compare hVac flow  for amp draw between the two.  The PWM speed controller should be significantly more efficient than the original resistor pack method used by Dodge.

Even if at low fan speed and amp draw the air it moves is pathetic, I would enjoy infinite speeds on the fan, instead of the 4 speeds that the stock resistor pack speed controller uses.

https://www.ebay.com/itm/173967335637?ul_noapp=true

I opened up mine, and there is a silicone seal on both end caps, and the wires themselves are pushed through this silicone, and the wire's insulation grips it so tightly, I bet it would have a pretty high Ingress protection rating. I had to smear the 14awg  wire  and ribbon cable from the  potentiometer's insulation with silicone grease just to get it back together.  Dust is certainly not getting in, water might if it was under pressure or the unit submerged.

I can't say anything about the design of the circuits, or the quality of the components, but all the soldering looks to be well done. 14 AWG is disappointing for something rated at 40 amps continuous, but I'll never push this beyond 20 and could replace it with thicker if it really bothers me..

 The row of MOSFETs attaches to a long aluminum bussbar/heatsink and the heatsink is pulled tightly to the extruded finned casing by three screws.  There is supposed to be a thermally conductive grease here. i found none there, but filed the bar flat and put a good dollop of arctic silver thermal grease on it, which squeezed out the sides nicely when i torqued the three screws in several stages. Heat from the transistors should transfer to the casing much more efficiently than before I opened it.

Most of the components from China that use thermal grease seem to use too little of what looks like Zinc oxide sunscreen, the arctic silver is several fold more effective in transferring heat and does not easily dry out.

I tested the PWM MSC on the worst balanced ~2 amp Jaro fan.  The fan slows perfectly and does not whine audibly, to my ears anyway. This unit could power 20 Jaro fans.  That's 4000 cubic feet per minute from 23.5" x19" and 500 watts, nearly the same size as a household 20x20 box fan, which moves 2500cfm

   



I have removed 3, 13 khz LED PWM dimmers  from several lights, as they would make my LEDs whine at reduced brightness, and replaced all of those with voltage buckers.  The 5 amp buckers dim the LEDs smoothly and without flickering, all the way down to barely visible, where the PWM controllers would dim them to a point, then they would shut off, and the newest LEDs were still a bit too bright dimmed all the way via PWM.

I am using a voltage bucker that has a current limiting pot, and the voltage pot and the current limiting pot are not marked on the circuit board.  When running some lights I could not tell which was the voltage pot  and which was the current pot, and could not find the link to the product on my phone and laptop was way too deep.  
   Turning either pot dimmed the lights just as effectively all the way to  tiny dim pinpricks, registering the same voltage and amperage.  I then turned off the lights for no current at all, and one pot lowered voltage nice and smooth, and the other pot kept voltage at 12v as I spun it CCW, then dropped to 2 abruptly.  Out came the sharpie with a V and a C. 
    I want to have the external pot I add, to control voltage, not current.  The current pot could be useful to keep the LEDs from getting too hot when the battery is charging at 14.7v and the voltage pot is dialed all the way up.
The amount of amperage some LED's consume at 14.4v is 50% more than at 12v and they get way too hot.

[sternwake]

The 40 amp motor speed controller has been tested, powering the Dodge blower motor.

First, since I had one red anderson 45 amp powerpole on the blower motor wiring close to the motor, I added a negative powerpole there too, and can now place a wattmeter right at the motor if I desire.

A few years ago when i replaced the blower motor, I had run 8awg from speed switch to fan on the + (replacing 14 awg) and had a 8awg from motor grounded to the nearby firewall for powering the blower motor. Now that ground wire is also 8awg but leads to the glove box area where the resistor pack resides and is grounded to firewall there, and I took all voltage amperage and wattage readings at this location instead of at the blower motor itself.

I then added powerpoles in the glove box in close proximity to the speed controlling resistor pack.
I then added powerpoles to 40 amp PWM MSC.

I have a whole bunch of data written down but here's the (relatively) quick of it.

The maximum voltage the stock wiring can send to the blower motor at maximum fan speed, is well below battery voltage by just about 1.45 volts. 13.6v in 12.15v out. @12.15v the motor draws about 9.67 amps. If I had the original 14 awg the voltage reaching the motor would be even less.

With the MEanwell power supply holding the battery at 13.6v,

1. Slowest stock speed the resistor pack lowers voltage to 6.8 volts and motor draws 3.73 amps
2. Medium stock speed, the resistor pack lowers voltage to 8.77v and motor draws 5.48 amps
3. high stock speed and the resisitor pack lowers voltage to 10.77v and motor draws 7.42 amps
4. highest stock speed bypassing the resistor pack yields 12.15v and 9.67 amps f motor draw.

Feeding the PWM MSC directly from meanwell power supply over 10' of 10awg yields much higher voltage, and up at 14.7v the motor can draw over 16 amps.

What I did not expect is that changing the lever from warm to cool, also allows the motor to draw more amperage
Moving the vents manually from floor and defrost, to the dash vents, normally controlled by engine vaccuum, also increases amp draw.
It sounds louder with the vents set to warm and to the defrost and floor. More resistance to airflow, and amp draw decreases and motor slows slightly, less resistance to flow and motor speeds up and consumes more amperage.

It sounds quieter with the vents set to blow out the dash and the temp lever set to cool.

the amount of air moved at 3.73, 5.48, and 7.47 amps, via the PWM controller is significantly higher than those same amperages flowing to motor through the stock resistor pack. Its hard to quantify but I will guess airflow wise, 2.5 amps through PWM MSC = 4.6 amps through the resistor pack.

The resistor pack is bleeding off lots of wattage at reduced speeds, a LOT more than the PWM motor speed controller does.

At 2 amps through tHe PWM MSC, the airflow out defrost and floor vents, or dash vents, is acceptable to me, and more than I'd expected. The noise of the blower motor is quite noticeable though. 2 amps of computer fan is more effective in airflow, and a different pitch, and probably louder .

When the engine is running, the alternator is powering the blower motor, but at reduced speeds the resistor pack is wasting much more alternator amperage than would the PWM motor speed controller. The PWm MSC can free up some charging amperage to the battery, instead of turning it to heat via the resistor pack.

Having infinitely variable speed, instead of 4 set speeds is very nice.
The efficiency is much better through the motor speed controller than through the resistor pack.
I suspect I will choose to run the blower motor always, from the PWM motor speed controller, instead of the stock circuit.

The 40 amp PWM MSC did not get the slightest bit warm passing 15+ amps for 10 minutes. I'd have no issues positioning this where it has Zero airflow over it, inside my glove box.

My stock Hvac blower motor circuit is rebuilt from the speed switch to the motor and healthier than in 1989. It will become a redundant backup, as I can get more voltage to the blower motor through the motor speed controller, for more airflow, and it is significantly more efficient at reduced speeds, and at max speed is able to move much more air and I can power it with the engine off and no key in the ignition.

The blower motor does not whine on the PWM MSC, but the HVAC unit could still use some sound dampening.

My dodge controls the output vents using engine vaccuum. With no vaccuum it blows out the defrost vents and the floor. Moving the lever by hand to blow out the dash vents is desirable, but requires a fair amount of force.



When it rains, the original blower motor can be used to crease positive pressure inside the van, so small leaks would have more difficulty getting inside, as opposed to having the ceiling exhaust fan causing negative pressure inside and actively sucking water inside the van through any imperfect sealing.

In the past I've found the slowest stock blower motor speed to be too high at times, and the highest speed not quite high enough. If I feed the PWM MSC I can get significantly higher voltage and airflow from the motor for 220+ watts of blower motor draw at 14.7v battery voltage,, and slow it all the way down to below 2 watts too.

I believe this is a worthy upgrade, and I will opt to run the Hvac blower motor parked fairly often in medium hot weather instead of setting up the acrylic shroud in the passenger window. The acrylic fan shroud with 2 190 cfm delta fans, is way more effective in exchanging air and keeping the front of the van cool than the stock Hvac system but setting it up and taking it down is obviously more work and less secure than spinning a dial past its detente to ON.

for testing I used some not so nearby powerpoles and was losing half a volt over the extension cord, but could wire a dedicated thick gauge powerpole circuit for minimal voltage drop and thus get maximum potential airflow from the motor.

I have no idea how well the blower motor will respond to long times at reduced speeds. Twice in the last year I've had the brushes in this relatively new blower motor get stuck and require me to open it up and free up the brushes. I reduced their dimensions and lubed them with silicone grease, so perhaps they will not get stuck again.

It should be noted that this PWM motor speed controller does not require one do any soldering to add a remote potentiometer. The provided potentiometer incorporates an On off switch and no separate on off switch need be installed to remove parasitic draw.

One can power any fan brushed or brushless from it, and at 21KHZ the whining is not audible to human ears whereas PWM speed controllers or LED dimmers at 13KHZ , the whining is atrocious to my ears with most fans.

This magic box is highly worthy of its 17.05$ price tag, in my opinion.

[rvpopeye]

Another episode of "fun with fans".
Pretty much as expected results .
Another winner award !
Well done .
I'm sure many will follow your trail on this one too.

[sternwake]

I had a brain fart moment regarding the current running through resistor pack, and comparing amperage above.
The wattmeter was placed before the PWM MSC, but after the resistor pack. 
The voltage was reduced by the resistor pack but feed voltage into the PWM MSC was held steady by the mean well above battery voltage.  I can place wattmeter after PWM MSC but the output voltage might be inaccurate.
 
The resistor pack is wasteful of amperage but not as wasteful as I posted above.

Should have gone by wattage, as that takes into effect different voltages.

I can;t really take amp readings easily on stock wiring before the stock resistor pack nor voltage, so I could then see wattage in vs wattage out at reduced speeds and see just how much the resistor pack is burning up as heat.  I guess some math can arrive at similar conclusions, but small errors in voltage could throw the wattage  numbers off pretty good. 

Either way it is pretty awesome having the ability to turn on the HVAC blower with engine off,  to any speed and noise amperage level I desire.  Its not the most electrically  efficient way to force fresh air inside, but it works.

I'm gonna run some 10awg to feed the PWM MSC, and also make a quick disconnect for the vaccuum operated lever which shifts vents from dashboard to defrost/footwell, but perhaps not for a while yet.  I can just hook it back stock for now and use a extension cord when I want to use the PWM MSC.

[sternwake]

The PWM MSC powering the stock blower motor has come in quite useful again. I've driven to Florida for Xmas, and the spare bedroom was taken, so Fiona and I slept in the Van as it is a million times more comfortable than the air mattress on office floor, while it rained, and my regular intake fan shroud had its window closed.

I never ran dedicated wiring to feed the PWM MSC, but have been grabbing the nearby anderson powerpole that is there for the passenger side window fan shroud. That is 18awg so voltage drop is limiting top fan speed, but not a big deal. When driving I have just been using the 4 set speeds of the Stock resistor pack.

If I have the stock Hvac blower on very slow speeds sub 1.3 amps or so, and it is windy outside, gusts of wind affect the speed/noise of the fan which I find a bit annoying, but can drown out with more speed of any of the other fans.

Speaking of the intake fan shroud with the 180mm SSfm 181 fan, the 140Mm noctua industrial 3k rpm fan and the 120mm jaro, the 140mm Noctua, just failed. I was hoping for a connection issue, but 12vdc is getting to the circuit board fine and dandy. I have the second warranty 140mm replacement still in California, in the box, unopened, untested, and honestly, I doubt I'll ever bother installing it.

ALL these industrial Noctua fans have been lucky to last 6 months in this location. I'd rather be refunded than have another industrial Noctua. I'd rather have one of their newest non industrial fans, as I've had no issues with those, but one whose wires corroded off the circuit board, easily fixed.

I am trying to decide what to do regarding this 5th failed industrial Noctua. Is it even worth informing them? The 6 year warranty applies since the date I bought the first one 3 years ago or so. I don't think it is worth the effort to even package the old one up and send it back even if they send the shipping label to do so. Kind of disgusted really. Industrial....my ass.

I think that 140mm hole in my intake shroud will just get covered with Black Gaff tape, while I see if Delta has any 140mm offerings. My voltage buckers as fan speed controller, or LED dimmers, opens up a whole new area of powerful fans.

[sternwake]

Looks like Delta offers some true monsterly powerful 140mm fans, some with monster price tags.

The 12v PFM1412DE-SP02 has a 7.5 amp consumption rating!! not sure of airflow and deltas website does not list this model number. perhaps a discontinued older model.

the 24v FFB1424SHG has a 2.3 amp rating and 463.9 cfm rating, which is rather insane.

I of course had to buy them, I have a bucker capable of handling 10 amps for the 12v fan and a buck/boost capable of handling the 24v version. These are slow boat from China and sent to California, and I am currently in Florida but should be back there before they arrive. They could be like the 252 cfm screaming banshee and not slow enough to be usable inside the van and a waste of money and time.

In the mean time I ordered this:
https://www.amazon.com/GDSTIME-140mm-Bea...HJ1ZQ&th=1

1.5 amps and 223 cfm rating. Appears to be a Delta clone, and it should be here tomorrow with a few new 5 amp buckers. If the cfm rating is accurate then that is ~55 more cfm than the failed noctua 140mm industrial fan it will be replacing, and likely a LOT higher static pressure rating. The static pressure ability seems to be directly related to air movement efficacy, more so than CFM, since none of these fans are in open air, not fighting air pressure or resistance to flow



I sent another Email to Noctua informing them of the 5th industrial fan failure and that I do not even want a warranty replacement as I am disgusted with the high failure rate of a fan marketed as 'industrial' when they all failed within a year. I said if they really want to replace the failed fan to send me their newest A12x25 non industrial fan, even though I don't really have a use for it.

[Blacktank]

wonder if there is some volt/amp sensitive part in those Noctua fans? something that doesnt like change and just wants to be at a certain level


when you find the perfect fan write it in big bold words

[sternwake]

No idea what is causing the industrial Noctua failures. I've been running them through Noctua's own PWM speed controller and provided cabling, not one of my voltage buckers.

They have not told me if they found anything regarding why all the units I've returned have failed, but the very first one that failed, i dissected, and the biggest processor chip looked all overheated.

There is no perfect fan, but the recent 190cfm 120mm Delta acquisitions, and the 24v Papst fan, especially for 10$, are my top two favorites at the moment.

The speed control portion of the Silverstone fm181 which resides on m intake fan shroud, appears to be fried, and it now just runs at full speed, and this full speed does not seem to be very powerful anymore. I am putting an older LM2596 3 amp voltage bucker on it right now as a speed controller, but suspect it will be replaced with a 24v Papst fan in the not too distant future. The Papst diameter is smaller than the fm181's hole. One of the two Delta 140MM's could go there too, since I have to modify the shroud anyway for anything but another 180mm fan. The fm181's cfm rating and static pressure rating seem way overrated. Two 140mm deltas with a 120mm delta can likely be way more effective in this location. The ss FM181 excels at very quiet air movement

With so many passing rain showers in Florida and the spare bedroom available again, I've only been running the roof exhaust Delta at about 1/3 max speed and every time I open the door it feels no hotter inside than out.

[sternwake]

Perhaps I should have reread some of this thread from a year ago.

The LM2596 based voltage bucker drops over 0.7v. 12.0v in 11.3v out max, Actually its more like 11.27v out max. Less max voltage out less maximum fan speed.

Since the ~150CFM rated flow of the silverstone fm181 fan already seems much less impressive than it once did, that loss of 0.73v compared to the XL4015 based bucker's 0.31v is much less desirable to this ventilation nerd.

The good news is the SS fm181 on the V bucker can slow the fan way more than the SS fan's built in speed controller ever could, for marginally less amp draw yet significantly less airflow on minimum speed, which can be quite desirable in the cooler seasons.

More xl4015 based buckers to arrive tomorrow with the 140mm 233 cfm semi cloned delta fan.

Looks like my removing the 10k ohm trimpot of the lm2596 bucker, and adding wires for a remote pot, was a waste of time, but I have gotten really good at getting wires in place of the pot. The trick is tinning them first, then cutting the tinned wire on a steep angle leaving a pointy tip, then putting the solder iron tip on the backside while pushing that pointy tip into where the legs of the pot once resided. A year ago i was using tiny drill bits in order to drill out the solder from the holes, then stick the wire through the holes then solder them and shittons of cursing and time was involved.

Soon the 120mm 190cfm Delta fans will replace the two remaining In service Jaro's, and the 140mm Delta clone will replace the failed 140mm Noctua. When a 24v Papst fan replaces the SS Fm181, then perhaps, maybe, I might be able to stop pursuing this van interior as a windtunnel insanity.