Whats the current best VENT FAN?

I have the 252 cfm Delta screaming banshee 120mm x 38mm fan. There is only one 120MM computer fan more powerful, and Sanyo San Ace, and it is only slightly more so, yet significantly more expensive.

There are some smaller 5 and 7 inch radiator fans which might be in the same power range.

http://www.skycraftsurplus.com/12vdcfanebm6inchdiameter.aspx

https://www.amazon.com/Spal-30103011-Paddle-Blade-Puller/dp/B009OBP0Z6

I was not able to tame its speeds to tolerable noise or power levels either through a PWM motor speed controller, or Via voltage, as below a certain point it just stops, and I measured the minimum speed I can attain at 1.83 amps. Below something like 7.8v IIRC, it stops, and it is still way too noisy to tolerate on an consistent basis at the minimums I was able to achieve.

I could also not get this Delta fan, or my 92MM version to respond to a PWM signal sent on the 4th blue wire.

I did not try it using teh Noctua NA-fC1 speed controller which I got well afterwards. I could have blown up the PWM driver in the fan trying to get it throttled on PWM from PWM motor speed controllers, but there is some info online about an inverted PWM signal required for Delta PWM fans, whatever that means. I gave up ( for now) on speed controlling the Delta PWM fans on the fourth wire.

The Bilge blower might have a setting below of which, it just shuts off.

Regardng computer fans on internal vents, you could split the blue wire from the Noctua speed controller to many PWM fans, and just power each fan from more local wiring, rather than running 3 wires from the speed controller itself to each pwm fan, or having one dedicated PWM speed controller for each 4 wire PWM computer fan.

The silverstone fm series fans with built in speed control, come with 10K ohm potentiometers to adjust that speed,

Knowing that range of resistance, someone more electrical savvy could likely influence these fans rpm according to temperature.

The speed control of fans is pretty key, and so is pure power when volume and amp draw is of much less concern that the fastest possible exchange of outside air for inside air. I love being able to crank 3 potentiometers and feel a wall of cooler air work its way from the intake fans to the ceiling exhaust fan, then dial them down accordingly.

If I could efffectively control that 120MM 252CFm 35.88 mm sstatic pressure screaming banshee Delta fan to tolerable speeds and amp levels, I would be happy to have it exhausting my ceiling, or scavenging filtered from below and forcing it into the cabin. I might do this with a 140Mm industrial Noctua NA-f14 since I know I can just send the blue wire a PWM signal from my existing Noctua speed controller, and 160CFM and 10.51MM of h20 static pressure for 0.5 amps is pretty respectable too.

The bilge blowers are nice, as they are easy to hook ducting to, but I would much prefer some sort high power PWM computer fan that I can throttle to near silent speeds and very low amp draw.

BUt honestly I do not need much more ventilation, I can keep the rig interior as cool or cooler than ambinet, until that brief period in late afternoon when ambient might be able to cool quicker than the rig can.

The cone style auto airfliters on a bilge blower certainly simplifies design.

Consider vibration isolation and sound blocking in your design, rather that trying to attend to those possible issues at a later date.

Keep us informed of your progress.

Looked up that delta fan its 7000rmp thats insane compared to everything else i see.

Im still trying to decide on computer fans. Going to use them for the bathroom vent, indoor air circulation, and might put a couple on the AC vents.

For ventilating the whole toyhauler im going with the 4" inline blower mounted under the trailer. Using an automotive air filter, thermostat, and PWM controller.

Heres what i bought so far:
Attwood 4" blower
4" dry air filter (will cover with outwears material)
thermostat
motor speed controller

The 92mm delta fan above is rated at 158CFM at 12v and some 25MM of h20 pressure. It is a monster.

That 92mm Gelid fan is rated at 38CFM and 2mm of static pressure.

You will be disappointed at 38cfm's airflow, but perhaps not the noise or amp draw.

landyacht318 wrote:
My filter fan is a 92MM delta fan. PFB0912UHE, Very powerful.

It is throttled by one of these

Which one?

Nice story i like how the quickSilver guy helped with space blankets that are silverish.....yah?

Space blanket on the roof of a car? Extra thick of course. You guys have some amazing advice here. My headliner fabric is falling down in the front. Need to buy a bottle and use 0.1% of it.

As an aside I saw the "insulation" that lays behind the headliner in my toad. It hasn't changed. I am going with Space Blanket extra thick when the car gets reupholstered. Look in Amazon.com for extra thick blanket.

I had a 1970's GM pickup that got full foaming by Dale Erb, the guy who did Quicksilver. The temperature difference was unbelievable whether it was for heat retention or heat rejection.

Yeah my cardboard box fan didnt work at all. Actually never tested the fan without the box. It probably blows like crazy pulling 6amps!!

Anyone have advice on temperature controlled fans like this?
https://gelidsolutions.com/thermal-solutions/case-fan-silent-9tc/

It spins faster as the temp increases. Im thinking about using one on my truck. I swear these computer fans have consumed my free brain thinking time. Its hot here, also dusty. Dont want to crack the window on my truck when its 100F outside.

So what about a 12v computer fan, placed in front of an AC vent, then manually close the other 3 vents. (i have 4 face level vents...2002 f250 7.3)

Hoping that would draw fresh air into the truck and not get so hot inside. Plugged into the cig lighter or maybe use a cheap solar panal if the truck will sit for a few days.

My filter fan is a 92MM delta fan. PFB0912UHE, Very powerful.

It is throttled by one of these


https://www.amazon.com/eBoot-LM2596-Converter-3-0-40V-1-5-35V/dp/B01GJ0SC2C/ref=sr_1_4?s=automotive&ie=UTF8&qid=1528997029&sr=1-4&keywords=voltage+buck+converter&dpID=61ot3zsbBwL&preST=_SY300_QL70_&dpSrc=srch

I added a stick on coper heatsink to the LM2596 chip, and an external potentiometer. Theis bucker loses a volt on the top end, but that fan is so powerful at 11 volts its loss is of no consequence.

The fan uses 4 4 inch deck screws on the intake side, to prevent filter material from getting sucked into impeller. The pan perimeter is covered in narrow strips of velcro to which the carbon filter material sticks.

The fan is mounted to an adjustable gooseneck similar to those designed to hold micrphones. the gooseneck is attached to a 2 inch spring clamp I can clmp in many places throughout my rig and aim the fan where required.

I used a paper stapler to join the carbon filter together to make the 92mm square sock. The sock keeps the filter far from the impeller, and vastly increases the surface area, presenting minimal restriction to the fan.

One cannot simply place a 20x20 filter on the backside of a 20 inch box fan and expect it to move much air, but if one were to move the filter 20 inches away and use more filters on the sides then there would be almost no restriction to flow and much greater surface are for filtering.

To respond to myself i think its a delta fan with a filtration sock. Did some searching and see the fans but not the sock.

Noctua seems like a great product!! Does it come with a briefcase (ktm joke)?

Jeez I'm getting old. My Vestfrost refrigerator and Vestfrost freezers have the original Danforth supplied fans. Even though they are 24 volts I can use buckers and some of the newer hot set-up fans. Their fans draw 2.3 amps EACH not counting evaporator fans. The fans have shrouds but I'll bet I can chop 25% off the total kWh by using non-stone age technology. I can unload the freezer unit into the refrigerator then set the dial at TEN. The refrigerator will stay at around 12F while the freezer defrosts.

NOTE about the air conditioning thermostats. They are utterly mechanical with a 25 amp at 240 volts contact rating for 10,000 cycles so with a tiny DC load their endurance will have two commas. The new breed of homeowner demands extremely complicated programming function, menus and sub routines so the mechanical thermostats can sometimes be had at bargain basement prices. Look for a third set of contacts within to set the Delta T temperature. Instead of six degrees factory I reset mine to engage two degrees warmer than the disengage. Mine is a white rogers brand. Wire it in before the speed selector dial.

Love the new age utterly brainless engineering on this stuff. New digital controls AC units shut off and stay off forever if power is interrupted. I have a mechanical control dial A/C unit. When power is restored, it has to pass through a 20-second delay on switch. Stops false triggers and starts. Jesus HATES his digital A/C. Power flickers and it means a middle of the night wakeup a half hour later to press buttons. Regular "Planet of The Apes Cutting Edge Technology".