Whats the current best VENT FAN?

Yea my Fantastic Fan in the roof vent is still looking pretty good to me.
I am sure you will find something that works for you too.....

Would love to see pictures of all this fun stuff. The mechanical thermostat is an option will check it out.

Wonder if i could get power for a fan inside the fridge behind the light bulb. Its your standard 110v/Propane fridge in a toyhauler.

Heres my first attempt at filtered positive pressure. Found a $25 automotive radiator fan off amazon. 12v DC and pulls almost 6amps. Barely pushes any air. Super loud. Like that joke you guys keep making. Not even sure what it is, i picture a small yapping dog.

I dont like how this cardboard shroud has air gaps. It does setup in seconds using a bungee cord. Also dont like how the window is open and shades are up. Could solve those problems with tape but its not ideal doing that every time.

Thinking the 4" Blower mounted under the trailer with an air filter on the intake will be the ticket. PWM dim it and can hook to the batteries directly which have solar charging. I should be able to kill all power to the trailer with the kill switch. Then be gone for weeks or months and not worry about the trailer being really hot inside.

I want to use these mega efficient computer fans instead. But dont want them on a window. Will definitely replace the bathroom vent fan, and also buy a couple to use for indoor circulation fans.

Been hoping to come across that filter sock that was mentioned. Filtering the inside air would be nice.

My fridge is a 12v compressor fridge. its condenser looks like a car radiator and is designed to accept a 120MM fan.

The fan it came with was rated at some 72CFM and was mounted to pull air through this condenser. It was louder than the compressor.

I removed this fan, and installed a Noctua NF-F12, the 1500 rpm version. I installed it to push air through the restriction, as this fan was designed and engineered to do.

The duty cycle of my fridge dropped by about 40 seconds esch time it cycled on, and the Noctua fan draws 0.05 amps, vs the 0.12 amps of the fan that came mounted on the compressor. The Noctua fan is also much quieter. The performance improvement was significant with this much better fan pushing air, instead of some sleeve bearing fan pulling air.

More recently I got the Noctua a12x15 fan and mounted that to my condenser. It reportedy outperforms two NF-f12's in a push pull configuration. Its thinner design also allows more room behind the impeller for it to scavenge cool air and push it through the condenser, once as i designed my fridge ventilation system so that it canot recycle air it itself has heated

I did not bother conducting duty cycle data, but this A12x15 is even quieter, and I moved the NF-f12 to exhaust my electrical cabinet, and depending on a few options, I can have the NF-f12 also pull cool filtered air through the condenser. At just 0.05 amps I let it run 24/7/365 though I could easily have it activated to come on with my fridge compressor as the compressor controller allows for fans of upto 0.5 amps. It could power 10 NF-f12's and move 530 CFM for that 0.5 amps.

Inside my fridge I have a Sunon 0.03 amp 40x15Mm fan running 24/7/365. One does not require large CFM numbers for internal fridge fans. This fan allows me to use a lower (~ 2.3 out of 7) setting on the fridge and maintain a very even internal temperature( 33.5f), though it does not reduce the amount of electricity the fridge uses.

Without the internal fan I need to bump it up close to 4 of 7, and the floor will be 28.8 degrees and the warmest spot in the fridge will be close to 41F.

Yup. I'm in the process of ordering FOUR Noctua fans to get stuffed inside a gutted Endless Breeze housing. Air Conditioner mechanical thermostat sends DC power to an ON / ON / ON switch (Delcity.net), to control two, three or all fans.

When (Flim) Flamtastic Fan is holding out it's gnarled fingers for another eighty bucks I will be laughing and maintaining 24/7/365 airflow -- even after a major hurricane power outage.

More than one way to remove fur from a cat.

And Landyacht's excellent info factored heavily in my selection of muffin fans.

By the way in my experience it is not uncommon for a pair of bilge blowers to hogg TWENTY FIVE AMPS of twelve volt current. Neat Huh?

Your information is so incredibly helpful!! Im blown away.

Fan on the fridge exhaust? Would like to learn more about that. I put a USB powered fan inside the fridge when we camp in 110F desert temps.

Thanks for the info on PWM dimmers and the proper frequency. Do you or anyone have ideas on how to control a fan with a cheap digital thermometer? Would be ideal if the PWM speed could increase when temps are really high.

If the thermostat idea wont work then i could set the PWM to a speed i like and then use a digital timer to turn the fan off and on while im away.

I was unaware of the Silverstone 140Mm fans, and cannot have an opinion on those specifically, only silverstone as a manufacturer, which is pretty high.

Every time I have places restriction behind a computer fan, and then in front of the fan, the fan seemed much happier and more efective pushing air rather than scavenging it from behind through a restriction.

I have no personal experience with Bilge blowers, and will limit my opinion on them until I do.

Regarding using PWM Motor speed controllers to control fans, one must seek controllers with 21Khz or higher. Many are 13Khz, and will make the motor whine loudly, annoyingly when it is slowed down. I have several 13Khz LED dimmers i used on fans ansd the whining is louder than the fan itself.

Many computer fans will be advertised as PWM fans, or 4 wire fans. These have a blue wire, fed a PWM signal by a computer mother board, which will control the fan speed, but this blue wire can also be controlled by a pwm generator.

One can make one or buy one. Noctua has fairly recently come out with a speed controller for their fans, but it also controls any other 4 wire PWm fan, with the possible exception of Delta PWM Fans.

https://noctua.at/en/na-fc1

I have one of thes controlling my two 3K rpm Industrial Noctuas and at minimum speed both together are something like 0.03 amps and dead silent. max speed approaches angry sikorsky, but when needed, better to have it.

Noctua fans come with a 6 year warranty, and they honor it quickly via an email. Never had something shipped from Austria but it was here in 4 business days. I said 'screw it' when one fan quit, and opened it up with elecrical nippers and saw the microprosessor looked and smelled like its magic smoke escaped. Took pics, emailed them. 7 days later new fan at no cost.

Regarding specs of Silverstone fm181 vs Ap182, I was always surprised that Ap182 was rated at 165CFM and fm181 atr ~150 cfm, considering the impeller is exactly the same, one turns 1300 rpm and the other 2000 rpm.

The AP 182 with the spiral faceplate concentrates the flow into a narrow column. If placed 8 feet away, i will estimate that the 180MM column of air has expanded to a 3.75 foot radius.

The Fm 181 there is no column, just 4 hot spots at much wider angles as there is no spiral faceplate to concentrate the flow. What I can say from experience with both, is th eAP 182 on high speed is impressive, and does not scream like a smaller radius fan.

The FM181 is 700 less rpm, but also 1 amp less at that rpm.. It is amazingly quietat max speed, but its airflow is not near as impressive as the AP182. Again my eye brow is raised a tthe only 15 more cfm rating of the AP182 vs the fm181.

They also have the thinner 180MM silverstone available, not sure of its ID. It has more, smaller fan blades. No experience with that one but it too has speed control and good CFM for the amperage.

If you do get the bilge blower which is wise if you want to run ductwork, I would definitely recommend a 21 KHZ PWM motor speed controller for it, one that you an put or relocate the speed control potentiometer somewhere conveninent, and also use some rubber mounting feet to isolate it from whatever it is mounted to.

The computer fan world is very competitive, regarding noise and CFM and static pressure, and we all benefit from companies like Silverstorne and especially Noctua, for pushing the designs to the degree that they have.

Look at all the tech in their latest flagship model:

https://noctua.at/en/products/fan/nf-a12x25-pwm

Sure one can get many higher rpm fans with impresie CFm specs for the same price as one of these Noctua's , but I think it is impressive one can still find this level of engineering and precision production for less than 30$.

I've got Noctua's everywhere. Fridge Electric cabinet exhaust, Meanwell power supply, Intake fans.

My one silverstone fm121 is my roof exhaust fan, has a counter rotating fan in line below it. An Arctic cool F12

Turning on the arctic cool fan, when the fm121 is on max speed reduces the noise by half and seemingly doubles the airflow.

I tried to feed an 120MM 3Krpm Industrial Noctua this same fan, and it got twice as lousd and airflow seemed to be halved. Os the silverstone stayed on my ceiling and the Noctua pushes filtered air into my rig.

Basically, parked in full sun, with reflecticx window shades on the sunny side, I can keep my rig cooler inside than outside ambinet temps, until late afternoon when the outside can cool quicker than my rig.

I can do this expending just 1.65 amps as my air intake and exhaustm are shrouded. Fans are not simply placesd in an aperture, but have shrouds so their entire volume of air moved, moves once and cannot do a Wuick U turn and pass through fan again, like a small fan in a bigger window can do.

Even with 30 year old door seals, I bet my fans could move a barometer needle

Add my kudos toward mister Land Yacht. He steps up with facts, figures and opinions which I have high regard for.

The older I get the more impatient I am with badly engineered electrical. Manufacturing a simple device like a fan motor with almost unlimited life would not be difficult but it would not be inexpensive either. Is it hard to imagine a society where recycling old but extremely durable parts becomes the norm?

To wit

In the 1930's WINCO built incredibly durable windmill generators for rural off-grid use. They designed stuff correctly. Vacuum pot varnished rotors and stators, cast iron housings and oil not grease lubricated bearings. Many of the generators lasted forty years or more before they were lowered from their towers for a maintenance turnaround. WINCO today is a fable. Older units are almost impossible to find and they bring heart-attack prices. Like a Bugatti Royale. A thousand times their original purchase price.

There is nothing wrong with over building. Today's RV's "last" so many years. What is wrong with the idea of building an expensive fan that has a coveted motor that is pre-sold before it even hits the market as being used. Throw away the garbage but keep the motor for resale. If it is near bulletproof a fan motor that costs 120 dollars new can be recovered and resold for say a hundred and five dollars. This keeps mount Everest quantities of toxic landfill being generated and reduces the raping of raw materials that is ravaging the (here comes a term liberals love) PLANET.

I worked with St. Mary's carbon to develop alternator brushes back in the nineteen eighties. Specialty brushes that ranged for 1/8" to 3/16" longer than OEM. They were a proprietary blending of carbon and graphite and boy were they pricey. Standard brushes will last "X" hours. My brushes lasted just a hair less than 140% as long. I replaced lube in both bearings and insisted in NTN LUA brand (except for needle bearings which called for genuine Torrington). By replacing OEM grade rectifiers with top capacity models from RENARD, and voltage regulators with top grade TRANSPO regulator models that used previously unheard of MOSFET finals my stuff carved a niche market. Especially in the RV and emergency vehicle markets in Los Angeles area. Yes my remans cost more. The cheap-at-any-price crowd, retail and wholesale turned up their "lifetime warranty" nose at them.

But chew and spit economics is destroying this world. Plastic in whales. Gobs of plastic at the bottom of the Marianas trench. I won't live long enough to endure the final catastrophe but some of you will.

So forgive my ranting at the chew & spit lifestyle. The market, the economy, the demand. It disgusts me.

Could even try something magnetic. Like a little torpedo level. Pop it on the motor and see if that changes how the vibrations sound.

wopachop wrote:
The harmonic frequency idea makes sense. What if you tape something heavy to the fan?

Huh. I think there's a joke in there somewhere but don't want to end up on the street. :W But I might just give that a try, thanks.

This is a possible 4" inline bildge blower. Can handle 13.5v. Claims 230cfm at 2.5amps.

https://www.amazon.com/Attwood-Quiet-Blower-Resistant-4-Inch/dp/B003EX02DA/ref=pd_sbs_200_3?_encoding=UTF8&pd_rd_i=B003EX02DA&pd_rd_r=YTEZ8HEF3TP44R07198Z&pd_rd_w=vC3Lt&pd_rd_wg=2VX0L&psc=1&refRID=YTEZ8HEF3TP44R07198Z