Simple Fan Setup

[Urban Fisher]

Hey All,

Hope I am posting this in the correct place. I have been converting my minivan into a weekend warrior camper. Not full timing yet, but consider it as practice for if and when I do. It may sound silly, but I have actually been "practicing" stealth camping in the parking lot of the apartments I live at. They would so frown on me if they knew, but I figured a perfect way to practice my stealthiness (if that's even a word). For now I really don't plan on adding a house battery and such. It is mostly just a fair weather weekend camper. I did buy some window visors so I can crack my front windows open as I sleep in it. It also has the back windows that just open a couple of inches. I prefer to keep those close in case it rains and for stealth reasons. My main thing is that I am worried about good air circulation while I sleep at night with just the front windows cracked a couple of inches.

So my question...I see those battery packs for portable phone charging. They say like 20000 mAH (which is 20 amp hours!?!?!). I guess because they are only 5 volts versus 120? I am college educated and consider myself reasonably capable, but when it comes to electric stuff...it mid-as-well be Japanese. I guess my goal was to put a small USB power supplied fan to push the air from the front window to the back. Not really to mimic an AC unit, more to just make sure fresh air is coming in while maintaining my stealthiness. Below are just examples of the power pack and fan I'm considering...again examples, I'm not actually buying those exact ones. So can anyone offer input as to if this would work? If I get like a 20k mAH battery pack, will it run a small 4"-6" fan for like 10 hours?

Any help anyone could offer would be greatly appreciated.

 https://www.amazon.com/Nekteck-2010...2-spons&keywords=portable+phone+charger&psc=1

https://www.amazon.com/iMBAPrice-US...e=UTF8&qid=1494429408&sr=1-2&keywords=usb+fan

 

[SternWake]

Problem with USB fans is no battery is 5 volts. 5 volts is a regulated output meaning conversion losses.


Many computer fans are 12v, and one could simply attach power leads to to a ciggy plug, and plug into the vehicle  12v power port.

The Noctua NF-f12 draws only 0.05 amps and moves 53CFM.  In 8 hours this consumes 0.4AH. A typical minivan battery is somewhere between 65 and 85 amp hours capacity.

Or one can get a small 12v AGM battery just for the fan itself.

This is often the battery found in lead acid jumper packs:

https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias=aps&field-keywords=UB12120

Just presenting options.  I feel it is more important for a fan to exchange inside air for outside air, rather than hoping open windows exchange enough air and simply circulating the air inside.

 

[John61CT]

Yes those power packs are very deceptive to use AH, especially when they have multiple voltage level outputs.

How much POWER is actually stored will always depend on "at what voltage?"

USB-only output at 5V 20AH probably means around 8AH compared to a 12V battery. These small units really should use watt-hour ratings to be comparable.

I would recommend getting a standard 12V deep-cycle setup started, more expensive up front but better value long-term. How will you recharge it? Small and light means **much** higher cost per AH.

Have a look through this recent thread: https://vanlivingforum.com/showthread.php?tid=23759


And what SW says about fans +1, get fresh air in stale air out, don't just move it around.

A low-profile MaxxAir on the roof with integral vent cover continues to work well in the rain and at low settings is nearly silent.

 

[Urban Fisher]

Thanks guys! I guess I was just looking for a simple....CHEAP way to run a small fan. I guess I should have described my idea more. I was actually thinking of running a small 3"-4" tube or duct if you will with the fan. For stealth I was thinking I could run one end of the duct to the cracked open front window and them mount the fan on the other end. Then I would run it towards the back of my van and have the fan either push or pull air from the window into the back of the van (via the duct). I was interested in the small portable chargers because...well they are cheap and small! I could also use it as a backup to charge my phone when not camping. I also have seen many of the small portable chargers that have built in solar panels. That way if I was out for a couple of days, I could leave it in the sun all day to charge and have it run a small fan as I sleep at night. Just trying to avoid the whole "house" battery setup and don't really want to cut a big hole in the roof of my van.

My next setup will hopefully be a full sized van and then I want to do the full solar, isolator, house battery setup. But that may be a few years away. For now I just wanted a cheap way of running a small fan (without the risk of draining the starter battery) to ventilate my van when I sleep in it (and yes my main goal is to bring fresh air in, not just move it around).

 

[John61CT]

If it really is a low current draw fan, use your starter battery, but get a low-voltage disconnect that shuts off your House loads when voltage drops.

Ideally an LVD with an adjustable setpoint, so you can tweak it to give as much as possible and still guarantee starting power.

Or get a small powerpack that will jumpstart your van, keep that fully charged and take a chance running down the starter.

When the starter dies from deep-cycling abuse, replace it with a much more robust true deep cycle, big as can fit in the tray, and **then** do the LVD to preserve your investment, maybe even control the cutoff from State of Charge via a proper battery monitor.

The computer server fans at 12 V are very efficient, check out "Sanyo Denki San Ace 80", I just picked up a dozen of these:
http://www.ebay.com/itm/252888899498

A much more powerful version here: ​
http://www.ebay.com/itm/131803865784

 

[SternWake]

Well your Idea will work.

I resisted the urge to buy a Lithuim jumper pack because I though they were neat, but they could also accomplish what you want, AND be an emergency jump starter, at least until the Lithium cells within degraded too much for that.

The Computer fans might be more easy to hook upto a Ducting system, and perhaps move more air for less noise and amperage consumed than a USB fan, whose power consumption was not really much of a design concern.

Computer fans do come in 5 and 12 volt versions. Notcua are the cream of the crop in my opinion, but I really like the silverstone FM121 and FM181 fans as they come with speed controllers.

The 120MM fm121 is 0.08 amps to 0.4 amps, 35 CFm to 110CFM. Quiet on low speed, not quiet at high speed.
the 180MM fm181 is 0.1amps to 0.29amps 65 to ~150CFM and very Quiet even at max speed

iMy opinion is that controlling the fan's speed/noise/amp draw is very important, and those two silverstones are designed to do it. other fans can have their speed controlled Via a PWM motor speed controller, or one can control speed feeding them variable voltage, and some fans have a 4th wire that takes a PWM signal to moderate fan speed.

If using a PWM motor speed controller get on that states 21KHZ or higher or the fan will likely whine audibly at reduced speeds

But simplest speed control is the silverstone fm 181 or 121 fans that come with a dial to remotely control the fan speed.

Even the Fm121 at max speed is only a 0.4 amp draw. A healthy fully charged 80Ah battery could power it at max speed for 150 hours straight before the battery might not be able to start engine. The starting battery would wear out faster, but batteries are rented anyway.

 

[gargoyle]

What's wrong with using the standard 12v fan?
Seems like you're complicating things. ??
$20 or so, at any truck stop. Available with oscillating  and or speed control.

 

[Urban Fisher]

Thanks again for all the replies guys! Well looks like I'll have to look into the Notcua fans. Seem reasonable in price, low draw and pretty much exactly what I have been looking for. But I kinda still wonder if I can use it with one of those portable cell phone chargers to power it. I know the starting battery can probably handle it, but I have had bad luck with that in the past and I am trying to avoid using it. Also I wish I would have asked and read the linked post earlier. Just a couple of weeks ago I put a new battery in my van. Just bought a cheap one...never thought about replacing it with a deep cycle one.

 

[John61CT]

What's wrong with using the standard 12v fan?
Seems like you're complicating things. ??
$20 or so, at any truck stop. Available with oscillating  and or speed control.

Fine if you want to push inside air around while driving, trucker's use case.

For quietly and efficiently drawing in fresh or pushing out stale air while camping for long periods without an engine or generator running, that requires a bit more consideration.

 

[John61CT]

Thanks again for all the replies guys! Well looks like I'll have to look into the Notcua fans. Seem reasonable in price, low draw and pretty much exactly what I have been looking for. But I kinda still wonder if I can use it with one of those portable cell phone chargers to power it. I know the starting battery can probably handle it, but I have had bad luck with that in the past and I am trying to avoid using it. Also I wish I would have asked and read the linked post earlier. Just a couple of weeks ago I put a new battery in my van. Just bought a cheap one...never thought about replacing it with a deep cycle one.

A 5V version will easily adapt from a USB power source.

The bigger jumpstart powerpacks have a laptop out at 19V, some also have a 12V outlet.

As SW points out, the PC cooling fans are designed for low noise and efficiency, and also better suited to fit ducting or a fixed opening.

 

[SternWake]

There are very few actual deep cycle 12v batteries, despite the sticker proudly saying so. The Marine batteries that have a deep cycle sticker, are not really deep cycle batteries, but slightly more durable starting batteries with slightly less CCA.

http://www.pbase.com/mainecruising/deep_cycle_battery

But a marine battery will tolerate deeper discharges better than the standard starting battery. At least most should.

The pessimist in me thinks many marine batteries are simply starter batteries, that have both threaded studs AND automotive posts and a lesser warranty, instead of just automotive posts.

The cell phone battery packs USB outputs are 5v, the Noctua Fans are all 12v as far as i know. If the cell phone battery pack has a 12v output on it then it can be used to power the 12v fan.

I find fan speed control to be very necessary. The Noctua's can be controlled, bu the PWM 4th wire, or by being fed variable voltage, or by using a PWM motor speed controller/LED dimmer, but the latter will make the windings on the motor whine audibly unless 21KHZ or higher, where it wil only annoy Fido.

The Silverstone FM121's built in speed controller makes it plug and play, with upto 110CFM available at the twist of a potentiometer. The Noctua NF-f12 (1500rpm)is an awesome fan, but only 53CFM. Their industrial versons of this fan have 2000 and 3000 rpms and are of course much louder and move a LOT more air. The 3000 rpm version moves ~110CFM but at a higher static pressure rating( better against resistance) for 1/4 less amperage draw, than the 2400 rpm silverstone fm121. Similar noise levels.

I think the lithium jumper pack would be good for your intentions as they do have USB outputs, AND can jumpstart most vehicles. So you could use the startinig battery to power fan, and in the unlikely event that your fan drains the battery too much for starting the engine, the jumper pack to the rescue. These can be recharged when driving through the 12v power port too.

https://www.amazon.com/NOCO-GB30-UltraSafe-Lithium-Starter/dp/B00M1OUBES

I've not owned one/tested one, and am not endorsing any specific brand/product.

 

[John61CT]

Notcua are the cream of the crop in my opinion, but I really like the silverstone FM121 and FM181 fans as they come with speed controllers.

Excellent detail there, thanks!

I want to stick to 3" (80mm) to minimize structural issues cutting through a unibody floor. Ideas?

Do you think pushing in fresh air and letting the stale exit the higher cracked windows is better, or pushing out below, drawing in from the windows? The latter is fighting the warm air's tendency to rise. . .

 

[SternWake]

I like Delta fans too.  Some can be ridiculously powerful, and loud.  I have a 120Mm delta fan which i call the screaming banshee.  It cannot be tamed enough on a simple PWM motor speed controller, needs the 4th PWM wire which I have not yet done.  It is too loud and powerful even when slowed to its minimum by 21KHZ of PWm motor speed controller, and is still a 2.1 amp draw and ~ 3 amp at full speed.


120MM provides the best selection of computer fans.  I'd reinforce floor rather than limit myself to 80MM fans.

The smaller the fan the louder it is, and worse, the higher pitch of the smaller fan turning faster to move the same air as a larger fan, is much more annoying

With no roof exhaust vent, I'd pull filtered air through floor and have a 100% sealing device for when driving.

I'd use the 120 or 140 MM 3000 rpm Industrial Noctua versions and speed control them via the 4th PWM wire

But one 180MM silverstone Ap 182 or Fm181 will move a lot of air for much less noise.

The AP182 is 1.3 amps on high speed, 0.05a on low, and does not like battery charging voltages.  Mine succumbed to salt air and potentially the damage caused by an initial overheating before I limited input voltage to 11 via a buck converter.

My  SS FM181 got Deoxit blue shield sprayed on circuit board and Dielectric grease ( perhaps amazing goop, cant remember) on the solder connections where wires enter, which seem to be the failure points on most of my computer fans.

Not sure of when I first employed the FM181 but I rarely turn it off . It resides about a foot from my head as an intake fan when in bed sleeping.  Can't hear it on low.

One of 2 80Mm fans employed in my van is a Vantec tornado.  it is mounted on a gooseneck located on my engine cover's ash tray and speed controlled via voltage by one of those universal car adapters with 3/4.5/6/7/9 and 12 volt options.  Very powerful on 12+ volts. concentrated airflow.  They have a 92 MM version I use in the rear for interior air circulation, same voltage controller.  Pretty much the only thing I use ciggy plugs for, at a max of ~15 watts.

MY other 80Mm fan is exhausting my electrical cabinet, and is a POS I pulled from a failed Wfco converter.  I slow it by the resistor cables provided by the Noctua as it is too loud without them.  Ideally it will be replaced with a NF-f12 for more airm moved for less amp draw and noise.

https://www.amazon.com/PowerLine-Co...1&keywords=12vdc+powerline+voltage+controller

Note this product has a design failure.  It can wobble in the receptacle and short out + and - in some receptacles, and blow the receptacle's fuse.  I solved this with heatshrink tubing  covering all but the spring loaded nipple tip.

Mine have been in use several years now.

This is the more budget friendly option:

https://www.amazon.com/CyberPower-C...rd_wg=496Eq&psc=1&refRID=9RB2HVMWBWCESRD718H9

 

[John61CT]

Wow, Mr Ventilation! definitely bookmarked, thanks

 

[Urban Fisher]

Wow...this is a lot of great info! Ok, the Silverstone does look better with the built in "speed control" I guess I can call it. The idea of a small computer fan works even better for my idea. I was hoping to find a small 2"-4" flexible tubing to use as my duct. That way I can just squeeze one end into the partially open window (kinda roll the window up until it squeezes on the duct) hidden with the window visor and then run it to the back of my van (more stealth, yet I can still keep the windows cracked open). I'll buy the fan first then decide on the duct size. I guess the main reason I was looking at the other fans is because they already have the USB type plug to plug into the portable battery pack. No real wiring for me to do.

I found some like the link below. Not really the brands mentioned, but it is 5v and already has the USB connector.
https://www.amazon.com/Gdstime-60mm...F8&qid=1494615757&sr=1-19&keywords=5+volt+fan

or

https://www.amazon.com/Gdstime-Powe...F8&qid=1494616582&sr=1-24&keywords=5+volt+fan

But I guess you guys can now see my goal. I don't want it to necessarily cool me off, more to just make sure there is some air exchange. I have slept in my van many times with just the widows cracked and thus far I haven't suffocated yet. But as the weather warms, the air can get rather stagnant. Think of a fish in a small bowl. He can live probably for a day or two, but add an air stone that is blowing fresh air into the water and he seems to live longer/happier.

 

[John61CT]

Do it enough you'll see, gets stifling pretty quick.

Also even in cold weather, condensation is an issue, seen some nasty rust damage from the inside from lack of good ventilation.

Dunno how "stealthy" a duct sticking out your window with even a quiet fan running is though.

If you don't want to put a hole in your body, maybe rig something using existing van fresh-air intakes?

 

[Urban Fisher]

Well my issue is I really don't want to cut holes in my vehicle nor do I have the ability (I live in a small apartment with no tools or work area). It's a minivan so it doesn't have to more huge amounts of air. If it can create negative or positive air pressure inside the van, then fine at least I know air is moving from inside out (or vice versa). Also, my current van I have a life expectancy of maybe 2 more years and then I plan to upgrade. Still not sure if I'll go full sized van yet because I really like the mobility and ability to stealth camp in a minivan...it is just me and I'm a weekend camper for now. A minivan is plenty big enough for my needs. So if this simple ventilating system works, it can be easily transferred to another vehicle with no modifications (maybe other than installing another set of window visors).

I installed window visors over my front windows. I want to use a duct small enough to fit in the cracked window but still be behind the visor. I think it will still be pretty stealthy (especially if I get or paint it black) and I can still run my setup in pouring rain. I also have a curtain behind my front seats. So the duct will run from the back part of an open front window then run behind the curtain (it will extend further back in the van, but that is the part anyone could possibly see). If it will fit in the open window but still be covered by the visor...perfect! You will only see maybe a foot or two of the duct running from the window to behind the curtain. If I paint it black, at night I think it will be hard to see.

 

[John61CT]

Sounds like a very interesting challenge, full reports back here with photos please!

 

[Zizzer_Zazzer_Zuz]

If all you meed is.weekends then I would.suggest one of those all in one jump packs and wiring a couple computer fans. Even cheaper would be a 12v motorcycle or lawn mower battery. Get a battery charger and wire up a couple of biscuit fans.

https://www.amazon.com/gp/aw/d/B001...fb0d-5b5f-982d-d16d1ad45fdb&pf_rd_i=389574011


https://m.newegg.com/products/N82E1...Fs6WVMqhQ4r9M6_b6n1-hxoCWkPw_wcB&gclsrc=aw.ds

Screens for your windows are also really noce.

Sent from my SM-G920V using Tapatalk

 

[BigT]

 For now I really don't plan on adding a house battery and such.
It has the back windows that just open a couple of inches. I prefer to keep those close in case it rains and for stealth reasons. My main thing is that I am worried about good air circulation while I sleep at night with just the front windows cracked a couple of inches.

What about a free-standing "Fantastic Fan"? -->  https://www.amazon.com/Fan-Tastic-0...&qid=1494725683&sr=1-3&keywords=fantastic+fan

You could hang it in one of the open rear windows.  I don't want to cut holes in my van either, so I'm hoping I can just stick the fan in one of my screened, sliding side windows and plug it into one of my Acc outlets.  The FF only draws 1.1 Amps on the Low setting, and I think its max Amp draw is 3 Amps on High.  

And you don't need to buy/install a dedicated house battery.  Just drop the largest 12V Northstar AGM battery you can fit, under the hood in place of your OEM starter battery. 
That was SternWake's advice to me a couple of years ago, and it's working out great!