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Discussion Starter · #1 ·
Got it into my head that I want to build something to increase airflow in the converted Caravelle when sleeping , I found an old thread on here from years ago about someone using two computer fans built into something that fitted in the sliding side window....they don't seem to be a member any longer so I need to ask you guys something..
If I used two fans would I need to have them blowing in opposite directions , one sucking clean air in the other bowling the air out or would they both need to blowing the same way...
I did think about getting a a tailgate stand off thing but think my head would be cold while I sleep as its right next to the tailgate...

Daft question I know

Thanks
Anthony
 

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I have two 120mm PC fans that I have modified (cut down) to fit into yacht style roof ventlites. The ventlites have an optional fly screen which restricts the flow quite a bit but I prefer that to having bugs get in.

I have tested them with smoke and they still move a fair amount of air and are quite happy to pull air in though the dash board vents, which means it's pollen filtered.:D

I normally have the front windows cracked a little when sleeping in her, I also have a 4 setting speed controller I made and generally I sleep with the fans on the the lowest (& quietest) setting.
High flow PC fans get noisy when going full blast.
I also use one of these fans on my enduro motorcycle as a radiator fan.T:
 

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Discussion Starter · #3 · (Edited)
Thanks for that, so maybe it's worth doing then , being a caravelle with all that glass and double thickness curtains , it's sometimes dripping wet on the windows in the morning.

So back to the two fans I take it both yours are going the same way , thought it might be an idea to have one sending bad air out the other sucking clean air in

Any pics of your install ? Any links to the fans you used

I shut the cab area off with full curtains behind the seats so using existing vents wouldn't be so effective

Cheers
Anthony
 

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I've cut n shut the original caravelle rear blower housing to accept 3 or 4 (bad memory!) 60mm quiet pc fans.

The idea being I can use the original ceiling vents to draw stale air out.
 

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Discussion Starter · #5 ·
That's a brill idea , only my caravelle doesn't have the roof vents although it does have the underfloor heater which has been removed , maybe I could do something there....

Is the idea to remove stale air on drag in clean air....also if you are dragging in cold new air does its cool down the inside noticeably ...
 

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similar to dubdick
we've an opening top vent with 2 old computer fans, one slow but quiet for night-time, another faster but noisier for when cooking in addition to another stronger one blowing steam etc across the hob towards the vent when cooking. could have 1 large one with a speed adjuster
both the vent ones blow outwards (otherwise they'd just interfere with each other - you want a flow through the van, pref front to rear). also very handy in hot weather.
fresh air comes in through the front windows - just open your curtains a little at the bottom.
a large fan going slow is quieter than a smaller one going fast, find it's the air movement that is noisy not the actual fan.
with a fan on the fridge & a 12" one in the front we are fan fans......................(handy them all being 12v & spares)

we have a home-made tailgate standoff but don't leave it open overnight
 

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So back to the two fans I take it both yours are going the same way , thought it might be an idea to have one sending bad air out the other sucking clean air in
you only need to go either in or out. personally i would go in from the vents, if you blow air out overnight then air might creep in from nooks and crannys causing a draught. it's just the way i would do it T:
 

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Discussion Starter · #8 ·
Thanks cumbrialad, it must be windy in your van ?

So if I left the front windows down a bit then maybe utilized the old rear heater vent I could get the air moving although it would be at the front of the van , I have no other outlets further back ....

Does the computer fan suck or blow ?? meaning could I set something up under the van to drag the air down the vent that is at the back of the drivers seat......or would I have to the fans at the top of the vent inside the van...

Maybe I might still go with the two fans built into something that fits in the sliding side window....front windows open slightly and two vans pushing it out of the side window....

Think I'm getting my head round it a little ....sorry guys bear with me ??
 

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I made a panel up for the side sliding window using 2 comp fans fitted into some ply board and clipped to the window. It worked ok. I had the fans set to draw air out and left the front windows cracked open slightly to let air in. (Got wind deflectors on the front windows)
My only problem was I didn't like all the wires hanging about, having to get up & down to turn em on/off & having to watch what I was doing if I wanted to be in & out of the door at night. (Old bloke) You know the problem, especially after a few beers.I: I ended up making one that fits in the roof over my sunroof. The wires are behind the roof panel, so out the way. It works great, I put switches on the panel so I can have both on, one on or none on & I can reach em when I'm in bed, Bonus.
Maybe just another idea for you or someone else :*
 

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Discussion Starter · #10 · (Edited)
Anyone used one of these....
http://www.amazon.co.uk/SEAFLO-IN-LINE-BLOWER-VENTILATION-COOLING/dp/B00KXYLLVU

Need to know how noisy they are , my thinking is make a nice black panel with a couple of yacht vents in that slides In the side window to let air in, then use the above mounted under the van to drag air out down my old rear heater vent that is behind the drivers seat...wire in a adjustable switch that can be located anywhere in the van ..Would a speed adjuster work and can you get them that have an on off switch built in ??, can't seem to find many speed adjusters online can anyone point me in the right direction ..

Only thing I'm worried about is noise levels during the night , don't want to disturbing the fellow campers ???
 

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think the noise aspect is a bit of a guess, & depends on where it's sited etc - we only wildcamp so only us to hear it.
we swapped our computer case & found the new main front fan noisy, but running it out of the case it's quite quiet

for a speed adjuster what about a 12v led dimmer to adjust the current, like
http://www.ebay.co.uk/itm/DC-12V-8A...116?pt=LH_DefaultDomain_3&hash=item418fcb8584

liking all the Heath Robinson ideas though, diy much more interesting & individual, our van's full of cheap made up bits
 

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Interesting thread T:
I'm about to try using a computer fan for the opposite effect.
When using our Hightop Autosleeper in the colder months with the propex heater on I find that the floor area is cold, but when I stand up the roof area is baking hot.
I've rigged up a computer fan attached to a spring clip, taped on a 9 Volt and a switch (******* style) to see if the heat can be recirculated back down into the sleeping area without causing a cold draught. It's the same principal that is used to reclaim heat in large factories.
If it works I'll make up a better quality version running on 12 volt.

Zerominor
 

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So back to the two fans I take it both yours are going the same way , thought it might be an idea to have one sending bad air out the other sucking clean air in

Any pics of your install ? Any links to the fans you used
Yes, both blowing outwards. The idea was to be able to get rid of cooking fumes and also the hot air that accumulates in the mornings during summer.

Some pictures of the install on page 1 and page 3 here

These are the vents

I haven't got any of the control box or the circuit but it's two 4 way rotary switches in a box.

Setting:
1. Front on at 12v &/or rear on at 12v - very noisy
2. Front and rear linked in series so it's 6volt across each.
3. as above with small resistor in line.
4 as above with another resistor to set lowest sustainable speed the fans can turn.
 

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Discussion Starter · #14 ·
Some great ideas here... Can someone check this out and see if my plan seems right

12v dimmer eBay
http://www.ebay.co.uk/itm/Wireless-...405?pt=LH_DefaultDomain_3&hash=item2c820fdbc5

So am I right in thinking (assuming above will work ) that you wire up as follows...

Sea flo blower or computer fan + to dimmer + then same out of other side then into + on leisure battery or smart charger

Same with negative...is it that simple ��

The dimmer above has an on/off switch so I assume I don't need another switch

Go on tell me I'm going to kill myself ����

Thanks all
Anthony
 

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Some great ideas here... Can someone check this out and see if my plan seems right

12v dimmer eBay
http://www.ebay.co.uk/itm/Wireless-...405?pt=LH_DefaultDomain_3&hash=item2c820fdbc5

So am I right in thinking (assuming above will work )
You'd have to give it a try, I'm not sure it will work though.
Those dimmer circuits work by pulsing the power, by varying the pulse to space ratio (known as mark-to-space ratio) to reduce the output power. This works when feeding simple electrical items but PC fans are brush-less so actually have controllers of their own built in and these will not like pulsed power.

As I said, it may work but I doubt it - you ideally need just basic resistive speed control, and the problem here is that it creates heat so it has to carefully spec'd. Firstly you need to know the specifics of the fans. I used fixed values of resistors so that I could experiment with the heat generated to make sure the wattage rating of each resistor was high enough.
 

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Discussion Starter · #17 ·
Oh eck knew it wouldn't be simple, I'm waiting to hear back as I can't find anything about how quiet they are or whether they would be ok to box in but I think I'm going to go with one of the seaflo inline blowers, I have put the link below , does this give you any ideas about which speed controller I could use and if so please point me in the right direction....

Thanks again for all the help

http://www.seaflo.com/en/productDetail_350.html
 

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Nope, it doesn't really help.
Best thing would be to ask them if they offer a speed controller, or could recommend one that would work.
Failing that it'll be trail & error I'm afraid.

Is that thing expensive btw?
I wouldn't want to play around with the supply power if it was..:eek:
 

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Discussion Starter · #19 ·
They are 15 quid delivered , so not a major disaster , apparently they are pretty quiet and they have said they will be ok in a box, so maybe it might be ok to just run at one speed with a switch inside the van.....

So the plan is ....black Perspex/plastic sheet moulded to fit in the opening side window with two black louvre yacht vents to let the air in and a seaflo inline blower mounted under the van under my old rear heater hole.....

So vents to let the air in and the seaflo to drag it out.......

This sound ok?

Thanks
 

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Having not slept in my Caravelle yet I was thinking about damp windows in the morning possibly being an issue, I was thinking of going down the mini dehumidifier route, which would be the better idea Fans or dehumidifier? :*
 
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