Anyone tried this 12v cooling option?

[drewker]

Looking at cooling options that do the job. I have already done reflectix on windows and hanging a curtain... 

What about a 12v thermo-electric cooler or a 12v freezer/fridge?  Basically, you leave the fridge / freezer door open to cool the van... would that work? 

fyi, I bought the kooleraire mini swamp cooler. that thing is a total joke / waste of money

 

[AngryVanMan]

A TEC (using the Peltier-Seebeck Effect) used in this manner is a (very inefficient) heat pump - it pulls energy from the cold side and sends it to the hot side.  In order to do so, the TEC itself dissipates roughly the same quantity of energy to the hot side from its electrical source.  This means there is over double the amount of heat on the hot side compared to what was removed from the cold side.  This would equate to a coefficent of performance of <=1, meaning for every one unit of energy spent electrically, the TEC can move 1 or less equivalent units of heat energy.

A phase-change system that takes advantage of the liquid-to-gas states used in common refrigeration and air conditioning can move heat much more effectively.  A high efficiency mini-split unit with a SEER of 22 can move a seasonal average of 6.74 units of heat energy for every 1 unit of electrical energy spent.  Nearly 7 times more efficient than the best TEC could hope to achieve.

In both cases, the hot side of the unit can't be in the same "conditioned space" as the cold side of the equipment, as Guy mentioned.

 

[drewker]

The refrigerator works by taking the heat from inside the box and moving it outside so at best you would still have the same average heat inside the living area. In reality you would be adding some heat from the electrical work being done.

Guy

you are probably right, but still i'm not convinced...might have to research this some more. i mean its gonna be 30 degrees inside the fridge, how in the world would that not cool your van if you have insulation, etc. i guess you mean that the motor of the fridge will generate too much heat. but again the freezer door will be open for hours...

what about a thermo-electric deal? coleman makes one, it sells at walmart for $97

 

[drewker]

or what if i cut a hole in it and had a pvc pipe sending the cool air out vs leaving the door open?

 

[drewker]

i'm not an affiliate or anything, but this is the kind of product i am referring to:

http://www.homedepot.com/p/Koolatro...PIPHorizontal1_rr-_-204704929-_-202467784-_-N

 

[AngryVanMan]

If the hot side of whatever heat pump you are using is inside the conditioned space, you are simply going to get the effect of adding heat to that space. All these systems do is pump the heat around, they don't create cold air from nothing.

If you run a refrigerator with a door open inside a van, and that fridge uses 100 watts of electrical power, you will achieve the same results as if you put a 100 watt heater in your van.

For the system to work, 1. it must be able to pump the heat out of the vehicle, and 2. it must have a capacity to move heat greater than the losses of the insulation of the van. If the system is not powerful enough, no noticeable effect will be had. Most refrigerators do not have enough power to move a van's worth of heat outside.

 

[drewker]

if no go above, what about a box fan? any idea how much power that would require to run. i can live with that vs actual ac because the box fan pushes out so much air, you hardly notice the temp

 

[AngryVanMan]

Most people seem to go with the MaxxAir MaxxFan or the Fantastic Fan, because they can work off the 12V battery of the vehicle and they move a lot of air, I think almost 1000CFM!  That's a lot of air, a very large van would have all of it's air sucked out and replaced about twice every minute on high speed!

I just happen to have a 20" box fan here, and while it doesn't have a label I measured it with my KillAWatt meter for you.  It is a Lasko brand from some big box store I got a few years ago.  It uses the following on each of its 3 speeds - 100W High, 80W medium, 60W low.  You would have to account for inverter losses as well, if you want to run it in a van.  You could probably get any number of 12V portable fans to create a breeze as well.

The Fantastic Fan uses less than 3 amps @ 12V on high speed, so that would be less than 36 watts.  Of course the 20" fan moves more air overall, but you have to weigh the pros can cons.  The Fantastic Fan or any other fan that is mounted in the roof would be drawing in fresh air, while the box fan could be set up in a doorway or window, or just blow around the air that is already inside the van to give you a breeze.

 

[highdesertranger]

drewker first off don't even bother with the coolers they suck power and will only drop the temp in the box with the lid closed by about 30-40 degrees. with the lid open it won't do squat. now for a refer, once you open the door and leave it open the inside temp is only going to be a couple of degrees cooler then the rest of the van. not 30 degrees like you said. don't believe me, go open the door of your refer and see how long it takes for your milk to get warm. a refer is design to remove heat from a box, not a van. highdesertranger

 

[drewker]

Most people seem to go with the MaxxAir MaxxFan or the Fantastic Fan, because they can work off the 12V battery of the vehicle and they move a lot of air, I think almost 1000CFM!  That's a lot of air, a very large van would have all of it's air sucked out and replaced about twice every minute on high speed!

I just happen to have a 20" box fan here, and while it doesn't have a label I measured it with my KillAWatt meter for you.  It is a Lasko brand from some big box store I got a few years ago.  It uses the following on each of its 3 speeds - 100W High, 80W medium, 60W low.  You would have to account for inverter losses as well, if you want to run it in a van.  You could probably get any number of 12V portable fans to create a breeze as well.

The Fantastic Fan uses less than 3 amps @ 12V on high speed, so that would be less than 36 watts.  Of course the 20" fan moves more air overall, but you have to weigh the pros can cons.  The Fantastic Fan or any other fan that is mounted in the roof would be drawing in fresh air, while the box fan could be set up in a doorway or window, or just blow around the air that is already inside the van to give you a breeze.

i was just looking at the 'endless breeze' on youtube. i think its a competitor to the one you mentioned. as long as i can run a high powered fan for several hours without draining the battery, i can live with that and just punt on getting an a/c unit ... i have also found that a wash cloth dipped in ice from the igloo does help with keeping you cool. that combined with a box fan should suffice. not the ideal, but i'm a low-budget vandweller right now and i need something that will let me be comfortable enough to sleep. i simply can't do that if i'm sweating ... i was van-dwelling in the northwest where this was a non-issue, but now i'm in nevada and utah is next due to work, so i've gotta step up my game asap

 

[rvpopeye]

Get a spray bottle full of water and spray yourself while sitting in the breeze

 

[drewker]

Get a spray bottle full of water and spray yourself while sitting in the breeze

ha ha funny ... not

 

[highdesertranger]

actually the spray bottle works really well in the arid west. I am in Nevada a lot in the summer just move up in elevation. I find Nevada quite comfy in the summer. highdesertranger

 

[AngryVanMan]

I've got to +1 the mist of water if it's not super-humid, a lot of amusement parks and outdoor restaurant patios seem to have mister systems in different areas of the country, very effective!

 

[Spaceman Spiff]

+2 on evaporative cooling.  I will keep my hair wet, along with a fan to provide a breeze.  Even in high humidity (<100%) it works, just not as well as low humidity.  Add wiping my face down it is amazing how much it cools me off.  I have a dedicated water bottle on my bicycle to soak my head as I am riding; makes those 90°+ rides enjoyable.

 -- Spiff

 

[rvpopeye]

I expected your response so I just waited a few minutes .................
At this point I just want to say......
DUDE , you'd be a human swamp cooler !
Add a Fantastic vent fan w 900cu-ft of air moving through any or all windows/doors.
Lots of us have done it ,you can too.

 

[drewker]

Everyone has different levels of tolerance regarding temperature. A spray bottle aint gonna cut it for me, but to each his own. On another note, my two cents on Reflectix - not impressed. I was psyched when I installed it, but I have not noticed any change in the comfort level inside the van regarding heat. Additionally, I think you definitely lose that stealth quality when you are driving around looking like you wrapped your van in aluminum foil. If they did not notice you before, they will now with that reflectix. I was willing to punt on the stealth in order to keep cozy in the van, but now I may just throw my beautiful reflectix install in the trash and put up some pleasant looking curtains.

 

[drewker]

Ok one last product - there are lots of positive reviews on youtube for MightyKool

Anyone tried? Its 399 bucks

 

[AngryVanMan]

I like the MightyKool evaporative coolers, of course as they say in the literature, it works much, much better in drier climates.  It's important to keep the van ventilated too, otherwise it will be a swampy sticky-fest.  I don't like the Ice versions as much, just because of how much Ice is needed to keep a van cool, potentially hundreds of pounds a day!  The price however is... well, crazy expensive for what it is IMO!

Have you seen the 5 gallon bucket version that is popular at Burning Man?  I think it would be similarly effective and cost less: https://eplaya.burningman.org/viewtopic.php?t=33842

 

[DannyB1954]

Evap coolers work well in dry climates, the down side is water is often hard to get in dry climates, (you have to buy it). You can go through several gallons a day in an evap cooler.