cooling your tent or van

[TT120]

You could add some clips to those wires for quick connecting.

Yup. Something like these little guys would work perfectly.

[Monkeystyle]

awesome, thanks guys... one last stupid question, does the wire have to be a certain minimum gauge?

[Popeye]

awesome, thanks guys... one last stupid question, does the wire have to be a certain minimum gauge?

Wire size depends on the how much current you are carrying and how physically strong it needs to be. Loads in amps should be on the label. If the load is labeled in watts divide the watts by the minimum battery voltage to get amps.
I suggest you use at least a #14 with XHHW insulation for strength.
#14= 15A, #12= 20A, #10= 30A, should be enough for most equipment. For starter motors, PV feeds and other large loads Google "Table 310-16" or ask.
The "Primary" wire you find in hardware and automotive stores has a light weight insulation that does not add any strength and breaks easily.
Suggest you use stranded wire, solid wire can break when flexed.
Wire nuts are great for making connections. Wrapping and taping splices is asking for the splice to come apart.

[FIGJAM]

The wire that came on this pump it tiny.

I'm guessing #20 or smaller.

It had 15' and I spliced the fan to that.

[Popeye]

Wow, #20 is pretty small. If it works it works.
I don't usually work with anything that size and don't have tables for it. From the internet, http://www.powerstream.com/Wire_Size.htm, number 20 has a maximum ampacity of 1.5 amps. At 12 volts this is 18 watts or .016 HP. Wire is derated as the temperature increases so I would probably guesstimate about 75% of this as a max load at BRC.
I think very light wire like this is a failure point. The breaking point of #20 is 29# plus the insulation strength. It will stretch before it breaks increasing the wires resistance and dropping the voltage to the pump which could cause the pump to burn up. #14 copper has a breaking strength of 119# plus insulation strength. I doubt anyone could snap 14 XHHW with their hands. You should be able to buy this wire for 12-20 cents per foot.
BTW Figjam, I don't see much airconditioning and zero swamp coolers up here, I've learned a lot from you. Thanks

[FIGJAM]

It could be 18, but the 2 insulated wires are in another sleeve of insulation.

No problems in 4 years.

[Popeye]

That's the final test, if it works it works.

[LowePro]

Used 16 gauge wire connected to battery clamps with no problems, could probably even use smaller wire, but the wire is so cheap why worry about it? Got mine on the e-auction site and spent less than $12 for 20feet of wire and clamps. Auto stores have stuff too, look for cig-lighter 12V adapters and you could cut off the battery clamps. I wired mine to an on-off switch (also cheap online) and run the switch next to my bed through a gap in the window frame, so I can reach over and click it On without leaving bed in the morning. When the heat wakes me up, click it on, the cool air blasts and I get another 90 minutes of sleep. Fantastic!

[DeeL2003]

Hi everyone. I don't plan to go to Burning Man this year but will be camping for the first time in Yosemite in August so it will be a toasty experience for us. I'm very interested in making my own swamp cooler and this is the only informative thread on this subject on the internet. Hope you guys/gals don't mind me asking a few questions.

The tent I'll be using is around this size: http://www.target.com/p/coleman-hampton ... A-12034513 and was thinking of making a unicooler to cool a tent of this size. Will the unicooler be enough to cool this tent at the low setting?


As for the box, I don't have the skills or proper tools to make my own so I will be using a square plastic trash can. What would be the best way to securely attach the vent and fan on to the plastic box? I think I read somewhere that permanent double sided tape will suffice and maybe 100% clear silicone for added measure?

Another alternative is the box Figjam linked: http://www.acrylicdisplaymfg.com/html/d ... cubes.html Would a dremel with a cutting wheel be enough to cut the necessary fan hole and vent? And will silicone adhere to the acrylic surface?

For the deep cycle battery: Is it safe to place the battery in the tent with the unicooler or does it need to be placed outside due to possible venting?


I think that's all the questions I have for now. Sorry there are so many of them. I just want to build this cooler right without dumping too much $$ in the process. Thanks in advance.

[FIGJAM]

Most of the trash containers that you would use for a cooler are made from a plastic that nothing will stick to.

Little angled brackets and screws will be needed to hold everything in place.

Use the silicone to seal the fan and registers to the container.

The first unicooler worked fine on low, but the intake register was too small to let the fan work on the higher speeds.

Make sure that the intake is twice the size of the fan. (20"x20" is about right)

Low speed for a tent that size is right on the borderline, so you may what the higher speeds for a quick cool down before depending on the low speed.

[DeeL2003]

Most of the trash containers that you would use for a cooler are made from a plastic that nothing will stick to.

Little angled brackets and screws will be needed to hold everything in place.

Use the silicone to seal the fan and registers to the container.

The first unicooler worked fine on low, but the intake register was too small to let the fan work on the higher speeds.

Make sure that the intake is twice the size of the fan. (20"x20" is about right)

Low speed for a tent that size is right on the borderline, so you may what the higher speeds for a quick cool down before depending on the low speed.

Thanks for the advice.

I don't think I can find a trash container big enough for a 20x20 vent and still be portable enough to fit my mid-size SUV.

How about those acrylic display boxes I linked on my first post? Will the silicone adhesive "stick" well? And will a dremel be strong enough to cut the needed holes?

Is it ok to keep the marine battery inside the tent with the cooler?

[FIGJAM]

Haven't tested acrylic yet.

Buy a small piece at home depot and test your guesses.

A true AGM deep cycle battery can be kept anywhere.

The off gassing of a regular lead acid battery won't matter while the cooler is running or if the tent is staying well vented.

If the tent is going to be completely seal up with you in it, set the battery outside just to be safe.

[fernley1]

My bucket cooler is finished, got my costco deep cycle battery, all wired up.
Now just waiting for a warm day to ops check it to see if it puts out cool air.

[sharpstick]

I'm designing mine now.
Unfortunately, I fly in from Florida, so shipping stuff is limited. Last year we started sharing a storage space, so I won't have to lug everything back and forth anymore.
I'm in a camp with AC power and had decided to use AC. Using a DC brick adds complexity, but I can easily convert to full DC someday.
I've been using a tent within a tent for my bed since 2003. By now it is little more than a shroud of housewrap suspended from the cabin tent frame. The bed enclosure is about 75 cubic feet, so I don't need a lot of volume. A 15 - 25 CFM fan will replace the air in 3 to 5 minutes. I considered keeping the cooler inside the big tent to lessen the dust but I think the humidity will rise and effect efficiency. The bed tent has loose flaps to allow air to pass out.

- I have a submersible pump rated at 135gph. I'm putting a tee just above the pump to adjust flow if needed.
- through the wall float switch to prevent running dry. Still looking, but the Temco floating paddle sw looks promising if it's not too big for a bucket. 16 amps is comfortable overkill. There are a lot of cheap chinese switches on ebay, but they are all rated too low. My pump is 1 amp and that fan is .6 amps. I prefer my switch to be rated much higher. (I could go with a relay, but that's just more complexity)
- Thermostat. No need to run past comfortable temp. I have a digital Ranco that I use for homebrewing, but hope to find something simpler. Maybe an old Honeywell mercury stat?
- blower. I have some lying around, but not sure if they are powerful enough. I think any 120mm fan should be adequate.
After 9 years on the playa, I've learned the value of redundancy, so I'm getting two of everything.

CONCERNS/QUESTIONS
- If I get a fan that is too powerful, will that lower the cooling efficiency? FrozenCPU has a 150mm 240cfm fan. Their 120mm fans are too low. My thinking is that the slower the air flows through the cooler, the more cooling it will have.

[FIGJAM]

The more air you can move the better off you'll be.

This is a good shopping chart.

http://www.frozencpu.com/brands/brand/b113/Delta.html

This is the fan I've been usung for years.

http://www.frozencpu.com/products/8556/ ... 5s1108b113

If you have access to AC, get an AC fountain pump and a small AC fan.

Should be able to get the AC stuff cheaper than the DC.

[sadie]

Although my first FIGJAM swamp cooler was somewhat successful, it was suggested that a lighter color bucket and smaller air intake holes would probably work better. So I made tarp washers out of the blue bucket and made another cooler.

rsz_swamp_cooler.jpg

All systems are go with this one.

[FIGJAM]

B........U........T.......ful!!!

[EmilyD]

Thanks for mentioning the Photobucket thing Figjam...I totally forgot about my account there. So now I can post my little cooler/fan concept. I'd fill it with layers of that swamp cooler material and ice. Anyone tried something like this?

[sharpstick]

The more air you can move the better off you'll be.
. . .
If you have access to AC, get an AC fountain pump and a small AC fan.
Should be able to get the AC stuff cheaper than the DC.

You had earlier said " get a fan that will replace the air inside the space every 3 to 5 minutes". In my case, that would easily be done with 15 to 25 CFM. Logic tells me that the slower the air moves through the filter pad, the more efficient the cooling would be.
I already found a 110VAC 132 cfm pump at a local hydroponics supply store for $13.

[sharpstick]

. . . pump from HF.

They do have the best prices, but after too many instances of premature failure of a tool, I no longer shop there. After all, how much money did you save if it broke and you had to replace it. Especially if you are on the playa! I don't mind springing for better quality if it's for a critical application, like cooling my tent.

[LowePro]

Sharpie, I think your math is missing something. Your earlier post says your sleeping enclosure is 75 cubic feet. Check that again; the cube-root of 75 is about 4', is your sleeping area really a 4x4x4 cube? That's about the size of a dishwasher. (Maybe you used the SQUARE feet instead of CUBIC feet?).

Using the numbers from your example, if a 25 CFM replaces air every 5 minutes, that's 125 CF of air; cube-root of 125 is 5 feet, corresponding with a 5x5x5' structure. At the lower end of the spectrum, a 15 cfm Fan replacing air every 3 minutes = 45 cfm of air, corresponding with a 3.5' cube. I wouldn't want to sleep in that! Personally I trusted the 1000's of other posts and comments on this thread and followed Fig's design to the letter and was very pleased. My campmates' weaker/slower/lower-CFM fans performed noticeably poorer. (If you're sleeping in a puptent or 1-person mini-backpack tent, I will stand corrected!)

On the other hand, a high-volume water pump seems less vital. For the bucket cooler, I used a pump rated at 240 *Liters per Hour*, which is only about 1 Gallon per minute, and it was enough. Keep an eye on your units and conversions, and good luck with your project, whatever you decide!

[sharpstick]

Sharpie, I think your math is missing something. Your earlier post says your sleeping enclosure is 75 cubic feet. Check that again; the cube-root of 75 is about 4', is your sleeping area really a 4x4x4 cube? That's about the size of a dishwasher. (Maybe you used the square feet instead of cubic feet? Or you were thinking cubic yards?).

Using the numbers from your example, if a 25 CFM replaces air every 5 minutes, that's 125 CF of air; cube-root of 125 is 5 feet, corresponding with a 5x5x5' structure. At the lower end of the spectrum, a 15 cfm Fan replacing air every 3 minutes = 45 cfm of air, corresponding with a 3.5' cube. I wouldn't want to sleep in that! Personally I trusted the 1000's of other posts and comments on this thread and followed Fig's design to the letter and was very pleased. My campmates' weaker/slower/lower-CFM fans performed noticeably poorer. (If you're sleeping in a puptent or 1-person mini-backpack tent, I will stand corrected!)

It's not a cube. I think you must have missed my first post on this. My bed tent is housewrap draped over a queen air mattress, roughly 5 x 7 feet = 35 sq feet. The housewrap wraps around the mattress on all 4 sides. It is supported by a bamboo crossbeam above the head end at about 3 ft high. It slopes down to nothing where it wraps around the foot end. A very rough guess estimates the average interior height is about 2 ft, hence 70 cu ft. Depending on how loose it drapes, that number may be considerably less. It's quite cozy, but I had to re-engineer it to have overlapping flaps on both sides so I could open it up to allow ventilation. After using this method for 8 years on the playa, I can assure you it works quite well considering it uses no cooling technology at all. I started with a smaller 3 man tent inside a cabin tent. I realized that carrying an entire extra tent was unnecessary because there is a perfectly good frame up there already. I've seen quite a few "tent within a tents" since then and like to think I invented the idea(in 2003). Maybe that's just hubris.
I trust Figjam's initial design too, but my application is radically different. I just ordered a 103 cfm fan, should be enough, fingers crossed.

[LowePro]

Aha, corrected I stand! I knew it wasn't a cube, I was just using cubic structures as an easy rule of thumb to help visualize sizes; but I didn't picture a sleeping enclosure wide and low like yours... sounds like a cool setup. You should be nice and chilly in a space of that size, since the bucket cooler can be used successfully in a much larger structure. Good luck! (You probably saw this already, but an enclosure w/ a swamp cooler needs an exhaust vent or gap as well)

[sharpstick]

. . . You probably saw this already, but an enclosure w/ a swamp cooler needs an exhaust vent or gap as well

Got that. I was considering putting the bucket inside the cabin tent, which is generally cooler and less dusty than out in the open. Might be doable if there is adequate ventilation so humidity doesn't build up. But that takes up more space. I think putting it just outside the tent with a hole cut in the wall and a small shade over it and shade cloth around to lessen dust flow. This might have been discussed, but I think that a curtain of 1 or 2 layers of shade cloth will slow down the breeze and dust will drop out from gravity.

[sharpstick]

I posted about this on the CR4 engineering nerd forum. Got a bunch of snarky remarks, but one interesting suggestion:

WJMFIRE - As you probably know, evaporative cooling works in humid environments like Florida, but must be addressed differently.
Our humidity is so high, a standard swamp cooler won't work well enough to make economic sense. We must therefore increase the efficiency to a point much beyond that of a swamp cooler.
Here (and other places as well) the water is atomized (misted) to increase the surface area, which increases evaporization, which causes more heat absorption.
Small nozzles to atomize water are cheap.
If you really want to design an efficient unit, atomize your water into an air flow.
Use the smallest micron droplet that you can, and adjust your air flow as required.

me - Misting does work well in the desert, but I don't want to spray my bed.

WJMFIRE - if atomizing can work in Florida, it will be incredibly efficient in the desert.
Regarding "spraying your bed", that is part of the design process.
Can you divine what factors might allow you to pass atomized water droplets through an air stream such that dry cool air is exhausted?

me - For the bed, I suppose it's just a matter of adjusting your spray to just the right amount so it evaporates before it lands. That might require some adjustment over time as the temp and humidity change while you're sleeping.
I don't now if my present pump has that much pressure, but it sounds intriguing. It will definitely use more water, though.

So, anyone tried adding mist to a SC?

[sharpstick]

One suggestion that was made was, "Why don't you just use an air conditioner?".
Some of our campmates do. It does make it cooler for people that insist on sleeping all day long. In a tent. Under a Costco carport. With power available, that is tempting. Some even rent those portable office buildings. The playa just isn't what it used to be sometimes.
I've thought about renting an RV or some of that other decadent shit. Not this year, though.
Just an old dyed in the wool hippy burner. when i die i want them to sneak my body up into the man base on burn night.

[LowePro]

Haven't tried misting, interesting idea, but the Figgy swamp cooler works so well as-is, and with a small sleeping enclosure like you describe, I don't think misting would be necessary. I think you'll be very cool, even cold, with the as-built bucket cooler if you follow the recommended equipment specs. Really I can't recommend it enough for simplicity, minimal moving parts, and efficiency.
Also I bet it would be tough to keep misters from getting clogged w/ dust. My 2 cents (or 4, maybe 8 by now)

[FIGJAM]

Maybe the dust, but the biggest problem people here in AZ. have with any mister is the emitters get clogged with calcium deposits from the hard water which causes them to drip instead of mist.

Just one more thing to fail.

Keep it simple unless you want to tinker with your cooler a lot on the playa.

I don't!

[unjonharley]

Larry should pull a lost in space theme out of his ass.. The Figjam could design a a space suit swamp cooler..

[EmilyD]

TRYING AGAIN!!!

[quote="EmilyD"]Thanks for mentioning the Photobucket thing Figjam...I totally forgot about my account there. So now I can post my little cooler/fan concept. I'd fill it with layers of that swamp cooler material and ice. Anyone tried something like this?