the only real 12 volt air conditioner

[rowerwet]

I have put this idea on here more than once, now I made an Instrucable out of it http://www.instructables.com/id/12-volt ... nditioner/ with lots of pictures and explanations
someone had actually tried it in a TD viewtopic.php?f=29&t=18104&hilit=rowerwet&start=15 , enjoy.

[jstrubberg]

Problem is, a swamp cooler is useless anywhere with humidity. I wish that weren't the case!

[grant whipp]

Yep, anything that relies on ice or water to cool the air is just a swamp cooler ... basically useless where there is heat and high humidity. Now, when someone comes up with a 12v AIR CONDITIONER that dries the air as it cools (like true air conditioners do), then they'll really have something ... ...!

Good Luck to anyone who wants to have a go at it!

CHEERS!

[rowerwet]

I guess you didn't read the I'ble, this REMOVES humidity by cooling the air, the ice and water are totally separated from the air you get to enjoy, the air in the TD is DEHUMIDIFIED AND COOLED. at no point does the ice or water come in contact with the air in the TD, instead the ice water chills the heater core, which WRINGS the humidity out of the air the EXACT same way a 110/220 ac does.
I know you guys have tons of experience and I like reading your advice and humor, but it would help if you read the Instructable before commenting on it
I actually made one of these and used it in my car, it wrung so much moisture from the air I thought the heater core had sprung a leak, which is why just like a high powered AC it needs a drain pan under the evaporator(only in my design it is a heater core)

[rowerwet]

blue is cold water being pumped into the heater core,
orange is water carrying heat back to the cooler
purple is the drain tube for all the condensation that the heater core puts off
green is a 12 volt marine water pump
in reality the water level should be just deep enough to keep flow from the pump, air is a better insulator than water being about 6 times thinner than water.
as long as the cooler has ice you get cold dryer air, the cooler size is exaggerated a little bit, I used a smaller one, and the heater core should be much bigger unless you are going to run a few of them at once. performance & time will depend on how hot where you are is and how well insulated your TD is.
one fan is to always blow fresh air into the TD, the other is to recirculate, the exhaust vent needs to be up high to let out hotter air.

[Shadow Catcher]

I can see how this might work for low volume (cubic foot) teardrop. It would be interesting to do the numbers in figuring out the actual cooling load.

[jstrubberg]

Rowerwet,

I did look at your design. I'm always interested in using less electricity.

There are hundreds of ice-based designs out there. They cool effectively. None of them remove significant moisture from the air. If yours does, I suggest you patent it right now because you've managed to do something that noone else has EVER been able to achieve.

When you lower ambient air temp, you have to remove a LOT of water because the ability of the air to hold moisture is drastically reduced. If you don't get rid of the water, you end up cold and clammy instead of cold and comfortable.

[emiller]

I have a swampy and just love it.
http://www.swampy.net/12vcombo.html

[rowerwet]

patenting such a simple idea seems crazy, there are many I'ble's that use this same idea only they tend to use a copper tube for the heat exchanger (HX in heating blog terms) I just used a pre-made HX (heater core) to cool instead of heat. the copper tube HX is only good for water to water HX, and even then they very low surface area compared to a flat plate HX. the secret to effective heat movement is surface area and temp differential (how far apart are the two temps). to maximize heat movement between water and air you need a lot of surface area. car heater cores and radiators are both very effective water to air HX's. Having spent many hours on my favorite heating forum hearth.com and being a boiler guy (I have an oil boiler that is heated by a pellet boiler ( I installed both of them, and the 85' of thermopex connecting them) in the back yard ( and yes I love it, you feed and clean the pellet boiler once a week)) I spend a lot of time figuring how to move heat in a cold world (my home state of Maine). removing heat is all about the same thing.
You could do the same thing for AC in your house by running cold well water through a car HX, other wise known as a RADIATOR, I have a member of my church who did that for AC 3 years ago, it worked fine with the HX mounted in the forced hot air duct work and the furnace blower on, EXCEPT his electricity bill was way to high from the well pump running non stop. Geo thermal systems do the same thing only they put a sort of AC system in the middle to extract the heat from the earth in the winter and pump heat into the earth in the summer.

[rowerwet]

there are plenty of guys on the hearth.com who are using a car HX (radiator or heater core) to heat their garage, shed or basement with their boiler water, rather than buying an expensive pre-made unit. car radiators work with the same temp and pressure water that a wood or pellet boiler does, and rigging a thermostat and a fan is simple compared to installing and running an alternative heating system.

[Mloves2camp]

Would this small, 12v dehumidifier help with the humidity factor of the ice air conditioners, or swamp coolers when used in higher humidity areas? http://www.sunpentown.com/sdmide.html

I'm not sure just how fast it removes the 11.8 oz according to their specs, though. Is it safe to say that's in 24 hrs? On air conditioners, it gives it per hour, so I'm confused.

Anyway, Walmart shows this item for $48 & is ac/dc. Weighs only 5 lbs, so I'd consider using two if need be, doesn't take up much room, either. Looks like it could be mounted on a wall. http://www.sunpentown.com/sdmide.html

Now, I'll sit back & let the smart ones here decide if this would be helpful in our quest for cool, non-humid air! Thanks to those who know these things!

Marianne

[rowerwet]

Rowerwet,
When you lower ambient air temp, you have to remove a LOT of water because the ability of the air to hold moisture is drastically reduced. If you don't get rid of the water, you end up cold and clammy instead of cold and comfortable.

if you have a basement with cold pipes that "sweat" they you know how this removes water, the cold metal of the HX causes condensation which drips off the HX into a drain. this is the same thing you get inside an air conditioner or a dehumidifier, a cold HX drops the density of the air, cold air cannot hold as much water vapor, the water condenses on the HX and drips off into a drain, in the dehumidifier it goes into the tank, in an AC it goes onto the ground, which is why your car leaves a puddle during the summer. It is all basic chemistry, density, pressure, dew point, condensation, evaporation.
there is no difference between what I do with ice to create a wide temp differential, and what your air conditioner, refrigerator, dehumidifier, ice machine, or heat pump do, they just rely on the wide temp swings induced in a gas (freon) when it is compressed and then squirted through a small orifice (rapid expansion causes a huge drop in temp). I still rely on the freon cycle to make the ice, all I am doing is using the most common and least expensive medium for heat movement (water) to take stored cold (ice) and use it as a heat sink.
there are off the grid refrigerators that burn kerosene to make cold, they aren't as efficient, but do work. http://en.wikipedia.org/wiki/Refrigerat ... tion_cycle they just depend on the expansion cycle of ammonia. any gas could work but the amount of energy absorbed (heat) compared to the amount of energy needed to compress and expand is what made them choose freon.

[rowerwet]

Would this small, 12v dehumidifier help with the humidity factor of the ice air conditioners, or swamp coolers when used in higher humidity areas? http://www.sunpentown.com/sdmide.html

I'm not sure just how fast it removes the 11.8 oz according to their specs, though. Is it safe to say that's in 24 hrs? On air conditioners, it gives it per hour, so I'm confused.

Anyway, Walmart shows this item for $48 & is ac/dc. Weighs only 5 lbs, so I'd consider using two if need be, doesn't take up much room, either. Looks like it could be mounted on a wall. http://www.sunpentown.com/sdmide.html

Now, I'll sit back & let the smart ones here decide if this would be helpful in our quest for cool, non-humid air! Thanks to those who know these things!

Marianne

I think your own body puts off more water vapor than that, and 60 watts is a high draw to run a bunch of them
found it, you sweat between 0.7 and 2.5 L of water a day.
a swamp cooler works because evaporating water absorbs heat as part of the chemical reaction, which works in the dry parts of the country, the rest of the country needs the water vapor removed mostly, as then your own HX (skin) will do its job and evaporate water (sweat) to cool you off.
Ice also gives a slight burst of heat as it transitions from solid to liquid, (from a chemistry experiment I remember in 7th grade) however it takes a bunch of heat to get it to that transition point.
I have heard in very dry areas like arizona they can tweak your cars a/c to run a little colder as you don't have to worry about all that water vapor being dropped out of air when it is extra chilled, since there is so little in AZ.

[bdosborn]

So what do you do for cooling 2 hours later when the ice melts?
Bruce

[rowerwet]

get a big enough cooler and more ice
you only have a few square feet inside a TD, if it is well insulated the ice should last for a while.