12v Air Conditioner for wilderness camping

[Borden]

Our roof will not support a traditional air unit, they do make an RV side wall unit made to take the shaking of a trailer ride. Problem is you need 120v and lot of it.

Thinking of getting a HD locking boat cooler mount a little rad (heater core) on top of wall inside seat area with low amp 12v fan on one side to blow into trailer, add intake air piping to back of fan, plus a 12v pump at floor below. Connect pump through lid into cooler full of water and ice block in cooler, piping up out through pump to rad out back into cooler to cool trailer. With grills and have tubing to cooler and pump use quick connects it would be easier to fill cooler. Pump could be on floor of trailer like the water pump under sink.

Extra battery to run this would work at a wilderness site. Block ice, cubes or crushed would work in cooler. Also could have a bypass water hookups for connecting to a cold stream with an input water filter. Quick connects would help in this optional stream hookup.

12v AC sounds good, any ideas for possible improvements?
project will be a go just want to get ideas to refine and avoid possible problems in advance.

[Borden]

Spring fed stream would probably work best they can be quite cold, ice just to take the edge of the heat and may not last long. Time will tell. Problem is power requirements of traditional AC. Propane unit would be great but any found are only for transport trucks very large and very heavy.

[steve dunham]

It takes approx 140 btu' s to melt one lb of ice , If you need 5000 btu' s to cool your trailer to an acceptable level , you would consume approx 36 Lbs of ice / hour ( Assuming 100% heat transfer) . Not very practical in my book . If you could park by a cool stream and use a single pass system with a large enough heat exchanger you may get sufficient cooling . I worked on an older bldg that used well water to cool the space at a rate of 60,000 gallons / hour . They used a single pass system and just dumped the waste water down the sewer . That type of system is not allowed any more in most jurisdictions.

[cpaharley2008]

Here you go Evaporative | 12volt Air Conditioning | Swamp | 12v AC Coolers
I have used one and they work great, in fact I'll sell you mine.

[Rob V]

Evaporation is an efficient way to cool a surface. So drink water, perspire, and sit in front of a fan.

Cools you, not the air around you.

[Borden]

Part of the fun will be in design and building it, single pass from stream back to stream sounds like best case scenario. With maybe two heater cores and a low voltage fan maybe stack the rads to use one fan or side by side with ducting to aim fanned air through both. Will start with one rad as it is easy to add a second just a little tin work for the change will not need a lot of air movement. Just want to take the edge off not like a house air system. Up high may work best as cold air falls maybe over closet would work better than under sweat? Will have to do some more planning. Thanks for the link will check it out.

[steve dunham]

I would also check on the legality of diverting water from a stream and then reintroducing the same heated water back into the stream . People in our area were placing coils in lakes to capture the latent heat to use with their heat pumps. This caused ice levels to change ,and fish and fish habitat was damaged . The state eventually forced them to remove the coils due to environmental problems .What you are considering will work but I am just pointing out something to ponder.

[MCDenny]

Originally Posted by steve dunham

It takes approx 140 btu' s to melt one lb of ice , If you need 5000 btu' s to cool your trailer to an acceptable level , you would consume approx 36 Lbs of ice / hour ( Assuming 100% heat transfer) . Not very practical in my book . If you could park by a cool stream and use a single pass system with a large enough heat exchanger you may get sufficient cooling . I worked on an older bldg that used well water to cool the space at a rate of 60,000 gallons / hour . They used a single pass system and just dumped the waste water down the sewer . That type of system is not allowed any more in most jurisdictions.

As always, ya just gotta do the math.


Denny Wolfe
Wanderingourway.wordpress.com