Home made Air Conditioner

Dave Thacker
Posts: 62
Joined: Tue Apr 16, 2013 8:18 pm
Location: Tipp City, Ohio

Home made Air Conditioner

Post by Dave Thacker » Sat May 04, 2013 12:16 pm

Troy,

Found a blog site showing the build of a swamp cooler. The lower the humidity, the better they work. Not sure what the average humidity is where you are. Might be just thing to knock down the edge of the heat inside the camper before bead time, or maybe just to run on a timer until midnight or something. Low energy bucket technology.

http://robotfun.wordpress.com/2011/12/21/swampcooler/

Would make a great video build and use series for your YouTube channel.

I've seen other projects people call swamp coolers but they rely on ice (too much energy to make) rather than evaporative temperature drop.
Last edited by Dave Thacker on Sat May 04, 2013 7:30 pm, edited 1 time in total.
Dave Thacker
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Radicalrc.com/blog Blogsite

Dave Thacker
Posts: 62
Joined: Tue Apr 16, 2013 8:18 pm
Location: Tipp City, Ohio

Re: Home made Air Conditioner

Post by Dave Thacker » Sat May 04, 2013 12:20 pm

The dreaded one link per post makes it messy to post complete ideas.

Here is the wiki page discussing evaportive cooling effect.

http://en.wikipedia.org/wiki/Evaporative_cooler
Dave Thacker
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Radicalrc.com/blog Blogsite

Dave Thacker
Posts: 62
Joined: Tue Apr 16, 2013 8:18 pm
Location: Tipp City, Ohio

Re: Home made Air Conditioner

Post by Dave Thacker » Sat May 04, 2013 12:52 pm

I was involved in building an AC unit for a houseboat that worked off the lake. I did many tests to determine the optimum depth to pick up cold water, what the temperature was there, how much cold was lost on the way up the hose and etc.... I owned the boat with a friend who was an engineer. Before we ever got around to building it, I got interested in another houseboat and sold out my share.

However, my friend continued to work on the idea and ended up building the unit. I think he did a really good job of following the orginal idea except he didn't use the optimum radiator setup (in my view) to get the most cold out of the water. Of course in proper physics terms I should say, "in order to put the most heat into the water".

However, here is how it worked. He used an RV water pump connected to a largish garden hose, Craftsman real rubber hose. It was sunk 50' in the lake (Cumberland is a deep lake). The end of the hose had a filter screen on it (large fish basket) to keep leaves and other lake monsters from getting into hose. The reason this works, is technically from a pressure point of view, the pump is only pulling water up from the lakes surface to the pump, a mere foot maybe. The water was pumped through an AC condenser, a 12v auto fan blew through that. The excess was dumped overboard. Incidentally the condenser accumulated condensation. So, this had to be housed in an aluminum box he made with a low point containing a small bilge pump to pump out the condensate as it accumulated.

The unit was capable of pulling the inside of the houseboat down about 10 degrees. Made it nice inside when you'd walk out of 90 degree humid into 80 degree dry air.

In retrospect, the unit would have been even better using a type of condenser with wider gaps in the fins and larger copper tubing. I had wanted to use a large transmission cooler for the heat exchanger. In fact, I wanted to use 2 of then, both fed at the same time with a manifold. This way, the hot air saw the first cool condenser, cooled off x-degrees, then pass through a second cold exchanger and drop x-more degrees. Maybe 3 would have been even better to get every last degree you could out of the air and into the water. It's important to know that from 50 foot of depth, you get water that is in the range of 54-56 degrees coming into the boat. So, I think with the right setup, you could possibly get 60 degree air out of the heat exchanger array. As well as it worked, it could have worked much better. Also, the unit should have been built above water level if possible so the condensation could drain out without any energy. The fans could have been a squirrel cage for more efficiency (sorry, no computer fans, you need some real head pressure to force air through condenser fins). And, a simple bilge pump could have been used to flow a lot of water at low pressure. The antique belt drive RV water pump he used had a big motor, belt drive, it was a 12 volt high pressure monster. Both the overdone fan and water pump cause him to have to run idle a 1000 watt generator just to hold the batteries up. Little more thoughtfully laid out (in other words, buying the right parts rather than using the sub optimal free parts) would have made it even more successful. Probably not more than an extra $200. Still, it worked very good as it was.

Now, you might ask, how do you use a bilge pump to get water up from 50 feet below the boat? It's simple and I tested it. I took a bucket, connected our nice rubber hose to the bottom of the bucket. You weight the bucket so it sits with the bottom about 14 inches or so below the water. As far as you can without sinking it. The cold water from below shoots up in a nice pillar filling the bucket. As You put the bilge pump in the bottom of the bucket pumping into the heat exchange array. The outlet of the heat exchanger array is put over the side of the boat down below the level of the lake. Now the head pressure the pump is working against is only the difference in the level of the buckets water surface to the actual lake surface. Maybe a few inches. And, the pump is always below water so there is never a priming issue. You can move LOADS of water for very little current in this way. We're using mother nature, (gravity) to fill the bucket and the pump to move it only from the bucket.

I know your not setup next to a lake, so this idea can't work for you unless you can find some shallow water table nearby, pick the water up in volume form one hole and return it to another some distance away. Just some more ideas to throw out there. The advantage of a setup like this in your camper, is your not in danger of a leak sinking it. ;-) Things are always more complex on a boat, pesky sinking.....
Dave Thacker
Radicalrc.com, Owner
Radicalrc.com/blog Blogsite

techman
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Re: Home made Air Conditioner

Post by techman » Mon May 06, 2013 7:00 pm

I know, I keep looking at that creek and lake and wishing I could use it for cooling. That would be so perfect. But then if everything was easy, noone would follow my videos. They could all do it themselves easily.

I am probably going to dig a hole and bury water filled pipes in the ground, but the rest of the system is essentially the same as what you mentioned for the boat.

Dave Thacker
Posts: 62
Joined: Tue Apr 16, 2013 8:18 pm
Location: Tipp City, Ohio

Re: Home made Air Conditioner

Post by Dave Thacker » Mon May 06, 2013 9:17 pm

Troy, they are not watching to see you struggle or fumble along. They are watching you to see you win. America loves hero's and winners. I enjoy thinking about the engineering problems. I want to see you solve them and keep improving your life. There is no end to it, you can always go back and address old systems with new fresh solutions and keep improving. Your slowly developing the blueprint for how you live with out power, away from water with minimal income. It's a concept you or anybody else can transport. How well can you live with minimal material input, maximum mental input?
Dave Thacker
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Radicalrc.com/blog Blogsite

techman
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Re: Home made Air Conditioner

Post by techman » Thu May 09, 2013 9:04 pm

I look at the pioneers and they made it just fine with very little.

I am going to succeed in all my projects, it just takes a bit longer due to the limited funds. The pioneers had no rent or taxes to hold them down so they could work all day, every day to build a log cabin by hand. I have to work to pay my taxes and rent, so I have less time, and less finances.

TonysShadow
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Re: Home made Air Conditioner

Post by TonysShadow » Sat May 11, 2013 10:36 pm

The idea that Dave described onboard a boat has been basically used for centuries on land....we call them root cellars..hehe.
Its extreme for Troy..but there are whole house systems these days that run plumbing underground for cooling and heating. No idea how much piping or how deep it would have to be in your area...but cycling air through it after initial cost would be nothing.

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Re: Home made Air Conditioner

Post by techman » Wed May 15, 2013 10:11 am

Actually I do plan to make a passive geothermal cooling system soon. I need to start digging before it gets too hot out for the work. Bury some pipe in the ground and let the ground temperature cool my camper.

But I have so many project and they all need to be done asap. Its hard to get them all done at once. Hope i get it done before the weather gets too hot.

tazmanddevil67
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Location: Illinois

Re: Home made Air Conditioner

Post by tazmanddevil67 » Sun Nov 17, 2013 4:48 pm

When a Swamp cooler works they are just as good as Air Conditioner like in Arizona, But where there is High Humidity they DO NOT WORK. Just Sayin.

techman
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Re: Home made Air Conditioner

Post by techman » Sat Nov 30, 2013 1:17 pm

Right. A swamp cooler will not work where I live. Its too humid. In my case taking out the moisture is the best way to go. Remember this summer when I ran my AC just long enough to take out the humidity. It feels so good at 85 degrees F with lower humidity.

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