DIY Air Conditioning

[tyromeo55]

Have a very similar setup for my airplane. uses ice and water with a heat exchanger, pump and a bilge fan. drawing air through a heat exchanger is the key. I can tell you that I can get about a 20 degree differential from the air coming out of the outlet vs air temp in the heat of the summer, but ice in a standard sized cooler will only last about 3 hours before the water is room temperature. It can knock the edge off of the heat in the cockpit netting an air temp difference of about ten degrees maintained at 90F+ ambient temperature, but only while the cooler has ice in it. then temp quickly begins to rise.

I use it on the ground and during climb out and descent. At cruise it's turned off to conserve the cold. The main reason I use it is because my plane doesn't have Air Conditioning and it can be removed during the winter (the plane has heat) for better payload capacity. Plus it doesn't require any certs.

It would take a VERY large version of this to cool a room. What you would save from your AC bill would go into making ice. you would be better served to use a swamp cooler for a dedicated home operation.

Your use is one of the very few I would think this project would be good for. I was thinking a heat exchanger of sorts would be mandatory in a confined space especially if you did not want to fog up the interior windows. Im guessing that you have a place for the condensate water to go and then pump it back into the ice bucket?

 

[NightShade]

I think you would be better off shutting down unused area's and sticking with a window air in the rooms you need to keep cool. Your going to be constantly trying to freeze enough ice to keep cool and never really have it be all that comfortable. Not to mention that when the little bit of cool is gone it's going to be SUPER humid and even more miserable. If your in a home you own throwing some more insulation in the attic and finding a way to insulate your walls will do a lot more good in the long run along with better windows or at the very least heavy curtains over the windows. It sucks to say it but if you have natural light coming into the house during the heat of the day your windows are transferring a ton of heat inside. The same applies for staying warm in winter, btw.

If you just want to try and keep yourself comfortable with as little fuss as possible I would recommend something like this: http://www.ebay.com/itm/DONJOY-ICEMAN-COLD-THERAPY-SYSTEM-W-PAD-AC-ADAPTER-EXC-1100-/360869800543 you stick water and ice in a cooler connect the hoses and plug it in. Drove from Lawton to Lubbock during the summer one year in an old s-10 blazer with no AC, even with the windows down and the rear glass open it was plain miserable. Had one of these put in the middle of my back while on the way back and though it was still a little warm it was not too bad really. And it still had ice in it when I got home.

 

[swampratt]

I built a small one from ice chest and old heater core and small squirrel cage fan from a 260Z and a small marine bilge pump.
I gave it to my mail carrier.. he loves it.. but like stated ice does not last long,, 2 hours.

A simple swamp cooler will also work.
As will cardboard with aluminum foil cut out to fit tight in the windows.
Another deal is lot's of insulation in the attic.

I just stuck in a bunch more in 3 houses last year..One guy would turn on his air at 11am as the house began warming up.
Now he can go to 3 pm before he needs to turn on the ac.

How thick do you have the insulation in your attic?

Another thing i noticed a couple years ago was plastic.
I built a chicken coop and used those corrugated plastic white roof panels from homedepot.
No feeling of heat under them... was amazing.
I also have a white metal roof on a shed.. that thing underneath it is like standing under a heat lamp..

Actually thought of tarping over my house in the heat of the day.. or make a grid panel with those plastic panels to place on top of the house.

Shade the outside ac unit....another cheap cheap deal is to use a soaker hose around the condensing unit.

Buddy did this and his water bill went up 20 bucks that month but his 270 dollar electric bill went to 140.
His unit was old undersized and ran all the time...
Just some thoughts.
Do you have a pond on your property?

 

[Perplexed]

The cost of the "ice" would be me freezing gallons of water at no cost given my deep freeze already runs daily.

There will be a cost involved in freezing the water - even if your deep freeze runs daily, it still has to use extra energy to convert the water to ice. There ain't no such thing as a free lunch.

 

[NikatKimber]

There will be a cost involved in freezing the water - even if your deep freeze runs daily, it still has to use extra energy to convert the water to ice. There ain't no such thing as a free lunch.

This.

 

[aviator41]

Your use is one of the very few I would think this project would be good for. I was thinking a heat exchanger of sorts would be mandatory in a confined space especially if you did not want to fog up the interior windows. Im guessing that you have a place for the condensate water to go and then pump it back into the ice bucket?

Yes, the heat exchanger is kept in a separate compartment from the ice water mix, when water condenses on the exchanger, it drips into a tray and makes it back into the bottom. This also prevents water from splashing out of the unit during steep turns and turbulence and helps mitigate the added humidity in the cockpit. The pump I'm using is nothing more than an aquarium pump wired for 12 volts. There are a few companies that make a "commercial" version of this. They sell for anywhere from $300 to $700 a unit, which is ridiculousness! I think I have less that $50 in this, including wiring and remote control. There are sensors for low water and low flow (blockage) as well as a temp sensor in the ice water, ambient intake and forced chilled air. Lets me keep an eye on efficiency. It typically takes a two bags of ice and a gallon of water to get going.

The exchanger has a very large surface area, so it's in a 'chamber' of sorts that allows the air to move slowly through the exchanger, then is sped up as it passes through the blower. There is basic air filter on the intake to just keep junk out, the intake is set up in such a way as to allow an outside vent to blow directly into the intake as it sits in the back seat. At altitude, I can turn the exchanger pump off, and just use it as a forced air vent with the blower running. The heat exchanger is nothing more than an aluminum transmission cooler radiator, it works perfectly (and was cheap).

One of the things I want to do is add a "T" and valve to the tubing coming from the pump. that way I can empty the water using the pump to make room for more ice Right now the unit has to be pulled and the bottom drain on the cooler opened in order to drain the melt off. I also plan on adding a false bottom to the cooler section, leaving the pump intake in a recess, ensuring it always has water. Pretty cool little unit.

Here's how it works.



This is the circuit board that I Cut for the pump and fan controller. It's about the size of a credit card, has backup circuits for both the pump and the blower and an auto-cutoff for low voltages. It's controlled with a simple wireless controller. So far, it's been flawless. All the relays are solid state FET's. which means no moving parts here. Just a black box with wires coming out, it's mounted on top, behind the blower.

 

[JackT]

There will be a cost involved in freezing the water - even if your deep freeze runs daily, it still has to use extra energy to convert the water to ice. There ain't no such thing as a free lunch.

It's nothing drastic.

 

[aviator41]

I can tell you that you will melt ice thrice as fast as you can freeze it.

 

[tyromeo55]

Im in with the... you'd be better of spending your money on insulation and/or running a single window air instead of cooling the entire house crowd

For a small enclosed space that does not have cold air ( classic car, tractor, plane) I'm really digging Aviators cooler. The best part is that it would remove humidity from the space.

Aviator41, What about adding a wire dish drying rack at the bottom ensuring a steady supply of water to the pump?

 

[twoguns?]

As said the xtra humidity will work the crap out of your existing unit... .....cool idea though