This DIY Zero-Electricity Air Conditioner Can Cool Down Homes

From:
Collective Evolution

By Alexa Erickson 18 June 2016

.
www.collective-evolution.com...

.
.

.
. . .
.
In Bangladesh, the threat of flooding forces 70 percent of the population to live in corrugated tin huts with no electricity supply. During the scalding hot summer months, this can prove unbearable, with the houses feeling more like ovens than a place of comfort and safety.
.
. . .
.
To create this nifty cooling system, plastic bottles are cut in half and then mounted into a grid through bottleneck-sized holes. The grid can be situated over a window with the narrower top end of the bottle facing inwards. When the wind blows through the bottles, cool air funnels into the hut. According to Eco-Cooler, this technique can decrease temperatures in the home by up to 5°C.
.
. . .
.

.
I love SIMPLE IS BEST solutions to real problems.
.
I realize that 5 degrees may seem pitifully little in some temperatures and locations. However . . . I've lived in such SE Asian humidity etc. and 5 degrees cooler can be most welcome.
.
I've often wondered what could be done that would be practical and not that expensive and functionally effective in various survival contexts. Maybe this would be an option if a lot of bottles were nearby! LOL.
.
And, if water were around, how about some fiber in the outer portion of the bottles . . . wet fiber . . . I'd think that could decrease the temp even more. It might require frequent wetting of the fiber . . . and in many regions water is hard to come by. But perhaps near rivers or the ocean it would be workable. I don't know.
.
Any other improvements ATS engineers could think of? Or alternatives?
.

a reply to: BO XIAN

obvious responses :

1 - ` wetted fibre ` , would increase the humidity in the space you are attempting to cool , at the same temperature - 95% RHA feels hotter that 40% RHA . this can be demonstrated in a sauna


2 - any contaminants in your " wetted fibre " would end up as aerosols in your ` cooled space ` - read up on the origins of legionaires desiese

a reply to: ignorant_ape


Ahhhhhhhh . . . I hadn't thought about the aerosols.

Thanks.

So, it would need to be distilled water. LOL. Sigh.

Would it not be easier to just have an open space so the cooler air can just enter?

I may be entirely ignorant on the subject, but if it relies on the Joule–Thomson effect then wouldn't it need to be much more compressed?

But yes, living in a very humid area, adding moisture to any moving air simply increases the intolerable uncomfortable persistent heat..

originally posted by: ignorant_ape
a reply to: BO XIAN

obvious responses :

1 - ` wetted fibre ` , would increase the humidity in the space you are attempting to cool , at the same temperature - 95% RHA feels hotter that 40% RHA . this can be demonstrated in a sauna


2 - any contaminants in your " wetted fibre " would end up as aerosols in your ` cooled space ` - read up on the origins of legionaires desiese

well spoken, Bo Xian

Thank you for presenting excellent direction.

a reply to: ignorant_ape

here in arizona,we have evaporative coolers,we call them swamp coolers.High cfm fan pulling air thru wet strands of wood pads.They do a great job,till the dew point hits 55 or so,then its a sticky humid mess.In the springtime,they can knock a house down 20 degree's,in the fall they are a waste of time.

That's a nifty idea, the in-turned bottles.

Although, theory and practicality don't always go hand-in-hand.

The idea of wetted fiber brought upon the idea of a thin sheet or curtain stretched upon the out side bottle frame.

A sheer fablic can help keep out the direct Sun light and also act as an air filter of sorts. But still be thin enough to allow proper air flow.

Problem solving is fun.

a reply to: blkcwbyhat
I have relatives who live in Tucson. They have a swimming pool.
Hang out in the pool when the temp is 100º and it feels great. Get out of the pool and start shivering uncontrollable because the low humidity sucks the water off your skin and your body heat with it.

Briefly.

Then it's back into the pool.

OOOOk. This is so totally bogus.

First principles - temperature of the air is dependent on the heat energy it contains. You can't cool it without removing heat from it.

There's nothing here that can remove thermal energy from the air. So it's not going to become cooler.

What are they claiming? As far as I can tell, it's nothing but a bunch of nozzles on a board. So, what do nozzles do? They exchange pressure for velocity while (in this case) reducing flow. So the 'eco cooler' will reduce the total airflow through the window, in exchange for an increase in air velocity. But it's not going to be any cooler. In fact, you'll get a probably unmeasurable temperature increase due to nozzle compression.

So the thing will make you get a bit stiffer breeze at the expense of reducing the total airflow, with no cooling whatsoever.

a reply to: Bedlam

In fact, you'll get a probably unmeasurable temperature increase due to nozzle compression.

Which is immediately lost upon expansion. No net change in heat content.

So the thing will make you get a bit stiffer breeze at the expense of reducing the total airflow, with no cooling whatsoever.

So, my floor fan doesn't make me feel cooler?

But it is, in effect, nothing more than a fan. It is not air conditioning.

Awesome for a treehouse.

originally posted by: Phage
Which is immediately lost upon expansion.

Except for friction work on the nozzle. You'll keep that.

So, my floor fan doesn't make me feel cooler?

Fans actually warm the air, through paddlewheel work. A more dramatic case would be the air at the outlet of your vacuum cleaner. It's warm because of the paddlewheel work the blower is doing.

But it is, in effect, nothing more than a fan. It is not air conditioning.

True. Yet they're claiming a physical reduction in temperature of the air on the other side of the window. Which is a lie.

Now, if you had some sort of windmill turning a ceiling fan inside the house, you might make things a bit more comfortable, although it still wouldn't be cooler.

a reply to: Bedlam

True. Yet they're claiming a physical reduction in temperature of the air on the other side of the window. Which is a lie.

What they say is the temperature inside is reduced by 5º. They don't say it's cooler than outside.

When I get home, before I open my doors and windows, my house is more that 5º warmer than outside. Why is that?

The more outside air gets into my house, the cooler it gets. Putting a fan in a window, blowing into the house, helps even more.

Now, when I was a yoot, some guy, whom I remember to have been Brazilian, had created a sort of step-up from a vortex tube. The principle was similar to a vortex cooler, but in the center of the tube was a sort of counter-rotating spindle thing that injected the air, the design supposedly got you a spectacular increase in efficiency, and the guy was claiming energy efficiencies way better than a typical AC unit of the time.

If you could take your pop bottles and make a wall o' vortex coolers somehow, it would actually reduce the temperature.

I wonder what happened to the guy and his vortex AC? Haven't thought about it again until now. I considered building one in machine shop for a science fair project in junior high but couldn't get a copy of a mechanical drawing.

originally posted by: Phage
What they say is the temperature inside is reduced by 5º. They don't say it's cooler than outside.

True, but is it going to help by obstructing the air flow through the window with a nozzle wall?

If we're talking temperature increases inside a structure being what they're on about, it might help more to make a reflecting cover over the roof. White cloth, aluminized Mylar, something of the sort over the roof as a reflector, with a gap of about a foot to a black roof will also reduce the interior temperature. Especially if you have a prevailing wind direction and arrange the cover to funnel airflow between the reflector and the roof.

a reply to: Phage

thats when the humidity is 30 or 40...try it in the monsoon season at 80 or so,you never get dry!

Ok different idea. But related. I saw a warehouse being cooled with a big drum fan. Only there was copper tubing running cold water on the back of the fan. This diy setup cooled the massive room by 30 degrees. As in the room next to us was almost 110 but hey what a difference.

a reply to: Bedlam

True, but is it going to help by obstructing the air flow through the window with a nozzle wall?

If the wind is perpendicular to the window, probably not. Otherwise, the data would seem to indicate otherwise. It seems that the airflow is more efficiently redirected.

If we're talking temperature increases inside a structure being what they're on about...

Sure. And while your at it, insulate the roof and walls too. This is cheap. Really, really cheap.

a reply to: Bedlam

hmmm,I believe it's Pascal's law of gases,#3 I think...a compressed gas increases in temp,and a released pressurized gas decreases in temp.If you fill an air tank,the tank will get hot..release the gas,its cold.
The device your thinking of is called a vortex chiller,runs on compressed air,somehow,but the air of the outlet end comes out around 40 degrees,we had a few in a machine shop I worked in.
Look up Georges Ranque, vortex tube

a reply to: Phage

there may be a small decompression effect as the opening is larger than the outlet,but I think there would have to be a typhoon to see a major effect.A mister system would work a lot better anyway,assuming you have water

a reply to: Phage

another thought,by putting in a few dozen (hundred?) 3 inch holes in the wall,you have basically made a 3 wall house,and eliminated a lot of thermal mass.