Bangladeshi air cooler made from plastic bottles uses no electricity

http://inhabitat.com/this-amazing-bangladeshi-air-cooler-is-made-from-plastic-bottles-and-uses-no-electricity/eco-cooler-plastic-bottle-air-conditioner-3/

by infodroid • 10 years ago

8 12 10 years ago

inhabitat.com

andrewl2• 10 years ago

I love solutions like this. I look at them and think "It's so simple and obvious! I could have invented that." But I never do invent them.

infodroid4• 10 years ago

Maybe such solutions are only really obvious in retrospect!

Some of my favourites in this category are the Q Drum (a rollable water container) and the GravityLight (a lamp powered by gravity).

[1] http://www.qdrum.co.za [2] http://gravitylight.org

andrewl2• 10 years ago

I'd seen the Q Drum before, and thought the simplicity and effectiveness were great. I had not see the gravity light, but I like it, too.

And I think you're right about solutions being obvious only in retrospect. The simple fact that I can understand a solution as soon as I see it doesn't mean I'll think of the solution as soon as I encounter the problem. Or ever.

In my coding, it's always easier to "see" the complex bad solution than the simple and elegant good solution.

yongjik2• 10 years ago

"Gravity light" will never be something more than a curious gadget.

If you lift a 20 kg weight by two meters, you gain a potential energy of 20 * 2 * 9.8 = 392J. Amazon seems to be selling "60W equivalent" LED lights which consume 8.5W. (I think that's about the realistic minimum for reading or cooking.)

Assuming 100% efficiency, you can power this LED light for 46 seconds.

upofadown2• 10 years ago

Anyone know how this is supposed to work. The part about "compressing and cooling the air" doesn't make any sense. The air wouldn't be compressed and it it was it would get warmer, until it wasn't compressed any more.

My guess is that it allows a relatively high level of ventilation but blocks the sun that would otherwise come in through the open window. So more or less the same effect as an awning.

HeyLaughingBoy• 10 years ago

It's the expansion of the compressed air that cools it. IANAME (I'm not a mechanical engineer) but thinking through the physics of it, you need a fairly strong airflow since the compression has to be adiabatic (air must be compressed quickly enough so it doesn't heat up), then once it expands, it cools.

Of course all of this still takes energy and I'm not motivated to do the math, but cooling a room by 5 deg C still takes the same amount of energy whether it's powered by wind or electricity.

upofadown2• 10 years ago

air must be compressed quickly enough so it doesn't heat up

The heating is inherent to the compression. Adiabatic means something else.

To make air based refrigeration work, you would have to compress the air and transfer the extra heat somewhere else. Then you would get cooling when you let the air expand again.

... which is all still moot as the air would not be compressed enough to matter in this case.

gameofdrones• 10 years ago

thunderf00t will debunk this as not a sanitary napkin-making machine-scale revolution.

Bangladeshi air cooler made from plastic bottles uses no electricity

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