

Student makes his own Air Conditioner to beat the summer heat. - karanbhangui
http://www.gmilburn.ca/2005/06/15/the-black-beauty/

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URSpider94
Let's calculate quickly: a typical small room might require 5000 Btu/h to
cool. One Btu is equal to a 1F temperature rise for 1 pound of water. Assume
that "Black Beauty" can get 20 degrees of thermal differential out of the
water running through it (incoming: 50F, outgoing: 70F). That means we must
pass 250 pounds, or just over 31 gallons, of water through the system each
hour.

That wouldn't be so bad if the water could be put to another use, like
bathing, watering a vegetable garden or flushing toilets. But, 750 gallons of
water a day is A LOT to use just for cooling -- consider that this is
equivalent to four times the typical American household usage for a day.

As with a lot of DIY geek hobbies, it's not so awful when one person does it,
but it would be an environmental disaster if this was adopted by the general
public.

EDIT: Corrected my units.

~~~
matthavener
would be interesting to see something like this combined with a solar hot
water heater.

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CapitalistCartr
Water is indeed an important resource, but it's not a particularly scarce one
in many areas. It's not a waste to use something one is paying for, in those
circumstances.

I've lived in areas where water is terribly scarce, and places of plenty, such
a I do now. In the places of plenty, some municipalities subsidize the price
of water because it's politically popular. Under the guise of helping the
poor, they help the middle class that is most of their electorate. Others do
not. The ones that subsidize scream about scarcity and waste. That doesn't
make it true. Subsidies distort the market.

~~~
imajes
I don't see your point here. Encouraging waste because a resource doesn't have
scarcity seems a bit strange. Perhaps it can be piped to areas that have
scarcity? Many rivers etc are dammed to provide municipal water; so oversupply
might encourage some muncipalities to un-dam water and let it flow naturally
again, which is an env++.

Most importantly, it's good to be in the habit of conserving water, recycling
and such because when you move into areas of scarcity, you don't have to
force-change your habits and suffer quickly, but instead act responsibly all
the way through.

I note your handle is 'capitalist' - being responsible isn't hippy anti-
capitalism. Saving a few bucks here and there by using less subsidized water
might mean that people will stop expecting subsidy, and instead want the money
redirected elsewhere...

and everyone is still richer.

EDIT: i don't disagree that subsidies distort markets, but it's tangental to
the parent post.

~~~
CapitalistCartr
Usage is not waste. Simply because you don't agree with his usage of a tub of
water to cool his room doesn't make it waste. He chooses on what to spend his
money. As for the ad-hominem attack on my handle, I'll simply say it's
unwarranted.

~~~
imajes
is it not a waste for someone to open a fire-hydrant so they can bathe their
dog's paws? Your definition of "usage is not a waste" is really questionable.

BTW, there was no ad-hom attack on your handle, but rather an observation of
your potential leaning -- i'm a capitalist too ( i think most HN'ers are) so I
figured i'd respond to make sure you weren't going to write me off as a hippy-
enviro.

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asmithmd1
He doesn't do anything to handle condensation that will form on the cooling
coil.

It is called air-conditioning because getting humidity right is just as
important as temperature.

~~~
weaksauce
That's so true. That is actually why you want to size your AC unit to how
large your house is otherwise you will either have the unit running too long
and remove all the moisture in the house or have the unit on for only a minute
at a time and it won't have the chance to remove any of the moisture. When the
latter happens you are cool but it feels like a swamp.

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pavel_lishin
Reminds me when we lost power a few days during a blizzard, and we just ran
hot water - supplied by the university, powered by generators - in a bathroom
to make a sauna.

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teilo
Isn't this a tremendous waste of water?

~~~
aarongough
It's only a waste of water if you assume the water is 'disappearing'
afterward. In ontario water is mainly provided by lakes, then after treatment
water is returned to the same lakes. The only waste is the power used to
move/treat the water, but this is the equivalent of power used by the
compressor/fan of a normal A/C anyway.

The situation is obviously different if the water supply is not a closed loop,
like in Australia where water is supplied from dams and then waste water in
dumped into the ocean...

~~~
teilo
Actually, I was thinking of my water bill...

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peregrine
I made one of these but used a single cooler with ice cubes+water+frozen
saltwater Jars. The system was closed as opposed to wasting water like this
guy did.

The big issue was that the water temperature rose very fast and the ice melted
way to quickly. You'd get maybe 10 minutes of really cool air and it would be
done.

I thought about maybe using hay to keep the ice colder but it was getting to
elaborate when the fan would work just fine.

~~~
someone_here
Were you making the ice in a freezer that was in the same room as your "air
conditioner"?

~~~
aplusbi
I get where you are headed, but you should probably think about the ice as
"fuel." The cost (in terms of heat/energy) of freezing the ice can be spent
during times when you are not in the room and/or not using the "air
conditioner."

Actually there are commercial HVAC systems that use ice as a coolant - the
water is frozen at night when electricity demands are lower and then is used
to cool the building during the day.

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bradleyland
This is a terrible waste of a very important resource: water. It's amazing to
me how many people take it for granted.

~~~
amock
In some places there is more than enough water for everyone, so wasting water
isn't a concern.

~~~
eru
Yes. And if you just have a pump in your garden, and let the water sink in
again, after you use it, nothing's being wasted at all.

