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Suppose you built a huge tunnel with one end at a cold beach and the other end thirty miles inland. Warm air rises, so you'd be sucking in the cold air at the beach and exhaling it at the warm inland side. You would literally have a wind tunnel.

Now suppose the warm end of the tunnel has lots of little hoses distributed to individual homes that require air conditioning. Now you have air conditioning as a public utility. Every home would draw in cool air from the beach and exhale it though a sun-warmed chimney.

At night, when the homes don't need as much air conditioning, everyone shuts their hose, opens their windows and goes to bed. There's still a temperature differential because the beach end of the tunnel is always colder. So at the warm end of the tunnel a huge door slides open to allow a new direction for the air to escape, past windmill-type generators. The generators would produce electricity all night and help pay for the tunnel.

In the winter, when you want warm air, the beach side of the tunnel is sealed and a solar concentrator one mile up from the beach comes online. It uses mirrors to focus sunlight on thermal mass around the tunnel to superheat it. The warm air would travel up the tunnel to the homes. The thermal mass at the solar concentrator side would stay warmer than the air for hours after the sun went down.

I realize none of this is practical or economical. It just bugs me that I need to pay money to change the temperature of air in my home when there's plenty of free air at exactly the right temperature just a few miles away. And that air wants to be where I am. It just needs a tunnel.

Is there a smarter (economical) way to solve this problem?

Votes:  +39

### Comments

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+13
Sep 26, 2012
"The one that has always bugged me is a smaller problem: refrigerators in the winter. I pay to heat my house, and I pay more to keep a smaller container cool within that heated area. Why can't the fridge have a hose to the outside, and when the outside air is cooler than the desired temperature in the fridge just pump in some of that air rather than running a compressor? "

Well, you can. It's called a thermal bridge, but it has it's own issues most of the time. Namely, even in winter one has to worry about temp variations. Your milk could freeze at night or warm up over 40 degrees during the warmest part of the day, either one being bad. BTW, you don't lose that energy while running the refrigerator during winter, the heat that the refrigerator is producing contributes to your heat demand, just like incandecent lights do. However, the heat that both these devices (and everything else that uses electricity, really) produce is counter-productive when you need air conditioning.

+2
Sep 26, 2012
Heat Sinks- passive and active.

http://www.jc-solarhomes.com/passive_solar.htm

+32
Sep 26, 2012
A long tunnel would be too expensive. I'd recommend trucking in the beach air.

+5
Sep 26, 2012
A better way to do the same thing would be to build a compressed air pipeline from Northern climates (Canada) to warm climates (Southern USA). Since Canadians need heat for a greater portion of the year, while Southern Americans need Air Conditioning; the Canadians use air compressors to push energy into the pipeline, using the waste heat (both from the actual consumption of electricity and from the heat of compression itself) to contribute to their home heat needs, while Southern Americans use the compressed air for pnumatic energy & air conditioning & refrigeration (via air-cycle decompressors). While absolutely zero ozone destroying freons are required, the pipeline itself is what makes this idea impractical; since leakage is the greatest loss in any compressed air system of any size.

+7
Sep 26, 2012
The one that has always bugged me is a smaller problem: refrigerators in the winter. I pay to heat my house, and I pay more to keep a smaller container cool within that heated area. Why can't the fridge have a hose to the outside, and when the outside air is cooler than the desired temperature in the fridge just pump in some of that air rather than running a compressor?

Sep 26, 2012
I like the idea of using the ground to cool the air, but again I wouldn't move the air itself; use metal to conduct the heat from one place to the other. It occurred to me that 1000 feet wouldn't be high enough to make the heat sink work efficiently, and would take a lot of copper. Maybe if we buried the copper; you wouldn't have to go much more than 40-50 feet down. Actually you could get away with less than that but I wonder about the negative effects of heating the ground around the house; over time it might cause problems. Better to go down a bit further and make it the problem of the next guy who owns your house.

Going down also can solve the opposite problem -- if we extend the sink far enough down, geothermal energy will start to warm it. We would have to have some sort of switching device, so that in summer the house would be connected to the closer metal rings and heat would flow down, but in the winter, it would be connected to the deeper ones and heat would flow up.

+10
Sep 26, 2012
The problem is, if you have a tunnel 30 miles long (or however long is required) then, yes, the warm air will draw the cold air up the tunnel. It will do this until an equilibrium is found - probably halfway along the tunnel, where the cool air has warmed to the point where the warm air pulling it has no effect.

Now, you put a bunch of holes in the tunnel (to connect to the houses along the way). Now you have the world's most leaky air-conditioning system. The first house gets all the cold air. Your house (30 miles away) sucks.

+11
Sep 26, 2012
Build your next house in a cave.

Not joking.

It's getting really trendy in some areas because cave-houses or hobbit-holes, whatever, tend to stay cooler in the summer and warmer in the winter.

+6
Sep 26, 2012
You don't have to pull air from miles away though: there's matter storing much cooler air just a few feet away in the dirt.

There a type of building called an Earthship that operates otherwise like you're describing. Pipes are exposed to fresh air outside, burried through a thick layer of dirt, and then enter the home at one end. At the other end of the house is a greenhouse facing the sun. When it's hot out, the greenhouse warms up, the air exits through holes at the top, bringing air into the home through the pipes that is cooled by the dirt.

See this incredibly ugly diagram:
http://upload.wikimedia.org/wikipedia/commons/2/2c/Convection_banner_1.jpg

+1
Sep 26, 2012
@tinyhands

[Apart from being in competition with oil & gas producers, meaning they'll never see anything other than marginal use, what's wrong with wind, wave, and photovoltaic electrical generation?]

Nothing. What's wrong with trying other things as well? Delius1967 and I demonstrated why Scotts idea won't work, but maybe Delius1967s heat sink idea its worth a try.

In addition to wind, wave and photovoltaic power of course.

+21
Sep 26, 2012
The thermodynamic problems aren't really the issue; unless your house is on a mountainside the elevation difference isn't enough to make the air flow in either direction. Imagine a triangle with a base 150,000 feet long (about 30 miles), and a height of, say, 85 feet, which is the elevation of San Jose. That's an angle of 0.03 degrees, i.e. completely flat to anyone who doesn't have sighting equipment and a lot of training. Even if your house sat atop Mount Whitney, the highest point in California -- which we somehow moved to within 30 miles of the ocean -- you'd still only get an angle of about 5.5 degrees. It would make for a tough bike ride home but still wouldn't be enough to take advantage of "hot air rising" in the sense you mean.

Next you'd have the problem of large, ugly tubes everywhere, which I'm sure would concern somebody (especially in California), and the effects of solar radiation, which would warm the air before it ever got to your house. We could solve both problems by burying the tubes, but that will bring in geothermal concerns, not to mention having to dig up almost all of a very large population center.

Why disturb the beach, anyway? There is much cooler air much closer to your house. Just go 3-4 miles straight up, and the air will consistently be 50 degrees colder than it is on the ground. Feel the window of a plane the next time you are flying. Now we are getting somewhere, because the "hot air rising" effect will actually work. Unfortunately gravity will be working against us, not to mention the FAA.

Instead of moving the air itself, I would try conducting the heat from one place to the other. Heat can be transferred much more efficiently through metal. Maybe we could build the world's largest heat sink, and use it to pull heat out of the air around your house and transfer it somewhere else. It doesn't have to go to the beach: extend the copper upward about 1000 feet, and allow the heat to dissipate there. You could use the flow of heat through the metal to power a fan to help the process along. This is how the CPU fan on your computer operates, just on a much larger scale.

Sep 26, 2012
Apart from being in competition with oil & gas producers, meaning they'll never see anything other than marginal use, what's wrong with wind, wave, and photovoltaic electrical generation?

Sep 26, 2012
Plant trees around your house and they'll keep you cooler in summer and warmer in winter.

+15
Sep 26, 2012
I question your understanding of thermodynamics. Why, exactly would cold air get sucked up to your house?

+1
Sep 26, 2012
If the beach part of the tunnel is at sea level and your home is above sea level (I would imagine the number of homes built below sea level is quite low) then the cool air from the beach is NOT going to rise to replace the warm air where your home is. Still, there might be an idea here. Find a place on Earth where the warm air is below cool air a few miles away and we could indeed make a generator like the one you're talking about. And if said cool air area is inhabited and needs heating...

That is, unless some engineering type logs in to tell us why this can't be done.

+7
Sep 26, 2012
Move to where the desired air is?

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