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?


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Sep 30, 2012
Am I the only one who feels that the system you are talking about exists in Nature for free? We learnt about this stuff in fifth grade Scott, and at the place where I come from in India we don't build tunnels - we just make windows on the south side (if we can) and keep them open. This system is called sea breeze, and it can be felt many miles inland (much more than 30).


And yes, your assumption that the beach end is always cooler is wrong. It is cooler during the day and warmer during the night. That's why land and see breezes keep the temperature moderate.
Sep 29, 2012
I feel compelled to point out the ignorance, hot air has higher pressure, so which direction is the air gonna flow again?
Sep 28, 2012

[You were not born in California, you moved there from somewhere a lot cooler. Stop !$%*!$%*! and put up with a bit of minor discomfort. Do you know how many people are homeless in your country? Neither do I. But I am not complaining that there is too much sun. (As I write this I am watching my furniture float out the back door. That is worthy of a complaint).]

What are you saying here dude? Sounds an awful lot to me like 'as long as anyone anywhere has it worse than you, you have no right to complain or try to improve your situation'. Scott has been doing a good job of not telling us about whatever millionaire problems he's been having that the rest of us can't relate to, and even if his worst problem was having a load of champagne go bad on him he'd have a right to try to improve his situation. In other words, bummer about losing your furniture but still gonna have to thumbs down your comment.
Sep 28, 2012
The heat sink you want is the earth beneath your feet and the technology is already widely commercially available. See http://en.wikipedia.org/wiki/Geothermal_heat_pump

[I priced that solution when building my home. It only pencils out for extreme climates, and in those cases it works great. Some of the problem is that these systems tend to be designed for one house at a time. If you built an entire community with shared underground geothermal infrastructure perhaps the economics work for California climates too. -- Scott]
+7 Rank Up Rank Down
Sep 28, 2012
Air tunnels?

Is the popcorn getting chatty?
Sep 28, 2012
Have you discussed this problem with a good therapist?
Sep 27, 2012
Why do you have to dig a 30 mile tunnel? Dig down 20 feet in your own backyard and you'll find ground that's cool in the summer and hot in the winter. Actually, its pretty much the same temperature, but the ground that deep is a lot cooler than the air in summer and a lot warmer than the air in winter. Look up geothermal heating/cooling.
Sep 27, 2012
Scott and I live in the East Bay area, east of San Francisco. You can always tell the tourists in SF in the summer, because they're the ones wearing shorts and T-shirts while freezing to death in the cold fog of a SF summer. The bay heats up while the Pacific stays cold; the air masses meet, and voila! Fog happens.

I live closer to the bay than Scott does - I can see it from my house. This morning, we were socked in with fog, and it was about 50 degrees F. The high at my house this afternoon is going to be in the mid-80's. Go a few miles further inland, and the temperature will be in the low 90's.

The joke here, in partial answer to Scott's post, is that if it's too hot for you, you get in your car, watch your temperature gauge while driving toward the water, and when you see the temperature you desire, stop the car. People who haven't ever been to this area are amazed at how much the temperature can vary in just a few miles. The old saw attributed to Mark Twain (which I understand he never really wrote, although he may have said it), was "The coldest winter I ever spent was a summer in San Francisco."

But all this doesn't help Scott's question, to wit: how can I stay cool cheaply? Here's an idea:

1. Go out and buy a few electric fans.

2. You and S h e l l y go out into your yard.

3. Have S h e l l y hose you down.

4. You then do the same to her.

5. Go inside and turn on your fans, and sit in front of them.

6. When the water all evaporates, start at step one again.

Cheap, environmentally friendly, and would not contribute to global warming, even if AGW existed.

You're welcome.
Sep 27, 2012
EVEN IF all of the basic problems raised in the comments were taken care of and there was an effective, economical way to transfer colder air to warmer areas and vice versa, there are bigger problems ahead. Imagine 100,000,000 homes doing this in North America, if it were a method that caught on. The warm areas get much colder (wherever they are) and the cold areas get much warmer (wherever they are). Result: massive environmental impact.
Sep 27, 2012
You were not born in California, you moved there from somewhere a lot cooler. Stop !$%*!$%*! and put up with a bit of minor discomfort. Do you know how many people are homeless in your country? Neither do I. But I am not complaining that there is too much sun. (As I write this I am watching my furniture float out the back door. That is worthy of a complaint).
Sep 27, 2012
Scott, I share your pain. It bugs me as well.

My fridge creates hot air and I can do nothing with it. Can't heat my hot water, can't warm my house in winter.

My roof also creates lots of hot air. Again, I have nothing useful I can easily do with this right now.

My air-conditioner in summer time creates lots of hot air and I can't use this to heat my hot water. In winter time my air-conditioner creates lots of cold air that I can't use to keep my cool room cool.

There are ideas such as these but the technology still needs more work and needs capital investment:


Sep 27, 2012
Love your creative thinking Scott... and other peoples contributes... The copper heat sink is interesting. Metal transfers heat well because it transfers energy well, same thing really... You could take the copper sink a bit further with an earth battery by burying a very large insulated chunk of copper to take advantage of lightning strikes and static electricity from particle friction blowing in the wind... of course the devil is in the details :) The biggest downside I see is corrosion, your shiny new copper sink will be green before you know it... weakening its conductivity.

One the best feasible power generations ideas I've heard about it are the solar steam turbine towers.
+3 Rank Up Rank Down
Sep 26, 2012
Oh, yes, silly me, I tried to write s u c k i n g. Should have known better.
+7 Rank Up Rank Down
Sep 26, 2012
Nope, the thermodynamics are wrong, as others have stated. What you actually want are earth tubes: buried tubes (several smaller ones are probably better than one large one) with the outside end uphill from the homes. Air cools to ground temperature inside the tubes and naturally sinks, flowing into the homes. Your huge 30 mile tunnel would likely do a very effective job of !$%*!$% the air out of the houses instead.
+5 Rank Up Rank Down
Sep 26, 2012
African termites use a fairly effective system:

Sep 26, 2012
The many underground solutions will need to worry about radon leakage.

Sep 26, 2012
An underground pipe full of air is going to cool down to ground temperature. What you would be better to do would be to build a big pipe sculpture in your back yard, half of it underground, the top part painted black. Get the air out of the ground to cool and out of the top to heat during the day.

As to how you stop undesirables like condensation and mould inside the pipes I don't know other than filtering just before the air inlet in the house.

Doesn't solve the keep warm at night issue though.
+2 Rank Up Rank Down
Sep 26, 2012

Then use the electricity for cooling.

Of course, you could try to build a house a bit closer to the sea. Or buy an old light house.
Sep 26, 2012
There are several ways to get passive and assisted heat transfer.

Ground source heating and cooling (not the same as geothermal)
supercooling towers (similar to your idea, only funneling air from the upper atmosphere to the ground)
High heat capacity building materials (like adobe)
High heat conductivity building materials (cooling columns)
Sep 26, 2012
Agreed -- in principle, you could use such a tunnel to cool down a hot room. (Even though you wouldn't be transporting air molecules, there'd still be a tendency for temperature to equalize, which means cooling the hot room.)

The only problem is that the rate of cooling is going to be very small for any tunnel of realistic size. So you wouldn't solve the problem of the room getting hot to begin with. (The rate of initial warming will be much higher than the rate of cooling.) So it wouldn't be as good as air conditioning.

Is there any way you could make it better? Yes -- if you used a substance with much higher thermal conductivity than air. But then it wouldn't be free, which defeats the point in the exercise.

Still, it's an interesting thought experiment. Nice post.
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