Natural Air Conditioning?

Discussion in 'Homesteading Questions' started by caberjim, Jan 28, 2005.

  1. caberjim

    caberjim Stableboy III

    Feb 19, 2004
    Has anyone ever seen this in action? Or tried something like it? I find it very intriguing.

    Natural Air Conditioning

    There was a technique used or invented by the Romans a long time ago. A natural form of air conditioning / ventilation was used roughly as follows:

    1. A trench 6 to 12 feet deep and 100 to 200 yards long was dug leading from the "house" in a straight line away from the house.
    2. Into this trench a large diameter pipe (these days corrugated drainage pipe 2 or 3 feet diameter) was laid, with holes drilled into the bottom to drain water that condensed inside the pipe. The trench was then covered over.
    3. At the far end a 90 degree elbow was attached and more pipe added so that it reached above ground and the end covered with some sort of wire mesh attached to keep out unwanted things such as rodents, etc., and then another elbow could be added at this end to shield against rain.
    4. The house end of the pipe entered the house and was the source of incoming air.
    5. The key to making this work is to add a convection chimney.
    6. The Convection chimney is built such that it's inside opening is at a high point inside the building.
    7. On the outside, two intersecting sides of the chimney; are painted flat black, and the resulting V formed by the two connecting sides face south. In other words, the V needs to face the mid point between where the sun rises and sets.
    8. The two other sides must be transparent, Plexiglas or some equivalent. Also, the higher/larger the chimney, the better.

    How it works: the sun heats up the chimney causing the air inside to rise, thus drawing air through the cool pipe. The pipe cools the air drawn from the outside to the temperature of the earth at the depth at which it is buried (which is virtually constant year around at this depth). By the way, an interesting note: Even in cold climates where the ground is frozen, the incoming air is only 32F when the air outside may be much colder, we need only heat the air by 38F to bring it to 70F; as opposed to heating outside air of say -15F to 70F we would have to heat the incoming air by 85F - quite a difference in the amount of heating energy we would have to supply by some other means.

    Of course, without the sun to warm the chimney (or some other source) the system isn't worth fooling with.
  2. marvella

    marvella Well-Known Member

    Oct 12, 2003
    here in the mountains, they built the old houses at the base of a hill, and near water. the cooler air comes down the hillside toward the water, so anywhere in between the mountain and the water gets a really cool breeze. my old house was in between the mountain and the water. this house both are behind the house, but i still get a really nice breeze in the summer. this last year, even using ac, my electric bill never got over 48 dollars because of it.

    of course the downside is, even in the winter the cooling breeze is there. fortunately we have generally short and mild winters.

  3. Jan Doling

    Jan Doling Well-Known Member

    May 21, 2004
    Zone 9b
    In Florida the humidity kills you before the heat can. If you forget to bring your clothes off the line before dark, they will be wetter than when you hung them!
  4. jack_c-ville

    jack_c-ville Well-Known Member

    Feb 19, 2004
    Sounds like a variation on geothermal climate control to me. I know somebody who spent about $30,000 on a geothermal heating/cooling system. The nice thing is that it costs essentially nothing to maintain. Nowadays people skip the chimney part and use electric fans to move the air around but the chimney idea sound smart.

    I'm always amazed at ancient Roman technology. Especially when I think of the fact that most of it was lost for over a thousand years and we had to invent it all over again. Living in a suburban Roman town would have been almost as comfortable as modern times in America. Good plumbing, soap and air conditioning are right at the top of most people's must-have list of creature comforts.

  5. doohap

    doohap Another American Patriot

    Feb 22, 2003
    Far northeast Texas
    My husband and I are intrigued by the information provided on this website:

    The more we talk about it, the more we like the idea. Will we use it when we build? Don't know yet!

  6. lacyj

    lacyj Well-Known Member

    May 14, 2002
    Calif, The Mother Lode
    I asked the same question, a few years ago, here. The drawbacks, I got were mostly about mold. We are still going to try it, probably this summer. We live on a hill and ours will start towards the bottom and go up to the house. We are planning on being able to cap off the bottom and putting bleach water into it occasionally. It will be hooked into the blower of the furnace for circulation, during the summer. It will also have a filter at one end. We are going to add the PVC to the electrical ditch, when we have permenant power.

    I think it's here: