On Sat, 26 Sep 2009 10:23:36 +0800, Bloke Down The Pub wrote:

"atec 7 7" "atec wrote in message
...
terryc wrote:
On Wed, 23 Sep 2009 18:44:47 +1000, atec 7 7 wrote:


( 2 metres down the earth never gets above 5 Deg C) in Brisbane

How and where did you do the trenching. The only trencher I can hire
is only 3'

used neighbours back hoe then a shovel
bloody hard work and near killed me

How many metres of pipe and what diameter would be necessary for this to
be effective? Or do you have a link that I could explore more?

It really is a case of how much cooling you want?
Volume of house to cool?
How fast do you want to cool it?
What is your annual soil temperature profile? (sets max cooling possible)
How deep can you afford to dig and lay the pipe? The deeper the better
the cooling effect
What size pipe can you afford/obtain? Generally the bigger the better
(think surface area for heat exchange).

Everything I've seen has been plastic pipe (long term cleanliness) with a
slow fan into a sealed house. This system isn't about air-con cooling
effect. There probably are a lot of other things you might need to do
before hand to improve the air tightness of your house.

Your cheapest experiment would be to hire a walk behind trencher, then do
a big loop trench from one side of your house out and long the side and
back fences and back to the other side. Lay 90mm plastic poly pipe in it.

Ideally your intake end is under your house (pier construction) or in a
shaded (southerly side) area. Make sure you have good insect screening on
the intake. I do not know if it matters if you push or pull the air.

Bring to a vent high in the main room.