The Earth Cooler Project

Digging the hole and setting up the testing system

Part Two

Date Log; March 6, 2009

In all fairness if you really are keen to get in there and dig a one metre deep hole by hand go for it. Good healthy exercise trims down the body and makes those muscles really ripple under the T shirt. In our case not so good. We would strongly advocate a post hole digger powered by a moderately large diesel engine and an equally large other person operating said machinery. In other words you would have to have rocks in your head to dig it by hand. By the way before you dig check out what's underneath the ground you have chosen...... good idea.....I think so.

Alright we have the hole dug down to our predetermined depth. We have the Earth Cooler pressure tested and good to go. Next we fit two shut off taps and then fill the Earth Cooler while it is out of the ground. It is easier to fill this way as you can move the cooler around to dislodge air trapped in the tubing. When you are satisfied that the majority of the larger air bubbles have been expelled the Earth Cooler goes to its new home in the ground.

Plenty of water here to displace the air in the hole and to liquefy the soil and clay mixture. A rammer or stick of some sort is needed to push the liquid soil mixture to various parts of the hole and to agitate the mixture.

In the next part of our project will be testing the Earth cooler with a predetermined heat value. To do this we will need to construct two specialized insulated heat baths each containing a 300 Watt aquarium heater.

The Heater Bath

First off we are going to cut some of the copper tubing we used for the Earth sink. It will need to be long enough to house the length of the aquarium heater element plus have tags to locate the heater bath so that it will not fall over during use. A mock up is shown below.

Next its out with the propane torch and we solder up the parts adding in two brass barbs to serve as inlet and outlet points..

We will face heat loss problems if the heater bath is not insulated. A piece of air conditioning neoprene solves the problem for the tubing section.

To finish off the base of the heater bath a small piece of adhesive neoprene is used to insulate the copper base.

Then it's time to fit a plastic base plate to the tubing section......this will stop our creation from falling over.

The final piece of insulation to be added is to the copper tags which locate and secure the base plate to the heater bath.

At about this stage you could be forgiven for thinking that our heater bath looks more like an LN2 pot.

Finally we can make up our top and we are ready to test out our Earth Cooler.

Before we do we will need to verify our wattage settings with this little jobby from Jaycar.

Next we can get ready to see if all of our hard work pays off when the testing starts.

Part Three........ Test results.