The Pain Mound can be used to heat hot tubs, greenhouses or hydronic heating systems. Plan out your location carefully ahead of time so that you are close to the thing you will be heating. In the diagram shown here, we hooked up a pain mound to a greenhouse. We buried the water lines so that we would not lose additional heat to the outdoor air.

For more information, CompostPower.org has an excellent detailed installation guide, which can be found here: http://www.compostpower.org/node/24