As a leading edge renewable energy company, we at Hellbent are always looking for ways to do things more efficiently and harness new technologies. One such technology, by Rehau, is called the ‘helix coil’. Widely used in Europe, this ground-loop technique is now making its way to North America. Optimal for projects with limited space, the helix coil technology allow us to dig much shorter boreholes (10 feet deep) while retaining the same system efficiency.
Here’s how it works.
Nature loves spirals. Look at the shape of a pinecone, the center of a sunflower or even our own galaxy! It is only natural that by embracing this circular flow, we gain in efficiency.
Conventionally, geo-exchange systems require either deep vertical boreholes or long horizontal trenches to function. Piping is stretched out and the loop fluid travels over long distances, thus effecting the needed change in temperature.
The main difference with the helix coil is that the liquid will travel about the same distance but it will be done in a much more compact way. The spiral shape of the ground loop also means that we don’t have to dig nearly as deep.
One of the benefits of such technique is a much lower installation cost when compared to drilled vertical boreholes. The deeper holes also require an industrial sized drilling rig to be brought on site, while the spiral loops only require a small excavator (equipped with an auger drill bit). This way, the impact on the landscape is lessened and it also makes it easier to retrofit an existing house to a geo-exchange system.