Duratherm specializes in geothermal systems. They asked me to draw the closed source system used for their website and brochures. The closed source system is mainly used by individuals.
This is the open source system. The open source system is mainly used by companies.
Duratherm also asked to animate the open source system. In the winter the warmth of the ground deep beneath the building is used to warm the building. In the summer this process is reversed. The animation shows this proces.