Geothermal manifolds

What is geothermal energy?

Geothermal energy is a CLEAN, RENEWABLE, and SUSTAINABLE energy for the future. It is now consolidated all over Europe being pioneered by countries like Sweden and Switzerland since the early 1980s. Germany, Austria, UK and France have now grown to significant markets for ground source heat pumps.

A geothermal system can be considered in three parts:

The “ground loop” for transferring heat out of or into the ground.
The geothermal heat pump to move heat between the ground and the building.
A ground loop “manifold distribution system” for delivering heating/cooling to the building.

1.Ground loop

There are three types of ground loop:

Vertical ground loop

Plastic pipes (normally in polyethylene with outside diameter 32 or 40 mm.) are installed in boreholes; the hole is back-filled with a thermally enhanced grout mixture for thermal conductivity. These boreholes are can be between 30 and 180 meter deep depending on the geography. The temperature of the ground increases by approximately 3° C every 100 m. depth. Multiple bore holes as is often the case require manifold connections for controlled distribution of the circulating fluid. Also not “energy pile” and “foundation piles” as methods for vertical loops.

collettori geotermici verticali

Horizontal ground loop

Plastic pipes (polyethyle-ne 25 mm up to 40 mm) are laid in trenches in the ground, usually a minimum of 1.2 m deep; the length of the trenches requires a sufficient land area; this heat comes primarily form the rain and the sun

geotermico orizzontale

Hybrids ground loop

To save surface area with ground heat collectors, some special ground heat exchangers have been developed; spiral system or spiral basket collector (vertical installation between 2 and 5 meter deep), slinky coils (overlapping coils of polyethylene pipe) or pond loops are the most common alternatives. The size of pipes is can be smaller, and in some cases are 25 mm. In more northern climates these loops can be up to a pipe diameter of 32 mm.

impianto geotermico ibrido

2.The heat pump

The geothermal heat pump performs the job transferring heat by using external energy. The amount of this external energy input is kept as low as possible to make the heat pump ecologically and economically desirable.
Because of lower operational temperatures values, this type of heat generation is perfect for under floor and wall heating system.

3.Manifold distribution system

ONDA THERM build geothermal manifolds using a polyamid reinforced with glass fiber. This achieves the mechanical characteristics similar to those of light alloys, but with a decisively higher resistance to external atmosperic influences. Geokal, Geomatic, Geotherm and Kombigeo 65/100 are modular manifolds that have been specifically designed and engineered for geothermal ground loop distribution. The design and construction of the manifold distribution system operate with minimal increase in resistance and module is equipped with an individual shut-off valve.