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N°7 – Horizontal collectors training (VTC to A level)

Heat is drawn out of the ground by a polyethylene tube or a copper tube sheaved in polyethylene, inside of which (preferentially) glycolated water circulates (dosage rate of 25% in our moderate climates).

  • The tube of approx 20 [mm] (between ¾ and 1 inch NPS) diameter is buried at a depth of between 0,6 [m] (1.97 ft) and 1,2 [m] (3.94 ft) maximum in the ground. At a greater depth, the surface intake (sun, rainfall) would be insufficient.
  • To avoid excessive chilling of the ground, the loops are at a minimum distance apart of 0.5 [m] (1.64 ft).
  • Preferably, the ground must be flat (or slightly sloped) and permeable (which helps « reheating » by rainfall).
  • Safety distances of 1.5 [m] (4.9 ft) are to be respected regarding other buried networks.
  • For current insulation levels, we need an available surface in the garden of approx 1.5 times the surface to heat.

Source géothermie13

Can we tarmac the collector zone?
Yes! Certain permeable tarmacs permit this.

Can we concrete the collector zone?
No! Concrete does not tolerate any deformation due to disturbed ground.

Can we drive on the collector zone?
Yes! After covering with a depth of earth of 60 cm (1.97 ft), the collector has no problem with the weight of a car or truck.

Can we plant trees on the collector zone?
Yes! All sorts of flowers and bushes. For trees a collector-free zone of 2m is required.

At what distance from the house, from the plot limit, roads and services can we place our collectors?

It is necessary to leave a space of 1.5m (4.9 ft) between the collector and these elements.

Is the nature of the terrain important?

The nature of the terrain is unimportant; however rocky terrains need a protective sand bed.

Can the collector zone exhaust itself?
The ground regenerates permanently and returns to its natural state in summer. Energy is inexhaustible.

Does under-floor heating provoke heaviness in the legs?
No! The temperature of the floor is very mild (only a few [K] more than ambient temp).

Can we heat with radiators, towel rails and fan coil units?
Yes, we can use these elements at low temperature.

Can we heat a swimming pool?
Yes! Between-seasons and permanently.