GREENHOUSE HEATING WITH SUN ENERGY – THE GREENHOUSE AS COLLECTOR

1. Changing solar radiation into heat energy

2. Storing heat energy for greenhouse heating

The possibilities for changing solar radiation into heat energy, can be reduced to three main principles, Fig. 1:

1. Separate solar collectors, working as air- or water-collectors beside the greenhouse, Fig. 1a

2. Solar collectors integrated in the greenhouse structure.
   Air- and water-collectors under the roof, Fig. 1b, c, and liquid filter flowing between the two panes of the roof.

3. The use of the greenhouse itself as solar collector.
   Bringing the surplus heat out of the greenhouse into a storage.

In the Institute for Horticultural Engineering, Hannover, detailed experiments with the system "greenhouse as collector" have been carried out.