Greenhouses

In greenhouses construction is very simple:
In the summer greenhouse's too hot air will be led to the
ground with pipes and the same but cooler air will come
back to the greenhouse.

You need not ventilation, less irrigation, less energy
and added carbon dioxide stays better in the greenhouse.
In the winter air circulates in same pipes and bring back
the same warm to the greenhouse.

Possible light will be perhaps very rapidly beated blue and
red leds because of economize electricity. The efficiency of
light will be more than 1% of ordinary light, and production
of food must be more economical. TH