Innovation in greenhouse heating – the blanket heating
The key element of blanket heating is the plastic blanket laid on the soil with a heat exchanger coil inside. There are planting holes on the blanket for the transplants. By controlling the temperature in the blanket, the thermal optimum of plant growth can be assured.
Due to its large surface, the heating blanket can utilize low temperature, so called waste heats, as well. The thermal efficiency of blanket technology is ca. two times higher than that of the traditional greenhouse heating methods.
The application of blanket heating in greenhouses offers a number of benefits:
- Less thermal energy is needed, as the heat is introduced below the vegetation zone, this way the formation of elevated temperature air layer under the roof that causes significant heat loss, can be avoided.
- Because of the large heat transfer surface, low temperature heating medium can be utilized.
- The blanket heating is less sensitive to the disturbances of heat supply, as the blanket, with its significant water fill, acts as a buffer.
The blanket heats the soil and the plants with unparalleled energy efficiency. The saving in energy use may often reach 50%.
The blanket heating is an ideal means of summer overheat control, too. In periods of high irradiation the closed greenhouses get too warm, and the development of the plants slows down or stops. This phenomenon is caused by the invisible infrared part of solar radiation.
Shading may lessen the intensity of irradiation, however, it reduces photosynthesis and the production of organic matter. This is seen in lower summer yields.
Blankets can control overheating without shading. If the water fill of the blankets is cooled down, shoots and roots can continuously develop at full irradiation.
