The purpose of a greenhouse is to preserve an environment in which crop production is perfect. Geothermal greenhouse is a geothermal heating greenhouse with geothermal energy. The construction of a geothermal greenhouse is like a greenhouse which uses conventional oils for heating energy. The differences involve the space heating energy source, the site selection and costs. For economic reasons, a geothermal greenhouse is basically always near the geothermal source. Geothermal greenhouse costs are a major advantage. The initial building costs are independent of heating energy, but in geothermal greenhouses, operating costs are usually greatly enhanced.
Geothermal heating greenhouse:
Soil and water beneath floor contain a great reservoir of thermal strength. Geothermal heating systems recover this power and convert it to warmth that can be applied in geothermal residential and also in greenhouses. Geothermal heat can be categorized into 3 categories.
Low temperature (50°F) :
The soil temperature at the floor varies appreciably over the year and intently follows the air temperature. At the five to six-foot depth, the temperature is extra uniform, averaging approximately 50°F with a variation that depends on soil characteristics and the environmental situations above ground degree. There is also a lag time of about eight weeks among the maximum floor temperature and the maximum soil temperature at this degree which is beneficial in winter heating and summer time cooling. For the greenhouse manufacturing of perennials, herbs, nursery stock and a few vegetables. This low-grade soil heated air or may be used directly, or, for heating the greenhouse to a better temperature, a heat pump can be used. Heat pumps are to be had as air to air, air to water, water to water or water to air systems.
Medium temperature (140-300°F) :
in certain areas of the world. Hot water can be used directly for heating in hot wells and springs. The Rocky Mountain and West Coast states heat up by medium-sized geothermal energy in dozens of greenhouse operations. the root zone heating distributes hot water from the ground.
High temperature (>300°) :
The vapor from geysers is used to generate power but not greenhouse heating in California, Nevada and Utah. There are actually about 20 sites under development, including several others. We generate 5-8 cents / kW hr of electricity.
Maintenance of temperature within the greenhouse:
Temperature control is complicated inside the greenhouse when external conditions are fluctuating. If the sun shines brightly, little heat will be needed to control the heating system, so as to prevent harm to the plant. The heat generated by hot water, steam, electric cables or hot-air furns. is generally controlled by thermostat. Temperatures are regulated according to the crop in greenhouses.
In warm summer days, cooling is often required. The easiest method is ventilation which lowers indoor temperature to below the outside temperature. Further cooling by freezing may be needed, the evaporating cooler is efficient in dry areas and also improves the structure’s relative humidity. The application of extra carbon dioxide to the air is a further method of environmental control if the crop needs an extra photosynthetic impact.
building a geothermal greenhouse:
The greenhouse is usually a structure with a transparent or clear roof and sides, helping the photosynthetic system to be accessed with ample solar radiation quality and amount. This helps crops to grow regardless of the external environment, as its inner temperature and humidity can be controlled. geothermal heating greenhouse range from small homes or interests to large commercial units covering one acre or more of land in size and complexity. A lightweight, but robust, frame that resists winds and other loads are the basics building of a greenhouse.
Greenhouses in the 17th century were usual brick and wooden shelters with normal proportion of window space and some heating facilities. When glass became cheaper, the greenhouse became a wall-covered structure made from glass with minimum wood or metal skeletons, and as a result advanced heat forms became possible.
geothermal heating greenhouse design:
Structural design – orientation:
The greenhouse structural material must protect against loads of corps, snow or wind, allowing the highest possible transmission of light. This means that the frames should be small and resistant to expected charges. The loads of nature include dead loads, live loads and snow and wind loads. Dead load is the structure’s weight which relies on the design, glassing method and amount of permanent structures supported by the frame. The heating and ventilation system, the water lines and so on are the pennant systems. For short periods, the live loads might hang plants or other elements supported by the frames and persons function on the roof. The real wind load relies on the wind angle, the shape and size of the greenhouse and whether or not wind breaks exist. The snow load can be more than 3 kg /m², .but the snow melts due to heating of greenhouses.
Previously greenhouses were made of cypress frames and single glass panels almost exclusively .. Substantial changes in building techniques and materials have been carried out in recent years.
Construction materials generally fall into one of the following four categories: steel, concrete, fiberglass or similar strong plastics. Glass as a cover medium allows excellent light transmission for greenhouses and is favored for sun-intensive plants. It’s also the most expensive material, the cost is high because of the glass quality but also because of the frame material that is strong enough to support the glass.
In constructing frames in greenhouses, wood steel, aluminum and reinforced concrete have been used. To protect against decay and improve lighting conditions, Wood must be painted. Preservatives should be used to prevent any wood in connection with soil from degradation, since it should be free of plant or human toxic chemicals.
Aluminum has extremely light weight and at the same time very solid properties as a frame element. It is malt-proof, durable and non-toxic. It doesn’t rust or erode and pushes electricity and heat.
The advantage of aluminum is the durability even when reused of all these items. When smelted, it does not sacrifice any of its benefits. It saves energy. It is recyclable; greenhouses in aluminum that really need repair can be reused almost completely in new greenhouse construction.
Greenhouse Heating Systems:
The energy-efficient option of geothermal heating in most parts of the country is low-temperature heating because the system design and expense of fossil fuel replacement provides a reasonable payback, normally ten years or less. that’s why we can say that geothermal greenhouses are passive geothermal greenhouse, The cost of fossil fuel is reduced, depending on the system design.
It is necessary to determine carefully the estimated gain on your scenario and to enforce energy conservation measures which usually only pay back a few years, before considering the installation of a geothermic device. These include: elimination of air penetration, construction of energy curtains and separation of sidewalls, use of spatial growth and the implementation of electronic environmental controls. First of all, they will reduce heat loss significantly reduce the size of the geothermal heating device required to power the geothermal heating greenhouse.