Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
  • A01G9/00—Cultivation in receptacles, forcing-frames or greenhouses; Edging for beds, lawn or the like
  • A01G9/24—Devices or systems for heating, ventilating, regulating temperature, illuminating, or watering, in greenhouses, forcing-frames, or the like
  • A01G9/246—Air-conditioning systems
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
  • A01G31/00—Soilless cultivation, e.g. hydroponics
  • A01G31/02—Special apparatus therefor
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
  • A01G31/00—Soilless cultivation, e.g. hydroponics
  • A01G31/02—Special apparatus therefor
  • A01G31/06—Hydroponic culture on racks or in stacked containers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
  • Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
  • Y02A40/25—Greenhouse technology, e.g. cooling systems therefor
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P60/00—Technologies relating to agriculture, livestock or agroalimentary industries
  • Y02P60/20—Reduction of greenhouse gas [GHG] emissions in agriculture, e.g. CO2
  • Y02P60/21—Dinitrogen oxide [N2O], e.g. using aquaponics, hydroponics or efficiency measures

Definitions

• the prior art planters are used in outdoor or indoor gardening and commercial growing in a glasshouse, poly-tunnel and open land farming. Majority are moulded from plastic material, which is used to hold soil or substrate to grow various plants. They play an important role from naturally preventing pathogen spread from one planter to another especially in a drain to waste irrigation system. They also assist in easier handling of protected crops grown in glasshouse or poly-tunnel and to some varieties of crop in open land farming. They are designed to have drainage holes in their bottom to allow for drainage of water. If not for these drainage holes the resulting water logging within the planter will have detrimental effect on the plant's root development. One of the main reasons for this problem is lack of continuous aeration to root zone.
• the plastic planters are normally manufactured with thin wall sections. This may be due to the high cost of plastic material. Furthermore, the plastic material used in planters have low 'R' value and thereby low insulating properties which do not provide adequate insulation to the plant roots against outside heat and cold. This will have a detrimental effect on root development during hot and cold seasons where plants are grown outdoors as well as in a climate protected greenhouse. The following description particularly focuses on issues in growing protected crops with or without planters/containers in a greenhouse and sums up the reasons for invention.
• Plants are grown within a protected environment for various reasons i.e. climate protection, quality of product and season extension.
• the protection would be provided via glasshouse or poly-tunnels (both termed as glasshouse or greenhouse).
• the greenhouses can be divided into three main categories.
• the first category is heated and cooled greenhouses.
• the second category is either heated or cooled.
• the third category is the greenhouse without heating or cooling facility, which is used either to grow protected crop for a limited period in a year between Spring and Fall (especially in cold regions) or used as climate protection to grow crops throughout the year in tropical or temperate regions.
• Examples of protected crops grown in greenhouses are vegetables (tomato, cucumber, capsicum, aubergine etc) soft fruits (strawberries, cherries, Raspberries etc), salad leaves, herbs, medicinal plants, cut flowers, ornamental and bedding plants.
• vegetables tomato, cucumber, capsicum, aubergine etc
• soft fruits strawberries, cherries, Raspberries etc
• salad leaves herbs, medicinal plants, cut flowers, ornamental and bedding plants.
• hot climatic conditions a greenhouse requires heating when the temperature inside the greenhouse rises above certain limit due to solar radiation which is detrimental to plant growth.
• the carbon footprint is a serious issue in growing protected crops especially in heated and cooled greenhouses. Burning of fossil fuels to heat the greenhouse in cold climates generates tremendous carbon footprint and the energy required to cool the greenhouse in hot climates also generates carbon footprint.
• the commercial greenhouses are either heated by steam boilers or from the waste heat from CHP (Combined Heat & Power) generators to maintain the entire volume of air at a certain temperature which in turn would transfer heat to the root zone.
• This conventional method of indirect heat transfer to the root zone generally fails to raise the temperature of the root zone to its optimum temperature levels and to maintain it uniformly throughout a greenhouse from a commercial large scale growing perspective. It has neither been economically viable nor technically sensible (in commercial scale context) to raise the root zone temperature to such established optimum levels during the day or night by indirect method of heat transfer to the root zone from heated air. This is because of
• the indirect method of heat transfer to the root zone from the heated air is not energy efficient because most of the heat in air is lost before it reaches the root zone. This is due to constant loss of heat in air resulting from lack of insulation to greenhouse walls and roof, frequent ventilation and leaks through openings in a greenhouse structure.
• Dissolved oxygen in the irrigation water reduces with the increase in its temperature and for this purpose irrigation water of lower temperature (typically 52° F) is administered to the plant roots in a separate irrigation system. It is found that the dissolved level of oxygen is at optimum level when the irrigation water is at 52° F and begins to deplete with the increase in temperature from this point. Therefore it is technically not a sensible idea to increase the root zone temperature to their established optimum levels unless there is a means to increase the oxygen supply. Hence the current methods of heating greenhouse on a commercial scale generally may limit the yield, extend the duration of growing cycle and make it almost impossible to manipulate root zone temperatures to control plant vegetative and generative growth.
• NFT Natural Film Technology
• DWC Deep Water Culture
• Hydroponic systems can provide direct heat or cold transfer to the root zone and possibly a better uniformity to the root zone temperature throughout the greenhouse (especially in DWC).
• these systems depend heavily on the levels of dissolved oxygen in the feed to prevent plants from wilting. Heating the feed beyond 52° F will deplete the level of dissolved oxygen in the feed hence these systems have increased application as a direct cold transfer system to the root zone in hot climates.
• the scope for these systems is limited because only few types of protected crops are successfully grown in these systems. It is a general opinion that majority types of the protected crops grow better on substrate having good air retention ability than on NFT or DWC systems.
• the oxygen demand from plant roots increases with the increase of temperature in the root zone. This further emphasises that plant roots cannot entirely depend on the dissolved oxygen levels in the irrigation water if they are to be maintained at optimum temperature.
• the indirect radiation heating can neither provide increased supply of oxygen nor make it possible to maintain accurate and uniform optimum temperature in the root zone throughout a greenhouse. Hence there is a good scope to increase the quality and the quantity of the yield if there is a cost effective means available to rise the root zone temperature to optimum levels and maintain it accurately and uniformly throughout a commercial greenhouse with increased supply of oxygen to the root zone.
• AHT overcomes all constraints of raising the root zone temperature to optimum levels in a greenhouse
• the preferred embodiment overcomes all the constraints of traditional methods of heating to raise the root zone temperature to optimum levels. It provides the plant roots growing in soil or in any substrate (sawdust, Rockwool, Stone wool, coco fibre, Clay pebbles, Perlite etc) with natural aeration simultaneously with direct heat or cold transfer combined with saving of water and nutrients which is otherwise drained to waste. It is a Thermodynamics principle which is engineered to work within a planter moulded to any shape, size and can be custom made to hold a plant or a number of plants.
• the preferred embodiment is designed to retain some volume of administered irrigation water at the bottom before it overflows through a return. Also designed are openings from underneath on its body supplemented with channels converging on to such openings to allow unobstructed air passage into the preferred embodiment when substrate or soil is loosely filled into the preferred embodiment or packed in a grow bag, plastic envelope, netted bag etc and placed into the preferred embodiment. This is engineered in a way to prevent the retained or overflowing irrigation water clogging or leaking through the openings of air passages allowing unobstructed passage to incoming air.
• Energy efficiency in preferred embodiment results from the combination of material used in manufacturing preferred embodiment, substrates or soil and the externally heated irrigation water or water mixed with nutrient (feed).
• the feed is heated to a desired temperature and administered into the preferred embodiment via irrigation pipes.
• some volume of the feed is retained in the bottom before it overflows through a return.
• Unnecessary heat loss from the retained feed is prevented from the natural insulation provided by the substrate or the soil covering the retained feed (reservoir) from above and the body of the preferred embodiment which is made from the material having good insulation property, for example Expanded Polystyrene (EPS or EPP) material covering the sides and the bottom of the retained feed.
• EPS or EPP Expanded Polystyrene
• the volume of the retained feed at the bottom will effectively create a zone which is warmer than the temperature outside preferred embodiment.
• the retained warm feed is pushed upwards to the root zone by capillary force which occurs naturally due to the porosity in the substrate material or the soil which is fully or partially connected to the reservoir and the additional suction force of the roots absorbing the feed.
• the combination of all these factors result in heat transfer to the level in the soil or substrate which is immediately above the retained feed and warm up the air which is present in their void spaces due to infusion of air into liquid medium assisted by conduction, convection and radiation.
• the warmed up air will start moving leaving a vacuum behind.
• the vacuum attracts comparatively cooler air from outside through the openings for air passage.
• the cool air when reaching the vacuum zone gets warmer and the cycle repeats. This becomes a constant phenomenon within the preferred embodiment as long as there is a temperature difference between the outside and the inside of the preferred embodiment.
• the preferred embodiment now works like an under floor heating system with an added advantage of direct heat transfer and additional aeration while providing optimum feed to the root zone. It heats the roots first to the desired optimum temperature followed by keeping immediate plant surroundings warm. It may not require supplementary heating of the air in a greenhouse during most periods of the cold climatic conditions or may only require air temperature in the greenhouse maintained as low as 52° F (as recommended by NCAT-ATTRA) as opposed to the air temperature maintained >72°F in the greenhouse which saves considerable energy. Also the loss of energy due to the loss of heat from the air resulting from the lack of insulation to the greenhouse walls and roof, ventilation and leak in the greenhouse structure that carry away useful heat is significantly minimised making it a highly energy efficient method of heating the root zone in a greenhouse.
• the feed itself is a supplementary source of heat which is protected against the heat loss with adequate insulation. This makes it possible to maintain near accurate temperature in the root zone uniformly throughout the greenhouse and makes it possible to control the root zone temperature as required during a growing cycle. Depletion of oxygen in the heated feed does not pose a problem due to constant aeration provided to the root zone from underneath of soil or substrate resulting in optimal quality and quantity in yield.
• BTU Blunt Thermal Units
• BTU/Hour A* ⁇ /R
• A Square feet Area of the greenhouse roof and walls
• ⁇ Temperature difference in °F between inside and outside of the greenhouse
• R the R value of the materials providing insulation i.e. Glass (Glasshouse), polythene sheet (Poly tunnel), Rockwool or Stone wool substrate slabs, Expanded Polystyrene (Body of preferred embodiment) and Elastomeric pipe insulation.
• the ⁇ is assumed as 40°F (i.e. temperature inside 72 °F minus outside 32 °F) and the glass or polythene sheet R value is 0.88.
• Tomatoes are grown in compressed slabs of Rockwool or Stone wool substrate.
• 384 units of slabs each measuring 1000 mm long (3.30 feet)
• X 100 mm high 0.33 feet would fit into the 3000 square feet floor surface area of the above example greenhouse.
• the surface area (excluding the bottom) of each slab is approximately 6 square feet.
• the planter holding them would measure approximately 7 square feet (excluding the top but including the bottom).
• administering chilled feed into the preferred embodiment keeps the root zone cooler than outside. It is already been established that the plants would withstand higher temperatures in a greenhouse especially during hot climatic conditions if the root zone is maintained at cooler temperature.
• AHT works like a under floor cooling system with an added advantage of direct cold transfer, additional aeration and optimum feed to the root zone. It cools the roots first followed by cooling immediate plant surroundings and protects the plants even if the air temperature in a greenhouse has to increase beyond tolerant levels due to solar radiation. Insulation to the irrigation pipes carrying chilled feed and the natural insulation provided by the expanded polystyrene (EPS or EPP) material makes it possible to maintain the chill temperature in the root zone accurately and uniformly throughout the greenhouse. This makes it a highly effective and energy efficient technology for the purpose of protecting the plants in greenhouse during hot climatic conditions.
• EPS expanded polystyrene
• Water efficiency in the preferred embodiment is due to the possibility to save irrigation water and nutrients which is otherwise drained to waste.
• the irrigated water that drains out due to gravitational force in prior art is instead collected as a shallow reservoir at the bottom of the preferred embodiment before it overflows through an outlet. This provides additional buffer to plant roots.
• the continuous aeration above the surface of the reservoir unlike prior art overcomes negative effects of any water logging and provides ideal condition for vigorous root development despite the presence of water reservoir.
• the substrate or soil may be loosely filled or the substrate which is packed in a grow bag, plastic envelope, netted bag etc is placed inside the preferred embodiment after making provision for partial contact between the underneath of the substrate and the reservoir.
• AHT Application & Heat Transfer
• FIG 1 A first figure.
• (33 ) is the insulating wall of sufficient thickness
• (34) is one of the several exit outlet for incoming air
• (35) is the channel converging on to the exit outlet hole for incoming air (34)
• (36) is the reservoir tank and
• FIG 2 is a diagrammatic representation of FIG 2
• FIG 3 Is the top view of FIG 1.
• FIG 3 Is the top view of FIG 1.
• (38) is a smaller block of a substrate for example stone wool or coco fibre used in this case to partially connect the underneath of the main substrate to the reservoir.
• FIG 4 is a diagrammatic representation of FIG 4
• FIG 5 is a diagrammatic representation of FIG 5
• the water reservoir (41) formed from the water flowing down the main substrate (43) due to gravitational force.
• (42) is the space filled with incoming air.
• the main substrate (43) for example stone wool or coco fibre packed in a plastic envelope (44) which has openings (45) on its surface for planting and openings (46) underneath to allow aeration as well as water and nutrient uptake from the reservoir via (38) via capillary and root suction force.
• (47) Shows the area covered by (45) which allows the unobstructed passage for incoming air via 'LT grove but prevent the water in the main substrate clogging or leaking through (34).
• (48) is the surface of (38) where the incoming air mixes together with the water from the reservoir and assist in aeration to root zone.
• FIG 6 is a diagrammatic representation of FIG 6
• (50) Shows a loosely filled substrate or soil (49).
• (50) is a separate non permeable material which caps (34). This allows the unobstructed passage for incoming air via 'U' grove but prevent the water in the main substrate clogging or leaking through (34).
• (51) is the mix of (49) and (41).
• FIG 7 is a diagrammatic representation of FIG 7
• FIG 8 Is the top view of a section showing the separate non permeable material (50) capping (34) and the unobstructed passage for incoming air (52).
• FIG 8 Is the top view of a section showing the separate non permeable material (50) capping (34) and the unobstructed passage for incoming air (52).
• FIG 9 Shows loose clay pebbles used as substrate in the preferred embodiment.
• FIG 10 is a diagrammatic representation of FIG 10
• FIG 11 Shows the top view of FIG 9.
• FIG 11 Shows the top view of FIG 9.
• FIG 12 Shows the preferred embodiment in the shape of a heart.
• FIG 13 Shows the preferred embodiment in the shape of a square.
• (55) is the insulated branch pipe feeding into a substrate for example stone wool, coco fibre, saw dust etc (56).
• (57) is the preferred embodiment body providing insulation to the water held in (56) as well as water reservoir (58) from sides and bottom.
• the substrate (56) provides insulation to (58) from above and prevents evaporation from reservoir.
• the insulation to irrigation pipes enhances energy efficiency.
• the warm or chilled water reservoir heats or cools the incoming air (60) and maintains the entire main substrate (56) at a constant predetermined temperature for longer duration making it energy efficient.
• the temperature outside the preferred embodiment will have lesser impact on the temperature inside preferred embodiment due to overall insulation. There will be continuous air movement within the preferred embodiment as long as there is a temperature difference between inside and outside the preferred embodiment.
• FIG 14 is a diagrammatic representation of FIG 14
• (62) is the stone wool or coco fibre block normally used in loosely filled medium to support initial development of plant roots before it establishes into the main substrate or soil
• (63) is the separate non impermeable material covering (34) and (64) is the unobstructed passage for the incoming air.

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• Life Sciences & Earth Sciences (AREA)
• Environmental Sciences (AREA)
• Greenhouses (AREA)
• Cultivation Of Plants (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

Family

ID=46147500

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Cited By (4)

Citations (3)

• 2012
  • 2012-04-03 WO PCT/GB2012/000306 patent/WO2013150255A1/fr not_active Ceased

Patent Citations (3)

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