GROUND BASED STRUCTURE

Abstract: A greenhouse (1) is described. It consists of an above-ground portion (3) comprising heat insulating glass panels (7) and an enterable pit portion (4) which is adapted to extend below ground surface (5). The greenhouse comprises a door (6). The heat insulating glass panels are mounted in heat insulating frame elements (8). The pit portion comprises substantially vertical heat insulating wall elements (9) being provided with a height that they extend at least to a frost-free level (10) below the ground surface (5). The different elements are connected by connectors (35) making it easy to erect the greenhouse. The floor (11) of the pit (4) is uninsulated and is arranged at said frost-free level (10) whereby the greenhouse is kept frost-proof during wintertime due to the use of earth heat.

Description: Ground based structure Background of the Invention The present invention relates to a ground based structure and is particularly, although not exclusively, applicable to a horticultural or garden greenhouse. More specific it relates to a ground based structure consisting of an above-ground portion comprising light-transmissive regions and an enterable pit portion which is adapted to extend below ground and which is covered by the above-ground portion, said structure comprises a door in the enclosure. During the past 30-40 years it has become still more common in the northern climes to use small unheated greenhouses in domestic gardens. Such greenhouses are used in a growth season from May till October when there is no risk for frost. Such greenhouses are made with an uninsulated glass structure to be placed on a frame arranged on the ground. During the past 30-40 years it has also been experienced that almost every house has been supplied with a central heating system. Simultaneously, larders or other rooms used for storing vegetables, fruits and other food stuffs have disappeared from the residences. Accordingly, persons living in modern houses and being interested in gardening do not have unheated basement rooms or other frost-proof rooms which could be used to store frost-sensitive items like vegetables or fruit such as potatoes, apples and the like or other frost sensitive plants and roots. For many years there has been an increasing interest in gardening, and also an increasing attention has been given to the problems with the storage of the garden products. Especially in northern climes where heat must be supplied by auxiliary means during cold periods in the beginning and in the end of the season there has been an increasing desire to have a system making it possible to prolong the period when the greenhouse could be used for growing plants and to have a storage system making it possible to store frost-sensitive vegetables, fruits and plants during wintertime. There have been a number of proposals to heat the greenhouses by solar energy and to optimise the effect of the solar energy in the early spring and in the late autumn in order to increase the length of the growth season in the periods wherein the solar energy is rather uncertain. An example of such system is disclosed in US 4 249 340. However, such systems are rather complex and expensive. Moreover, the solar energy could only be used for a limited period to maintain the greenhouse frost-proof. The system will not be suited for storing plants during wintertime. In prior art there are also proposals for systems for storing solar energy absorbed dur- ing sunny periods to be used during periods when the temperature has dropped. An example of such a system is disclosed in US 4 262 656. The heat from the greenhouse is transferred to a heat storage bed, e. g. comprising rock material underneath the floor in the greenhouse. Also this system is rather complex and expensive. However this system will only be usable in the growth season and will be useless during winter pe- riods as it is not possible to maintain the temperature level in the greenhouse above freezing-point. From EP 0 089 246 a ground based structure mentioned by way of introduction is known which consists of an above-ground portion comprising light-transmissive re- gions and an enterable pit portion which is adapted to extend below ground and which is covered by the above-ground portion. This structure provides sufficient height for a person to stand in the pit without bending. Moreover it is foreseen that the pit portion may incorporate heat-retentive salts for improved heat-storage. This structure would only have a limited use during wintertime as it is not frost-proof. Summary of the Invention In order to maintain the temperature at acceptable levels in summertime with strong sun it is necessary to provide for a sun screening in the form of sun curtains or the like, and also ventilation system will be required. Such systems will involve costs and it is necessary to control such systems carefully in accordance with the weather conditions. It is the object of the present invention to provide a ground structure as mentioned above and in which the above drawbacks are overcome and which is simple to erect and to use and which makes it possible to prolong the growth season and which may be used to store frost-sensitive items during wintertime. According to the present invention this object is obtained with a structure being characterised in that the light-transmissive regions of the above-ground structure comprise heat insulating glass panels which are mounted in heat insulating frame elements, that the pit portion comprises substantially vertical heat insulating wall elements being provided with a height such that they extend at least to a frost-free level below the ground surface, that the different elements are connected by connectors, that the door is made of heat insulating materials and that the floor of the pit is uninsulated and is arranged at said level. Hereby it is possible to make use of the earth temperature. Accordingly the inner of the structure could be kept frost-proof during wintertime as the floor will function as a heating source which has a temperature being approximately at a constant level of 8°C. Thus it is possible to store frost-sensitive items in the structures even during wintertime with freezing temperatures outside and with very few or no sunny hours. Especially, if the structure according to the present invention comprises growth tables having their surfaces at a level approximately at the level of the ground surface, it is possible to use the surface of the table to store plants which should be kept at a frost- free temperature, but also should have sunlight during the winter, as for example patio plants. Moreover the volume underneath the tables as storing space during wintertime, especially for light-sensitive vegetables such as potatoes. Moreover the growth season may be prolonged without the need for relying on the uncertain supply of energy originating from the sun. There will be a constant supply of energy from the earth. Accordingly, it is possible to establish a sufficient high tem- perature level for growing in the early spring and to maintain such level till late autumn. Due to the use of connectors between the different elements the structure is easy to erect and may for example be supplied as a do-it-yourself product which may be assembled without the need of specific skills and without the need of specific tools. This is especially the case if the above ground-structure comprises frame elements which are vertical providing walls and frame elements which are inclined providing a roof, said frame elements being connected by hinge elements, preferably in the form of tube sections secured to said frame elements and being interconnected by a rod member. Preferably, the vertical and horizontal spaces between the elements are filled with insulating strips and being covered by a cover plate. In case the structure has a polygonal base, preferably a equilateral polygonal base and all elements of one type are identical, the structure will be especially easy to assemble without the risk of erroneous connection of any element of the structure. It is possible to ensure that the walls of the pit extend to a frost-free level in different ways. According to a first embodiment the walls of the pit extend approximately 1 meter below ground surface. In this embodiment a hole is made with a depth of one meter. The insulated wall elements are arranged in the hole and the above-ground structure is arranged upon and covers the pit portion. In case it is intended to dig a hole having less depth, it is possible to arrange the earth being dug up in a bank of earth surrounding the structure. In this case, the walls of the pit should extend approximately 1 meter below the surface of said bank of earth. Accordingly, it is possible to dig a less deep hole and to avoid any problem with earth to be removed. Alternatively, the walls of the pit portion could comprise a substantially horizontal insulating annular element, preferably insulating mats, surrounding said vertical wall elements. The vertical distance from the outer circumference of the annular element to the vertical walls makes it possible to have less depth in the pit and still maintain the floor at a frost-free level. The insulating mat could be of the type commonly used as insulting mat for houses. The structure is primarily intended to be a free-standing greenhouse, however, it might also be arranged as an extension to a house, for example as a winter garden. In such embodiment it is advantageous to have the level in the winter garden approximately at the same level as the floor in the house. Accordingly, a floorage could be provided substantially at the ground level. Thereby a room is provided below said floorage and above the floor of the pit. Such room could contain a heat storage system and/or a heat exchanger or could simply be used for storage purpose. The wall elements for the pit could be a sandwich construction having cover plates of steel plastic or other water repellent material between which insulating material is arranged, for example mineral wool, polystyrene or polyurethane. Description of the Drawing The structure according to the invention will be described in further detail with reference to the accompanying schematic drawing, in which Fig. 1 is a perspective view, with parts broken away, of a greenhouse according to the present invention, Fig. 2-4 are cross sections through further embodiments for greenhouses according to the present invention, Figs.5-6 are cross sections through the greenhouse of fig. 3, Figs.7-8 are cross sections through a winter garden illustrating a day and a night situation, Fig. 9 are illustrations of four different polygonal bases for a greenhouses according to the present invention, Figs. 10-12 fragmentary cross sections through different connections between different elements in a greenhouse according to the present invention, and Fig. 13 a fragmentary cross section through a ventilation valve in a greenhouse ac- cording to the present invention. Description of Embodiments In the drawing 1 denotes a greenhouse and 2 denotes a winter garden according to the present invention. In the different Figures of the drawing, identical items are denoted with identical reference numerals and there will not be given a detailed description in connection with each figure. The greenhouses of Figs. 1-6 and the winter garden 2 of Figs. 7-8 consist of an above- ground portion 3 and a pit portion 4 extending below ground surface 5. Figs. 1,5 and 6 disclose a heat insulating door 6 which is partly arranged in the enclosure for the pit portion and partly in the enclosure for the above-ground portion and which is used for entering the pit. The above-ground portion 3 comprises heat insulating glass panels 7, preferably sealed double glass being mounted in frame elements 8, which are also made of a heat insulating material, for example plastic or wood. There are vertical glass elements 8 forming the side walls of the greenhouse and inclined tapering glass elements 8' forming the roof. The pit portion 4 comprises heat insulating wall elements 9 that are arranged substantially vertical and extending to a frost-free level 10 below the ground surface 5. The glass elements 8 are identical and the wall elements 9 are identical. The elements are interconnected by connectors to be explained later. The floor 11 of the pit is arranged at the level 10 thereby ensuring that the floor 11 in winter times functions as a heating source and that during summer times it functions as a chilling source. The greenhouse 1 comprises a growth table 12 having its surface 13 approximately at the level of the ground surface in order to have sun light to plants on the table surface. This leaves a volume 14 below the table surface 13 to be used for storing frost- sensitive items during wintertime as the greenhouse will be kept frost-proof due to earth temperature. The table 12 may be a central table or an annular table 12' as illustrated in Figs. 5 and 6. The greenhouse 1 comprises a ventilation valve 15 (see Fig. 13) consisting of an insulated valve body 16 arranged in a valve housing 17 which constitutes a symmetrical frame element for supporting the glass elements 8' in the roof. The valve may be operated manually or automatically. Fig. 2 discloses a greenhouse 1 having wall elements extending to a level 10 approximately 1 meter below a ground surface 5 being a normal ground surface. In Fig. 3 a raised ground surface 5 has been established as a bank 18 of earth surrounding the greenhouse. The bank 18 is formed by earth from the hole to the pit. Accordingly, there will only be a need for a hole of a rather small depth in order to provide for the frost- free floor 11. Thus the level 10 will be less than 1 meter below the normal ground level. In Fig. 4 the pit portion comprises horizontally insulating annular elements 19. This ensures that the floor 11 will be frost-free even if it is arranged at a level 10 which is shortly below the normal ground surface 5. Figs. 5 and 6 illustrate a 12-edged greenhouse 1 of the type illustrated in Fig. 3. It occurs that entrance is established through a stair 20 leading down to the level 10 of the floor 1 1. Arrow 21 indicates that earth heat is supplied from the uninsulated floor 1 1. Arrow 22 indicates that heat will be reflected from the insulated walls in the pit. Ar- rows 23 and 24 indicate that some of the heat 25 from the inner of the greenhouse is reflected and some heat goes through the glass panels 7. Figs. 7 and 8 illustrate a winter garden 2 in day time and night time, respectively. The sun light 26 causes heat 27 to be transferred through a floorage 28 into a room 29 arranged below the floorage and above the floor 11 of the pit. Said room 29 contains water to accumulate heat to be distributed 30 to the inner 31 of the winter garden during night time. The winter garden 2 may have a control system 32 to regulate the operation of pump, valves and other equipment which may be associated with the heat transfer system. The room 29 may also be an empty room for storage purpose. Fig. 9 illustrates different polygonal shapes for the base 33 of a greenhouse 1. As en example the length of the sides 34 may be within 0.8 and 1.2 m. This will make it easy to erect the greenhouse as a do-it-yourself job. However, other sizes may also be used. Figs. 10 -12 illustrate connectors 35 between the glass elements 8 and wall elements 9 of the greenhouse 1. Fig. 10 illustrate a connection between two glass elements 8. The frame comprises a profile 36 onto which tube lengths 37 are attached in such a way that tube lengths from two adjacent elements 8 will be placed in line whereby a locking rod 38 is used to interconnect the two elements. The space 39 between two frames 8 is filled with insulating strips 40 and is covered by cover plates 41. In Fig. 11 a corresponding connector 35 is used between two wall elements 9 being provided as sandwich elements having water repellent cover plates 42 and an inner insulating 43. The plates may be reflecting heat waves in order to enhance the insulation properties. Fig. 12 illustrates a connector 35' between a glass element 8 in a vertical wall and a glass element 8' in an inclined roof for the greenhouse. In this connection a hook- formed member 44 on the inclined glass element 8' is in engagement with an angular profile 45 on the vertical glass element 8. Alternatively, a connector 35 could also be used for interconnecting these elements 8,8'.

Claims: CLAIMS 1. A ground based structure consisting of an above-ground portion comprising light- transmissive regions and an enterable pit portion which is adapted to extend below ground and which is covered by the above-ground portion, said structure comprises a door in the enclosure, characterised in that the light-transmissive regions of the above ground-structure comprise heat insulating glass panels which are mounted in heat insulating frame elements, that the pit portion comprises substantially vertical heat insulating wall elements being provided with a height such that they extend at least to a frost-free level below the ground surface, that the different elements are connected by connectors, that the door is made of heat insulating materials and that the floor of the pit is uninsulated and is arranged at said level. 2. A structure according to claim 1, characterised in that the walls of the pit extend approximately 1 meter below ground surface. 3. A structure according to claim 1, characterised in that the walls of the pit portion further comprises a substantially horizontal insulating annular element, preferably insulating mats, surrounding said vertical wall elements. 4. A structure according to claim 1, characterised in that the structure is surrounded by a bank of earth and that the walls of the pit extend approximately 1 meter below the surface of said bank of earth. 5. A structure according to any of the preceding claims, characterised in that the above ground-structure comprises frame elements that are vertical providing walls and frame elements that are inclined providing a roof, said frame elements being connected by hinge elements, preferably in the form of tube sections secured to said frame elements and being interconnected by a rod member. 6. A structure according to any of the preceding claims, characterised in that the vertical and horizontal spaces between the elements are filled with insulating strips and are covered by a cover plate. 7. A structure according to any of the preceding claims, characterised in that the structure has a polygonal base, preferably a equilateral polygonal base. 8. A structure according to any of the preceding claims, characterised in that all elements of one type are identical. 9. A structure according to any of the preceding claims, characterised in that it comprises growth tables having their surfaces at a level approximately in the level of the ground surface. 10. A structure according to any of the preceding claims, characterised in that a floorage is provided substantially at the ground level, and that a room is provided below said floorage and above the floor of the pit.

Inventors: JENSEN THONNI, JENSEN, THONNI
Applicants: JENSEN THONNI, JENSEN, THONNI
Application year: 1999
Main classification: A01G9
IPC codes: A01G9