Abstract: The present invention provides a door system for a temporary, movable structure having a plurality of spaced apart frame members and a membrane stretched between adjacent frame members. The door system has multiple modules movable between open and closed positions. Each module has its own membrane, separate from the membranes of the structure, which is stretched taught over the surface of the module. In the open position, the modules do not obstruct the opening in the structure, and the membranes of the modules and the structure do not go slack. The membranes of both the structure and the modules are always under tension, thus being less susceptible to damage.

Abstract: The present invention provides a door system for a temporary, movable structure having a plurality of spaced apart frame members and a membrane stretched between adjacent frame members. The door system has multiple modules movable between open and closed positions. Each module has its own membrane, separate from the membranes of the structure, which is stretched taught over the surface of the module. In the open position, the modules do not obstruct the opening in the structure, and the membranes of the modules and the structure do not go slack. The membranes of both the structure and the modules are always under tension, thus being less susceptible to damage.

Abstract: There is provided an opening assembly for an extended end of a stressed membrane structure having a fixed part, said opening assembly comprising: at least a part of said end separated from said fixed part and moveable relative to said fixed part; a pivot assembly for permitting movement of said at least a part of said extended end between an open and a closed position relative to said structure; a support frame for maintaining the integrity of said part in stressed membrane condition at all times during said movement and when in said open and closed position; rolling transport means for supporting said frame and said assembly during said movement.

Abstract: A door system for a stressed fabric structure comprising a stationary arched anchor beam, the ends of which are supported on the base at one end of the structure, a plurality of movable arched beams of similar size and shape on the side of the anchor beam away from the structure and having supporting ends pivotally secured at the ends of the anchor beam, the movable beams to pivot along the same radial path about common pivot points at the ends, between raised, open position adjacent to the anchor beam and closed position in which the beams are spaced progressively from the anchor beam to the structure base. Fabric panels are secured to and extend between each of the anchor beam and its adjacent movable beam and adjacent pairs of movable beams so as to be under similar tension when the beams are in closed position.

Abstract: A method and structure for environmental control of plant growth in greenhouse conditions. The structure comprises a translucent stressed fabric shell on a base, the shell and base enclosing a predetermined space within which to grow horticultural plants, the shell and base sealing the environment within the space against external environmental air conditions. Temperature, humidity carbon dioxide are monitored and controlled within the space by a microprocessor programmed to provide optimum temperature, humidity and carbon dioxide conditions within the space. The structure and method are ideally suited to nutrient film techniques, wherein nutrient being fed to the plant roots is monitored and controlled by the microprocessor.

Abstract: A method and structure for improved natural lighting for plant growth, particularly for mass production of horticultural crops in environmental conditions where normal solar lighting may be inadequate for horticultural production within a greenhouse structure. The structure comprises a translucent shell on a base, the shell and base enclosing a predetermined space within which plants are to be grown. A reflective surface is situated adjacent major portions of the base, outside the shell and preferably below the level of the base, to reflect solar radiation into the space through the shell. The structure may also be provided with other features tending to increase the exposure of solar radiation to the plants.

Abstract: There is provided a new and useful propagation assembly consisting of at least one propagation tray comprising a lower plant support section including at least one longitudinal channel for nutrient solution flow; and an upper space section having a series of spaced openings positioned longitudinally above each at least channel.

Abstract: A method and system for purification of water for plants in a greenhouse structure. The method comprises condensing water vapor in the air in the greenhouse on the greenhouse walls, collecting the condensed water at the base of the walls and passing the collected water to the roots of the plants. To accomplish this method the system comprises a water supply for water to be purified, a mist generator for the air in the greenhouse from the water supply means and a heat source to generate heat in the greenhouse for vaporization of the mist. Cooling means are provided for the walls to cause water vapor in the air in the greenhouse to condense on the interior surfaces of the walls. The condensed water is collected and carried by conduit means to a nutrient solution reservoir for admixture with nutrient to be supplied to the roots of the plant.

Abstract: There is provided a new and useful support system for growing plants comprising a supporting framework; at least one elongated support tray on the framework, the support tray having feeding and catchment ends and comprising a channel shape of substantially horizontal transverse profile and with upstanding elongate sides; and having at least one longitudinal depression extending the length of the bottom of the tray; a catchment tray supported to extend below the catchment end of at least one support tray, the catchment tray including an outlet; and wherein at least one support tray is sloped downwardly from the feed end to the catchment end.

Abstract: A heating system for warming the space within a greenhouse or similar structure. The heating system comprises a heater means having a heating chamber for air, mounted in a plenum chamber. The plenum chamber is located below the base of the structure and is in fluid communication with the space to be heated. Means are provided to draw air from the plenum chamber into the heating chamber. Air heated in the heating chamber is passed through conduit means to the space. The heating system according to the present invention provides efficient space utilization and improved air circulation over conventional heating systems for greenhouse structures.

Abstract: A greenhouse structure for growing plants using nutrient feed solution. The structure comprises a plurality of elongated greenhouse production areas. Each area has a shell and a base enclosing a predetermined space within which plants are grown. The areas radially extend outwardly from a central supply area in which nutrient feed solution is supplied to the production areas is kept. The base of each of the production areas are sloped upwardly in the direction away from the central supply area so that excess nutrient feed solution passing to the production areas will return by gravity flow to the central supply area. The structure further provides pump and conduit means to supply nutrient feed solution from the central supply area to the production areas. The conduit means are sloped to return by gravity flow excess nutrient from the production areas to the central supply area.

Abstract: A cooling system for a greenhouse comprising a plurality of water pipes mounted over the exterior surface of the structure to carry water from a source, with water outlets in the pipes to enable water to spray over the exterior surface, and controls associated with the pipes to control and regulate the amount of water and duration of spray received by the exterior surface of the structure.

Abstract: There is provided a new and useful aeration assembly for a nutrient feed solution for a nutrient film propagation system for plants comprising a short tubular member having a pair of circular holes extending radially through the wall of the member: and a pair of feeder tubes extending through the openings and positioned to discharge solution generally along the inside wall of the member and respectively in opposite directions.

Abstract: A stressed membrane space enclosure having a supporting frame comprising a plurality of spaced individually separable arch-like members with a strip of fabric stretched between each adjacent pair of arches and by means of which separable arches the fabric is tensioned. The feet of the arches rest on load-bearing pads that are individually shiftable as during the frame spreading for the purpose of tensioning the fabric and that each finds its own proper resting place when all the stresses on the structure have been normalized and is then secured against unauthorized movement by ground anchors, thereby achieving the greatest possible strength and stability of the supporting frame. The fabric is applied in reinforced elongated strips one such strip between each adjacent pair of spreadable frame members and stretched to a predetermined tension to bear maximum loads of wind and snow.

Abstract: A building structure employing an easily erected and dismantled frame with a stressed membrane cover wherein the framework comprises a plurality of transversely disposed arch-like members spaced longitudinally of the building with a strip of fabric stretched between each adjacent pair of arches, each of said frame members being of an extruded aluminum alloy I beam having a web with an exterior crosshead and an interior crosshead. The I beam's exterior crosshead has a fabric capturing device interacting therewith to secure the edge of the fabric strip against escape and provide a weatherproof joint between the fabric and the beam. Extendable spreader beams are mounted on the upper side of the interior crosshead, they and any appurtenances other than the fabric capturing device already mentioned connected to or slung from the arch frame beams being positioned below the fabric membrane where they are protected from the weather and readily accessible from within the structure.