An optical element is provided which comprises a plurality of fluorophores disposed in a medium. The fluorophores have a quantum yield greater than 50% and an absorption spectrum with a maximum intensity at wavelengths less than 400 nm, and emit a spectrum of light having a maximum intensity at wavelengths within the range of 400 nm to 1200 nm. The optical element is at least partially transparent over the visible region of the spectrum. The optical element is especially useful as a window or other optical component of a greenhouse structure.

An atmospheric water generation system absorbs water from an atmospheric air stream into a desiccant flowing along a flow path of a closed desiccant circulation loop. To ensure that the desiccant remains within the closed desiccant circulation loop, the atmospheric water generation system encompasses a membrane-based water extraction device that the desiccant flows through. The desiccant flows through the membrane-based water extraction device on a first side of a membrane, and the membrane separates the desiccant from a water-collection flow. Water absorbed into the desiccant passes from the desiccant, through the porous membrane, and into the water-collection flow, at least in part due to differences in temperature and/or pressure characteristics of the water flow and the desiccant flow. Water collected within the water-collection flow is directed to a storage tank for usage.

A structure for growing plants comprising a main support, vertical supports along the perimeter of the foundation, a perimeter frame connected to the vertical supports, cables connected to the main support, vertical supports and perimeter frame, and an inner and outer shell formed from transmissive panels supported by the cables.

Greenhouse comprised of a ridge beam extending some distance above its roof defining two elongated side zones at either side of the ridge beam. The ridge beam is comprised of one or more elongated hollow spaces and with one or more closable openings in both side zones. The openings fluidly connect the exterior of the greenhouse with its interior and may be closed at one side and opened at its other side depending on the direction of the wind.

A greenhouse is disclosed having a light-transmitting barrier and a floor surface. The barrier and floor surface are connected to define an enclosure within the greenhouse for plant cultivation. The barrier includes an inner layer delimiting the enclosure and an outer layer. The inner and outer layers are impermeable to air to substantially prevent air from entering the enclosure through the inner layer. The outer layer is spaced apart above the inner layer to define an air passage therebetween. The air passage is in fluid communication with at least one air inlet in a bottom portion of the outer layer and with an air outlet in a top portion of the outer layer. Air within the air passage flows passively from the at least one air inlet to the air outlet upon being heated.

A process for conditioning the air within a greenhouse comprising transparent walls and a structure including one or more ridge beams as part of a roof of the greenhouse. The process comprises maintaining a pressure difference between an average pressure within the greenhouse and a pressure exterior to the greenhouse, taking in air from the exterior of the greenhouse and mixing this air with air taken from the interior of the greenhouse to obtain conditioned air, distributing the conditioned air via a forced flow to the interior of the greenhouse, and discharging a volume of air from the interior of the greenhouse via openings present in the one or more ridge beams such to maintain the pressure difference.

The present disclosure provides a multilayered polymeric film for covering an agricultural structure or greenhouse, wherein the film contains adjacent layers that are capable of delamination from one another.

Objects of the present invention are to provide a film for an agricultural greenhouse that can maintain a CO.sub.2 concentration necessary for the photosynthesis of plants even when ventilation is not performed and to provide an agricultural greenhouse using the film. The film for an agricultural greenhouse of the present invention is a cellulose film which contains a cellulose acylate resin and has an equilibrium moisture content of 4% to 8% at a temperature of 25° C., a relative humidity of 80% and a thickness of 60 to 200 μm.

A growing room for providing a controlled growing environment comprises a thermally insulated, light-transmissive inner enclosure (8) for containing the controlled growing environment (4). The inner enclosure 8 encloses, in use, a controlled atmosphere for the controlled growing environment (4). A light-transmissive outer enclosure 6 surrounds the inner enclosure (8) and is arranged to protect the inner enclosure (8) from the external environment, in use. A ventilated cavity (10) is defined between the out er enclosure (6) and inner enclosure (8). The outer enclosure (6) has at least one lower ventilation opening (11) and at least one upper ventilation opening (12) for allowing controlled ventilation of the ventilated cavity (10). A radiation control layer is located in the ventilated cavity (10) between the outer enclosure (6) and the inner enclosure (8) and is arranged to provide controlled absorption of incident solar radiation, whereby to control the level of solar radiation within the controlled growing environment (4).

A structure for growing plants comprising a main support, vertical supports along the perimeter of the foundation, a perimeter frame connected to the vertical supports, cables connected to the main support, vertical supports and perimeter frame, and an inner and outer shell formed from transmissive panels supported by the cables.