Greenhouse and method for operating a greenhouse

Abstract

The present invention relates to a greenhouse (10) comprising upright walls (1), gable walls (2) and at least one at least partially transparent roof surface (3), wherein the roof surface (3) or a roof sheet extending parallel thereto is formed from a roof covering causing diffuse light scattering. The interior of the greenhouse (10) can be subdivided into at least three climate zones (11, 13, 15) by at least two screen units (12, 14) that cover the ground plan and each have at least one screen, which climate zones are stacked vertically one above the other and are formed when the screen units (12, 14) are closed, wherein the screens of the screen units (12, 14) can be retracted and extended separately from one another such that a lower climate zone (11) and a central climate zone (13) can be separated from one another by a lower screen unit (12), and a central climate zone (13) and an upper climate zone (15) can be separated from one another by an upper screen unit (14).

Description

[0001] Greenhouse and method for operating a greenhouse

[0002] The invention relates to a greenhouse having the features of the preamble of claim 1 and a method for operating such a greenhouse.

[0003] When operating a greenhouse for growing plants, it is necessary to be able to influence the level of sunlight. Sunlight contains light with a wavelength necessary for plant photosynthesis. The light that plants need for photosynthesis is called photosynthetically active radiation, or PAR radiation. The wavelength of this light is between 400 and 700 nm.

[0004] Secondly, solar radiation contains infrared radiation, which can be used to increase the temperature in the greenhouse to promote plant growth. On the other hand, excessive solar radiation leads to excessive temperature increases inside the greenhouse, which is either detrimental to plant growth or even damaging the plants. Therefore, it is common practice to install shading devices parallel to the roof. If these are mounted on the outside, they are exposed to the elements and thus subject to increased wear and tear.If they are installed inside, the photoactive wavelengths can be completely or partially blocked from affecting the plants, depending on the nature of the shading membrane. However, after penetrating the at least partially transparent roof membrane, the infrared radiation is at least partially absorbed by the shading membrane, thus further heating the air inside the greenhouse. Increasing the reflectivity of the shading membrane to limit the effect of infrared radiation also reduces the transmission of the photoactive light waves. However, these are needed to continue stimulating plant growth. Strong or even complete shading, unless only for a short time, is counterproductive.

[0005] The object of the present invention is therefore to improve a greenhouse of the type mentioned above in such a way that the proportion of PAR light with wavelengths required for photosynthesis and the internal temperature in the greenhouse, which is influenced by the incident infrared radiation, can be adjusted independently of each other.

[0006] This object is achieved by a greenhouse having the features of claim 1.

[0007] The invention proposes to create at least three climate zones in the interior of the greenhouse, arranged vertically one above the other. These zones exist only temporarily and can be dissolved again. Neighboring climate zones can also be combined into a single climate zone.

[0008] According to the invention, these climate zones can be set up and dismantled using extendable screen units inside the greenhouse. The screen units are made of rollable or foldable semi-finished products, such as textiles or films, or combinations thereof. They cover the floor plan of the greenhouse and create separate air layers. Covering the floor plan does not necessarily result in complete airtightness when the screen is extended, but edge airflows past the extended screen should be severely limited to prevent excessively rapid temperature exchange between climate zones.

[0009] The screen units can be raised in particular by a motor drive.

[0010] The screen units can also be designed as double screen units, i.e., two flat structures arranged parallel to each other at a distance of 5 cm to 50 cm, in particular at a distance of 10 cm to 30 cm. Preferably, they are arranged or motor-driven in such a way that they move in opposite directions within the pair.

[0011] A "shade unit" within the meaning of the present invention covers the entire open floor plan in the plane in which the shade unit is positioned and can also be formed by several partial shades arranged in one plane and jointly covering the floor plan. A division into adjacent partial shades is particularly useful for long greenhouses. In these cases, the so-called trusses, which act as crossbeams to ensure the structural stability of the greenhouse, are preferably used to subdivide the greenhouse into several sections, with each section having at least one partial shade or partial double shade.

[0012] The distances between the umbrella units, which separate one climate zone from the vertically adjacent climate zone and thus also determine the heights of the climate zones, are significantly larger than previously specified with regard to the distances for double umbrella units.

[0013] The arrangement of the shade units within the greenhouse can be horizontal, parallel to the roof, or trapezoidal. The lower shade unit, between the two lower climate zones, is generally arranged horizontally, as this requires the least structural effort at this point. Existing components such as lattice trusses can be used to brace and guide the shade units. The upper shade unit can be parallel to the roof, i.e. triangular in side view, or trapezoidal, provided components can be used for attachment. However, there must be sufficient clearance from the roof skin to create an uppermost climate zone with sufficient volume. As a rule, a horizontal orientation is therefore also preferred for the upper shade unit.

[0014] A lowest climate zone extends from the ground to a height of at least 2 m, specifically one-third of the total height inside the greenhouse measured to the ridge. This minimum height is necessary to ensure easy access to the plants stored on the ground or on racks in this zone.

[0015] A second climate zone and a third climate zone above it can divide the remaining height inside the greenhouse after subtracting the height of the lowest climate zone. This can be done either by choosing an equidistant division, where the height of the two upper climate zones is approximately the same, or by adjusting the volume so that the volume in the upper roof zone is approximately equal to the volume in the middle zone. This can be particularly advantageous for greenhouses with gable roofs.

[0016] For example, the climate zones are designated as follows:

[0017] - Climate zone I (cultivation): below a closed reflective screen of a lower screen unit, the so-called energy screen; this is where the plants to be grown are arranged.

[0018] - Climate zone II (middle): between a closed upper screen and the closed reflective energy screen below;

[0019] - Climate zone III (roof): between the outer roof skin and the closed upper umbrella.

[0020] To separate the lowest climate zone I, hereinafter referred to as the "growth zone," from the middle climate zone II above it, which serves as a dehumidification zone and heat buffer, a heat-reflecting screen unit can be installed. The screen unit, or its individual components, is formed, in particular, by cut sheets of foil, particularly ETFE foil, which reflects approximately 50% of the incident infrared radiation, preferably on both sides.

[0021] A double-sided coating ensures that heat radiated upwards from the growth zone is reflected when a shade of the lower shade unit is extended, while simultaneously reflecting infrared radiation entering from outside. The reflection is partial in each case, so the growth zone is not completely shaded when the shade is extended.

[0022] The separation between the middle climate zone II and the upper climate zone III is formed by an upper screen with high light transmission. This screen unit, or its individual components, is also formed primarily from cut foil, particularly ETFE foil, but without an IR-reflective coating.

[0023] The two independently extendable shade units allow for the creation and dissolution of zones. Unlike conventional greenhouses with overhead shading, particularly parallel to the roof, the invention allows for the regulation of humidity in the multi-zone greenhouse in addition to PAR light, UV light, and the interior temperature.

[0024] Humidity-laden air from the growth zone (climate zone I) can be transferred through the lower screen unit into the middle climate zone II by fully or partially opening the screen unit. Since the extended, i.e. closed, screen of the lower screen unit forms a barrier between the air layers in the two adjacent climate zones, this prevents warm, moisture-laden air from quickly rising to the top of the greenhouse and being replaced by cold air, which reaches the plants directly through the conventional roof ventilation flaps in the ridge area. Rather, the moisture transport in the greenhouse according to the invention takes place from one climate zone to the next.

[0025] The screen unit above the growth zone is fully or partially raised for dehumidification. This allows the moist air to escape into the next higher, intermediate climate zone II, while the slightly cooler, but drier air mass stored in intermediate climate zone II moves downwards. This exchanges the air masses of climate zones I and II. Because there is no direct air exchange with the outside air, but rather buffered and preheated air in the intermediate climate zone moves downwards, the humidity in the growth zone is quickly reduced, reducing the risk of fungal growth without cooling the plants too drastically or too quickly.

[0026] The upper canopy between climate zones II and III forms an upper boundary of the air layer of the middle climate zone II, but is not a condensation surface, since it is separated from the roof skin by the air layer of the uppermost climate zone III and is heated by this air layer.

[0027] After the lower screen unit has been closed, the upper screen unit is opened. This allows the moist air mass temporarily stored in the middle climate zone II to escape into the uppermost climate zone III and from there through the ventilation flaps commonly found in the roof area of ​​greenhouses.

[0028] It is also possible to use a screen unit designed as a double screen as a sluice by only partially opening the counter-rotating screens, thus slowing the air exchange between the layers above them. Rising air enters the screen unit through an opening in the lower screen and initially flows through a channel formed between the upper and lower individual screens until it escapes through an opening in the upper screen into the climate zone above. The air exchange from top to bottom through the sluice takes place in the opposite direction. The duration of the air exchange can be regulated via the opening area in the sluice formed in this way.

[0029] When warm, humid air from the uppermost climate zone is released to the outside, drier, cooler air can flow in. After the airlocks are closed, this air mass is trapped between the open screens, or possibly within the screen unit in a double screen, forming a heat sink without the cold air coming into direct contact with the plants in the soil area of ​​the lowest zone. The trapped air mass warms up via the two adjacent zones.

[0030] The two shades allow for various settings to accommodate different constellations of light intensity and outside temperature. Here are some examples:

[0031] When outside temperatures are moderate and the sky is sunny or partly cloudy, both shade units are opened to allow the full amount of light to be available to the plants in the lowest climate zone for photosynthesis. The infrared components of the light result in a moderate heating of the interior, which is roughly balanced by the simultaneous cooling effect of the outside air temperature. This creates favorable conditions for plant growth.

[0032] At higher outside temperatures, especially during the summer months, the upper shade unit is closed first to prevent the interior from overheating. The lower shade unit is opened, so that the air is heated primarily by infrared radiation in the two upper climate zones II and III, which in this case are not separated from each other.

[0033] In the winter months, when outside temperatures are very low, both screen units are closed. A partially heat-reflecting energy screen as part of the lower screen unit keeps the heat in the lower climate zones and reflects a portion of the infrared radiation entering from outside into the middle climate zone, which leads to additional warming of the middle climate zones. The heated air within it is kept in the middle zone by the so-called upper screen, which has a high light transmittance of more than 90%, in particular 94%. Due to the high light transmittance, a high energy input through the screen into the lower climate zones is possible. Furthermore, it serves as an air mass boundary for the air masses below, which may be higher.moist air masses without it representing a condensation surface, since it can be freely stretched out in the interior of the greenhouse and, due to the large distance from the cold roof skin and a correspondingly large insulating layer of air in the uppermost climate zone, in many scenarios it remains so warm that no condensation occurs, but the moist air can be discharged through locks from the middle climate zone.

[0034] The upper screen can be installed horizontally, parallel to the roof, or trapezoidally. Angled mounting can be advantageous, for example, to reduce reflections of incoming sunlight or to adapt the shape of the climate zone to the roof shape. Furthermore, the volume of the climate zone below is formed into a wedge shape with a trapezoidal cross-section. With this shape, an elongated zone is created on one side, allowing the air from the climate zone below to be directed to this side, for example, to be discharged via flaps located there.

[0035] The uppermost zone, i.e., the roof zone above the closed upper canopy, can heat up the most. If heat is needed to regulate the temperature inside, for example, after sunset, both canopy units can be opened to allow the air masses to mix. The upper canopy therefore neither blocks the wavelengths of sunlight necessary for photosynthesis nor the infrared component, but rather serves the sole purpose of preventing the exchange of air masses between the two upper climate zones and / or the direct rise of warm air to the roof of the greenhouse.

[0036] The lower screen unit, which serves as a so-called energy screen and can separate the two lower climate zones, is made up of two layers of foil that can be extended in opposite directions. This achieves a reflection of approximately 40-60% of infrared radiation both inward and outward. This leads to greater energy savings for external heating in winter and a better climate in summer. The lower screen unit can also be installed horizontally or at an angle.

[0037] The air layer enclosed in a double-layer design provides additional thermal insulation for the lower climate zone, which serves as the growth zone. Each of the two layers of the lower shade unit causes a light reduction of less than 35%.

[0038] In addition, the diffuse roof covering allows the so-called lateral upright walls, which adjoin below the transparent roof surfaces, as well as the gable walls, to be designed preferably as non-transparent. The scattering provided by the diffuse roof covering makes it possible to avoid any light entering through the side walls and the gable. If the upright walls and gable walls are not already shaded due to the geographical location of the greenhouse and / or local conditions such as adjacent buildings, but can be exposed to strong sunlight, their non-transparent design becomes a necessary feature of the climate house according to the invention, as this is the only way to achieve targeted control of the light incidence via the two shade units. The diffuse roof covering is preferably formed by a diffuse plastic film made of ethylene tetrafluoroethylene (ETFE). This ensures a particularly even light distribution inside the greenhouse without casting shadows.The incidence of light into the growth zone is therefore largely independent of the direction of the sunlight and thus of the time of day and is still sufficient even when all films of the two shade units are closed.

[0039] The thickness of the ETFE film is selected based on the expected local loads. If high snow loads and / or hailstorms are expected, it can be 250 μm. Otherwise, a minimum thickness of 100 μm has proven sufficient.

[0040] Overall, the following advantages arise from a single-layer diffuse roof covering:

[0041] - High light transmittance of more than 90%,

[0042] - Greater light and energy input compared to other roof coverings.

[0043] - Minimal light absorption.

[0044] - IR blocking in the long-wave range possible through additional coating;

[0045] - Uniform light distribution across the entire cultivation area without shadows.

[0046] - Sustainability through long service life and 100% recyclability.

[0047] - UV resistance for 20 years or more.

[0048] - Possible anti-dew coating, resulting in higher light transmission in the event of condensation by forming a water film instead of individual drops; thus avoiding the magnifying glass effect of drops.

[0049] - Fire class B1 (flame-retardant, non-burning dripping) or better (for ETFE roof covering).

[0050] - High elongation at break;

[0051] - Good hail resistance with sufficient film thickness; - High tear resistance;

[0052] - Permanently self-cleaning due to low surface roughness (“lotus effect”).

[0053] The standing walls and / or the gable walls can be made, for example, in the form of sandwich panels with a thickness of at least 60 mm, for example 80 mm, which results in a thermal transmittance U = 0.288 W / (m2 K). A U-value of <0.3 W / (m 2 K). This makes it possible, in particular, to eliminate the need for radiators for additional heating on the standing walls and the gable. They are also characterized by their windproofness. This design eliminates the cold bridges typically found on transparent standing walls and gable walls.

[0054] Furthermore, the standing walls and / or the gable walls are preferably made of non-transparent materials in order to be able to control the incidence of light solely via the roof skin and the screen units below.

[0055] Due to the diffuse distribution of the incoming sunlight across the roof, it is also possible to use sections of the side and gable walls for the positioning of photovoltaic modules and thus generate additional energy for the greenhouse from sunlight.

[0056] Further energy savings are possible through optimized control technology in the three climate zones. For this purpose, measuring sensors are provided in each climate zone as well as outdoors, in particular the following sensors:

[0057] - Sensors for wind, rain, temperature and light outdoors, especially mounted on a weather mast and

[0058] - indoors in climate zones I and / or II and / or III for temperature, light and humidity, in particular above and below the respective shade unit.

[0059] With a greenhouse according to the invention, the following advantages are achieved when used for horticulture:

[0060] - Low external energy requirements. - Higher light input for hardened and compact plants.

[0061] - Energy savings of 60% and more and minimization of operating costs compared to glass greenhouses with a screen.

[0062] - Reduction in cultivation time due to increased photosynthesis and the resulting possibility of growing more crops per year than with conventionally designed greenhouses;

[0063] - Higher energy utilization from natural light due to higher energy input and use of the entire light spectrum;

[0064] - Lower room temperature for plant hardening through increased light and increased photosynthesis. The lower room temperature actually promotes growth, as leaf temperatures of 25°C and above, at which hardly any growth occurs, are avoided.

[0065] - Lower hysteresis, i.e. less pronounced temperature fluctuations over the course of the day and year;

[0066] - No or little need for the use of growth-inhibiting sprays;

[0067] - Better controllable humidity balance: Humidity can be dissipated via the middle climate zone, and cold air does not reach the plants directly. Moisture transport occurs, for example, from climate zone I to climate zone II, then from climate zone II to climate zone III, and finally from climate zone III to the outside via the existing roof ventilation.

[0068] - Overall, a significant reduction in CO2 emissions for greenhouse operation is achieved.

[0069] When operating the greenhouse according to the invention, the adjustable parts, i.e. the screens of the screen units and the roof ventilators, can be combined as required, particularly depending on the outside temperature and daylight, in order to create and dissolve climate zones within the greenhouse that protect the plants placed therein from excessively high or too low temperatures and at the same time allow sufficient light with a wavelength relevant for plant growth to reach the plants. The preferred heights and volume ratios of the climate zones as well as the design of the screens are shown below as examples:

[0070] To dehumidify the lower climate zone (11), a procedure can be carried out in which the following steps are carried out one after the other:

[0071] - at least one screen of the upper screen unit (14) is closed;

[0072] - the lower screen unit (12) is opened;

[0073] - a period of air exchange is waited for;

[0074] - at least one screen of the lower screen unit (12) is closed;

[0075] - the upper screen unit (14) is opened;

[0076] - at least one roof ventilator (5) is opened;

[0077] - at least one screen of the upper screen unit (14) is closed; and

[0078] - the roof ventilator (5) is closed.

[0079] Put simply, this process forces the moist, heated air upwards in layers before it can escape to the outside through roof vents. This simultaneously shields the growth zone with the crops, preventing cold air flowing in from outside from seeping through to the bottom during air exchange. The fresh air is first trapped and preheated in the upper climate zones before the lower screen unit is opened again to allow air exchange down to the lowest climate zone. The invention is explained in more detail below with reference to the drawings. The figures show in detail:

[0080] Fig. 1 shows a greenhouse constructed according to the invention in a schematic, perspective view and

[0081] Fig. 2 a possible wall structure of the greenhouse in a schematic, perspective view;

[0082] Fig.3 a tabular overview of control specifications for a method for operating the greenhouse;

[0083] Fig. 4 to 6 the greenhouse in different operating states, each in perspective view.

[0084] Figure 1 shows a perspective view of a greenhouse formed from upright walls 2 and gable walls 1, as well as a gable roof with two roof surfaces 3. The height of the upright walls 2 is at least as great as the ridge height of the triangular gable on the gable walls 1. This creates a large volume of space below the gable roof, which can be divided vertically into three climate zones 11, 13, 15, with the subdivision being achieved by a lower screen unit 12 and an upper screen unit 14.

[0085] Both shade units 12, 14 are each designed as double shades, each with two opposing shades. These can be extended individually to form climate zones 11, 13, 15 and can be gathered to the side or wound up on a shaft to eliminate the separation of the climate zones 11, 13, 15. Drive motors 9 of the shades in the shade units 12, 14 are connected to a control unit 7 via data lines 6, which can also be wireless. Sensor units 8 for recording the temperature and light intensity and, if necessary, also for measuring the humidity in the greenhouse and / or outside the greenhouse 10 are also connected to the control unit 7. In the lower climate zone 11, the crop plants to be grown are placed on the floor 4 or on racks erected thereon. For ergonomic work in climate zone 11, the clear height there is at least 2.50 m.The middle climate zone 13 is approximately the same height to allow for rapid air exchange between the zones. The uppermost climate zone below roof surface 3 can have a lower height, as it serves, on the one hand, to provide thermal insulation for the middle climate zone 13 upwards and, on the other hand, to direct air, after the upper screen is opened, to flaps 5 located in the area of ​​roof surfaces 3 or the ridge on the roof.

[0086] Figure 2 shows only the standing walls 2 and gable walls 1. These are made of non-transparent sandwich panels with high thermal insulation properties. The sandwich panels are supported by a steel girder framework 7. A band of externally mounted photovoltaic modules 9 runs beneath the base of the roof surfaces to generate additional electrical energy.

[0087] Figure 3 shows possible specifications for the control unit 7 in order to implement a method for operating the greenhouse 10:

[0088] The sensor units 8 first measure the illuminance in the greenhouse 10 in climate zone 11, and use this to establish criteria for distinguishing between day and night operation. The allocation is independent of the local time at the location of the greenhouse and of the human perception of brightness; it is solely dependent on whether the illuminance is still sufficient to enable relevant plant growth. This threshold is generally around 1000 lux. Furthermore, in many geographical locations, this threshold is higher than the illuminance at twilight, so that night operation is already established before sunset. This means that sunshades, for example, can be closed in good time for the purpose of thermal insulation. During night operation, the incidence of light through the diffuse roof covering therefore plays no role. The sunshade units 12, 14 are controlled solely for the purpose of insulation.On cold nights with outside temperatures of +10°C and below, the double screens in both screen units 12, 14 are completely closed, as shown in Figure 1. Due to the stacked climate zones 11, 13, and 15, which are also delimited to the outside by the insulated upright and gable walls, heat dissipation from the greenhouse 10 is significantly delayed. The heat stored during the day can be effectively retained.

[0089] However, at outside temperatures above 10°C, all umbrellas are opened, even at night. Climate zones 11, 13, and 15 are eliminated or combined into a single climate zone. This situation is illustrated in Fig. 4.

[0090] During daytime operation, the temperature in the growth zone in the greenhouse 10, the climate zone 11, in particular, must be regulated. As shown in Figure 3, at temperatures around freezing point only the screens of the upper screen unit 14 are closed. These are transparent and hardly reduce the diffuse light reaching the plants on the ground 4, but they do divide the greenhouse into a base climate zone, which includes the lower and middle climate zones 11, 13, and the upper climate zone 15. In the upper climate zone 15, the enclosed air can heat up to a temperature that is higher than the temperature in the base climate zone below. Since heat transfer from the colder to the warmer medium is not possible, the plants are protected from air that is too cold. At the same time, the heated air in the uppermost climate zone 15 remains trapped under the roof membrane due to its density. This prevents the plants from overheating.This operating situation is shown in Figure 4.

[0091] At temperatures of +10°C and above, there is no risk of plant damage. Therefore, all of the screens can be opened (see Figure 5). A gradual temperature equalization takes place at the various altitudes in greenhouse 10 corresponding to climate zones 11, 13, and 15. At temperatures above 20°C, the greenhouse must be adjusted so that the leaf temperature of the plants does not rise above 25°C. To do this, at an outside temperature of 30°C, one screen in each of the two screen units 12, 14 is initially closed; see Figure 6. At even higher temperatures, both screens on both screen units 12, 14 are closed; see Figure 1.

[0092] If a dynamic drop in the outside temperature is detected by the control unit starting from a high outside temperature of more than 20°C, for example towards the evening, and at the same time the interior temperature at certain altitudes of the greenhouse is higher than the outside temperature, not only can the screen positions be continuously adjusted according to the diagram in Figure 3, but the flaps 5 in the roof surfaces 3 can also be opened in order to release strongly heated air into the environment.

Claims

Patent claims:

1. Greenhouse (10), with standing walls (1), gable walls (2) and at least one at least partially transparent roof surface (3), wherein the roof surface (3) or a roof sheet extending parallel thereto is formed from a roof covering which causes diffuse light scattering; characterized in that the interior of the greenhouse (10) can be divided into at least three climate zones (11, 13, 15) by at least two screen units (12, 14) covering the floor plan, each having at least one screen, which are formed when the screen units (12, 14) are closed and are layered vertically one above the other, that the screens of the screen units (12, 14) can be extended and retracted separately from one another, that a lower climate zone (11) and a middle climate zone (13) can be separated from one another by a lower screen unit (12) and that a middle climate zone (13) and an upper climate zone (15) can be separated from one another by an upper screen unit (14).

2. Greenhouse (10) according to claim 1, characterized in that at least one screen unit (12, 14) is designed as a double screen.

3. Greenhouse (10) according to claim 2, characterized in that the double screen is designed with at least one pair of individual screens which can be moved in opposite directions to one another and which are arranged at a distance of 5 to 50 cm, in particular 10 cm to 30 cm, from one another.

4. Greenhouse (10) according to one of claims 1 to 3, characterized in that the screen units (12, 14) by which the climate zones are to be formed and / or separated from one another are arranged at a distance of 0.80 m to 3.00 m from one another.

5. Greenhouse (10) according to one of claims 1 to 4, characterized in that at least one screen in one of the screen units (12, 14), in particular a screen in the lower screen unit (12), is at least partially reflective for infrared radiation with a reflection factor of at least 40% and has a transmission factor for light rays with other wavelengths of at least 80%.

6. Greenhouse (10) according to one of the preceding claims, characterized in that the diffuse roof covering is formed from an ETFE plastic film.

7. Greenhouse (10) according to one of the preceding claims, characterized in that the standing walls (2) and the gable walls (1) are non-transparent.

8. Greenhouse (10) according to one of the preceding claims, characterized in that photovoltaic modules (9) are attached to the standing walls (2) and / or the gable walls (1).

9. Greenhouse (10) according to one of the preceding claims, characterized in that the roof surface (3) has at least one openable flap (5) or another roof ventilator.

10. A method for operating a greenhouse (10) according to one of the preceding claims, characterized in that the interior of the greenhouse (10) is divided into at least three climate zones (11, 13, 15) by at least two screen units (12, 14) covering the floor plan, each having at least one screen, depending on an illuminance measured on or in the greenhouse and / or on an outside temperature and / or on an inside temperature, which are layered one above the other when the screen units (12, 14) are closed, in that the screens of the screen units (12, 14) are retracted and extended separately from one another, and in that a lower climate zone (11) and a middle climate zone (13) are separated from one another by a lower screen unit (12), and a middle climate zone (13) and an upper climate zone (15) are separated from one another by an upper screen unit (14).

11. A method for operating a greenhouse (10) according to claim 10, wherein the screen units (12, 14) are each designed as double screens, the screens of which can be moved separately from one another, characterized in that - that during daylight at a low outside temperature of less than 10°C only at least one screen of the upper screen unit (14) is closed; at a moderate outside temperature of 10°C to below 30°C all screen units (12, 14) are opened; and at a high outside temperature of 30°C and above one screen each of the lower screen unit (12) and the upper screen unit (14) or both screens of both screen units (12, 14) are closed; and that in the dark, when the outside temperature is less than 20°C, all screens of both screen units (12, 14) are closed and when the outside temperature is above 20°C, all screens of both screen units (12, 14) are opened.

12. Method according to claim 11, characterized in that daylight is defined as an illuminance of 1,000 lux and above and darkness as an illuminance of less than 1,000 lux.

13. Method according to one of claims 10 to 12, characterized in that for dehumidification of the lower climate zone (11) successively: - at least one screen of the upper screen unit (14) is closed; the lower screen unit (12) is opened; an air exchange period is waited for; - at least one screen of the lower screen unit (12) is closed; the upper screen unit (14) is opened; - at least one roof ventilator (5) is opened; - at least one screen of the upper screen unit (14) is closed; and the roof ventilator (5) is closed.

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