VENTILATION OF A SPACE FOR ANIMALS OR PLANTS This invention relates to a ventilation valve, also referred to as air inlet valve, for ventilation of a space in which animals or plants can be kept. The invention further relates to a method and a system for ventilating such s ace and also to such space provided with this ventilation system.

In the intensive farming sector, it is common to automatically control the indoor climate of spaces for keeping animals or plants by maintaining or improving properties, such as composition, temperature and/or humidity, of the inside air through supply of fresh air.

It is known from the patent publication EP 0 485 036 Al to provide a ventilating device for, in particular, an animal housing space with means for generating a reduced pressure in that space and with inlet means for admitting outside air to it. Conventional valves for admitting ventilating air, such as outside air, have insufficient throw in the minimum range, so that cold incoming air warms up insufficiently before the fresh air reaches the spot in the space where the animals or plants are. Further, in

conventional air inlet valves, a good controllability of the flow in

combination with a good throw in an initial opening range from a fully closed position leaves to be desired. Especially when the flow of the admitted ventilating air is minimal, it is important that the air current has a good throw. This means that the air current has a cross-sectional profile such that the air current does not come to a stop too rapidly, but has sufficient throw to allow it to properly mix with the inside air before reaching the spot in the space where the animals or plants are.

Accordingly, it is an object of the present invention to eliminate at least one of the disadvantages of the prior art or to alleviate the

disadvantages thereof. It is also an object of the invention to provide improved, or alternative, solutions that can be implemented in a simpler manner and moreover can be obtained comparatively inexpensively. Alternatively, it is an object of the invention to provide to the public an, at the least, useful option.

To realize these objectives the invention provides inter alia a ventilation valve for ventilation of a space exclusively for keeping animals or plants, the ventilation valve including: an opening-defining circumferential framework for mounting in a wall of the space for keeping animals or plants, and a panel that is movably attached to the circumferential framework to allow it to be moved relative thereto between a fully closed position, in which substantially no ventilating air can pass between the circumferential framework and the panel, and a fully open position in which substantially the complete opening is available for passage of ventilating air, while on the circumferential framework a profiled edge is provided which in an initial opening range between the fully closed position and a predetermined partly opened position provides a non-linear relation between a passage opening for the ventilating air and an associated relative movement position, or opening position, of the panel relative to the circumferential framework. The movably attached panel may be movable relative to the circumferential framework by, for instance, sliding or pivoting.

More particularly, the invention provides a ventilation valve, method and system for ventilation of a space for animals or plants, as defined in one or more of the appended claims.

A practical option is constituted by a ventilation valve in which a nonlinear edge contour of a profiled edge is fully integrally incorporated. This, preferably also wholly insulated, version of the ventilation valve has aerodynamically shaped edges on the inflow side for a higher air output. Further, for a higher air output, there are also partitions arranged having a cross -sectionally elongate aerodynamic oval shape instead of a rectangular cross section. With a nonlinear edge contour integrated in the bordering frame (further also referred to as circumferential framework), the opening behavior (valve characteristic) of a linearly opening ventilation valve can be influenced so that, with the opening being small, a non-linear relation is provided between a passage opening for the ventilating air and an

associated relative movement path of the panel relative to the

circumferential framework.

The exit angle of the air when the opening of the ventilation valve is smallest (about 1% or less) is defined by a tunnel or jet inlet to be 20° or thereabout. Until approximately 50% opening is reached, the exit angle of the air remains 20°. Also defined by the tunnel or jet inlet is an initial passage opening, which is bundled better for the minimal flow of the admitted ventilating air. Due to the thus-obtained better throw in the minimum range of the air inlet valve, it becomes possible, when refreshment demand is small, to further reduce the amount of incoming air per air inlet valve, from, for instance, currently approx. 250 m ³ to approx. 25 m ³ at 20 Pa reduced pressure. As a consequence, no air inlet valves need to be set out of operation by manual closure, but all air inlet valves can remain in use at all times, so that the air distribution along the length of the house remains better. The ventilating air can enter, at equal speed, for instance through a specific rectangular cross-sectional opening, of preferably 8x2.5 cm, in a better bundled manner, so that a good throw can be guaranteed.

It is thus of importance that an initial passage opening, which is cleared between the circumferential framework and the panel, has an area that has been brought into a nonlinear ratio to the opening position of the panel and also has a boundary of the passage opening such that an air current with a good throw is ensured.

Further, it is advantageous to make the ventilation valve in the closed position completely airtight to prevent freezing of the moving panel due to leakage air. To that end, the moving panel may be provided all around with "weather stripping" to limit such leakage air. A particular option is constituted by the provision of a separate top-piece which can be combined with an existing ventilation valve, or one already arranged in an object, possibly not insulated. Also with this top-piece, not only the opening behavior can be made more gradual but also the direction of the air current when the opening is relatively small can be controlled.

This top -piece with a nonlinear edge contour can be offered as an accessory for existing and/or previously installed ventilation valves. These are commercially available in different forms and for every variant an adapted top-piece can be offered. Also in this variant, the exit angle of the air becomes approximately or exactly 20° until an approximately 50% valve opening is reached. With the contours of the free edge of the top-piece according to the invention, a different opening characteristic can be achieved than with the conventional ventilation valves without top -piece.

Also, being able to preserve a rectangular outer shape in the ventilation valves according to the invention is advantageous in installing them in an animal house or like structure.

The invention will now be clarified and elucidated with reference to the appended drawings of examples of embodiments, wherein:

Figure 1 shows in perspective a ventilation valve according to the invention in a first exemplary embodiment, as seen from an interior of a space to be ventilated (outflow side);

Figure 2 shows the valve of Figure 1 as seen from the opposite side (inflow side);

Figure 3 shows the valve according to Figure 1, but then in a minimum opened position (1% opening);

Figure 4 shows the valve according to Figures 1 and 3, but then in a somewhat further opened position (15% opening);

Figure 5 shows a sectioned half of the valve in the opening position of Figure 4; Figure 6 shows the valve of the preceding Figures 1-5 in a half opened position;

Figure 7 shows the valve of the preceding Figures 1-6 in a fully open position;

Figure 8 shows in perspective a ventilation valve according to the invention in a second exemplary embodiment, as seen from an interior of a space to be ventilated (outflow side);

Figure 9 shows the valve of Figure 8 as seen from the opposite side (inflow side);

Figure 10 shows the valve according to Figure 8, but then in a minimum opened position (1% opening);

Figure 11 shows the valve according to Figures 8 and 10, but then in a somewhat further opened position (15% opening);

Figure 12 shows the valve of the preceding Figures 8-11 in a half opened position;

Figure 13 shows the valve of the preceding Figures 8-12 in a fully open position; and

Figure 14 is a graph reflecting the relation between a passage opening for ventilating air and an associated relative movement position, or opening position, of the valve according to the invention in comparison with a valve according to the prior art.

Ventilation valve 1 as shown in Figure 1 is formed by a

circumferential framework 3 which surrounds an opening within which a movable panel 5 is arranged.

This ventilation valve 1 is intended to be used as air inlet valve in for instance animal housing arrangements as described in EP 0 485 036 Al.

Referring to Figure 1, there is shown in perspective a front side of the air inlet valve 1, as seen from an interior of a building in which it is intended to be arranged. In Figure 2 the same air inlet valve 1 is shown from its rear side, that is, the side in use facing towards the outside of the building. The ventilation valve 1 is depicted in Figures 1 and 2 in a fully closed position.

The circumferential framework 3 as shown in the Figures 1 and 2 is substantially rectangular with two pairs of opposite rectangle sides, and has an insertion part 7 for inclusion in a wall of a building and an outwardly directed flange edge 9 to abut against the inner wall of the building. The panel 5 is hingedly attached along a lower edge to the circumferential framework 3 by means of hinges 11, 13. In the proximity of an upper free edge 14 of the panel 5, an upper horizontal rectangle side of the

circumferential framework 3 is provided with a profiled edge 15 extending in the opening direction of the panel 5. Through a nonlinear edge contour 17 thereof the edge 15 adjoins the upper free edge 14 of the panel 5.

This edge contour 17 of the profiled edge 15, integrated into the circumferential framework 3, influences upon opening of the panel 5 the course of clearance of a passage area between the free edge 14 of the panel 5 and the edge contour 17. The effectively cleared passage area is thereby brought into a non-linear relation with the substantially linearly opening panel 5. Further, the profiled edge 15 is provided with a tunnel or jet inlet 19, whose operation will be described in more detail hereinbelow. As can be seen in Figure 2, the ventilation valve 1, on the inflow side of the insertion part 7, has aerodynamically shaped sidewalls and upper and lower edges 21, 23, by which an inflow opening 25 is bounded. Partitions 27, 29 arranged in this inflow opening 25 are preferably also aerodynamic in shape and then have an oval-shaped transverse cross-section.

In Figure 3 the ventilation valve 1 is shown in an initially just opened position. The opening position of the panel 5 will be expressed in the following description, as is also customary in practice, as a percentage. A fully closed position of the panel 5, and hence of the ventilation valve 1, then corresponds to an opening position of 0%. A fully opened position then corresponds to an opening position of 100%. The different opening positions of the panel 5 are set by a cable operating system (not shown, but

conventional), with the panel 5 spring-biased to the fully closed position (not shown either, but also conventional). Also, for operating the cable system, often a computer-controlled control unit is used which automatically responds to received measuring signals concerning inside air parameters of the space to be ventilated. Such control units are commercially available and are not a subject of the invention described here.

The opening position of the panel 5 relative to the circumferential framework 3 as shown in Figure 3 corresponds to substantially 1%. In this opening position, an initial passage opening indicated with the reference numeral 31 has arisen between the free edge 14 of the panel 5 and the jet inlet 19. With the aid of the jet inlet 19, it is ensured that, also at a minimal flow of admitted ventilating air, an air current with a good "throw" is obtained. Preferably, the initial jet opening 31, which corresponds to the jet inlet, has a width dimension of between 2 and 3 cm, more precisely 2.5 cm, and a length dimension of between 7 and 10 cm, more precisely 8 cm. As a result, the air current keeps a mass density and concentration such that a substantially laminar air current is obtained. Moreover, by the jet inlet 19 an exit angle for the air current of approximately or exactly 20° is accomplished. Thus, also the minimal air refreshment current is properly mixed before the incoming air reaches the spot in a space where animals or plants are.

In Figure 4 the panel 5 is again opened further relative to the circumferential framework 3. In this position, a passage opening 33 is bounded by the free longitudinal edge 14 of the panel 5 and the nonlinear edge contour 17. The nonlinear edge contour 17 is more particularly formed by diverging edge parts 17A, 17B extending left and right of the central jet inlet 19. As long as the free longitudinal edge 14 of the panel 5 moves between the positions drawn in Figures 3 and 4, the increase of the passage opening 33 will be non -linear with respect to the opening angle of the panel 5. The opening position in Figure 4 corresponds to 15% of the fully opened position and is at the transition between the non-linear opening range and the further linear opening range of the ventilation valve 1.

In Figure 5 a cross section is shown of the ventilation valve 1 with the panel 5 in a partly opened position, as in Figure 4. In the cross section, it is recognizable that the ventilation valve 1 is manufactured from a thermally insulating plastic material. A suitable material for this is polyurethane, which can be shaped in a mold. This makes it possible to form both the circumferential framework 3 and the panel 5 in a single production step. Assembling them to form a ventilation valve then merely requires the hinges 11, 13 to be fitted. An insulated ventilation valve 1 provides still better possibilities of efficiently controlling the indoor climate of a space in which animals or plants are kept. The reference numerals in Figure 5 referring to the different elements are the same as described for Figures 1-4 and serve for further clarification of the construction. Further, with reference numerals 35, 37 and 39 it is indicated in Figure 5 where sealings can be provided along the panel 5 to limit leakage air in opening positions between 0% and 15% (the non-linear range). Especially in these limited opening positions, leakage air is unwanted because of the high risk of ice formation and freezing on. As can be recognized in Figure 5, the vertical edge 35 of the panel 5 is still substantially completely within the

circumferential framework 3. A sealing strip 37 on the hinge side of the panel 5 will retain its effectiveness in the non-linear range.

A sealing strip 39 on the upper edge 14 of the panel 5 may also be alternatively arranged on the inside of the profiled edge 15.

The ventilation valve 1 as shown in Figure 6 represents a half opened position. Figure 7 next shows the fully opened position. The earlier- discussed reference numerals are again included in Figures 6 and 7 for clarification of the construction, but in this connection do not require any further discussion. An alternatively implemented ventilation valve 101 is shown in Figures 8-13. This ventilation valve 101 is shown in Figure 8 in the fully closed position as seen from a space to be ventilated. Figure 9 shows the ventilation valve 101 from the opposite, air inlet side. The ventilation valve 101 shown here is formed by providing a conventional ventilation valve with a separately fitted edge top-piece 115. The conventional ventilation valve is here formed by circumferential framework 103 and hinging panel 105. In connection with this alternative ventilation valve 101, the same reference numerals as in the above-described constructional variant, increased by 100, will be used as much as possible for functionally comparable elements. The edge top-piece 115 is provided with a protruding flange edge 141 which coincides with an outwardly directed flange edge 109 of the circumferential framework 103. The construction is such that the protruding flange edge 141 of the edge top-piece 115 is attachable as airtightly as possible to the upper part of the flange edge 109 of the circumferential framework 103. For this purpose, screws, clips or other suitable fasteners can be used. Also, the conventional part of the air inlet valve 101 is provided with an insertion part 107 for inclusion in the wall of a building that includes the space to be ventilated. The upper and lower edges on the air inlet side, as well as partitions 127, 129 do not have an aerodynamically adapted shape here, but do have a thinnest possible design so as to obstruct the air flowing in as little as possible. Further, it can be seen in Figure 8 that the edge top- piece 115 by an edge contour 117 thereof adjoins a free edge 114 of the panel 105. The edge contour 117 is again formed by diverging edge parts 117A, 117B on both sides of a central jet inlet 119.

In Figure 10 the ventilation valve 101 is shown with the panel 105 in an initially opened position relative to the circumferential framework 103, corresponding to 1% of the total opening. In this position, an initial jet opening 131 bounded by the jet inlet 119 is cleared by the free edge 114 of the panel 105. The jet inlet 119 may then be so positioned again that the exit angle of the air current again approximates 20°.

In a further-opened position as shown in Figure 11, the free edge 114 of the panel 105 has cleared a passage opening 133 that is bounded by the diverging edge parts 117A, 117B, the jet or tunnel inlet 119 and the free edge 114 of the panel itself. This position of the panel 105 corresponds to 15% of the fully opened position and represents the end of the non-linear control range of the ventilation valve 101. The other reference numerals are again included in accordance with Figures 8-10 to further clarify the construction.

The Figures 12 and 13 next show the half opened and fully opened positions of the ventilation valve 101. In the alternative ventilation valve 101 described here, the separate edge top-piece 115 has the advantage that it can also be fitted on previously installed conventional ventilation valves.

The effect of the profiled edge, or the profiled edge top-piece, of the above -described constructional variants is illustrated in the graph of Figure 14. On the horizontal axis of the graph the length displacement in centimeters (cm) is indicated of an operating cable for opening and closing the pivotable panels. This length displacement has a substantially linear relation with the opening position of the panel opened by the operating cable. Plotted along the vertical axis of the graph in Figure 14 is the air flow capacity in cubic meters per hour (m ³ /h) of a ventilation valve according to the invention. The dashed line reflects the course of a conventional ventilation valve, while the solid line (designated "JET 20Pa") reflects the course of the ventilation valve according to the invention. It can be clearly seen that the relation with the opening position of the ventilation valve according to the present invention has an appreciably flatter course in the range between 2.5 and 10 cm displacement. This range, which is designated in the graph with "JET", corresponds to a panel opening position between 1% and 15% and makes it possible, in the case of a minimal air refreshment demand, to control more accurately whilst maintaining a good throw.

It will be clear that for the purpose of setting the opening positions, use can be made of an automatic control system responsive to measuring signals of the parameters measured in the space to be ventilated that are relevant to the desired air climate in that space.

The invention thus provides a ventilation valve (1; 101) for ventilation of a space for keeping animals or plants, including an opening- defining circumferential framework (3; 103) for mounting in a wall of that space, and a movable panel (5; 105). The panel (5; 105) is movably attached to the circumferential framework (3; 103) to allow it to be moved relative thereto between a fully closed position, in which substantially no ventilating air can pass between the circumferential framework and the panel, and a fully open position in which substantially the complete opening is available for passage of ventilating air. Provided on the circumferential framework (3; 103) is a profiled edge which in a range between the fully closed position and a predetermined partly opened position provides a non-linear relation between a passage opening for the ventilating air and an associated relative movement position, or opening position, of the panel (5; 105) relative to the circumferential framework (3; 103). Also provided by the invention is a ventilation system for ventilating a space for keeping animals or plants, having at least a single specimen of the ventilation valve and having means for carrying out the method steps of periodically determining parameters of inside air present in the space, and adjusting the opening position of the ventilation valve on the basis of the determined parameters of the inside air.

The construction and the operation of the invention are believed to be clearly apparent from the foregoing description. However, the invention is not limited to any embodiment described herein and, within the ability of those skilled in the art, changes are possible that are understood to be within the scope of protection. While in the exemplary embodiments described the profiled edge with which the effective passage opening is made non-linear with respect to the opening position of the panel is provided on the circumferential framework, this profiled edge can also be part of a free edge of the movable panel. Further, the above-described exemplary embodiments in each case show a hinging panel. It will be clear to those skilled in the art that a movable panel may also be a sliding panel, as described in the earlier-mentioned document EP 0 485 036 Al. Also in the case of a slidable panel, a profiled edge can be provided on the panel or on the circumferential framework with success.

Also, all kinematic inversions are understood to be within the scope of protection of the present invention. Expressions such as "consisting of, when used in this description or the appended claims, should be construed not as an exhaustive enumeration but rather in an inclusive sense of "at least consisting of. Expressions such as: "means for ..." should be read as: "component configured for ..." or "member constructed to..." and should be construed to additionally include all equivalents of the structures described. The use of expressions such as: "critical", "advantageous", "desired", et cetera, is not intended to limit the invention. Moreover, also features familiar to those skilled in the art that are not specifically or expressly described or claimed may be additionally included in the construction according to the invention without departing from the scope of protection.