Abstract:
An air duct valve arrangement for use ain an air circulation system comprising an air handler unit and an air treatment unit. The valve arrangement being disposed to prevent short-circuiting of the air treatment unit, but not to hinder the operation of the air handler unit.

Description:
BACKGROUND  
         [0001]    The present invention relates to an air duct valve arrangement configured to inhibit short-circuiting of the airflow between the inlet and outlet of a ventilation unit.  
           [0002]    Modern buildings quite often are tightly sealed and insulated to facilitate heating and prevent unwanted elements, such as dust and pollution to enter. While the insulation of buildings provides a lot of benefits, it can also unfortunately prevent fresh air from entering a building and exhausted air from leaving the building.  
           [0003]    As a result, more and more modern buildings are being outfitted with air treatment units which can introduce outside air into the building, provide purification of the air, or a combination of both.  
           [0004]    In the case of large building with multiple rooms and areas, it becomes necessary to have an air circulation system which connects the air treatment unit to the different rooms and areas. Since it would be inconvenient to provide a new air circulation system for existing buildings, these air treatment units are usually hooked up to existing air circulation systems within the buildings. These air circulation systems are often connected among other things to an air handling unit which heats or cools air. The heated or cooled air is then circulated through the building through the air circulation system (e.g. an air handling unit).  
           [0005]    There are, however, some problems which may arise from connecting an air treatment unit to an existing air circulation system. One of the biggest problems with this is that if the inlets and outlets of the air treatment unit are placed too closely together then a short circuiting of the air flows entering and exiting the air treatment unit may occur. This is not desirable because it leads to a portion of the air being treated over and over again, thereby reducing the amount of treated interior air.  
           [0006]    The simplest solution to this problem is to provide a blocking system between the air inlet and the outlet of the air treatment unit. This way the short circuiting is prevented. This solution can, however cause additional problems in buildings where the air treatment unit is connected to an air circulation system containing an air handling unit.  
           [0007]    In a building where the air treatment unit is connected to the same air circulation system as an air handling unit, blocking the passage between the air inlet and outlet of the air treatment unit can result in impaired flow of air. The reason for this is that air handling units usually drive air through the air circulation system at much higher volumes than that which pass through an air treatment unit. Therefore, if the passage were to be blocked between the air inlet and outlet of the air treatment unit, all the air would have to pass through the air treatment unit. Thus the air handling unit would be unable to operate at its full capacity.  
           [0008]    Additionally, if the air treatment unit is hooked up to an air circulating system including an air handling unit which drives air through the air circulating system then it is not always necessary to have a blockage between the air inlet and outlet of the air treatment unit. The reason for this is that the air handling unit drives air through the air circulation system thereby making short circuiting of the air treatment unit not possible.  
           [0009]    While it looks as though the simplest solution would be to not have a blockage if a air handling system is in use in the building, in reality things are not quite as simple. In reality, an air handling unit would not be used all of the time, and would not always be synchronised with the air treatment unit.  
           [0010]    Therefore, it can be seen that a blockage would be required when the air treatment unit is running, but the air handling unit is not running. However, a blockage would not be needed, and would be inconvenient when the air handling unit is running. Various solutions have been developed for this problem, such as having means which synchronise the use of the air treatment unit and the air handling unit, and/or valves which are set to open and close as the air handling unit is turned on and off.  
           [0011]    However, there are certain problems with these solution. In the case of means for synchronising the use of the air treatment unit and the air handling unit, the means in question can quite often be costly, and in addition, problems may arise since the air treatment unit and the air handling unit may not need to be active for similar periods of time. For instance on a very cold day the air handling unit may need to be active almost constantly, while the air treatment unit would not. Alternately, there might be a period of time when the air treatment unit is running almost constantly, but the air handling unit is not. In both of these cases if the units were synchronised this would, over longer periods of time, lead to excess expenditures on power and such for the two units.  
           [0012]    It would therefore seem that including valves which can be opened and closed as needed would be a better solution. While this does appear to be true, previous devices for this use have commonly had some problems. The main problem with prior art devices is how to synchronise the opening and closing of the valve with the use of the air handling unit. In most solutions various detection mechanisms and movable blockages have had to be included in the air circulation system.  
           [0013]    These systems are not always desirable because they are quite complex and therefore the cost associated with them can become high, especially since many parts would have to be built to fit the different sizes of different air circulation system.  
           [0014]    As can be seen from the above, there is a need for a simple and easily scalable valve arrangement for use with an air circulation system.  
         STATEMENT OF THE INVENTION  
         [0015]    In accordance with one aspect the present invention provides a valve arrangement comprising:  
           [0016]    a first side;  
           [0017]    a second side;  
           [0018]    a plurality of valves displaceable between an open and a closed position;  
           [0019]    valve biassing means for biassing said plurality of valves to the closed position;  
           [0020]    said plurality of valves and said valve biassing means being configured and disposed such that  
           [0021]    a flow of air coming from the first side can displace the plurality of valves from said closed position to said open position and pass through said plurality of valves, and  
           [0022]    a flow of air coming from the second side will not be able to pass through the valves.  
           [0023]    In accordance with another aspect the present invention provides a ventilation system for ventilating an enclosed space comprising  
           [0024]    an air handling unit, said air handler unit receiving an air stream from said enclosed space through a return air pathway, and said air handler unit returning said air stream to said enclosed space through a supply air pathway; and  
           [0025]    an air treatment unit connected to said return air pathway by an inlet duct and an outlet duct, such that air may pass into the air treatment unit from said return air pathway through said inlet duct, and such that air may pass out of the air treatment unit to said return air pathway through said outlet duct;  
           [0026]    said inlet duct and said outlet duct being connected to said return air pathway such that said outlet duct is connected downstream of said inlet duct;  
           [0027]    the improvement comprising a valve arrangement comprising  
           [0028]    a first side;  
           [0029]    a second side;  
           [0030]    a plurality of valves displaceable between an open and a closed position;  
           [0031]    valve biassing means for biassing said plurality of valves to the closed position;  
           [0032]    said plurality of valves and said valve biassing means being configured and disposed such that  
           [0033]    a flow of air coming from the first side can displace the plurality of valves from said closed position to said open position and pass through said plurality of valves, and  
           [0034]    a flow of air coming from the second side will not be able to pass through the valves;  
           [0035]    said valve arrangement being included in said return air pathway between said inlet duct and said outlet duct, such that said first side point in the direction of said inlet duct and such that said second side points in the direction of said outlet duct.  
           [0036]    In accordance with a further aspect the present invention provides a ventilation system for ventilating an enclosed space comprising  
           [0037]    an air handling unit, said air handler unit receiving an air stream from said enclosed space through a return air pathway, and said air handler unit returning said air stream to said enclosed space through a supply air pathway; and  
           [0038]    an air treatment unit connected to said supply air pathway by an inlet duct and an outlet duct, such that air may pass into the air treatment unit from said supply air pathway through said inlet duct, and such that air may pass out of the air treatment unit to said supply air pathway through said outlet duct;  
           [0039]    said inlet duct and said outlet duct being connected to said supply air pathway such that said outlet duct is connected downstream of said inlet duct;  
           [0040]    the improvement comprising a valve arrangement comprising  
           [0041]    a first side;  
           [0042]    a second side;  
           [0043]    a plurality of valves displaceable between an open and a closed position;  
           [0044]    valve biassing means for biassing said plurality of valves to the closed position;  
           [0045]    said plurality of valves and said valve biassing means being configured and disposed such that  
           [0046]    a flow of air coming from the first side can displace the plurality of valves from said closed position to said open position and pass through said plurality of valves, and  
           [0047]    a flow of air coming from the second side will not be able to pass through the valves;  
           [0048]    said valve arrangement being included in said supply air pathway between said inlet duct and said outlet duct, such that said first side point in the direction of said inlet duct and such that said second side points in the direction of said outlet duct.  
           [0049]    Operating advantages of the present invention will become apparent by referring to the following description wherein example embodiments of the present invention are described.  
           [0050]    In the annexed drawings, like reference characters indicate like elements throughout. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0051]    In the drawings which illustrate example embodiments of the present invention:  
         [0052]    [0052]FIG. 1 shows a schematic front perspective view of a valve arrangement according to an embodiment of the invention.  
         [0053]    [0053]FIG. 2 shows a perspective view of a valve means used with the valve arrangement shown in FIG. 1.  
         [0054]    [0054]FIG. 3 shows a cross section of the valve arrangement shown in FIG. 1 taken along the line  2 - 2 , showing the valve arrangement in a closed position.  
         [0055]    [0055]FIG. 4 shows the cross section of the valve arrangement shown in FIG. 3, showing the valve arrangement in an open position.  
         [0056]    [0056]FIG. 5 shows a perspective view of the valve arrangement shown in FIG. 1.  
         [0057]    [0057]FIG. 6 shows a schematic diagram of an air circulation system wherein an air treatment unit has been short circuited.  
         [0058]    [0058]FIG. 7 shows a schematic diagram of a first air circulation system using a valve arrangement according to the invention, wherein an air treatment unit and an air handling unit are both operating.  
         [0059]    [0059]FIG. 8 shows a schematic diagram of the air circulation system using a valve arrangement according to the invention as shown in FIG. 7, wherein the air handling unit is operating, but the air treatment unit is not.  
         [0060]    [0060]FIG. 9 shows a schematic diagram of the air circulation system using a valve arrangement according to the invention as shown in FIG. 7, wherein the air treatment unit is operating, but the air handling unit is not.  
         [0061]    [0061]FIG. 10 shows a schematic diagram of a second air circulation system using a valve arrangement according to the invention, wherein an air treatment unit and an air handling unit are both operating. 
     
    
     DETAILED DESCRIPTION  
       [0062]    [0062]FIG. 1 shows a first exemplary embodiment of a valving arrangement  10  according to the present invention. The valving arrangement  10  may comprise a support means  20 , and one or more valve means  30  (in this case valve means  30 ,  30 ′, and  30 ″). While the support means is shown in FIG. 1, as a frame it can easily be any other suitable means.  
         [0063]    As can be seen in FIG. 2, the valve means  30  are each made up of two parts. The first part is the valve plate  32 , which is the larger part of the valve means  30 . As can be seen in FIG. 2 the valve plate  32  may be slightly curved such that air blowing on the concave side can more easily move the valve. However, other embodiments wherein the valve plate  32  is not curved, may also be used.  
         [0064]    The second part of the valve means  30  is the valve support  34  which may comprise a round bar which is attached to the valve plate  32 , for instance by welding or any other appropriate means. Alternately, the valve support  34  may also be formed integral with the valve plate  32 .  
         [0065]    It should be noted that any appropriate valve support means may be use which allows the valve plate  32  to be attached to the support means  20 , while still being able to rotate.  
         [0066]    In the embodiment shown in FIG. 2, the valve support  34  is attached to the valve plate  32  such that the surface of the valve plate  32  is divided into two parts  36  and  38 , with part  38  being larger than part  36 . This is done so that when the valve means  30  is suspended by the valve support  34  the valve plate  32  will be suspended substantially vertically.  
         [0067]    Turning back to FIG. 1, we can see that a plurality of valve means  30 ,  30 ′, and  30 ″ may be attached to the support means  20  by journaling the valve supports  34 ,  34 ′, and  34 ″ into the sides of the support means  20 . The valve means  30 ,  30 ′ and  30 ″ are then pivotably suspended within the support frame  20 , with gravity tending to keep the valve arrangement  10  in a closed position.  
         [0068]    [0068]FIG. 3 shows a cross section of the valve arrangement  10  shown in FIG. 1 along line  2 - 2 , with the support means  20  being drawn in dashed lines. In this figure we can see the valve arrangement  10  in the closed position. It can be seen that in the closed position the valve plate  32  of a first valve means  30  overlaps with a second valve means  30 ′ such that the lower edge of valve plate  32  close to the height of the valve support  32 ′ of the second valve means  30 ′. The same holds for the lower edge of valve plate  32 ′ and the valve support  34 ″ of third valve means  30 ″.  
         [0069]    Thus the valve means  30 ,  30 ′, and  30 ″ may freely pivot in a counter clockwise direction, but will be prevented from pivoting in a clockwise direction. The valve arrangement  10  may then be cause to enter an open position by a stream of air moving in the direction of arrow  40  and hitting a first side  12  of the valve arrangement  10 , but not by a stream of air moving in the direction of arrow  42  and hitting a second side of the valve arrangement  10 .  
         [0070]    [0070]FIG. 4 shows the valve arrangement of FIG. 3 in the open position. In this position the valve means  30 ,  30 ′, and  30 ″ are being held open by a stream of air moving in the direction of arrow  44 .  
         [0071]    [0071]FIG. 5 shows a perspective view of the valve arrangement  10  as shown in FIG. 1.  
         [0072]    Moving on to FIG. 6 we see an air circulation system having an air treatment unit  100  and a air handling unit  110 , which is not supplied with a valve arrangement according to the present invention.  
         [0073]    During normal operation an air stream would be taken from within a building (not shown) through the return air duct  120 . Passed to the air handling unit  110  and then returned to the building via supply air duct  130 .  
         [0074]    Also attached to return air duct  120  is the air treatment unit  100 , which removes a portion of the air stream and treats it. Treatment of air may for instance mean purification, replacement with outside air, or a combination of both. The air treatment unit  100  has an air inlet  102  through which air can enter the air treatment unit, and an air outlet  104  through which air is released back into the air circulation system.  
         [0075]    In the embodiment shown in FIG. 6, the air treatment unit also has exterior inlet  106  and exterior outlet  108 , which are used to draw fresh air from the outside of the building, and release exhausted air from the inside of the building.  
         [0076]    In the instance shown in FIG. 6, the air handling unit  110  is not in operation and is therefore not driving air through the air circulation system. The air treatment unit  100 , on the other hand is in operation. As a result, an air flow as shown by the arrows  140  may result.  
         [0077]    As can be seen from arrows  140 , the air flow of the air treatment unit  100  has been short circuited such that the air inlet  102  instead of drawing exhausted air coming from the inside of the building through the return air duct  120 , draws on the air being released from the air outlet  104  of the air treatment unit  100 . The result is that the air treatment unit continuously treats the same air, thus being virtually ineffective.  
         [0078]    [0078]FIG. 7, 8, and  9  on the other hand show an air circulation system similar to that shown in FIG. 6, which has been fitted with a valve arrangement  199  according to the invention. The valve arrangement  199  has a first side and a second side such that a flow of air coming from the direction of the first side may open the valve arrangement, but a flow of air coming from the second side will not.  
         [0079]    The air circulation system comprises an air treatment unit  200  for treating exhaust air, an air handling unit  210  for handling (e.g. heating or cooling), as well as driving air through the air circulation system, a return air duct  220  for air returning from a building, and a supply air duct  230  which supplies air to the building.  
         [0080]    The air treatment unit  200  further has an air inlet  202 , an air outlet  204 , an exterior air inlet  206 , and an exterior air outlet  208 .  
         [0081]    In the embodiment shown in FIG. 7, 8 and  9 , the valve arrangement  199  has been placed in said return air duct  220  between said air inlet  202  and said air outlet  204 , such that said first side faces or points in the direction of said air inlet  202 , and such that said second side faces or points in the direction of said air outlet  204 .  
         [0082]    In the instance shown in FIG. 7, both the air treatment unit  200 , and the air handling unit  210 , are operational. The path of an air stream passing through the air circulation system is shown by the arrows  240 . In this instance an air stream is drawn from inside the building through the return air duct  220 , this air stream then passes by the air inlet  202  of the air treatment unit  200  where a portion of the air is removed from the air stream an is treated by the air treatment unit  200 . The remaining air stream then passes through the valve arrangement  199  which is in an open configuration due to the flow of the air stream pushing on the first side of said valve arrangement  199 . As the air stream passes by the air outlet  204  of the air treatment unit the treated air is returned to the air stream. Finally, the air stream passes through the air handling unit  210 , where it is heated or cooled as desired, before being released back into the building through supply air duct  230 .  
         [0083]    In the instance shown in FIG. 8, the air handling unit  210  is operational, while the air treatment unit is not. In this instance an air stream drawn from inside the building through the return air duct  220 , the air stream then passes through the valve arrangement  199  which again is in the open configuration due to the flow of the air stream pushing on the first side of said valve arrangement  199 . The air stream then passes through the air handling unit  210 , where it is heated or cooled as desired, before being released back into the building through supply air duct  230 .  
         [0084]    Finally, FIG. 9 shows the air circulating system when the air treatment unit  200  is operating, but the air handling unit is not. In this instance the air treatment unit  200  will draw a small air stream in through its air inlet  202 , thus causing an equal amount to be drawn into the air circulation system through the return duct. After the air stream has been treated the air stream is then released back into the air treatment system through air outlet  204 . This air stream will now pass through the inactive air handling unit and back into the building.  
         [0085]    Due to the fact that only the air treatment unit  200  is driving air through the air circulation system, there will not be a sufficient air pressure on first side of the valve arrangement  199  to cause it to displace to the open configuration. The valve arrangement is thus in an closed configuration, thereby effectively blocking the return air duct  220  between the air inlet  202  and the air outlet  204 . Short circuiting of the air flow of the air treatment unit is thereby prevented.  
         [0086]    In fact, the air treatment unit  200  creates an air pressure which is an inversion of the air pressure which would have been created by the air handling unit  210 , thus creating a pressure on said second side of said valve arrangement. This further works to ensure that the valve arrangement  199  remains closed.  
         [0087]    Moving on, FIG. 10 shows an alternate configuration of an air circulation system using a valve arrangement according to the present invention. This air circulation system comprises an air treatment unit  300  having air inlet  302 , air outlet  304 , exterior air inlet  306 , and exterior air outlet  308 . Additionally the air circulation system comprises air handling unit  310  which heats or cools the air as needed and which can drive air through the air circulation system, return air duct  320  through which air is drawn from the interior of a building, and supply air duct  330  to which the air treatment unit  300  is connected and through which air is returned to the building.  
         [0088]    While the principles of this invention has been described in connection with specific embodiments, it should be understood clearly that these descriptions, along with the chosen examples and data, are made only by way of illustration and are not intended to limit the scope of this invention, in any manner. Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. No concerted attempt to repeat here what is generally known to the artisan has therefore been made. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the appended claims with the scope thereof determined by the reasonable equivalents, as understood by those skilled in the art.