[0001] The present application claims the benefit of the filing date of U.S. Provisional Application No. 62/394,075, filed September 13, 2016, the disclosure of which is hereby incorporated by reference herein in its entirety. FIELD OF THE DISCLOSURE

[0002] The present disclosure is related to a fluid (liquid or gas) discharge system, for example for evacuating and discharging air from a building or another enclosure or space.

BACKGROUND

[0003] Exhaust systems can be used to exhaust air out of a building, room, or other enclosure or space for a number of different purposes. For example, an exhaust system can be used in a laboratory setting (e.g., pharmaceutical lab) to exhaust air contaminated with chemicals or other substances from the laboratory. For certain applications (e.g. , pharmaceutical), the discharge velocity of an exhaust system is required to remain relatively constant. This requirement can be present to ensure that a certain discharge plume is created and that exhaust from the exhaust system is adequately dispersed out of the building, room, enclosure, etc. Existing exhaust systems sometimes seek to meet this requirement by utilizing a bypass intake. When a main intake of the exhaust is partially or completely closed (e.g. , because the exhaust system is not being used or is only partially active), the bypass intake can be opened to maintain a constant level of air flow inside the exhaust system. Such an operation, in existing exhaust systems, can ensure that air exhausted from the system maintains a relatively constant discharge velocity. Yet, such a solution can be wasteful in terms of energy usage and efficiency, amongst other deficiencies.

[0004] Other existing exhaust systems might not use a bypass intake as described above, but can use a valve or another mechanism that has a variable position to change an amount of air exhausted out of a main exhaust of the system. Generally, however, these systems use a valve that can be moved to a number of different positions from slightly open to more fully open (e.g. , to change the amount of air exhausted from the system). Such exhaust systems, when a main intake is partially or completely closed, might change the position of its valve (e.g. , move the valve to a slightly closed position) to ensure that a discharge velocity of air out of the main exhaust remains somewhat constant. Yet, these systems suffer from design difficulties and can require extremely precise tolerances to ensure that there is no leakage around the body of the variable-position valve when the valve partially occludes the main exhaust. In addition, the aforementioned systems can suffer from downsides, such as increased turbulence at the main exhaust.

[0005] The present disclosure therefore provides a unique discharge system and methods of operation thereof that overcome the deficiencies of existing systems. SUMMARY

[0006] To better illustrate the system disclosed herein, a non-limiting list of examples is provided here:

[0007] Example 1 includes a discharge system comprising an intake passage fluidly coupled to a venting system and to an intake plenum or a main intake duct, an air mover fluidly coupled to the intake plenum, the air mover being positioned within a housing and coupled to a motor configured to drive the air mover at varying speeds, a plurality of exhaust passages fluidly coupled to the housing of the air mover, each of the exhaust passages including a damper, wherein each damper is movable from a fully closed position in which the damper substantially completely occludes its exhaust passage to a fully open position in which air flow through each exhaust passage is at a maximum for its respective damper, a first sensor positioned upstream of the air mover, the first sensor configured to at least measure volumetric flow of air moving towards the air mover, a second sensor positioned upstream of the air mover, the second sensor configured to at least measure pressure inside of the intake plenum, and a controller communicatively coupled to the first and second sensors. The controller can comprise circuitry configured to perform the operations of, in response to readings from the first and/or second sensors, changing the position of at least a first of the plurality of dampers between its fully open and closed positions, and, in response to readings from the first and/or second sensors, changing the speed at which the air mover operates.

[0008] Example 2 includes the discharge system of Example 1 and a plurality of actuators, each actuator being coupled to a respective one of the plurality of dampers.

[0009] Example 3 includes the discharge system of any one of or any combination of Examples 1 -2, wherein the second sensor is positioned within the intake plenum. [0010] Example 4 includes the discharge system of any one of or any combination of Examples 1 -3, wherein the first sensor is positioned within an intake passage leading into the housing that contains the air mover.

[0011] Example 5 includes the discharge system of any one of or any combination of Examples 1 -4, wherein the air mover is a fan or a pump.

[0012] Example 6 includes the discharge system of any one of or any combination of Examples 1 -5, wherein the circuitry is configured to perform the operations of receiving a volumetric flow reading from the first sensor, receiving a pressure reading from the second sensor, when the pressure reading from the second sensor rises above a pre-set pressure threshold, causing the motor to decrease its speed, and when a volumetric flow reading from the first sensor rises above a pre-set volumetric flow threshold, causing one or more of the plurality of dampers to move from the fully closed position to the fully open position.

[0013] Example 7 includes the discharge system of any one of or any combination of Examples 1 -6 and a bypass intake passage fluidly coupled to the intake plenum.

[0014] Example 8 includes the discharge system of Example 7, wherein the bypass intake passage includes at least one of the plurality of dampers.

[0015] Example 9 includes a discharge system comprising an intake passage fluidly coupled to a venting system and to an intake plenum or a main intake duct, an air mover fluidly coupled to the intake plenum, the air mover being positioned within a housing and coupled to a motor configured to drive the air mover at varying speeds, a plurality of exhaust passages fluidly coupled to the housing of the air mover, each of the exhaust passages including a damper, wherein each damper is movable only between a fully closed position in which the damper substantially completely occludes its exhaust passage and a fully open position in which air flow through each exhaust passage is at a maximum for its respective damper, one or more sensors configured to measure air-flow conditions inside the discharge system, and a controller communicatively coupled to the one or more sensors. The controller can comprise circuitry configured to perform the operations of, in response to readings from the one or more sensors, changing the position of at least a first of the plurality of dampers between its fully open and fully closed positions, and changing the speed at which the air mover operates.

[0016] Example 10 includes the discharge system of Example 9, wherein the one or more sensors is configured to at least measure volumetric flow of air moving towards the air mover. [0017] Example 11 includes the discharge system of Example 10, wherein the one or more sensors comprise a sensor configured to at least measure pressure inside of the intake plenum.

[0018] Example 12 includes the discharge system of any one of or any combination of Examples 9-11 and a plurality of actuators, each actuator being coupled to a respective one of the plurality of dampers.

[0019] Example 13 includes the discharge system of Example 11, wherein the circuitry is configured to perform the operations of receiving a volumetric flow reading from a first of the one or more sensors, receiving a pressure reading from a second of the one or more sensors, when the pressure reading from the second sensor rises above a pre-set pressure threshold, causing the motor to decrease its speed, and when a volumetric flow reading from the first sensor rises above a pre-set volumetric flow threshold, causing one or more of the plurality of dampers to move from the fully closed position to the fully open position.

[0020] Example 14 includes the discharge system of any one of or any combination of Examples 9-13 and a bypass intake passage fluidly coupled to the intake plenum.

[0021] Example 15 includes the discharge system of Example 14, wherein the bypass intake passage includes at least one of the plurality of dampers.

[0022] Example 16 includes a method of venting and discharging air from a space comprising sensing volumetric flow and/or pressure of air moving through a passage of a discharge system using one or more sensors, operating an air mover of the discharge system at a first speed to move air through the passage of the discharge system to maintain proper pressure in an intake plenum, moving air through a plurality of exhaust passages of the discharge system by operating the air mover at the first speed, each of the plurality of exhaust passages including a damper, and in response to readings from the one or more sensors: (i) changing the speed of the air mover to a second speed different from the first speed to alter the speed at which the air flows through the passage, and (ii) moving a first one of the dampers from a fully closed position in which the first damper substantially completely occludes air flow inside its exhaust passage to a fully open position in which air flow through its exhaust passage is at a maximum.

[0023] Example 17 includes the method of Example 16, wherein the one or more sensors comprise a first sensor, and the method further comprises sensing volumetric flow of the air moving through the discharge system using the first sensor. [0024] Example 18 includes the method of Example 17, wherein the one or more sensors comprise a second sensor, and the method further comprises sensing the pressure of the air moving through the passage using the second sensor.

[0025] Example 19 includes the method of any one of or any combination of Examples 16-18, further comprising, in response to readings from the one or more sensors, moving the first damper from its fully open position back to its fully closed position.

[0026] Example 20 includes the method of any one of or any combination of Examples 16-19, further comprising performing steps (i) and (ii) of claim 16 to keep an exhaust velocity of the air moving through the plurality of exhaust passages and out of an exhaust area of the discharge system within a pre-defined velocity range.

BRIEF DESCRIPTION OF THE FIGURES

[0027] The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the disclosure itself will be better understood by reference to the following description of examples taken in conjunction with the accompanying drawings, wherein:

[0028] Fig. 1 is a side perspective view of a first example of a discharge system.

[0029] Fig. 2 is a side perspective view of a second example of a discharge system.

[0030] Fig. 3 is a side perspective view of a third example of a discharge system.

[0031] Fig. 4 is a schematic view of a discharge system as used in an exemplary building.

[0032] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate examples of the disclosure, and such exemplifications are not to be construed as limiting the scope of the disclosure any manner.

DETAILED DESCRIPTION

[0033] In describing the examples of the disclosure illustrated and to be described with respect to the drawings, specific terminology will be used for the sake of clarity. However, the disclosure is not intended to be limited to any specific terms used herein, and it is to be understood that each specific term includes all technical equivalents.

[0034] The present disclosure is directed to discharge systems and methods, which can utilize a unique arrangement of passages and other components to ensure that air is discharged from the system within an acceptable range of velocities. The present disclosure also encompasses installations and buildings in which the aforementioned discharge systems are installed and operated.

[0035] Referring to Fig. 1 , a first example of a discharge system 10 is shown. Discharge system 10 can have a plurality of passages or ducts 12, each passage 12 opening out into an exit or exhaust opening 14. As shown, air can move in direction 15 as it is exhausted from discharge system 10. Passages 12 and exhaust openings 14 are shown to be a rectangular or square shaped, but any shape is contemplated by the disclosure, including circular, oval, diamond, polygonal, or another suitable shape. Within each passage 12 can be a damper or valve 16. Dampers 16 can be coupled to an actuator or multiple actuators 18, which are configured to move dampers 16 between open and closed states. Indeed, in an example, a single actuator 18 can be coupled to each damper 16, and the single actuator 18 can be configured to move each of the dampers 16, independently or in conjunction, between their open and closed states. Alternatively, as illustrated in Fig. 1 , individual actuators 18 can be coupled to each damper 16, and each actuator can be configured to move its respective damper 16 between its opened and closed states. The individual actuators 18 can also be programmed to move certain dampers 16 between their opened and closed states in conjunction with each other. Actuators 18 can each include a controller, circuitry (e.g., a processor(s), memory, and other computing components), and a motor controlled by the controller and circuitry. Each actuator 18 can drive dampers 16 between their opened and closed states.

[0036] In an example, the open state can refer to a state in which the respective damper 16 does not occlude air flow through its passage 12 to any material degree. In other words, the open state can refer to a state in which the respective damper 16 is completely open to allow full or maximum air flow through its passage 12. In an example, the closed state can refer to a state in which the respective damper 16 occludes air flow completely or substantially completely through its passage 12. In other words, the closed state can refer to a state in which the respective damper 16 is completely or substantially completely closed to completely or substantially completely shut off air flow through its passage 12. In the closed state, damper 16 can form an air-tight seal with an internal wall of its respective passage 12 to prevent air flow past damper 16 within its passage 12. Such binary states of dampers 16, as described in more detail below, can be advantageous to the operation of discharge system 10. In an example, dampers 16 can only move between the open and closed states and cannot move to an intermediate state or position (e.g. , partly open or closed). Merely as examples, actuators 18 can be linear actuators or any other suitable actuator, and dampers 16 can be rotating blade dampers, parallel blade dampers, opposed blade dampers, gate dampers, butterfly dampers and any other type of isolation dampers.

[0037] As shown in Fig. 1 , upstream of dampers 16 can be a fan housing 28, which can contain a fan, pump, or another fluid mover (not shown), in this example, configured to move air towards dampers 16 and out of exhaust openings 14. A motor 24 can be coupled to the fan or air mover to drive the fan or air mover and cause air to move in discharge direction 15. Motor 24 can itself be coupled to a motor variable speed drive 22, which can control and/or set the different speeds at which motor 24, and thus the fan or air mover, operate. In other words, motor 24 can be a variable-speed motor 24, whose speed set points can be controlled by variable speed drive 22. Variable speed drive 22 can cause the speed of motor 24, and thus the fan or air mover, to increase or decrease depending upon other states within discharge system 10, as described in more detail below. Variable speed drive 22 can also be coupled to a controller 26, which can be programmable or manually-operated to set the speed set points for variable speed drive 22. In an example, controller 26 can be a control panel that is part of a building automation system, or another controller configured to manually or programmably control variable speed drive 22, and thus motor 24. If controller 26 is programmable, it can be programmed with a particular algorithm 27 to operate discharge system 10 in an efficient manner, as detailed more fully below. Controller 26 can include circuitry (e.g. , a processor(s), memory, and other computing components) for running algorithm 27 and transmitting commands to other components within discharge system 10, as detailed more fully below. In an example, the circuitry or any circuitry or computing components disclosed herein can be temporary, permanent, an integrated circuit, an application-specific circuit, a computer with a processor(s) and memory, or other suitable circuitry.

[0038] Fan housing 28 can be coupled to an intake passage or duct 32, which can in turn be coupled to an intake plenum 30. One or more (e.g. , a plurality) of intake demand value sensors 34 can be positioned inside of intake plenum 30, and one or more (e.g. , a plurality) of discharge sensors 20 can be positioned inside of intake passage 32. Each intake demand sensor 34 and each discharge sensor 20 can be coupled or associated with a transmitter configured to transmit (e.g. , wirelessly) values read at the position of the respective sensor 34, 20. Intake demand sensor 34 can measure pressure, flow, velocity, and/or other values to determine whether intake demand requirements are being met. In an example, intake demand sensor 34 can measure pressure, flow, velocity, and/or other values to determine whether pressure is sufficient within intake plenum 30 to draw air through one or more (e.g. , a plurality) of intake exhaust passages 36, and/or whether flow or velocity of air through plenum 30 is sufficient to draw air through intake exhaust passages 36 and move the air towards the fan (not shown). As detailed more fully below, depending upon the readings of intake demand sensor 34, different states of discharge system 10 (e.g. , its damper 16 positions and/or motor 24 speed) can be altered. In another example, discharge sensor 20 inside intake passage 32 can be configured to measure and transmit (e.g. , via its associated transmitter) the volume of air moving through intake passage 32, velocity of air through intake passage 32, and/or other values to determine the air discharge volume. In an example, discharge sensor 20 can be configured to measure volumetric velocity (e.g. , volumetric flow rate) or flow of air moving through intake passage 32 (e.g. , cubic- feet per minute (CFM)). As described more fully below, with discharge volume being read and calculated by sensor 20, an appropriate discharge velocity can be created and maintained through passages 12 and out of exhaust openings 14 by changing the position of dampers 16 and/or altering the speed of motor 24. Altering the position of dampers 16 can increase or decrease a discharge area through which the aforementioned volume of air must travel, which can impact the discharge velocity of the air out of exhaust openings 14.

[0039] As shown in Fig. 1 , discharge system 10 can also include one or more (e.g., a plurality) of exhaust intake passages 36, which can be fiuidly connected to intake plenum 30. Exhaust intake passages 36 are referred to as such since such passages 36 can both exhaust air from a building, room (e.g. , laboratory), or another enclosure and intake air into discharge system 10. In other words, as detailed below, exhaust intake passages 36 can be fiuidly coupled to an exhaust system inside the building, room (e.g. , laboratory), or other enclosure. Fig. 4 illustrates an exemplary schematic of discharge system 10 connected to such a laboratory. The exhaust system can, for example, take the form of a hood exhaust (e.g. , as commonly used in pharmaceutical or other laboratories), or any other exhaust system. In an example, the aforementioned exhaust system can be regulated between multiple different orientations, including but not limited to completely open, partly open, intermediate, partly closed, and completely closed. As shown in Fig. 4, dampers 16 can be provided to regulate the exhaust system (e.g., hood exhaust). In other words, such exhaust systems can be controlled by a user between a number of different set points to change the quantity of air removed or suction produced by the exhaust system. In an example, the exhaust system can be placed into a state in which air flow into exhaust intake passages 36 is occluded or otherwise below its maximum capacity (e.g. , by closing a damper 16 (Fig. 4) somewhat). Upon changing the output of the exhaust system, as detailed below, discharge system 10 can respond accordingly to ensure that air is discharged from discharge system 10 out of exhaust openings 14 at or within a certain range of discharge velocities. As shown in Fig. 1 , air flow can occur in direction 38 through exhaust intake passages 36.

[0040] Intake plenum 30 can further be coupled to one or more bypass intake(s) 40. Bypass intake 40 can be used in fail-safe situations or other scenarios in which increased air flow is desired inside discharge system 10. Bypass intake(s) 40 can allow air flow in direction 42, and can include a damper 44 inside bypass intake passage 40. Damper 44 can be positioned in a continuum of open and closed positions to allow certain levels of air flow into bypass intake 40. For instance, during operation, damper 44 can be moved to occlude bypass intake passage 40 by anywhere between about 0-100%. Bypass intake 40 can further include one or more (e.g. , a plurality) of sensors (not shown) that can measure pressure, flow, volume, and/or other values to determine an amount or volume of air being drawn through bypass intake passage 40. Alternatively, bypass damper 44 can be controlled without any bypass intake sensors via inputs from intake demand sensor 34 and/or a combination of inputs from controller 26. Each bypass intake sensor can be coupled or associated with a transmitter, as with the other sensors detailed above, to transmit readings from the sensor to other components of discharge system 10. As detailed below, bypass intake 40 can be opened during operation as a fail-safe (i.e. , if air flow inside system 10 is not sufficient to maintain discharge air velocity), or during transition periods to ensure a smooth transition.

[0041] The operation of discharge system 10 is now described. It should be understood that the order of operation of certain elements or steps below is not essential, and that no particular order is implied in terms of how the elements or steps are laid out in the disclosure.

[0042] As mentioned previously, discharge system 10 can be a discharge system for a building, laboratory (e.g. , pharmaceutical laboratory), room, enclosure, or another space that is in need of exhaust or venting. The disclosure uses a laboratory as an example, particularly in Fig. 4, but it is to be understood that discharge system 10 can be useful in a number of different settings or spaces. Exhaust intake passages 36 can be fluidly coupled to a venting or exhaust system within the laboratory or other space requiring venting, as shown in Fig. 4. In an example, a vent hood or other venting mechanism can be provided in the laboratory or other space in need of venting, which can be positioned in a number of different states. For instance, the vent hood can be set to operate at full venting capacity, it can be completely closed when venting is not needed in the laboratory or space of interest, or it can occupy a number of intermediate set points to control the amount of venting or air flow within the laboratory or other vent space. In an example, the vent hood can have one or more (e.g. , a plurality) of dampers or valves 16, as shown in Fig. 4, that can serve to occlude air flow into exhaust intake passages 36. As such, dampers or valves 16 can be moved to occlude air flow into exhaust intake passages 36 by some degree or percentage (e.g. , anywhere between about 0- 100%). When occluded 100%, the respective damper 16 can form an air-tight seal with its corresponding intake so that air flow is stopped to exhaust intake passages 36. Fig. 4 also depicts an air handler system for providing air back into the laboratory, which itself can utilize dampers 16 and ducts, as shown, for air supply and possibly return.

[0043] Passages 12 of discharge system 10 and the exhaust openings 14 thereof can be positioned to exhaust air outside of the laboratory. In an example, exhaust openings 14 can be positioned to exhaust air outside of the building containing the laboratory to the external environment. Further, bypass damper 44 can be arranged by the controller 26 so as to be able to draw air into discharge system 10, through bypass intake 40 when needed (e.g.. , when discharge control dampers 16 in Fig. 1 fail to close, VSD 22 fails to reduce fan speed, or when the system is in transition modes).

[0044] In operation, particular set points can be programmed into system 10 so as to ensure that the discharge velocity of air being exhausted out of passages 12 and exhaust openings 14 remains within a pre-defined range. The range of acceptable velocities for system 10 can be anywhere between about 1000 feet per minute to 4000 feet per minute depending on the situation, but usually targeted around 3000 feet per minute. In an example, controller 26 can be programmed with set points (e.g., thresholds) for discharge sensor 20, intake sensor 34, and/or the bypass intake sensor (not shown), which can act to control system 10 in terms of the position of its dampers 16, 44 and/or the speed of motor 24 and the fan (not shown) coupled thereto. For instance, as mentioned previously, controller 26 can be a control panel that is part of a building automation system, or another controller configured to manually or programmably control variable speed drive 22, and thus motor 24. As detailed below, controller 26 can receive data transmitted from discharge sensor 20, intake sensor 34, and/or the bypass intake sensor (not shown), determine if such data meets the set points by way of algorithm 27, and then transmit directives to other components of discharge system 10 (e.g. , (i) actuators 18 and dampers 16, and (ii) motor 24) to change air flow through system 10.

[0045] In an example scenario, a demand set point for intake sensor 34 in the form of a pressure set point (e.g. , threshold) or pressure range can be programmed into sensor 34 and/or provided by controller 26. During use, air flow into exhaust intake passages 36 might be reduced by, for instance, closing or opening a vent hood or another venting mechanism by some amount, as shown in Fig. 4. If, as an example, the vent hood or other venting mechanism were closed somewhat to lessen air flow into exhaust intake passages 36 (e.g. , during off-peak hours or because a certain vent hood was not being used), the pressure inside of intake plenum 30 might build up due to lack of air flow. This can also cause the discharge velocity of air out of exhaust passages 12 to drop. With the pressure set point or range for intake sensor 34 being relatively fixed, the build up of pressure might exceed the pressure set point or fall outside of the pressure range for intake sensor 34. Such readings can be transmitted to controller 26 and/or variable speed drive 22, which, due to algorithm 27, can act to change the speed of motor 24 and consequently the fan (not shown) coupled thereto. In other words, algorithm 27 can compare the readings of intake sensor 34 with the set point or range to determine if the pressure inside intake plenum 30 has exceeded the set point or fallen outside the range. If so, in an example, the speed of motor 24 and the fan (not shown) can be decreased to lower the build up of pressure inside intake plenum 30 to back below the pressure set point or to within the pre-defined pressure range.

[0046] At the same time, discharge sensor 20 can act to read the volume of air travelling through intake passage 32, transmit such readings to controller 26 and/or directly to actuators 18, which can then act to open or close any number of dampers 16 to maintain a relatively constant air discharge velocity or a discharge velocity within a certain acceptable range. Indeed, discharge sensor 20 can be configured to read the volume of air travelling through intake passage 32 over a certain period of time (e.g. , CFM, etc.) Such readings can, when sent to controller 26 and processed by way of algorithm 27, cause controller 26 to transmit a signal to actuators 18 to open or close any number of dampers 16. In this way, discharge system 10 can ensure that the discharge velocity of air out of exhaust passages 12 and the corresponding exhaust openings 14 remains relatively constant or within a certain range. Merely as a concrete example, if 3000 CFM (ft ³ /min) of air were read by discharge sensor 20 to be moving through intake passage 32, and a discharge velocity of 3000 ft/min out of exhaust openings 14 was required, discharge system 10 could calculate that 1 ft ² of area within exhaust passages 12 would be needed to meet the required discharge velocity of 3000 ft/min. Any number of dampers 12 could then be opened or closed, as needed, so that a certain combination of exhaust passages 12 satisfies the 1 ft ² area criteria. In this way, discharge system 10 can respond to changes in vent or exhaust demand, while maintaining a relatively constant discharge air velocity (e.g. , a discharge air velocity within a certain range). As can be appreciated, a reverse situation to that described above can occur if, for example, more venting were needed and any number of vent hoods were opened to a greater degree (e.g. , in a peak-demand situation). In such a situation, discharge system 10 could act, by way of controller 26 and algorithm 27, to increase the speed of motor 24 and/or open certain dampers 16 to ensure a relatively constant discharge air velocity.

[0047] As can be appreciated from the preceding, readings from discharge sensor 20 and intake demand sensor 34 can be transmitted to controller 26 so as to cause motor 24 to alter its speed (e.g. , increase or decrease its speed) for changing fan speed, and/or to open or close any number of dampers 16 within exhaust passages 12 so that air is discharged out of exhaust openings 14 at a pre-defined acceptable velocity or within a pre-defined acceptable velocity range. Discharge system 10 is therefore dynamic while maintaining a constant discharge velocity or a discharge velocity within a set range.

[0048] Bypass intake 40 can be used in fail-safe conditions or in other scenarios to ensure proper air flow within discharge system 10. For instance, if certain dampers 16 were malfunctioning, all dampers 16 within discharge system 10 (not the laboratory) might be moved to a completely open position and then bypass intake 40 could be used to ensure that the discharge velocity of air was relatively constant or within a certain range of velocities. In an example, with all dampers 16 of discharge system 10 in an open condition, if exhaust intake passages 36 were occluded (e.g. , because the vent hood was closed somewhat or completely closed), intake demand sensor 34 could read an increase in pressure inside of intake plenum 30. Such readings could be transmitted to controller 26, which could send a signal to open bypass damper 44 and allow air to flow in direction 42 through bypass intake 40. In this way, bypass intake 40 could cause pressure to equalize inside of intake plenum 30 and allow for an appropriate volume of air to flow through intake passage 32 and out of exhaust passages 12 and openings 14 at a relatively constant discharge velocity or within a range of discharge velocities. As mentioned previously, bypass damper 44, unlike dampers 16 (in an example), can be configured to move amongst a continuum of open or closed positions. For instance, bypass damper 44 can be configured to move so that it occludes bypass intake 40 by anywhere between about 0-100%. At complete occlusion, bypass damper 44 can form an air-tight seal with bypass intake 40 to cut off air flow through bypass intake 40.

[0049] Bypass intake 40 can also be used to smooth transitions of discharge system 10. In an example, if the closing of a damper 16 of a particular exhaust passage 12 would cause the discharge air velocity out of passages 12 to fall outside of an acceptable range or set point (e.g. , because opening the particular exhaust passage 12 would decrease the discharge air velocity by too great a degree), bypass intake 40 can be opened by a certain amount to provide for the correct flow and velocity conditions in discharge system 10.

[0050] Referring now to Fig. 2, a second example of a discharge system 10' is shown. Here, like reference numerals refer to like elements, except that a prime designation is added with respect to the components of discharge system 10'. In addition, only the differences between discharges systems 10, 10' are discussed. Thus, it is to be appreciated that discharge system 10' can have any of the components of discharge system 10, and can function in a like or the same manner as described above, unless set forth differently below.

[0051] Discharge system 10' can be similar to discharge system 10, except that discharge system 10' can have different positions for its exhaust passages 12'. As shown, exhaust passages 12' can be positioned upstream of dampers 16' in a main stack 1 1 '. In addition, exhaust passages 12' can have their own dampers 16' that can, as detailed previously, move between open and closed states to either open flow into exhaust passages 12' or close flow off from exhaust passages 12'. In operation, discharge system 10' can have its dampers 16' in any number of different orientations (e.g. , opened/closed), in any combination, to affect flow through discharge system 10', and consequently, the discharge velocity of air out of system 10. As with discharge system 10, dampers 16' of discharge system 10' can be positioned to ensure that a relatively constant discharge air velocity is exhausted out of discharge system 10', or that the discharge air velocity stays within a pre-defined acceptable range. In an example, damper 16' downstream of exhaust passages 12' can be closed, and either or both dampers 16' inside of exhaust passages 12' can be opened so that air is exhausted solely out of exhaust passages 12'. In an example, damper 16' downstream of exhaust passages 12' can be a single damper with multiple damper blades that can be positioned in opened/closed states, as detailed above. In another example, either or both dampers 16' inside of exhaust passages 16' can be closed, damper 16' inside main stack 11 ' can be opened to allow air flow out of main stack 1 1 '. The different combination of positions of dampers 16' can be selected and actuated by actuators 18 ', controlled by way of controller 26', so that a relatively constant air discharge velocity or a range of velocities is maintained. Thus, as with discharge system 10, the position of dampers 16' of discharge system 10' and the speed of its motor 24' (and consequently its fan) can be controlled by way of controller 26', as operated through algorithm 27' and the readings from sensors 20', 34'.

[0052] Referring to Fig. 3, a third example of a discharge system 10" is shown. As with above, here like reference numerals refer to like elements, except that a double-prime designation is added with respect to the components of discharge system 10". In addition, only the differences between discharges systems 10, 10', 10" are discussed. Thus, it is to be appreciated that discharge system 10" can have any of the components of discharge systems 10, 10", and can function in a like or the same manner as described above, unless set forth differently below.

[0053] Discharge system 10" is similar to discharge systems 10, 10', except that discharge system 10" can have a different configuration and/or shape for its exhaust passages 12" and main stack 11 ". As shown in Fig. 3, exhaust passages 12" can be circular or oval, and main stack 11 " can be circular or oval, as well. Exhaust passages 12" can be positioned inside main stack 11 ", as illustrated. In addition, as with discharge system 10, exhaust passages 12" of discharge system 10" can each have their own damper 16". Discharge system 10" can operate similarly to discharge system 10. Thus, its operation is not discussed in detail herein.

[0054] It will be readily understood to those skilled in the art that various other changes in the details, material, and arrangements of the parts and method stages which have been described and illustrated in order to explain the nature of the inventive subject matter can be made without departing from the principles and scope of the inventive subject matter as expressed in the subjoined claims. For example, the order of method steps or stages can be altered from that described above, as would be appreciated by a person of skill in the art.

[0055] It will also be appreciated that the various dependent claims, examples, and the features set forth therein can be combined in different ways than presented above and/or in the initial claims. For instance, any feature(s) from the above examples can be shared with others of the described examples, and/or a feature(s) from a particular dependent claim may be shared with another dependent or independent claim, in combinations that would be understood by a person of skill in the art.