Patent Publication Number: US-6338437-B1

Title: Process and apparatus for individual adjustment of the temperature set points of a plurality of VAV devices through a network server

Description:
RELATED APPLICATION 
     This is a continuation-in-part application of my prior application, Ser. No. 09/311,379 now U.S. Pat. No. 6,220,518, filed May 13, 1999. 
    
    
     TECHNICAL FIELD 
     The present invention relates, in general, to heating, ventilating and air conditioning (HVAC) systems, and more particularly to HVAC systems having variable-air-volume (VAV) diffusers or VAV boxes with adjustable temperature set point controllers. 
     BACKGROUND ART 
     The use of variable air volume (VAV) devices in order to control the temperature and/or ventilation in large buildings is wide spread. Such HVAC systems typically have at least one, and sometimes a plurality of VAV devices located in the various spaces, rooms or offices within the building for control of the discharge of conditioned air into the offices. The air will be provided by a central source, and the volume air discharged into each office within the building will be varied in accordance with the control mechanism for the VAV device. Such VAV devices typically have a damper or set of blades, which is moved by an actuator so as to change the area of the opening from which conditioned air is discharged from the VAV device. VAV boxes most often are positioned upstream of a plurality of passive (damperless) air diffusers, while VAV diffusers include actuators and dampers at the structure discharging air into the space or office. 
     The control assembly for a VAV device will have one or more temperature set points which are used as a basis for regulating opening and closing of the damper by the actuator so as to drive the room temperature toward the set point. One set point may be used, for example, when the system is in a heating mode, while another may be used for a cooling mode. In some systems, however, the same temperature set point is used for heating and cooling. 
     In large office buildings, the HVAC system will be coupled to a plurality of thermostats located in the various offices or to a central building HVAC computer for monitoring and adjusting the set points for the VAV devices. In multiple thermostat systems, wiring must be run between individual VAV devices and the thermostats. In central computer systems, the computer is coupled through an HVAC building computer network that is coupled to the VAV devices. The central building control computer, therefore, can be used to monitor and adjust the set point temperatures of the various actuators in the VAV devices for individual offices. 
     One of the major disadvantages of thermostat-based systems is the wiring required during installation, which can be tricky in open office environments having free-standing work stations and space-dividing partition systems. A major disadvantage of building-wide HVAC computer monitoring systems is that the temperature set point adjustments must be made from a central monitoring station. Thus, the occupants of the individual offices in the building are not able to provide direct input as to the desired temperature set point for the VAV device effecting their office. Instead, occupants typically communicate with the building central monitoring and adjustment computer by telephone so as to make their wishes known with respect to environmental demands in their office. 
     It would be highly desirable, therefore, to have an HVAC system suitable for large buildings in which the individual VAV devices are capable of having their temperature set point independently directly adjusted by occupants of the offices through a method other than using wall-mounted thermostats. Thus, the occupants, who know best what environmental conditions are most suited for their office at a given time, would like to have a way of adjusting the HVAC system for their space without having to communicate with, or go through, a central monitoring computer, and without having to go to a wall-mounted thermostat. 
     Accordingly, it is an object of the present invention to provide a process and apparatus for individual adjustment of the temperature set points of a VAV device located in an occupant&#39;s office without affecting other offices and without using a thermostat or having to communicate by telephone to a person at a central computer. 
     It is a further object of the present invention to provide a means for the occupant of a space in the building to easily adjust the temperature set points of the VAV device discharging air into his or her space using computer equipment commonly available in an office environment, such as personal computers, local area or wide area network and network services. 
     It is still a further object of the present invention to provide a VAV device adjustment system which is easy to install, is user-friendly, is relatively low in cost and provides a wide range of user flexibility. 
     The process and apparatus of the present invention have other objects and features of advantage which will become more apparent from, and are set forth in more detail in, the following Description of the Best Mode of Carrying Out the Invention and the accompanying drawings. 
     DISCLOSURE OF THE INVENTION 
     A process for individual adjustment of the temperature set point of a plurality of VAV boxes in an HVAC system for a building is provided, which is comprised, briefly, of coupling a plurality of computers, located in a plurality of spaces or offices in the building for input of a temperature set point based signal which can be communicated, directly or through a network server, to the VAV device located for the discharge of air into each space in which the computer is located. The temperature set point based signal can be a signal from a computer input device which is directly communicated, using a wired or wireless coupling, to the VAV device, or it can be a signal which is input to a network server device and thereafter is used to control the VAV device. Each VAV device is responsive to the temperature set point based signal to adjust the temperature set point for the VAV device in the space of the selected computer. The method includes further the steps of inputting a temperature set point from a selected computer for adjustment of the VAV device located in the same space; and communicating a temperature set point based signal from the selected computer to the VAV device by using one of a direct coupling and encoded signals through a network server to effect adjustment of the temperature set point independently of other VAV devices in the HVAC system. 
     The HVAC system of the present invention comprises, briefly, a plurality of VAV devices each adapted for receipt of a signal to adjust a temperature set point for operation of the VAV device, at least one of the VAV devices being located in each of a plurality of spaces in a building, and a plurality of computers each adapted to produce signals suitable for adjusting the temperature set point of a VAV device and being located in the plurality of spaces having the VAV devices therein. The plurality of computers each further are directly or indirectly coupled and adapted for the transmission of a signal to the VAV device located in the same space so as to adjust the temperature set point of the VAV device. 
     In the most preferred form, a desktop, laptop or other multipurpose computer of the type commonly employed in business, government and educational applications is coupled through a first computer network to the network server, and the network server is coupled to a second network which is connected to each of the VAV devices. Temperature set point based signals can be stored periodically in the server, retrieved and communicated as temperature set point based encoded signals on the second network to the VAV devices so as to enable adjustment of the VAV device temperature set point in the office or space having input the server. Optionally a building control computer can be coupled to the server or the second network. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a fragmentary, schematic, top plan view of a typical building floor plan having an HVAC system with a plurality of VAV devices monitored and adjusted in accordance with the present invention. 
     FIG. 2 is a schematic flow diagram of the VAV device temperature set point adjustment process of the embodiment of FIG.  1 . 
     FIG. 3 is a schematic representation of an alternative embodiment of the HVAC system of the present invention showing use of a network server assembly to effect temperature set point based signal communication. 
     FIG. 4 is a schematic flow diagram of the process of the embodiment of FIG.  3 . 
    
    
     BEST MODE OF CARRYING OUT THE INVENTION 
     In recent years the multipurpose business or personal computer has become omnipresent in modern office buildings. Such computers may take the form of desktop, laptop or even hand-held devices, and they may be stand-alone or coupled by wires or coupled wirelessly to local area or wide area networks. In accordance with the present invention, such computers may be adapted for use to individually adjust an operating parameter of a VAV device, such as the temperature set point. Thus, a personal computer located in the same office or space in which the VAV device is controlling the environmental conditions can be used, in the apparatus and method of the present invention, to monitor and adjust the temperature set point(s) of the VAV device. 
     Referring now to FIG. 1, a first embodiment of a typical HVAC system installation for an office building is schematically illustrated. Building  21  has a plurality of offices, rooms or spaces  22  that are air conditioned using a plurality of VAV devices supplied with conditioned air from a central source  23 . The operation of the VAV devices can be monitored and adjusted by a central or building computer at monitoring station  24 . Ducts  26  for the flow of supply air from a central air conditioning source  23  to the VAV devices are provided. Alternatively, building  21  could be initially provided with a plurality of wall-mounted thermostats (not shown) which are wired to the various VAV devices so as to control the flow of supply air from source  23  being discharged into offices  22 . 
     VAV devices usually take one of two forms, namely, an air diffuser which has an actuator and movable damper assembly in it (graphically symbolized in the drawing by a square with diagonal crossed lines), or a VAV box (also a square with a cross) upstream of passive or damperless air diffusers (squares only) which discharge supply air into spaces  22 . A large office or space  22   a,  for example, can include a VAV box  27  employed to vary air flow to a plurality of passive air diffusers  28 . In smaller spaces, such as space  22   b,  VAV air diffusers  29  having movable dampers will more typically be employed. 
     Although VAV devices  27  and  29  are not always linked together for monitoring by central computer  24  (e.g., when a thermostat system is used), in the illustrated HVAC system, central computer  24  is attached to an HVAC building system computer network  32 , which in turn, is coupled to each of the VAV devices  27  and  29 . Each of the VAV devices  27  and  29  includes a control assembly in which there is an actuator and interface so that encoded temperature set point based signals received from central computer  24  through network  32  can be used to adjust the set point(s) temperatures about which a given VAV device operates. Each VAV device may be thermally powered, pneumatically powered or electrically powered, and typically each VAV device will have one or more temperature set points governing its operation. One temperature set point, for example, might be used when the central source of conditioned air  23  is in a heating mode, while another temperature set point at each VAV device might be employed when source  23  is in a cooling mode. 
     Such HVAC systems using VAV devices are well-known in the art, and they allow central computer  24  to monitor the current temperature set points of each of the VAV devices, as well as send encoded signals along the HVAC computer network  32  to individual VAV devices so as to adjust or change the temperature set points, and thus operation of the system, on a space-by-space basis. 
     The primary drawback of such central computer systems has been that occupants in any one of offices or spaces  22  either have little ability to adjust the operation of the VAV devices in their office, or they must do so through cumbersome techniques, such as telephoning an operator or computer at the central computer  24 . In thermostat-based systems, the occupant must get up from his or her desk and go to the wall thermostat, and such thermostat-based systems also have initial installation disadvantages in terms of wiring costs. 
     The present invention utilizes the fact that computer hardware is in wide-spread use in office buildings of the type which are air conditioned using VAV devices. Thus, as shown in FIG. 1, offices  22  will usually have one or more personal computers  34  located in them. In some offices, such as office  22   c,  computer  34  will be a stand-alone computer, while in others, for example office  22   a,  computers  34  will be coupled together by a local area network  36 . In conventional configurations neither the stand-alone computers nor those coupled together through a local area network will interact or be coupled in any manner to building HVAC computer network  32 , nor to any of the VAV devices. Building computer network  32 , therefore, normally is operated totally independently of computers  34  in use by the building occupants. 
     In the process and apparatus of the present invention, however, a plurality of multipurpose business computers  34  located in a plurality of offices or spaces  22  in building  21  are coupled for input of temperature set point based signals directly (in the embodiment of FIG. 1) or indirectly (in the embodiment of FIG. 3) to at least one VAV device located for discharge of air into the same office or space in which computer  34  is located. Thus, computer  34   d  in space  22   d  is coupled for the direct input of temperature set point based signals to VAV device  29   d,  while computer  34   e  is coupled to directly input signals to VAV device  29   e  in space  22   e.    
     As can be seen for space  22   a,  VAV box  27  is typically located outside space  22   a,  but computers  34   a  in space  22   a  are coupled to VAV box  27  to enable monitoring and adjustment of the set point temperatures for VAV device  27  so as to vary the discharge of air from passive diffusers  28  in space  22   a.  As used herein, therefore, computers are coupled to the VAV device “located for the discharge of air” into the same space or office as the computer, even though the VAV device, an upstream control box  27 , may be located in a space outside that in which the computer is located. 
     The direct coupling of computers in spaces  22  to their respective VAV devices can be accomplished in several different manners. A wireless approach is illustrated in office  22   c  in which a transmitter, or preferably transceiver, graphically shown at  37 , at computer  34   c  communicates with receivers, or preferably transceivers,  38  at one or more VAV devices. In office  22   c,  two VAV devices  29   c  are provided with transceivers  38  which can communicate with the transceiver  37  at computer  34   c.  The same signal when transmitted from computer  34   c  will be capable of adjusting the set point temperature of each of the VAV devices  29   c.  Computer  34   c  will include a program which causes the transceiver  37  to broadcast signals to the two VAV devices. The VAV devices, in turn, have an interface between transceivers  38  and the controller for the diffuser actuator so that adjustment of the set point for the controller in each of the VAV devices can be accomplished. Such interface and diffuser controller technology is well-known in the art. The computer  34   c,  however, normally will not be capable of transmitting a signal which would effect a change in the temperature set point of VAV device  29   d.  This can be accomplished easily by using encoded transmissions or limiting the power of the transmitter or crippling (limiting) the sensitivity of transceivers  38 . 
     In the most preferred form, transceivers  37  and  38  are radio frequency transceivers, but it will be understood, optical or other forms of transceivers also could be employed. 
     An alternative manner of directly coupling computers  34  to VAV devices  27  and  29  would be simply to provide an electrical signal communicating wire, link or cable. Thus, in office  22   d,  a stand-alone computer  34   d  is coupled directly to VAV device  29   d  by a cable  33  for the communication of signals to the controller of VAV device  29   d.  Still a further approach is shown in connection with the computer  34   e  in space  22   e.  Computer  34   e  is coupled by cable  35  to a router box  40  which, in turn, enables encoded signals to be sent through cable  35  and router  40  and thereafter over building HVAC network  32  to VAV device  29   e.  When this type of coupling technique is employed, computer  34   e  should include software, or another adaptation, which causes the output signal from computer  34   e  to be capable of adjusting only the set point of VAV device  29   e.  An encoded output signal, for example, would suffice. 
     Local area network  36  for computer  34   a  also can be coupled by cable  36   a  to a router  41  inserted in building management HVAC network  32 . Encoded signals generated by input at any of computers  34   a,  therefore, would travel through local area network  36 , link  36   a,  router  41  and building HVAC network  32  to VAV device  27 . 
     Still a further direct coupling technique is shown in connection with offices  22   f  and  22   g . Computers  34  are connected to a local area network  42 , which can then be directly coupled at  43  to diffusers  29 . This approach does not require connection to building HVAC network  32 , but it does require encoded signals or the like so that the computer in space  29   f  does not adjust operation of the VAV device in space  22   g.  It would be possible, of course, to link local area network  42  to building network  32 , which usually would be preferred since less wiring would be required than employing a plurality of cable links  43 . 
     In the preferred direct coupling embodiment, all computers  34  would enable communications in both directions so that the occupant in a space  22  can poll the VAV devices  27  and  29  to determine what their current temperature set points are and thereafter send a signal back to the appropriate VAV device changing the same. 
     Referring now to FIG. 2, the process for independent adjustment of temperature set points of a plurality of VAV devices in the HVAC system of FIG. 1 can be described. The first step  51  of the process is to couple each of a plurality of computers to at least one of a plurality of VAV devices. Each computer is formed or adapted to produce signals suitable for adjustment of a temperature set point of a VAV device to which it is coupled. Most typically this will be accomplished by providing each computer with a VAV temperature set point adjustment software program that can generate an encoded output signal suitable for transmission directly to the VAV device or communication via a network or a plurality of networks to the VAV device. 
     It should be noted that in a given building  21  having a plurality of offices  22 , not all of the offices need to have VAV devices which are individually adjusted using individual computers. Thus, a plurality of spaces  22 , perhaps less than the entire building, may be individually adjustable by occupant computers, while another set of spaces or offices are not so coupled. 
     The second step  52  in the present process is to input into a selected computer a temperature set point adjustment input for the VAV device discharging air into the space in which the computer is located. Thus, in the broadest form of the process each computer would merely be capable of inputting temperature set points, for example, through a keyboard or through a graphical interface displayed at the computer and manipulated using a mouse. The graphical display, for example, can simply be a thermometer in which the curser driven by the mouse is used to adjust a graphical temperature symbol on a screen to change the temperature set point. 
     While the broadest form of the process merely requires inputting, it is most preferable that the individual computers  34  further be adapted to retrieve temperature set point data from VAV devices  27  and  29 . Thus, an optional step  53 , prior to inputting step  52 , would be to retrieve the current temperature set point from the VAV device by polling the controller of the VAV device to determine its current temperature set point setting. Once this information is retrieved, an additional optional step  54  in the present process would be to display the retrieved current setting, either as a numeric display or a graphic display. 
     Having retrieved the current temperature set point setting and displayed it, the present process would then proceed with user inputting  52  for adjustment of the temperature set point for the VAV device discharging air into the space having the computer. Finally, the software in computer  34  communicates, at step  56 , the new temperature set point to the VAV device  27  or  29  in the form of a temperature set point based signal, usually encoded, directly to the VAV device through direct links or network links. 
     In FIG. 3, the process and apparatus of the present invention are implemented using a network server assembly, or equivalent data storage and retrieval device that can have temperature set point based signals or data stored therein and have such data or signals selectively retrieved for communication to the VAV devices. 
     In FIG. 3, office spaces  22   f  and  22   g  are used, as shown in FIG. 1, except that local area network  42  is not directly wired to VAV devices  29  nor to building local area network  32 . Instead, first network  42  is shown coupled through ethernet adapter card  62  to a network server assembly, generally designated  61 . Server  61 , in turn, is coupled through network adapter card  63  to a second network, namely, building local area network  32 , which is connected to transmit signals to the VAV diffusers  29  in spaces  22   f  and  22   g.  Network server  61  will include its own computer and software, as well as data storage capacity. Building control computer  24  also is connected to server  61  for input thereto. It will be understood, however, that in some systems a building control computer need not be present, and the HVAC system can be run using software on server  61 . The coupling between first network  42  and server  61  could also be wireless, as could the coupling between server  61  and second network  32  and/or network  32  and VAV devices  29 , as well as between server  61  and building computer  24 . 
     Thus, in the illustrated system building control computer  24  can be used to input to server  61  from the building control network database, and the first local area network or business intranet  42  can access the data in server  61  and input signals or commands to server  61 . This allows each computer  34  to retrieve current VAV operating parameters stored in server  61 , and, as permitted by the VAV control circuit, change them. In the preferred embodiment, the temperature set point controlling VAV diffuser operation can be changed. 
     Referring now to FIG. 4, the operation of the system of FIG. 3 can be described. The step  51  of coupling a plurality of computers  34  to at least one of a plurality of VAV diffusers or devices  29  of FIG. 2 remains as the first step in FIG.  4 . The coupling step is indirectly accomplished in the FIG. 4 embodiment, for example, by coupling computers  34  to local area business network  42 , which in turn, is coupled to server device  61 , that in turn, is coupled to local area building network  32  and VAV devices  29 . 
     As was the case for the embodiment of FIG. 1, the broadest aspect of the FIG. 3 embodiment also includes an inputting step  52 . Usually, however, a database is established in server  61 . This can be accomplished by a program in building control computer  24  which polls or determines the current operating parameters set points, at step  64 , of the various VAV diffusers  29  to obtain current operating parameters, such as, the current temperature set point, flow rate, supply air temperature, room air temperature. At step  66  building computer  24  stores these data in server  61  and optionally in computer  24 . It will be understood that server  61  could have the software for polling the VAV devices for their operating parameters, as well as storing the same in a storage device in server  61 . 
     The user at a selected computer  34 , for example, the computer in space  22   f,  can then access data, at step  67 , stored in server  61  and display or view the current operating parameters of the diffuser  29  in space  22   f  at step  54 . Next, as was described in connection with FIG. 2, the user inputs a temperature set point adjustment using the computer keyboard, graphical interface, etc., at step  52 , which is communicated to server  61  at step  56   a.    
     The final step is to communicate, at step  56   b,  the user temperature change to the VAV device  29 . This is accomplished in the HVAC system of FIG. 3 by sending an encoded temperature set point based signal from server  61  via second or building network  32 . Communicating step  56   b  may be accomplished by software in building control computer  24  or by software in server  61 . In the preferred approach, the software in the server makes the change to the server database and then automatically probagates or communicates the change to the VAV device. It will be apparent that the building computer also could periodically poll the server database and then send or communicate changes to the VAV devices. In any event, new temperature set point based signals are sent by computer  24  or server  61  as encoded signals to the VAV diffusers, including diffuser  29  in space  22   f  via building or second network  32 . The encoded temperature set point based signal on second network  32  is reacted to by only the controller for the VAV diffuser in office  22   f,  and the temperature set point is thereby changed. 
     Thus, unlike the approach used when central building computer  24  controls each VAV device, in the present invention a plurality of computers  34  are positioned in a plurality of spaces  22  in the building and coupled, directly or indirectly, to VAV devices so that they are able to adjust, and preferably monitor, the temperature set point in the VAV device which discharges air into the same space as the computer is located. This allows the occupant of an office to be able to make an adjustment of only the VAV device which affects his or her environment, without even leaving his or her desk or work station. The only requirement is wired or wireless coupling of the occupant&#39;s computer directly or indirectly to the VAV device. Direct coupling can be accomplished through transmitters and receivers, direct electrical connection to the VAV device or the building HVAC network, coupling a local area network directly to the VAV device, or coupling a local area network to the building HVAC control network which is coupled to the VAV devices. 
     Indirect coupling occurs through the use of a network server or data storage and retrieval assembly, and software which allows the user to determine the current operating conditions from a database, input a change to the database, and communicate the change to the diffusers using an encoded signal to effect the change. 
     The present apparatus and process, therefore, allow the individual occupants of offices to monitor and adjust their environment at their work stations using conventionally available equipment, the multipurpose business or personal computer, local area networks and network servers. A rather simple temperature set point programs can be provided for the computers and servers employed. The VAV device, of course, must further be capable of having its temperature set point adjusted through the receipt of temperature set point based signals to the controller for the VAV device. 
     One example of a VAV device suitable for adjustment by a multipurpose personal or business computer is the device described in detail in commonly owned, co-pending, patent application Ser. No. 09/218,370, entitled VARIABLE-AIR-VOLUME DIFFUSER ACTUATOR ASSEMBLY AND METHOD. In this VAV device, thermal actuators are electrically controlled, using a resistance heater. Other VAV devices, including pneumatically controlled and motor-driven diffusers and VAV boxes also are suitable for use in the system of the present invention.