Abstract:
An automatic air duct register system operating within an HVAC system comprises an automatically controlled register. The register includes louvers which are electromechanically adjusted in order to control the airflow through the register. The register may be opened or closed, responsive to a programmable electronic timer or clock, an occupancy sensor, or in response to a measured temperature. The register system may be part of a control network, wherein the network communicates programming information to the register system, and wherein the network reads information from the register system. The register system may be self-powered, utilizing an electrical generator powered from airflow from the duct attached to the register system.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a system comprising automatically controlled air duct registers in a heating/ventilation/air conditioning (HVAC) system. 
         [0002]    As is well known, buildings, including homes and businesses, are typically equipped with a centrally-controlled HVAC system. A common type of HVAC system is known as a forced-air system, and comprises a central furnace (for heating) or air conditioning system (for cooling) to provide heated or cooled air, respectively, to a network of air ducts throughout the building. The air ducts deliver the heated or cooled air to various rooms within the building through registers, which are affixed to the terminus of the various ducts where they enter the rooms. 
         [0003]    Often, HVAC systems are equipped with a single thermostat which controls the temperature in the building according to the thermostat&#39;s temperature setting. The thermostat is installed in a central location, and turns on the furnace or air conditioning system when the temperature at the thermostat falls below, or rises above, its temperature setting, indicating a need for heating or cooling, respectively. 
         [0004]    HVAC systems with a single thermostat control are referred to as single-zoned systems. It is commonly known that the drawback to single-zoned HVAC systems is that the temperature in various rooms away from the thermostat can vary significantly from the thermostat&#39;s temperature setting, since the temperature in these rooms does not influence the thermostat to affect the cycling of the furnace or air conditioning system. The degree of air flow from the register, individual doors being open or closed, exposure to open windows, and other environment factors determine the temperature in these rooms. Thus, while the thermostat maintains the temperature of the room in which it is installed, other rooms in the building may become uncomfortably hot or cold. 
         [0005]    Further, some rooms in the building may not be occupied for certain periods. In this case, it may be desirable to reduce the amount of heating or cooling of these rooms during these periods in order to save energy costs. In single-zoned HVAC systems, adjusting the thermostat&#39;s temperature setting can reduce the amount of heating or cooling, but affects the temperature in the entire building rather than individual rooms. If fitted with louvers that can be opened and closed mechanically, such as with lever  110  shown in  FIG. 1 , individual registers in the rooms may be manually closed off during unoccupied periods, but this is inconvenient, requiring the occupant to operate the lever manually at certain times. 
         [0006]    Buildings can be equipped with HVAC systems with multiple zones. Buildings with multiple-zoned HVAC systems have multiple thermostats, each controlling the temperature in a portion (zone) of the building&#39;s rooms. Each thermostat may turn on or off the airflow through the subset of ducts that service those rooms, utilizing electrically controlled in-line dampers, thus controlling heating or cooling of these areas. The thermostats may work together to control the turning on and off of the central furnace or air conditioning system, such that any thermostat indicating a need for heating or cooling may turn on the central system. 
         [0007]    The main drawback of multiple-zoned HVAC systems is cost. The material cost of in-line dampers, power transformers used to power the dampers, control electronics, wiring, and additional thermostats can be substantial. However, the installation cost may exceed the material cost, especially if the zones are being added to an existing HVAC system; in this case, ducts must be retrofitted inside crawlspaces, walls and ceilings, and wiring routed to a controller located near the furnace or air conditioning unit. The installation work is typically done by a contractor specializing in HVAC work, resulting in high skilled labor costs. 
       SUMMARY OF THE INVENTION 
       [0008]    The invention disclosed is an automatic air duct register system (“register system”) operating within an HVAC system, comprising an automatically controlled register. The register includes louvers which are electromechanically adjusted in order to control the airflow through the register. 
         [0009]    In one embodiment, the register may be opened or closed, responsive to an electronic timer or clock included within the register system. The timer or clock may be programmed, so that the register is closed at certain predetermined times. Thus, energy is saved, as the room is effectively cut off from the HVAC system when the register is closed. The airflow from the central furnace or air conditioning system that had been intended for this room may service other rooms within the building or home. 
         [0010]    In another embodiment, the register may be opened or closed, responsive to an occupancy sensor determining when the room serviced by the register system is unoccupied. Thus, energy is saved, as the room is effectively cut off from the HVAC system when the register is closed. The airflow from the central furnace or air conditioning system that had been intended for this room may service other rooms within the building or home. 
         [0011]    In another embodiment, the register system may include an infrared temperature sensor, designed to accurately measure the temperature in a room, the register&#39;s airflow controlled in accordance with the comparison of a measured temperature and a desired temperature setpoint. Thus, the temperature of the room is locally controlled with the register system, reducing temperature fluctuations and increasing comfort. 
         [0012]    In another embodiment, the register system is part of a control network, wherein the network communicates with the register system. The register system accepts commands to set the timer or clock, or set the desired temperature setpoint. The register system may send information about the temperature measured in the room, or other information about the register system. Thus, the register system may be operated remotely with network control, obviating the need to program the register system on-site, improving the convenience of the system. 
         [0013]    In another embodiment, the register system is self-powered, utilizing power generated from the flow of air through the register. The power may be derived utilizing a turbine connected to an electric generator. The power may be stored in a large value, low voltage capacitor (supercapacitor) or rechargeable battery, thus eliminating the need to replace batteries in the system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings. 
           [0015]      FIG. 1  illustrates an example of a prior-art air duct register. 
           [0016]      FIG. 2A  illustrates an air duct register system according to one or more embodiments of the invention (top view). 
           [0017]      FIG. 2B  illustrates an air duct register system according to one or more embodiments of the invention (bottom view). 
           [0018]      FIG. 2C  illustrates an air duct register system according to one or more embodiments of the invention. 
           [0019]      FIG. 2D  illustrates an air duct register system according to one or more embodiments of the invention. 
           [0020]      FIG. 3A  illustrates an air duct register system according to one or more embodiments of the invention (top view). 
           [0021]      FIG. 3B  illustrates an air duct register system according to one or more embodiments of the invention (bottom view). 
           [0022]      FIG. 4  illustrates an air duct register system according to one or more embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0023]    The Figures (FIG.) and the following description relate to preferred embodiments of the present invention by way of illustration only. It should be noted that from the following discussion, alternative embodiments of the structures and methods disclosed herein will be readily recognized as viable alternatives that may be employed without departing from the principles of the claimed invention. 
         [0024]    Reference will now be made to several embodiments of the present invention(s), examples of which are illustrated in the accompanying figures. Wherever practicable similar or like reference numbers may be used in the figures and may indicate similar or like functionality. The figures depict embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein. 
         [0025]      FIG. 2A  illustrates an air duct register system  201  according to one embodiment of the invention, showing the top view. Register grille  210  may be mounted flush against a wall or ceiling, and is attached to the end of an air duct which is part of a forced-air HVAC system. Register grille  210  acts as an air diffuser as well as a mechanical base for air duct register system  201 , and is designed to conform to the dimensions of common industry-standard register grilles for ease of retrofit installations. Air duct register system  201  includes an electromechanical means to automatically open and close louvers contained within air duct register system  201 , thus controlling the airflow by allowing or impeding the flow of air through the registers (described later). 
         [0026]    In one embodiment, the register may be opened and closed responsive to an electronic timer or clock included within the register system. The timer or clock may be programmed, so that the register is closed at certain predetermined times, such as during times when the room is unoccupied. Thus, energy is saved, as the room is effectively cut off from the HVAC system when the register is closed. 
         [0027]    Control knob  211 , a 24-position, single-pole detent-type switch, in conjunction with pushbutton/indicator  212 , a combination 4-color LED assembly and SPST pushbutton switch, together may serve to set the clock, as well as the desired time periods during which the register is to remain closed. An operation to program the clock and these time periods may proceed as follows. The user presses pushbutton/indicator  212  until pushbutton/indicator  212  flashes yellow. The user then turns control knob  211  to the current hour of day (each detent position has a corresponding label 0-23, with 0 signifying midnight, 23 signifying 11 PM, and the numbers in between signifying the hours between midnight and 11 PM). Pressing pushbutton/indicator  212  again programs the hour of day indicated by control knob  211 , setting this hour of day value as the current real-time-clock (RTC) value included in a microcontroller (described later). Next, the user presses pushbutton/indicator  212  again until pushbutton/indicator  212  flashes green. The user then turns control knob  211  to the hour of day at which it is desired that the register be opened. Pressing control knob  211  again programs this “register open” hour of day into air duct register system  201 , writing this value into the RAM included in the microcontroller. Finally, the user presses pushbutton/indicator  212  again until pushbutton/indicator  212  flashes red. The user then turns control knob  211  to the hour of day at which it is desired that the register be closed. Pressing pushbutton/indicator  212  again programs this “register close” hour of day indicated by control knob  211 , writing this value into the RAM included in the microcontroller. Thus, the air duct register system is programmed to open and close at the “register open” and “register close” times. As described previously, energy is saved, as the room is effectively cut off from the HVAC system when the register is closed, while saving the user from the inconvenience of manually opening and closing the register. 
         [0028]    While one example of setting the time periods during which the register is to remain closed has been described, any number of alternative methods may be used, including those utilizing knobs, buttons, indicators, and interfaces to a personal computer such as USB. 
         [0029]      FIG. 2B  further illustrates an air duct register system  201  according to the current embodiment of the invention, by showing the bottom view. Louvers  222 ,  223 , and  224  are ganged together using arm  221 , and so may be opened and closed together. When in the “open” position, the louvers permit air flow through the register, and when in the “closed” position, the louvers restrict air flow through the register. Gear-reduced motor  220  rotates the fulcrum of louver  224 , opening or closing the ganged-together louvers depending on the rotational direction of the motor. Gear-reduced motor  220  may be a low cost DC motor suitable for operation from low voltages, such as 3.6V from 3 primary AA batteries, combined with a gear reduction assembly which reduces the rotational speed of the gear-reduced motor shaft which rotates louver  224 . 
         [0030]    Battery assembly  226  comprises 3 primary AA batteries connected in series and held with a plastic housing, and provides the source of power air duct register system  201 . Power provided from the AA batteries in battery assembly  226  is routed to microcontroller  225 . Microcontroller  225  may include an 8 bit processor, embedded RAM, embedded ROM, general purpose input/output (GPIO) lines, real-time clock (RTC), and a collection of analog-to-digital (A/D) and digital-to-analog (D/A) converters, integrated into a single IC. The ROM contained in microcontroller  225  includes basic programming code which, for example, enables the programming steps to set the timer (described previously). Microcontroller  225  also may control H-bridge MOSFET switch  227 , utilizing its logic-level GPIO lines. H-bridge MOSFET switch  227  provides power to gear-reduced motor  221  derived from the AA batteries in battery assembly  226 , via four switches in an H-bridge configuration. By setting the configuration of H-bridge MOSFET switch  227  using its logic-level inputs, microcontroller  225  may cause power to be applied to gear-reduced motor  220  in either a positive polarity, a negative polarity, or neither polarity (in which case power is turned off entirely). Microcontroller  225  can therefore control the gear-reduced motor  220  to rotate clockwise, counter-clockwise, or turn off, and thus control the opening or closing the ganged-together louvers  222 ,  223  and  224 . The ROM contained in microcontroller  225  includes basic programming code which compares the programmed desired times against the current RTC value, and thus may close the louvers based on the programmed desired time periods during which the register is to remain closed, and opens the louvers at all other times. 
         [0031]      FIG. 2B  may also be used to illustrate another embodiment of the invention. IR sensor IC  228  is an infra-red detector IC, capable of measuring the room temperature and providing the temperature reading to microcontroller  225  in a digital format. IR sensor IC  228  may be the device MLX90615 manufactured by Melexis Microelectronic Systems. The ROM contained in microcontroller  225  includes basic programming code which may command the opening and closing of the louvers based on a mathematical comparison of the temperature reading from IR sensor IC  228  and a programmed desired temperature setpoint. The programming code may add hysteresis to the temperature comparison, to prevent excess cycling of the control loop. 
         [0032]    Referring back to  FIG. 2A , control knob  211 , in conjunction with pushbutton/indicator  212 , a combination 4-color LED assembly and SPST pushbutton switch, together may serve to set the desired temperature setpoint. An operation to program the temperature setpoint may proceed as follows. The user presses pushbutton/indicator  212  until pushbutton/indicator  212  flashes blue. The user then turns control knob  211  the desired temperature setpoint (each detent position has a corresponding label 60 to 80, signifying the desired temperature). Pressing pushbutton/indicator  212  again once programs the system to be in “heating” mode, while pressing the button twice programs the system to be in “air conditioning” mode, and in both cases programs the desired temperature setpoint indicated by control knob  211 , writing this value into the RAM included in a microcontroller (described previously). Thus, for an HVAC system that is programmed to “heating” mode, the air duct register system  201  is programmed to open the register if the temperature falls below the desired temperature setpoint, and to close the register if the temperature rises above the desired temperature setpoint. For an HVAC system that is programmed to “air-conditioning” mode, the air duct register system  201  is programmed to close the register if the temperature falls below the desired temperature setpoint, and to open the register if the temperature rises above the desired temperature setpoint. Since the room is effectively cut off from the HVAC system when the register is closed, further heating or cooling of the room via the register is prevented, and thus the temperature of the room is locally controlled with the register system, reducing temperature fluctuations and increasing comfort. 
         [0033]    As described previously, air duct register system  201  is fitted with an IR sensor (for example IC  228 ) which measures the room temperature. IR sensor IC  228  itself may be fitted with a lens which, through a lens opening in register grille  210  (not shown), detects IR energy reflected from a surface such as a wall. The wall may be at least 10 centimeters away from register grille  210 . This reflected IR energy represents the temperature at this wall surface with reasonable accuracy. Since the temperature of the wall is a good indication of the temperature of the room, IR sensor IC  228  may in this manner measure the temperature of the room. Advantageously, measuring the temperature some distance away from the register provides a more accurate measurement of room temperature, without interference from the airflow from the register or from the temperature of the grille, as would be present in a simpler measurement or ambient temperature (for example, using a thermistor). Thus, a reflected IR temperature measurement as described improves the accuracy of the measurement of the room temperature. 
         [0034]    While the aforementioned embodiments describe a timer and temperature control of the register, a combination of these techniques may be applied to enable a system which provides both timer and temperature control to air duct register system  201 . For example, referring back to  FIG. 2A , control knob  211  may function to help program both the timer and the temperature control. Each detent position on control knob  211  may be provided with two corresponding labels: (a) a label for setting the desired time periods (each detent period has a corresponding label 0-23, with 0 signifying midnight, 23 signifying 11 PM, and the numbers in between signifying the hours between midnight and 11 PM during which the register is to remain closed), and (b) a label for the setting of temperature (each detent position has a corresponding label 60 to 80, signifying the desired temperature). Thus, the programming steps in the aforementioned embodiments may be used together to program both timer and temperature control to air duct register system  201 . Thus, the register duct may be opened and closed in accordance with the comparison of a measured temperature and the programmed temperature setpoint, reducing temperature fluctuations and increasing comfort. Further, the register may be closed at certain predetermined times in accordance with the programmed time periods, saving energy, as the room is effectively cut off from the HVAC system when the register is closed. 
         [0035]      FIG. 2B  may also be used to illustrate another embodiment of the invention. As described earlier, IR sensor (for example IC  228 ) may be fitted with a lens opening in register grille  210  (not shown), which detects IR energy. The IR sensor and lens may be positioned to measure IR energy across a large portion of the room. With this arrangement, a measured change in IR energy can be detected when the room is occupied, since a person emits substantial IR energy due to natural body heat. Thus, the measurement of a change of IR energy in the room can be used to detect room occupancy. The ROM contained in microcontroller  225  includes basic programming code which may command the opening and closing of the louvers based on a mathematical change in reading from IR sensor IC  228 . When a decrease in IR energy is detected, the room is considered unoccupied, and the register duct may be closed. Energy is saved, as the room is effectively cut off from the HVAC system when the register is closed. The airflow from the central furnace or air conditioning system that had been intended for this room may service other rooms within the building or home. 
         [0036]    While one example of occupancy detection is described, any other method may be used to command the opening and closing of the louvers in the register. 
         [0037]    Air duct register system  201  may additionally be equipped with a means of determining the temperature of the air within the duct feeding the register of air duct register system  201  (duct temperature). Since the temperature of register grille  210  generally cools or warms to the duct temperature, and since microcontroller  225  is located in the direct vicinity of register grille  210 , the temperature of microcontroller  225  is a reasonable approximation to the duct temperature. A diode-based temperature detector may be integrated within microcontroller  225  to effectively measure temperature of microcontroller  225 , and consequently the duct temperature. A diode integrated into microcontroller  225  (not shown) may be biased with a fixed current, and the voltage drop across the diode may be converted to digital form periodically by the ADC integrated with microcontroller  225 . A program contained within the ROM of microcontroller  225  may periodically compare the digitized diode voltage drop to a table of values which correlate the diode drop voltage to temperature. In this way, the temperature of microcontroller  225  can be measured, and thus a reasonable estimate of the duct temperature can be determined. 
         [0038]    The measurement of duct temperature affords three further refinements to the described invention. First, the duct temperature (when the furnace or air-conditioning system is on) indicates whether the HVAC system is operating in “heating” or “cooling” mode. The ROM contained in microcontroller  225  may include basic programming code to determine if the duct temperature rises substantially higher than the ambient temperature (indicating the HVAC system is operating in “heating” mode), or if the duct temperature drops substantially lower than the ambient temperature (indicating the HVAC system is operating in “cooling” mode). Earlier, a method describing a programming sequence involving pushbutton/indicator  212  was used to program the system to switch between “heating” or “cooling” modes. Thus, the measurement of duct temperature removes the need for this programming step, and removes the need to reprogram the registers at seasonal changes when the HVAC system changes its mode of operation. 
         [0039]    Second, a rapidly rising (in “heating” mode) or falling (in “cooling” mode) duct temperature indicates that the air duct is experiencing a commenced air flow from the HVAC system. On the other hand, a rapidly falling (in “heating” mode) or rising (in “cooling” mode) duct temperature indicates that the air duct is experiencing a turning off of air flow from the HVAC system. The ROM contained in microcontroller  225  may include basic programming code to periodically record the duct temperature and calculate the rate of change of the duct temperature and make this determination. Air duct register system  201  may inhibit the opening or closing of the register unless it is determined that the register is experiencing air flow from the HVAC system. Thus, advantageously, the battery life of air duct register system  201  may be extended, because fewer cycles of opening and closing of the register results, reducing the frequency of operation of gear-reduced motor  220 . 
         [0040]    While one example of the measurement of the duct temperature is described, any other method may be used to determine the duct temperature. 
         [0041]      FIG. 2C  illustrates an air duct register system  201  according to another embodiment of the invention, illustrating the use of a tethered temperature sensor  240 , capable of measuring the room temperature and providing the temperature reading to microcontroller  225  in a digital format. Tethered temperature sensor  240  may be the device DS18S20 manufactured by Maxim Integrated Products. In this embodiment, tethered temperature sensor  240  essentially replaces IR sensor IC  228 . All function and programming are otherwise identical to the system described when utilizing IR sensor IC  228 . Tethered temperature sensor  240  essentially replaces IR sensor IC  228 . All function and programming are otherwise identical to the system described when utilizing IR sensor IC  228 . Tethered temperature sensor  240  has advantage of lower cost compared with IR sensor IC  228 . However, tethered temperature sensor  240  has a disadvantage that a wire connecting it to the air duct register system  201  is required. 
         [0042]      FIG. 2D  illustrates an air duct register system  201  according to two more embodiments of the invention, illustrating the use of wireless temperature thermometer/thermostat  250 , capable of measuring the room temperature and optionally providing temperature control to air duct register system  201 . Wireless temperature thermometer/thermostat  250  may comprise a radio conforming to the Zigbee radio protocol, communicating with corresponding Zigbee radio module  251 . 
         [0043]    In one embodiment, wireless temperature thermometer/thermostat  250  provides the temperature reading across a wireless link to radio module  251 . Radio module  251  may then communicate the temperature reading to microcontroller  225  in a digital format. In this embodiment, wireless temperature thermometer/thermostat  250  essentially replaces tethered temperature sensor  240  described earlier. All function and programming are otherwise identical to the system described when utilizing tethered temperature sensor  240 . Wireless temperature thermometer/thermostat  250  may be thermostat manufactured by ecobee, Inc. which communicates with radio module  251 . Wireless temperature thermometer/thermostat  250  has the advantage of removing the need for a wired connection to air duct register system  201 , providing further freedom to place wireless temperature thermometer/thermostat  250  at a convenient location within the room. However, wireless temperature thermometer/thermostat  250  has a disadvantage of higher cost. 
         [0044]    In another embodiment, wireless temperature thermometer/thermostat  250  controls the opening and closing of the register across a 2.4 GHz wireless link to radio module  251 . Radio module  251  may then communicate the register opening and closing commands to microcontroller  225  in a digital format. In this embodiment, wireless temperature thermometer/thermostat  250  essentially provides the function of a complete thermostat function, allowing the user to program wireless temperature thermometer/thermostat  250  to set the desired temperature. Wireless temperature thermometer/thermostat  250  may be a commercially available wireless thermostat communicating via the Zigbee wireless protocol, operating in the unlicensed 2.4 GHz band, such as ecobee&#39;s smart thermostat. Radio module  251  may be the radio module associated with the wireless thermostat, also communicating with the Zigbee wireless protocol. In this embodiment, wireless temperature thermometer/thermostat  250  has the advantage of removing the need for a wired connection to air duct register system  201 , and further for allowing simple remote control and programming without the user needing to access the controls on air duct register system  201  such as control knob  211  and pushbutton/indicator  212 . However, in this embodiment wireless temperature thermometer/thermostat  250  has a disadvantage of still higher cost. 
         [0045]      FIG. 3A  illustrates another embodiment of the invention. Air duct register system  201  includes turbine/electrical generator  310 , which is mechanically attached to register  210 . The airflow through register  210  spins turbine/electrical generator  310  and generates power, advantageously allowing air duct register system  201  to operate without batteries and without the need for the user to replace such batteries. 
         [0046]      FIG. 3B  illustrates a more detailed view (bottom). Turbine/electrical generator  310  may be mechanically attached to register duct at a sufficient spacing so as to allow free movement of louvers  222 ,  223  and  224 . Turbine/electrical generator  310  may be a modified or unmodified fan of a type typically utilized to cool electrical circuitry in a computer, such as Link Depot&#39;s model FAN-80-BK. The fan may be modified such that the electrical phasing circuitry, designed to synchronously energize the stator coils, is disconnected or bypassed, and current is generated from the coils is utilized directly. Specifically, the coil current generated by the rotation of the fan blades driven by the duct airflow is directly fed into diodes, which rectify the AC current and feed energy storage capacitor  311  either directly or through additional electronic conditioning circuitry to accurately control voltage. Energy storage capacitor  311  may be a supercapacitor type PB-5R0H474-R manufactured by Cooper Bussman. A small secondary battery may replace storage capacitor  311 . Thus, power generated from turbine/electrical generator  310  is stored in storage capacitor  311  which may be used to power the circuitry in air duct register system  201  previously described, as well as to power gear-reduced motor  221  used to open and close the register. 
         [0047]      FIG. 4  illustrates another embodiment of the invention, where the air duct register system  201  is connected to a wireless control network. Wireless node/router  411 , wireless temperature thermometer/thermostat  250 , and computer  410  may be components of the wireless control network. Computer  410  may contain executable software which is designed to set up the programming of one or more addressable air duct register systems such as air duct register system  201 , and is capable of communicating with a common WiFi protocol. Programming in this context means the programming of functions of air duct register system  201  as described previously, such as setting the desired temperature setpoint and setting of the time periods during which the register is to remain closed. The function performed by Computer  410  may also be performed by a wireless handheld device such as an iPhone 3GS manufactured by Apple Computer, Inc. connected via a cellphone network or a common WiFi protocol. Wireless node/router  411  may format and route programming signals from computer  410  to one or more addressed air duct register systems, by buffering and forwarding these signals on a radio system compatible with the radio module  251  installed in air duct register system  201 . 
         [0048]    The wireless network may provide bidirectional communication with air duct register systems such as air duct register system  201 . For example, air duct register system  201  may provide measured temperature data, battery conditions, duct “open” or “closed” status, or other information locally measured by the air duct register system. This information may be obtained when wireless node/router  411  queries air duct register system  201 , based upon a request for this information from computer  410 . 
         [0049]    Thus, the register system may be operated remotely with network control, obviating the need to program the register system on-site, improving the convenience of the system.