CA2877075A1 - Heating and cooling zone control system - Google Patents

Abstract

The present invention relates to a HVAC wireless zone control system comprising a plurality of air distribution registers at the discharge ends of the HVAC air flow ducts, one or more slave thermostats wirelessly communicating with registers within its zone to control the opening and closing of registers, and a master thermostat for controlling the air handling appliance and wirelessly communicating with each slave thermostat.

Description

Heating and Cooling Zone Control System TECHNICAL FIELD
[001] This disclosure relates to heating and cooling systems. In particular, this disclosure relates to a zone control system for regulating temperatures in different sections or zones in a residential or commercial building.
BACKGROUND

[002] Air temperatures within residential buildings are typically maintained by one or more heating and cooling systems. Different types of heating and cooling systems are known and used. This disclosure is directed to forced air heating and cooling systems. These are commonly referred to as HVAC systems, where HVAC means "heating, ventilation, air conditioning".

[003] In a traditional HVAC system, a single centrally located thermostat is used to control the temperature at or near a set-point temperature by switching heating or cooling devices (Furnace/Air condition) on or off. The thermostat has a sensor to determine the temperature in its immediate vicinity. In heating mode, if the sensed temperature is below the set-point temperature, the thermostat transmits a signal to the heating and air handling system to turn on. When temperature reaches the set-point the thermostat transmits a signal to the heating and air handling system to turn off. In cooling mode, if the sensed temperature is above the set-point temperature, the thermostat transmits a signal to the cooling and air handling system to turn on. When temperature reaches the set-point the thermostat transmits a signal to the cooling and air handling system to turn off. In some systems the heating or cooling part of the appliance may turn off and the air handling part continues to run.

[004] The central thermostat may be programmable to automatically or manually change the set-point to different temperatures over a 24 hour period and/or for several days, such as weekdays and weekend days.

[005] Heating and cooling residential spaces present several challenges to an HVAC system. Buildings may have multiple levels, rooms that face different directions (i.e. north, south, east or west), rooms having different window sizes, large open rooms with different ceiling heights, unfinished rooms, rooms over unheated garages or crawl spaces, or rooms that are frequently used and others that are only used occasionally.
These different environments often result in different room temperatures in different rooms or sections of a house. Moreover heating or cooling low use or unused interior spaces increases energy costs.

[006] One solution to uneven heating and cooling within a residential building is to divide the residential space into several zones or areas. A sensor or zone thermostat is provided for each room or zone for monitoring temperature in the zone. Such systems include a central controller and zone motorized dampers installed in the ductwork for each zone. When a zone needs to be heated or cooled, a signal is transmitted by the zone thermostat to the controller board. The controller board transmits a signal to the heating and cooling appliance and to one or more zone dampers causing the dampers to move to an open position to deliver conditioned air until the set point condition of the zone thermostat is met. When heating or cooling is not needed in a zone, the damper closes to save energy and maximize flow to other zones.

[007] The foregoing zone system with dampers within ductwork can be sized and more readily installed as part of a new construction but such damper systems are relatively expensive and are less suited and even more expensive to install when upgrading existing HVAC systems. The ducts in an existing residential building are not always accessible for installing the necessary motorized dampers. This results in considerable increased costs and a longer period of return on the capital cost for an upgraded HVAC system.
SUMMARY

[008] In one embodiment, the disclosure provides a new home HVAC zone control system comprising three basic units: a master thermostat, one or more slave thermostats, and air distribution registers at the discharge ends of the HVAC
air flow ducts.

[009] The master thermostat is programmable and controls the heating and cooling devices, such as a furnace and air conditioning unit. The master thermostat can also sense the temperature within its surrounding area. The master thermostat receives and transmits wireless signals to the slave thermostats. The master thermostat also processes system and operation data. The master thermostat may be controlled via a thermostat LCD interface or remotely via one or more computer processing units connected to a wired or wireless local area network (such as Wi-Fi or Bluetooth) within the residential space. If the residential network is connected to the Internet, the master thermostat may be controlled by computer processing units remote from the residential space. Computer processing units includes desk and laptop computers, tablets, and cell phones.

[0010] One or more slave thermostats are installed in different areas or rooms within the residential structure. A slave thermostat senses the temperature within its immediate area and transmits wireless signals to and may receive wireless signals from the master thermostat. A slave thermostat processes data received, such as its area temperature. A slave thermostat also transmits and receives signals to and from one or more registers located within the zone controlled by the slave thermostat.

[0011] Each air distribution register is provided with means to receive wireless signals from a slave thermostat and/or the master thermostat and means to wirelessly transmit signals to a slave thermostat and the master thermostat. Each register is provided with means to regulate the discharge air flow. A register may be assigned or paired with the master thermostat and/or a slave thermostat. The register receives commands from the master thermostat or slave thermostat to regulate the discharge air flow by opening and closing air vanes within the register.

[0012] The communication among master thermostat, slave thermostats and registers may be by any wireless communication means. For example, an IEEE
802.15.4 standard RF (Radio Frequency) link with unlicensed frequency band may be used for such wireless communication. The Frequency Band used in North American is 902-928MHz or 2400-2483.5MHz. For Europe, the Frequency Band is 868-868.6MHz.
BRIEF DESCRIPTION OF THE DRAWINGS

[0013] An embodiment will now be described in detail by way of example, with reference to the accompanying drawings in which:

[0014] Figure 1 is a block diagram of one embodiment of a zone control system according to the present disclosure.

[0015] Figure 2 is a block diagram of a master thermostat or microcontroller of the system in Figure 1.

[0016] Figure 3 is a block diagram of a zone thermostat or microcontroller of the system in Figure 1.

[0017] Figure 4 is a block diagram of a register of the system in Figure 1.
DETAILED DESCRIPTION

[0018] The description, which follows, and the embodiments described therein, are provided by way of illustration of an example, or examples of particular embodiments of principles and aspects of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention. In the description that follows, like parts are marked throughout the specification and the drawings with the same respective reference numerals.

[0019] Figure 1 shows one embodiment of the HVAC zone control system. A
centrally located master programmable thermostat or controller transmits and receives signals to the furnace/air conditioning appliance (also referred to as the "air handling appliance"). The master thermostat may be controlled via a thermostat interface or remotely via a wired or wireless local area network (such as Wi-Fi, Bluetooth and other wireless protocols) within the residential space. If the residential network is connected to the Internet, the master thermostat may also be controlled by remote computers, cell phones, tablets and similar devices. The master thermostat may be programmed to transmit and receive wireless signals to one or more room registers discharging conditioned air into a room or zone. For example, the master thermostat may control one or more registers in the room in which the master thermostat is located.

[0020] The master thermostat receives wireless signals from one or more slave or satellite thermostats located in different rooms or in zones comprising one or more rooms of the residential building. A slave thermostat senses temperature within its zone. Each slave thermostat may be set to the same or a different set-point temperature than the set-point temperature of the master thermostat.

[0021] Each room has one or more registers for discharging conditioned air into each room. The registers are located at the end of a duct that supplies conditioned air from the air handling appliance. Each register has one or more vanes than may be automatically or manually opened or closed to adjust the discharge air flow from the register. Registers may be battery powered and have low battery audible and visual alerts. Each register also has signal receiving and transmitting means and motorized means for opening and closing the vanes of the register. Each register may also have means for selecting different bands of wireless frequencies.

[0022] When the temperature in a zone falls below the slave thermostat set-point temperature (in the case of heating), the slave thermostat transmits a wireless signal to the master thermostat to turn on the air handling appliance. The slave satellite transmits a second wireless signal to the registers within its zone to activate the motorized means to open the vanes of each register. When the slave thermostat set-point temperature is met, the slave thermostat transmits a wireless signal to the master thermostat to turn off the air handling appliance. The slave thermostat may optionally also transmit a wireless signal to the registers to close the vanes of the registers. Each satellite thermostat may be set to use separate wireless band frequencies.

[0023] The communication among master thermostat, slave thermostats and registers is by wireless ferquencies. An IEEE 802.15.4 standard RF (Radio Frequency) link with unlicensed frequency band is used in wireless communication. The frequency band commonly used in North America is 902-928MHz or 2400-2483.5MHz. For Europe, the commonly used frequency band is 868-868.6MHz.

[0024] Figure 2 shows features of the master thermostat. The master thermostat has high-accuracy temperature measurement from 0 C to 35 C ( 0.5 C) with a resolution 0.1 C.. The master thermostat has a LCD Screen which allows programming and display of mode of operation, fan level setting, temperature measurement (celsius/fahrenheit), temperature setting, temperature schedules, setting real-time-clock (RTC) (12/24 hour format) with days of the week, and Wi-Fi network status. The thermostat also has capacitive touch buttons, a Wi-Fi module, an 802.15.4 wireless module, an AC and battery power supply, and furnace and cooling control.

[0025] Figure 3 shows features of a slave thermostat. A slave thermostat has a 802.15.4 wireless module, status LEDs (battery, alarm), transmitting and receiving means for controlling the opening and closing of one or more registers within its zone.

[0026] Figure 4 shows features of the registers used in the zone control system. A
register comprises a microcontroller for transmitting and receiving wireless signals, an 802.15.4 wireless module, a battery power supply, status LED lights (e.g.
battery, alarm), means for opening and closing vanes of the register and may optionally include battery power supply recharging by a solar panel.

[0027] While the embodiment has been described with reference to a residential building, the zone control system of the present disclosure may be used in comparable sized commercial and industrial buildings.

[0028] While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the embodiment illustrated in the drawings. Other modifications and applications, or equivalents, will occur to those skilled in the art. The terms "having", "comprising" and "including" and similar terms as used in the foregoing specification are used in the sense of "optional" or "may include" and not as "required". Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and attached drawings. All such changes, modifications, variations and other uses and applications which do not depart from the scope of the invention are deemed to be covered by the invention which is limited only by the claims that follow.
The scope of the disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular is not intended to mean "one and only one"
unless specifically so stated , but rather one or more.