US20150204551A1

US20150204551A1 - Energy saving method for room level heating and cooling system

Info

Publication number: US20150204551A1
Application number: US14/581,782
Authority: US
Inventors: Rajesh M. Nair; Charles Nasser; Walter E. Phelps
Original assignee: Degree Controls Inc
Current assignee: Degree Controls Inc
Priority date: 2013-12-30
Filing date: 2014-12-23
Publication date: 2015-07-23

Abstract

A heating, ventilating, and air conditioning (HVAC) system includes a thermostat, a temperature sensor, a plurality of occupancy sensors in a plurality of zones in a room in a building, a plurality of airflow vents in the plurality of zones in the room, and a motor coupled to each of the plurality of airflow vents. The system receives temperature set point data from the thermostat, receives temperature data from the temperature sensor, receives occupancy data from the occupancy sensors, turns on a heating unit or a cooling unit as a function of the temperature set point data from the thermostat and the temperature data from the temperature sensor, and controls the flow of heated air or cooled air into the zones in the room by transmitting a signal to one or more of the motors so as to adjust the plurality of airflow vents in the room.

Description

RELATED APPLICATION

This application claims the benefit of and priority to U.S. Provisional Application No. 61/921,825, filed on Dec. 30, 2013, entitled Energy Saving Method for Room Level Cooling System, the contents of which are hereby incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to heating, ventilating, and air conditioning (HVAC) systems, and in an embodiment, but not by way of limitation, an energy saving method for a room level heating and cooling system.

BACKGROUND

In a Heating, Ventilating, and Air Conditioning (HVAC) system, cooled air and/or heated air are valuable resources that should be minimized in spaces that do not need much of it at a particular point in time, and should be delivered in greater volume to areas that require more of it at a particular point in time. Additionally, the space demands for cooled and/or heated air can be dynamic based on equipment load and/or the number of people occupying different locations at different times.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a heating, ventilating, and air conditioning (HVAC) system.

FIG. 2 illustrates an embodiment of a room or zone level HVAC system.

FIGS. 3A and 3B are a block diagram illustrating operations and features of an energy saving method for a room level or zone level HVAC system.

FIGS. 4A and 4B illustrate airflow paths of an HVAC system.

FIG. 5 illustrates pressure optimization among a plurality of fans in an HVAC system.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural and electrical changes may be made without departing from the scope of the present embodiments. The following description of example embodiments is, therefore, not to be taken in a limited sense, and the scope of the present embodiments is defined by the appended claims.
One or more embodiments of energy saving methods for room level, and more particularly, zones within a room, heating, ventilating, and air conditioning (HVAC) systems are disclosed herein. The HVAC systems include several features and advantages. The HVAC systems permit better control through the creation and management of virtual zones. Virtual zones are zones demarcated by computer processor intelligence and/or the placement of output airflow vents and intake airflow vents, and can include several areas or zones within a single room or area. The embodiments can also function in a conglomeration of several physical rooms, and/or actual rooms or areas formed by physical barriers such as walls or partitions.
Another feature and advantage of the HVAC systems of the present disclosure are that the HVAC systems permit occupancy override. For example, when a zone is occupied by one or more persons, two controls are implemented. First, the airflow vents in the occupied room or zone are opened, kept open, or opened more to permit airflow or more airflow into that occupied zone or room. Second, the airflow vents in unoccupied rooms or zones are closed, allowed to remain closed, or closed to a greater degree to restrict airflow to the unoccupied room or zone. The intelligent control of the airflow vents supplies heated air or cooled air to occupied zones and withholds heated air or cooled air from unoccupied zones.
An example of the controlled opening or closing of airflow vents is illustrated in FIG. 5. Referring to FIG. 5, a simple airflow vent system includes a blower unit 510, a duct 520, and vents 530A, 530B, and 530C. Vent 530C is the nearest to blower unit 510, and vent 530A is the farthest from blower unit 510. In this example system, to double the airflow at airflow vent 530A, the blower unit 510 has to generate four times the pressure and consume eight times the power (when compared to an HVAC system without intelligent airflow vent control). The reason for this is that some of the airflow travels to and through vents 530B and 530C, thereby doubling the airflow at all airflow vents (and not just airflow vent 530A). However, by intelligently managing airflow vent control at 530B and 530C, the airflow at vent 530A may be doubled with less than eight times the power.
In an embodiment, the positioning or repositioning of airflow vents results in airflow path optimization and eliminates uncooled or unheated areas or zones (dead spots) and overheated or overcooled areas or zones. For example, referring to FIG. 4A, the airflow vents 410A, 420A are not properly spaced in a room or zone, and this improper spacing results in a short circuit 430 of airflow, which results in a potentially overheated or overcooled area or zone 440 and an under heated or undercooled area or dead zone 450. In contrast, referring to FIG. 4B, the air flow vents 410B, 420B are properly spaced at opposite ends of a room or zone, and airflow is evenly distributed throughout the entire room, area, or zone. As can be seen from FIGS. 4A and 4B, the location of the air inlet and air exhaust airflow vents determines the efficiency of cooling or heating because the airflow path within a room, area, or zone is maximized. If needed, existing airflow vents in a room, area, or zone should be repositioned. The resulting air pressure optimization minimizes air mover (i.e., air handling unit, blower, fan) power utilization.
Another feature and advantage of an HVAC system with intelligent vent control are that the virtual zones can be synchronized for minimum HVAC resource utilization. For example, if there are multiple HVAC units, and a particular virtual zone is in need of cooling air because it is occupied by one or more persons, a HVAC unit that is closest to the virtual zone can be selected. Similarly, in a building that has multiple HVAC units, the use of the multiple units can be optimized based on zone occupancy, temperature in the different virtual zones, relative location of the demand for heated or cooled air, and the locations of the multiple HVAC unit locations. For example, if multiple occupied zones are in need of heated or cooled air, the units that are closest to the multiple zones can be used to supply the heated or cooled air (in connection with opening or keeping open the vents in those multiple occupied zones).
These features and advantages are particularly evident when considered in view of prior HVAC systems. Referring to FIG. 1, a typical room in a building, especially a large office building and a large room with cubicles in that building, includes a thermostat 110, a temperature sensor 120, and a plurality of airflow vents 130. The airflow vents 130 in FIG. 1 are positioned on the ceiling, but in other systems, the airflow vents 130 can be positioned on the floor and/or walls. In some systems, the thermostat 110 and temperature sensor 120 are a single unit, in other systems, the thermostat 110 and temperature sensor 120 are distinct and separate units. The airflow vents 130 have either no controls, or only manual controls. As further illustrated in FIG. 1, such systems provide imperfect heating and/or cooling, with no attention paid to particular zones or areas within the room, which results in some occupants of the room or zones within a room being uncomfortable.
FIG. 2 illustrates an embodiment of a room level or zone level HVAC system. Specifically, FIG. 2 illustrates an example of the creation of virtual zones in a room or area. In FIG. 2, there is a first virtual zone 210 and a second virtual zone 220. Each zone has its own temperature sensor 230. Each zone can also have its own thermostat 240. In another embodiment, the zones 210, 220 share a thermostat, and/or there is a central thermostat for a plurality of zones and/or an entire building. Each zone 210 and 220 further includes its own occupancy sensors 250. The occupancy sensors 250 can include video sensors, motion sensors, infrared sensors, pressure sensors, or any other type of sensor that can detect the presence of a person or persons in a room or zone. If pressure sensors are used, the pressure sensors can be installed under carpet or tile in a floor to sense the presence of a person or persons. Each zone further includes its own airflow vents 260, and also includes control servomotors 265 to control the opening and closing of the airflow vents 260. The temperature sensor 230 and thermostat 240 are coupled to a computer process controller 270, which determines when the heating unit or air conditioning unit should be turned on or turned off based on the set point of the thermostat 240 and the temperature sensed by the temperature sensor 230. In order to simplify the drawing, FIG. 2 illustrates that the computer processor is connected only to the temperature sensor 230, the thermostat 240, the occupancy sensor 250, and the control servomotors 265 in first virtual zone 210. However, in an actual implementation, the computer processor 270 would also be connected to the temperature sensor 230, the thermostat 240, the occupancy sensor 250, and the control servomotors 265 in second virtual zone 220 and any other virtual zone in the building. In an embodiment, when there are multiple thermostats in multiple zones, the temperature data and set point from a single zone can cause the heating unit or air conditioning unit to turn on or turn off. The occupancy sensor 250, airflow vents 260, and control servomotor 265 are also coupled to the computer processor controller 270. The computer processor controller 270 receives data from the occupancy sensor 250, and transmits a signal to the control servomotor 265 to open or close the airflow vent 260 based on the data received from the occupancy sensor 250. The controlled opening and closing of the airflow vents allows for zones within a room to be controlled independently around local temperature sensors, allows for precise temperature zone control, and allows zone control operation to be overridden by occupancy of the zone.
This process of occupancy-based zone control is illustrated is FIGS. 3A and 3B, which is a block diagram illustrating operations and features of an energy saving method for a room level or zone level HVAC system. FIGS. 3A and 3B includes a number of process blocks 305-375. Though arranged substantially serially in the example of FIGS. 3A and 3B, other examples may reorder the blocks, omit one or more blocks, and/or execute two or more blocks in parallel using multiple processors or a single processor organized as two or more virtual machines or sub-processors. Moreover, still other examples can implement the blocks as one or more specific interconnected hardware or integrated circuit modules with related control and data signals communicated between and through the modules. Thus, any process flow is applicable to software, firmware, hardware, and hybrid implementations.
Referring to FIGS. 3A and 3B, at 305, a computer processor receives temperature set point data from a thermostat in a building. At 310, the computer processor receives temperature data from a temperature sensor in the in the building. At 315, the computer processor receives occupancy data from occupancy sensors. In an embodiment, the occupancy sensors are located in virtual zones within a room in the building. Each virtual zone has its own occupancy sensor. The virtual zones can be within a large open area that is without any physical partitions, and are formed by the combination of the placement of airflow vents and computer logic. Each virtual zone can have its own thermostat, a single thermostat can serve several virtual zones, or a single thermostat can serve all virtual zones. In most instances, each virtual zone has its own dedicated temperature sensor. However, two or more virtual zones could share a temperature sensor.
At 320, the computer processor turns on a heating unit or a cooling unit as a function of the temperature set point data from the thermostat and the temperature data from the temperature sensor. In an embodiment, the temperature data and set point from a single virtual zone can cause the heating unit or air conditioning unit to turn on or turn off. At 325, the computer processor controls the flow of heated air or cooled air into the several virtual zones in a room in the building by adjusting several airflow vents in the several virtual zones as a function of the data received from the occupancy sensors. In an embodiment, the computer processor transmits a signal to a servomotor associated with an airflow vent, and the servomotor opens or closes the airflow vent based on the signal received from the computer processor.
At 340, it is noted that the occupancy sensor can be an infrared sensor, a video sensor, a motion sensor, and/or a pressure sensor. Each type of sensor may have a particular advantage or disadvantage for a particular application, and a person of skill in the art will be able to determine which sensor or combination of sensors is appropriate for any particular application.
At 350, a first airflow vent is placed at a first edge of a virtual zone and a second airflow vent is place at an opposite second edge of the virtual zone. This placement is ideally done when a building is constructed. However, such airflow vents can be repositioned in a retrofitting or refurbishing of a room and/or building. As noted above in connection with FIGS. 4A and 4B, the proper placement of the airflow vents can prevent dead zones of unheated or uncooled areas.
As illustrated at 360, the computer processor can turn on a heating unit or a cooling unit as a function of the temperature set point data and the temperature data in a single virtual zone in a room in the building. In this manner, whenever any particular virtual zone requires heated or cooled air, that virtual zone is supplied with such heated or cooled air, and the heated or cooled air may be withheld from other virtual zones based on the occupancy-controlled airflow vents in those other virtual zones.
At 370, it is noted that the thermostats can be personal thermostats, and at 375, it is noted that the personal thermostats can be part of a smart phone. Such a smart phone not only has a thermostat associated therewith, but also a location sensor so that it can be determined in what virtual zone the smart phone is located. The use of a smart phone provides the ultimate in personal comfort control. Set point data, temperature sensor data, and location data can be transmitted from the smart phone to the computer processor, and the computer processor can control the opening and closing of the airflow vents in the appropriate virtual zones as dictated by the occupancy sensor, the temperature set point, and the temperature data.
The Abstract is provided to comply with 37 C.F.R. §1.72(b) and will allow the reader to quickly ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
In the foregoing description of the embodiments, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting that the claimed embodiments have more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Description of the Embodiments, with each claim standing on its own as a separate example embodiment.

Claims

1. A process comprising:

receiving into a computer processor temperature set point data from a thermostat in a building;

receiving into the computer processor temperature data from a temperature sensor in the building;

receiving into the computer processor occupancy data from a plurality of occupancy sensors in a plurality of virtual zones in a room in the building;

turning on a heating unit or a cooling unit as a function of the temperature set point data from the thermostat and the temperature data from the temperature sensor; and

controlling the flow of heated air or cooled air into the plurality of virtual zones in the room in the building by adjusting a plurality of airflow vents in the plurality of virtual zones in the room in the building as a function of the data received from the occupancy sensors.

2. The process of claim 1, comprising:

receiving temperature set point data from a plurality of thermostats in the plurality of virtual zones in the room in the building; and

turning on the heating unit or the cooling unit as a function of the temperature set point data from the plurality of thermostats in the plurality of virtual zones in the room in the building and the temperature data from the temperature sensor.

3. The process of claim 1, wherein the plurality of occupancy sensors comprises one or more of an infrared sensor, a video sensor, a motion sensor, and a pressure sensor.

4. The process of claim 1, comprising placing a first airflow vent at a first edge of a first virtual zone in the room in the building and placing a second airflow vent at an opposite second edge of the first virtual zone in the room in the building.

5. The process of claim 1, comprising turning on the heating unit or the cooling unit as a function of the temperature set point data and the temperature data in a single virtual zone in the room in the building.

6. The process of claim 1, wherein the thermostat comprises a personal thermostat.

7. The process of claim 6, wherein the personal thermostat comprises a smart phone.

8. The process of claim 1, wherein the plurality of virtual zones in the room in the building is defined by an output airflow vent and an input airflow vent.

9. The process of claim 1, wherein the plurality of virtual zones in the room in the building is defined by an output airflow vent, and input airflow vent, and computer processor logic.

10. A heating, ventilating, and air conditioning (HVAC) system comprising:

a computer processor;

a thermostat coupled to the computer processor;

a temperature sensor coupled to the computer processor;

a plurality of occupancy sensors coupled to the computer processor, the plurality of occupancy sensors located in a plurality of virtual zones in a room in a building;

a plurality of airflow vents; and

a motor coupled to each of the plurality of airflow vents and to the computer processor;

wherein the computer processor is operable to:

receive temperature set point data from the thermostat;

receive temperature data from the temperature sensor;

receive occupancy data from the plurality of occupancy sensors in the plurality of virtual zones in the room in the building;

turn on a heating unit or a cooling unit as a function of the temperature set point data from the thermostat and the temperature data from the temperature sensor; and

control the flow of heated air or cooled air into the plurality of virtual zones in the room in the building by transmitting a signal to one or more of the motors coupled to each of the plurality of airflow vents so as to adjust the plurality of airflow vents in the plurality of virtual zones in the room in the building as a function of the data received from the occupancy sensors.

11. The HVAC system of claim 10, comprising a plurality of thermostats in the plurality of virtual zones in the room in the building.

12. The HVAC system of claim 10, wherein the occupancy sensor comprises one or more of an infrared sensor, a video sensor, a motion sensor, and a pressure sensor.

13. The HVAC system of claim 10, comprising a first airflow vent at a first edge of a first virtual zone in the room in the building and a second airflow vent at an opposite second edge of the first virtual zone in the room in the building.

14. The HVAC system of claim 10, wherein the computer processor is operable to turn on the heating unit or the cooling unit as a function of the temperature set point data and the temperature data in a single virtual zone in the room in the building.

15. The HVAC system of claim 10, wherein the thermostat comprises a personal thermostat.

16. The HVAC system of claim 15, wherein the personal thermostat comprises a smart phone.

17. The HVAC system of claim 10, wherein the plurality of virtual zones in the room in the building is defined by an output airflow vent and an input airflow vent.

18. The HVAC system of claim 1, wherein the plurality of virtual zones in the room in the building is defined by an output airflow vent, and input airflow vent, and computer processor logic.

19. A computer readable storage device comprising instructions that when executed by a processor executes a process comprising:

receiving temperature set point data from a thermostat in a building;

receiving temperature data from a temperature sensor in the building;

receiving occupancy data from a plurality of occupancy sensors in a plurality of virtual zones in a room in the building;

20. The computer readable storage device of claim 19, comprising instructions for: