U.S. patent number RE40,437 [Application Number 11/804,324] was granted by the patent office on 2008-07-15 for thermostat system with remote data averaging.
Invention is credited to Howard Rosen.
United States Patent |
RE40,437 |
Rosen |
July 15, 2008 |
Thermostat system with remote data averaging
Abstract
A thermostat system according to the invention includes: a
central control device (typically a programmable thermostat with a
processor having: a CPU, real time clock and a memory for storing a
control program and data information), multiple rooms comprising a
conditioned space, environmental control equipment, and multiple
environmental sensors capable of sensing an environmental condition
(such as temperature, humidity, or other condition). The sensors
are associated with transmission means, which control transmission
of sensor signals, and occupancy sensors. Each sensor measures a
local environmental condition. Occupancy sensors comprise infrared
or other motion sensors, light detection sensors, door opening
sensors, and other such sensors that detect the presence of humans
in a room of the conditioned space where its associated sensor is
located. Space conditioning equipment is activated by comparison of
a setpoint to a control value averaged from values of environmental
conditions in occupied rooms.
Inventors: |
Rosen; Howard (Montreal Quebec,
CA) |
Family
ID: |
36569025 |
Appl.
No.: |
11/804,324 |
Filed: |
May 16, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
10995574 |
Nov 23, 2004 |
07058477 |
Jun 6, 2006 |
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Current U.S.
Class: |
700/277; 236/51;
700/276; 236/1C |
Current CPC
Class: |
G05D
23/1931 (20130101); F24F 11/30 (20180101); F24F
2120/10 (20180101) |
Current International
Class: |
G05D
23/00 (20060101) |
Field of
Search: |
;700/276-278
;236/1C,51,91F,91R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kosowski; Alexander
Attorney, Agent or Firm: Hankin; Marc E. Hankin Patent Law,
APC
Claims
What is claimed is:
1. An occupancy response system with a central control device
adapted to control space conditioning equipment affecting a
conditioned space, the central control device located at a single
physical location in one of multiple rooms comprising the
conditioned space, where remote sensors are located in physical
locations substantially apart from the central control device, the
improvement comprising: A) two or more environmental sensors
adapted to measure a local environmental condition and generate
signals indicating its value; B) two or more occupancy sensors
adapted to detect occupancy of space around an environmental sensor
and generate signals indicating occupancy; C) either the central
control device and one or more of the remote sensors or two or more
of the remote sensors each comprise an environmental sensor and an
occupancy sensor; D) a central processor for the central control
device including: 1) a central processing unit; 2) a real time
clock; 3) a memory coupled to said central processing unit for
storing a central control program and data, said data including at
least one of the values of the environmental conditions sensed by
the environmental sensors; and 4) an input/output unit coupled to
the central processing unit, to the space conditioning equipment
for issuing control signals thereto, and to a reception interface
adapted to receive signals representing environmental conditions at
a remote sensor; E) a remote processor for each of the remote
sensors including a central processing unit, a .[.real time.].
clock, a memory coupled to said central processing unit for storing
a transmission control program, and an input/output unit coupled to
the central processing unit and to a transmissions interface
adapted to send to the central control device signals representing
environmental conditions from a coupled environmental sensor; and
F) for the central control device or remote sensors having
environmental sensors and occupancy sensors, their input/output
units further including a sensor input coupled to an environmental
sensor and an occupancy input coupled to an occupancy sensor; G)
the control programs causing a coupled central processing unit to
selectively: 1) detect occupancy or vacancy of a nearby space from
signals from a coupled occupancy sensor; 2) read current signals
from a coupled environmental sensor and transmit them for storage
in the memory of the central control device only if occupancy is
detected; 3) for the central control program, calculate an average
of the received environmental sensor values and use the average
result as a control value which is compared with a setpoint stored
in the memory of the central control program to determine actuation
of the space conditioning equipment.
2. The system of claim 1 wherein averaging of received
environmental sensor values is calculated by simple averaging or a
weighted averaging depending on relative spaces of occupied
rooms.
3. The system of claim 2 wherein a display and a user interface are
coupled with the input/output unit of the central processing device
so the central control program causes a display of averaging
methods for averaging received environmental sensor values.
4. The system of claim 3 wherein the central control program
further causes a display indicating that a user may select an
averaging method through the user interface and thereafter
accepting user input selecting one of the averaging methods.
5. The system of claim 1 wherein the space conditioning equipment
comprises zone control means so that only occupied rooms have their
space affected by the space conditioning equipment.
6. An occupancy response system with a central control device
adapted to control space conditioning equipment affecting a
conditioned space, the central control device located at a single
physical location in one of multiple rooms comprising the
conditioned space, where remote sensors are located in physical
locations substantially apart from the central control device, the
improvement comprising: A) one or more environmental sensors
adapted to measure a local environmental condition and generate
signals indicating its value; B) one or more occupancy sensors
adapted to detect occupancy of space around an environmental sensor
and generate signals indicating occupancy; C) either the central
control device and one or more of the remote sensors or two or more
of the remote sensors each comprise an environmental sensor and an
occupancy sensor; D) a central processor for the central control
device including: 1) a central processing unit; 2) a real time
clock; 3) a memory coupled to said central processing unit for
storing a central control program and data, said data including at
least one of the values of the environmental conditions sensed by
the environmental sensors; and 4) an input/output unit coupled to
the central processing unit, to the space conditioning equipment
for issuing control signals thereto, and to a reception interface
adapted to receive signals representing environmental conditions at
a remote sensor; E) a remote processor for each of the remote
sensors including a central processing unit, a .[.real time.].
clock, a memory coupled to said central processing unit for storing
a transmission control program, and an input/output unit coupled to
the central processing unit and to a transmissions interface
adapted to send to the central control device signals representing
environmental conditions from a coupled environmental sensor; and
F) for the central control device or remote sensors having
environmental sensors and occupancy sensors, their input/output
units further including a sensor input coupled to an environmental
sensor and an occupancy input coupled to an occupancy sensor; G)
the control programs causing a coupled central processing unit to
selectively: 1) detect occupancy or vacancy of a nearby space from
signals from a coupled occupancy sensor; 2) read current signals
from a coupled environmental sensor and a coupled occupancy sensor
and transmit them for storage in the memory of the central control
device so that values of environmental conditions are associated
with their source of occupied or unoccupied rooms; 3) for the
central control program, calculate an average of the received
environmental sensor values and use the average result as a control
value which is compared with a setpoint stored in the memory of the
central control program to determine actuation of the space
conditioning equipment.
7. The system of claim 6 wherein averaging of received
environmental sensor values is calculated by simple averaging or a
weighted averaging where environmental condition values from
occupied rooms are given substantially more value than those of
vacant rooms.
8. The system of claim 6 wherein where occupancy sensors include
infra-red motion detectors.
9. The system of claim 6 wherein environmental sensors include
temperature sensors and humidity sensors.
10. The system of claim 7 wherein a display and a user interface
are coupled with the input/output unit of the central processing
device so the central control program causes a display of averaging
methods for averaging received environmental sensor values.
11. The system of claim 10 wherein the central control program
further causes a display indicating that a user may select an
averaging method through the user interface and thereafter
accepting user input selecting one of the averaging methods.
12. The system of claim 6 wherein the space conditioning equipment
comprises zone control means so that only occupied rooms have their
space affected by the space conditioning equipment.
13. The system of claim 6 wherein a device motion sensor is coupled
to the remote sensor's input output unit so that movement of the
remote sensor results in transmission of a movement signal of the
device motion sensor to be received by the central control device
from the remote sensor and said movement signal is associated with
previously received environmental sensor signals from said remote
sensor and used for said averaging.
14. The system of claim 13 wherein the central control program of
the central control device acts to remove data associated with said
movement signal from calculations averaging environmental signals
to arrive at a control value.
15. The system of claim 13 wherein the transmission control program
of the remote sensor acts to stop transmission of environmental
sensor signals to the central control device for a predetermined
period of time after receipt of a movement signal.
Description
FIELD OF THE INVENTION
This invention relates to the art of thermostats and, more
particularly, to a thermostat system incorporating a central
control device receiving remote environmental sensing data from
remote sensors.
BACKGROUND OF THE INVENTION
Thermostats have been used for many years as a temperature
sensitive switch which controls heating and/or cooling equipment
for conditioning a space in which the thermostat, or a temperature
sensor connected to the thermostat, is placed. In the well known
manner, a simple thermostat can be adjusted to establish a
temperature set point such that, when the temperature in the
conditioned space reaches the set point, the thermostat interacts
with the heating and/or/cooling equipment to take suitable action
to heat or cool the conditioned space as may be appropriate for the
season.
Modern thermostat systems, which take advantage of the ongoing
rapid advances in electronic technology and circuit integration,
have many features which provide more precise supervision of the
heating and/or cooling equipment to achieve more economical and
more comfortable management of the temperature of a conditioned
space. Many modern thermostat systems include a real time clock, a
memory and a data processor to run a process control program stored
in the memory to accurately measure the temperature of a
temperature sensor disposed in the conditioned space and to send
control signals to the heating and/or cooling equipment to closely
control the temperature of the conditioned space. Modern thermostat
systems permit anticipating and minimizing hysterisis or overshoot
of the temperature in the conditioned space. In addition, the
program can specify different set points at different times of the
day and week and may also include a "vacation" mode which employs
different set points when the conditioned space is not occupied for
an extended period.
Many modern thermostat systems have a central control device or
unit that receives environmental sensor data from sensors remote
from the central control device. These sensors can detect
temperature, humidity, or other parameters that may be used in a
control program by the central control device to control
environmental control equipment. The environmental control
equipment (comprising HVAC equipment, among others) responds to
signals from the central control device to affect the ambient
comfort in rooms of a conditioned space. Typically, a remote sensor
signal is received by the central control device and its value
compared with that of a pre-set setpoint. If the sensor value is
sufficiently different from the setpoint, environmental control
equipment is activated or de-activated in response thereto. Remote
sensors can be connected by wire directly to the central control
device or by wireless connection so that the control program can
store the output of each sensor and associate it with an identifier
for the remote sensor where the output originated.
Modern programmable thermostat systems also may act to control
temperature in some rooms of out of all those in a conditioned
space as a "zone". Unfortunately, zone control requires dedicated
equipment for the zone or duct dampers or deflectors to direct
conditioned air to the zone rooms. This requires complexity and
additional cost to the system. One form of zone control uses
storage in a central control device storing all the signals from
multiple remote environmental sensors in the zone. The control
program calculates an average value from the stored values of the
remote sensors and uses that average value as a control value. The
control value is compared with a setpoint, whereafter environmental
control equipment is activated or de-activated. The control value
established by prior art thermostat systems can easily over- or
under-condition a room where a user most desires environmental
control.
There is a need for zone control in a thermostat system where
remote sensor values are averaged for occupied rooms at a central
control device. The averaged sensor data establish a zone control
value. This zone control value more accurately reflects
environmental conditions of rooms where the user most desires
control of those environmental conditions.
SUMMARY OF THE INVENTION
A thermostat system according to the invention includes: a central
control device (typically a programmable thermostat with a
processor having: a CPU, real time clock and a memory for storing a
control program and data information), multiple rooms comprising a
conditioned space, environmental control equipment, and multiple
environmental sensors capable of sensing an environmental condition
(such as temperature, humidity, or other condition). With exception
of those provided within or close to a housing of the central
control device, environmental sensors are located remote from the
central control device. "Remote" as used herein means effectively
remote from the central control device as to a sensed environmental
condition. A remote sensor may be located in another room as
compared with the central control device. Alternately, a remote
sensor may be located some distance away from the central control
device in a large room. A communications interface is adapted to
establish reception of signals (via wired or wireless connections)
between the processor and the environmental sensors.
In one embodiment, the sensors are associated with transmission
means, which control transmission of sensor signals, and occupancy
sensors. Each sensor measures a local environmental condition.
Occupancy sensors comprise infrared or other motion sensors, light
detection sensors, door opening sensors, and other such sensors
that detect the presence of humans in a room of the conditioned
space where its associated sensor is located.
In one form of the invention, transmission means enables
transmission of environmental sensor signals to the central control
device only upon input of signals from the occupancy detector. In
another form of the invention, transmission means provide
continuous transmissions from environmental sensor signals to a
central control device, albeit where such signals are associated
with indications of occupancy or non-occupancy of a room where the
sensor is located sensing occupancy of a room or an area of a large
room. Such remote sensor signals are transmitted to the central
control device and stored in its memory as a table of data
indicating environmental conditions only in occupied rooms. The
values of this table are averaged in one of several selected modes
to yield a control value. This control value more accurately
reflects the desired environmental conditions of the rooms where
user's are present. Alternately, all sensor data may be stored at
the central control device and associated with indications of
occupancy or non-occupancy of a room where the sensor is located
and a time of the sensing of the environmental condition and
occupancy status of the room.
In a second embodiment, remote sensors and occupancy detectors are
associated as in the first embodiment. However, this second
embodiment comprises transmission means that causes transmission of
environmental sensor signals to the central control device with
additional signals indicating whether the sensor signal originates
from an occupied or non-occupied room. Transmission means may
transmit continuously, periodically or upon the occurrence of a
sensed event. The occupancy status of the room is determined by the
input to the transmission means of the occupancy sensor. These
remote sensor signals are transmitted to the central control device
and stored in its memory as a table of data indicating
environmental conditions of both occupied and un-occupied rooms.
The values of this table are averaged in one of several selected
modes to yield a control value. This control value more accurately
reflects the overall desired environmental conditions of the rooms
where user's are present.
A user may optionally select from one of several forms of averaging
of sensor data to derive a control value. The control program may
cause a display screen connected with the CPU to provide a user
with a list of averaging options, where by the user can select one
of the options through a user interface with touch sensitive
buttons or other well known means.
Averaging of sensor data may be accomplished by one of several
methods. The sensor data table may contain sensor data from sensors
located at the central control devices as well as from remote
sensors. Simple averaging of sensor data associated with room
occupancy occurs when all environmental sensor data are added
together and divided by the number of data items in the table.
A second form of averaging uses weighting depending on square
footage of the room where the sensor is located. Greater weighting
is assigned to sensor data associated with occupancy in rooms with
greater relative square footage.
A third form of averaging uses sensor data from occupied and
unoccupied rooms and assigns greater weight to sensor data from
occupied rooms.
A fourth form of averaging uses historical data to determine rooms
most heavily occupied over a pre-determined period (such as a week
or month) and averages current sensor data only from those heavily
occupied rooms to arrive at a control value regardless of current
occupancy status.
Current thermostat systems can include mobile remote temperature
sensors with wireless transmitters. These mobile temperature
sensors send sensed, local temperature signals to a central control
device and are usually battery powered and enclosed in a handheld
housing. The mobile sensors can include a display of locally sensed
temperature. In one form of the invention, mobile sensors detect
room occupancy and also have means to detect motion of the device
itself relative to its surroundings. Without such means, movement
of the mobile sensor by a user would result in a false indication
of occupancy to the occupancy sensor. For example, an infra-red
motion detector in the mobile sensor would falsely interpret
carrying the mobile sensor from one room to another as the presence
of a person moving in a room. Instead, transmission means are
connected to a device motion sensor. The device motion sensor in
one form comprises a circuit that opens, closes or alternates
between those states when the mobile sensor is picked up and moved.
A set of fixed contacts for the circuit can be arranged so that
rolling or sliding metallic pieces in an enclosed cavity break or
complete the circuit when the device itself is picked up and
carried to another room. The transmission means delays receipt of
inputs from the occupancy sensor until the mobile sensor has come
to rest and/or after a predetermined period of time. These
adaptations allow the mobile sensor to come to rest before setting
room occupancy and thereafter transmitting local environmental
conditions.
It is a feature of some modern thermostat systems to control duct
dampers or diverters so that conditioned air from air handlers and
fans is directed only to certain rooms of a conditioned space. In
the present invention, occupancy sensed in a room creates a signal
via the occupancy sensor which is transmitted from a remote device
to the central control device. The central control device can act
to average temperatures to calculate a control value and at the
same time divert substantially all conditioned air only to the
occupied rooms.
In some situations, environmental conditions in separated but
occupied rooms may be quite different. A side of a building with
its wall receiving full sun can dramatically heat a room on that
side. A room on the opposite side of the building may be quite cool
and have a temperature close to a desired setpoint. Simple
averaging of local temperatures in those rooms may result in a
control value near a desired setpoint for the central control
device. A fifth form of averaging would cause the data table values
of sensed environmental conditions to be subtracted from the
setpoint to calculate a table of differences, some positive and
some negative depending on the relationship of a sensor value to
the setpoint. Differences beyond the setpoint value at which
environmental control equipment is activated (such as the setpoint
temperature at which air conditioning equipment is turned on) would
be averaged and given greater weight than an average of differences
outside of that activation range. For example, temperature sensors
might indicate degree Fahrenheit temperatures of 80, 79, 77 and 75.
If the setpoint is 78 for air conditioning to be turned on, the
differences would be 2, 1, -1 and -3. Simply averaging the sensor
values would not result in the overheated rooms being cooled. In
one scenario, the positive differences are weighted 70% and the
negative differences at 30%. The resulting control value will be
sufficient to activate the air conditioning at the cost of
overcooling some occupied rooms.
It is an object of the invention to average sensed environment
conditions only in occupied rooms in order to calculate a control
value.
DESCRIPTION OF THE DRAWING
FIG. 1 is a plan view of a conditioned space with several rooms, a
central control device and remote environmental sensors arranged in
the rooms.
FIG. 2 is a block diagram of a central control device and its
relationship to environmental control equipment, the conditioned
space, and remote sensors.
FIG. 3 is a block diagram of a remote sensor.
FIG. 4 is a high level process flow chart describing the operation
of the remote sensor in a first embodiment.
FIG. 5 is a high level process flow chart describing the operation
of the remote sensor in a second embodiment.
FIG. 6 is a high level process flow chart describing the operation
of the central control device in the invention thermostat
system.
DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
Referring first to FIG. 1, a structure 10 defines within its walls
conditioned space for a thermostat system. Structure 10 comprises
sides 11 and 12, rooms 13 through 18, lighting fixture 19,
fireplace 20, and exemplary doors 21 and 22. The thermostat system
includes central control device 23 and remote sensors 23A through
23F. Remote sensors 23A through 23F are located respectively in
rooms 13 through 18. Alternately, any of the remote sensors 23A
through 23F may be mobile sensors capable of being moved to any
room in structure 10.
Referring now to FIG. 2, central control device 23 is shown in a
block diagram form with a processor 30 connected to an
environmental temperature sensor S1 and an occupancy sensor S2
which are disposed with access to conditioned space 38. The
processor 30 and the sensors S1 and S2 may be situated in a common
housing (not shown) or separated, all as very well known in the
art, so that said sensors have effective access to the room in
which the housing for processor 30 is located.
The processor 30 includes a central processing unit (CPU) 31 in
communication with a memory 32 which stores data and program
information and also, via an input/output unit (I/O unit) 34, an
optional user interface 35 and a liquid crystal or other type
display (LCD) 36. The memory 32 may include a read-only part which
is factory-programmed and a random-access part which stores data
subject to change during operation. A settable real time clock 33
is used to keep time in the central control device to facilitate
diverse operations, such as different temperature set points
(desired temperatures), during different periods of the day cycle.
The thermostat system may be suitably powered by a battery (not
shown) and/or from equipment to which is connected. The I/O unit 34
includes a wired or wireless communications interface 41 for
coordinating communications between the CPU 31 and one or more
remote sensors.
Referring now to FIG. 3, remote sensors 23A through 23F are shown
in a block diagram form with a processor 50 connected to an
environmental temperature sensor S3, an occupancy sensor S4, and
device motion sensor S5 which are disposed with access to
conditioned space 56. The processor 50 and the sensors S3, S4 and
S5 may be situated in a common housing (not shown) or separated,
all as very well known in the art, so that said sensors have
effective access to the room in which the housing for processor 50
is located.
The processor 50 includes a central processing unit (CPU) 51 in
communication with a memory 52 which stores data and program
information and also, via an input/output unit (I/O unit) 54, and a
liquid crystal or other type display (LCD) 55. The memory 52 may
include a read-only part which is factory-programmed and a
random-access part which stores data subject to change during
operation. A settable .[.real time.]. clock 53 is used to keep time
in the remote sensor to facilitate diverse operations, such as
receiving and transmitting sensor signals. The remote sensor may be
suitably powered by a battery (not shown) and/or from power supply
integral with structure 10. The I/O unit 54 includes a wired or
wireless communications interface 59 for coordinating
communications between the CPU 50 and the central control
device.
Thus, in the usual manner during normal operation, one or more
environmental sensors send an electrical signal (e.g., if the
sensor S1 is a simple thermistor, a resistance value; several types
of temperature sensors are widely used) representative of the
temperature within its local conditioned space (i.e., the room)
which the processor can average to calculate a control value to
compare against a previously entered set point to determine if
control signals need to be sent to the space conditioning equipment
37. For example, if the control value temperature in the
conditioned space is found to be too low when operation is in the
heating mode, the processor 31 signals the space conditioning
equipment 38 circulate, through ducts 39/40, air from/to the
conditioned space 38 which is heated by the space conditioning
equipment before return to the conditioned space. This heating
phase continues until the calculated control value indicates that
the space is now too hot (or approaching too hot) with reference to
the set point such that the processor 31 sends signal(s) to the
space conditioning equipment 38 to cease the heating function, all
as very well known in the art. In a cooling mode, a counterpart
procedure is followed. Those skilled in the art will understand
that the control process typically includes such refinements as
anticipation, hysterisis accommodation, fan control, etc. which are
acknowledged, but are not directly relevant to the invention.
Consider now a first embodiment of the invention referring to FIG.
4 as well as FIGS. 1, 2 and 3. Continuously or at one or more
predetermined times of day (and/or on-demand if provided for in a
sensor control program), occupancy sensor S4 determines whether or
not its local conditioned space (i.e., a room) is occupied. An
occupancy sensor S4 may detect motion in the room, the opening of
doors 21 or 22, or the turning on of a light fixture 19, all of
which indicate presence of a human occupant. Processor 50 comprises
a sensor control program that determines whether occupancy sensor
S4 has detected occupancy in conditioned space 56. If occupancy is
not detected, the control program optionally waits a predetermined
period of time before evaluating input from occupancy sensor S4
again or monitors such inputs continuously. If occupancy is
detected, the sensor control program inquires to determine if an
optional device motion sensor S5 has detected movement of the
remote sensor from a resting or installation location. If remote
sensor movement is detected, the control program optionally waits a
predetermined period of time before evaluating input from occupancy
sensor S4 again. If remote sensor movement is not detected, the
control program receives input from environmental sensor S3 and
transmits its signal (or value) to the central control device 23
for storage in memory of processor 30. Each remote sensor has a
known data communications "address" so that a control program of
the central control device can determine which remote sensor has
transmitted sensor signals or values.
Consider now a second embodiment of the invention referring to FIG.
5 as well as FIGS. 1, 2 and 3. Continuously or at one or more
predetermined times of day (and/or on-demand if provided for in a
sensor control program), occupancy sensor S4 determines whether or
not its local conditioned space (i.e., a room) is occupied. An
occupancy sensor S4 may detect motion in the room, the opening of
doors 21 or 22, or the turning on of a light fixture 19, all of
which indicate presence of a human occupant. Processor 50 comprises
a sensor control program that determines whether occupancy sensor
S4 has detected occupancy in conditioned space 56. If occupancy is
not detected, the sensor control program receives and transmits to
the central control device 23 the signals (or values) from
environmental sensor S3 with signals indicating that the sensor
value is associated with a vacant room. The remote sensor
optionally waits a predetermined period of time before evaluating
input from occupancy sensor S4 again. If occupancy is detected, the
sensor control program inquires to determine if an optional device
motion sensor S5 has detected movement of the remote sensor from a
resting or installation location. If remote sensor movement is
detected, the control program optionally waits a predetermined
period of time before evaluating input from occupancy sensor S4
again. If remote sensor movement is not detected, the control
program receives input from environmental sensor S3 and transmits
its signal (or value) to the central control device 23 for storage
in memory of processor 30 with signals indicating that the sensor
value is associated with occupied room. Each remote sensor has a
known data communications "address" so that a control program of
the central control device can determine which remote sensor has
transmitted sensor signals or values.
Consider now the first and second embodiments of the invention
referring to FIG. 6 as well as FIGS. 1 through 5. At the start of a
portion of a control program for the central control device 23, a
user may select one of a set of averaging methods for environmental
sensor values stored in memory 32 to generate a control value to
compare with a setpoint for control of equipment 38. The control
program determines whether or not a user has selected an averaging
method. If no averaging method is selected, a default method is
used for averaging said environmental sensor values. In one form,
the default averaging method adds together all stored sensor values
in a data table and divides them by the number of sensor values to
arrive at a control value. This form of averaging is referred to
herein as the simple form. After an averaging method is selected,
previously stored sensor values in the data table are erased and
new sensor values are received and stored in the data table.
Alternately, previously stored values from the data table are
stored with an associated current time and date so that historical
occupancy and vacancy may be determined for a particular room of
structure 10. New values of sensors S1 and/or S3 are received into
a data table in memory 32 of the central control device to be used
for averaging environmental condition values detected in certain
rooms of structure 10. The averaging calculation results in a
control value used in comparison with a previously input setpoint
to control operation of equipment 38 for changing an environmental
condition in the conditioned space of structure 10.
If the central control device is programmable, the control program
installed during manufacture will provide for user entry of above
user input following conventional instructions similar to those
used in user-programming the climate control operation of the
thermostat system.
As used herein, a second form of averaging uses weighting of values
of environmental conditions detected by environmental sensors S1
and S3 in occupied rooms depending on square footage of the room
where the sensor is located. Greater weighting is assigned to
sensor data in rooms with greater relative square footage. For an
example using the environmental condition of temperature, assume
that room 13 is four times the size of room 15 in structure 10. If
rooms 13 and 15 are the only ones occupied, the second form of
averaging would divide the sensed temperature at central control
device 23 by 0.80 and the sensed temperature at remote sensor 23C
by 0.20 to arrive at the control value. The denominator in the
divisions is arrived at by the pro rata amount of space or square
footage of the rooms relative to each other.
For the second embodiment of the invention, a third form of
averaging uses weighting of values of environmental conditions
detected by environmental sensors S1 and S3 in occupied and
unoccupied rooms and assigns greater weight to sensor data from
occupied rooms. For an example using the environmental condition of
temperature, assume that rooms 13 through 15 are occupied and the
rest vacant. The third form of averaging would divide the sensed
temperatures at central control device 23 and remote sensors 23B
and 23C by 0.90 and the sensed temperatures at the remained of the
remote sensors by 0.10 to arrive at the control value. The
denominator in the divisions is arrived at determining the value of
conditioning the air in the unoccupied rooms.
A fourth form of averaging uses historical data to determine rooms
most heavily occupied over a pre-determined period (such as a week
or month) and averages current sensor data only from those heavily
occupied rooms to arrive at a control value that may or may not
depend on current occupancy. Historical data would indicate that,
for example, rooms 13, 15 and 17 are occupied above a predetermined
threshold level, i.e., three times per week or fifteen times per
week. For those rooms where historical data indicated frequent
occupancy and in the second embodiment of the invention, the
environmental sensor data used to determine a control value would
be those environmental conditions from occupied rooms and those
environmental conditions from rooms where there is frequent
occupancy regardless of current occupancy status. This form of
averaging anticipates actual occupancy of a room. However, if a
mobile environmental sensor it moved from one room to another and
such motion is detected as above, historical environmental data for
the moved sensor will be erased for the purposes of averaging in
this embodiment of the invention. Environmental sensor data must
begin anew with respect to room occupancy for a moved environmental
sensor.
While the principles of the invention have now been made clear in
an illustrative embodiment, there will be immediately obvious to
those skilled in the art many modifications of structure,
arrangements, proportions, the elements, materials, and components,
used in the practice of the invention which are particularly
adapted for specific environments and operating requirements
without departing from those principles.
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