U.S. patent application number 13/087175 was filed with the patent office on 2011-10-20 for zone-based hvac system.
Invention is credited to John G. Posa, Barry H. Schwab.
Application Number | 20110253796 13/087175 |
Document ID | / |
Family ID | 44787494 |
Filed Date | 2011-10-20 |
United States Patent
Application |
20110253796 |
Kind Code |
A1 |
Posa; John G. ; et
al. |
October 20, 2011 |
ZONE-BASED HVAC SYSTEM
Abstract
A zone-based heating, ventilating, and air conditioning (HVAC)
system uses occupant sensors and controllable vents to favor
environmental conditions in occupied areas. A plurality of comfort
delivery devices are provided, each being associated with at least
one of the zones, each comfort delivery device being responsible
for delivering a change in climate to its respective zone through
the HVAC unit. A sending unit is disposed in each zone, the sending
unit including a first sensor for determining whether the zone is
occupied by one or more persons, a second sensor for determining an
environmental condition in the zone, and a communications device
for outputting a signal relating to the occupancy and environmental
condition. A control unit includes an input for receiving the
signal from each sending unit and selectively activating and
deactivating the comfort delivery devices to prioritize the climate
control provided by the HVAC unit to zones that are occupied. The
control unit further may incorporate information from other
sources, both internal and external, and learned behavior from
previous measurements. Unoccupied areas may be utilized as sources
of pre-conditioned air, previously stored for efficiency or economy
reasons.
Inventors: |
Posa; John G.; (Ann Arbor,
MI) ; Schwab; Barry H.; (West Bloomfield,
MI) |
Family ID: |
44787494 |
Appl. No.: |
13/087175 |
Filed: |
April 14, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61323921 |
Apr 14, 2010 |
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Current U.S.
Class: |
236/49.3 |
Current CPC
Class: |
F24F 2120/10 20180101;
F24F 11/30 20180101; G05D 23/1934 20130101 |
Class at
Publication: |
236/49.3 |
International
Class: |
F24F 11/00 20060101
F24F011/00 |
Claims
1. A system for controlling an HVAC unit servicing a plurality of
comfort zones, comprising: a plurality of comfort delivery devices,
each associated with at least one of the zones, each comfort
delivery device being responsible for delivering a change in
climate to its respective zone through the HVAC unit; a sending
unit disposed in each zone, the sending unit including a first
sensor for determining whether the zone is occupied by one or more
persons, a second sensor for determining an environmental condition
in the zone, and a communications device for outputting a signal
relating to the occupancy and environmental condition; and a
control unit including an input for receiving the signal from each
sending unit and selectively activating and deactivating the
comfort delivery devices to prioritize the climate control provided
by the HVAC unit to zones that are occupied.
2. The system of claim 1, wherein the HVAC unit is a furnace and
the change in climate is temperature.
3. The system of claim 1, wherein the HVAC unit is an air
conditioner and the change in climate is temperature.
4. The system of claim 1, wherein the HVAC unit causes a change in
humidity.
5. The system of claim 1, wherein the comfort delivery devices are
controllable louvers or vents.
6. The system of claim 1, wherein the first sensors are infrared
sensors.
7. The system of claim 1, wherein the second sensors are
temperature sensors.
8. The system of claim 1, wherein the communications devices are
wireless transmitters.
9. The system of claim 1, wherein each sending unit is coded,
enabling the control unit to determine the zone or zones within
which the sending units are disposed.
Description
REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional
Patent Application Ser. No. 61/323,921, filed Apr. 14, 2010, the
entire content of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to heating and cooling and,
in particular to a zone-based heating, ventilating, and air
conditioning (HVAC) system that uses occupant sensors and
controllable vents to favor environmental conditions in occupied
areas.
BACKGROUND OF THE INVENTION
[0003] Energy costs continue rise. Over the years, ideas have been
proposed to control heat loss in buildings and limits to the use of
air conditioning are being proposed.
[0004] As one example of many, U.S. Pat. No. 4,407,447, entitled
"Energy Control System," has a plurality of occupancy sensors, with
each sensor adapted to detect the presence of a human being in a
room. The occupancy sensors are all connected to a computer with
the computer controlling a plurality of dampers that regulate the
air flow in the air ducts into the various rooms. Upon the
detection of the presence of a human being in a room by the
occupancy sensor, the computer sends a signal to the air damper
controlling the air flow into that room to open the air flow
through that air duct.
[0005] While systems of the type just identified may prove
beneficial in some situations, they could do more in terms of
energy management. In the '447 patent, for example, there is no
provision for any control of return-air. Nor is there any provision
for shifting air [or energy] between rooms, or for using the heat
capacity of unoccupied rooms for energy "storage."
SUMMARY OF THE INVENTION
[0006] This invention resides in a system for controlling a
heating, ventilating, and air conditioning (HVAC) unit servicing a
plurality of comfort zones. A plurality of comfort delivery devices
are provided, each being associated with at least one of the zones,
each comfort delivery device being responsible for delivering a
change in climate to its respective zone through the HVAC unit. A
sending unit is disposed in each zone, the sending unit including a
first sensor for determining whether the zone is occupied by one or
more persons, a second sensor for determining an environmental
condition in the zone, and a communications device for outputting a
signal relating to the occupancy and environmental condition. A
control unit includes an input for receiving the signal from each
sending unit and selectively activating and deactivating the
comfort delivery devices to prioritize the climate control provided
by the HVAC unit to zones that are occupied.
[0007] The HVAC unit may be a furnace or an air conditioner, with
the change in climate being temperature. The HVAC unit may cause a
change in humidity. The comfort delivery devices may be
controllable louvers or vents. In the preferred embodiment the
first sensors are infrared sensors and the second sensors are
temperature sensors. The communications devices may be wireless
transmitters. Each sending unit may be coded, enabling the control
unit to determine the zone or zones within which the sending units
are disposed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a simplified, schematic diagram illustrating the
basic operation of one embodiment of the invention; and
[0009] FIG. 2 depicts an alternative embodiment of the invention
wherein controlled vents are disposed at or near a furnace; and
[0010] FIG. 3 is a simplified block diagram of a typical OSTTU
according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] This invention reduces energy consumption and enables
potential equipment downsizing by providing a heating/cooling
system that operates on a zone basis (i.e., room-by-room).
[0012] Broadly, the invention uses occupant sensors and
controllable vents to favor environmental conditions in area(s)
occupied by people, disfavoring other areas if/until people
actually visit or frequent such places.
[0013] Advantageously, the system reclaims warmed or cooled air
that has been applied to now-vacated zones, and redirect the warmed
or cooled air to zones that are currently occupied.
[0014] The system may also utilize unoccupied zones to "store"
heated or cooled air to be drawn upon at a later time, with the
intention of advantageously utilizing this "reserve capacity" to
mitigate the effects of other energy-saving features, such as
electrical power distribution systems that automatically interrupt
the power for air conditioners at peak periods of usage, or using
lower overnight temperatures to store cool air in unoccupied zones
so that it can be utilized during the hotter daylight hours.
[0015] Depending on the specific circumstances and financial
considerations, heat-exchangers or other apparatus may be employed
to optimize the efficiency of transfer of energy between zones. In
addition, equivalent facilities may be implemented to redirect air
from one zone to another, based on temperature, humidity, air
purity, or other environmental considerations.
[0016] The system makes intelligent decisions based upon various
input factors, such as the allowable degree of variation in
temperatures, or "learned behaviors," such as patterns of movements
throughout the zones at particular times of day or certain days of
the week. For example, the system may "learn" that the occupant of
a home likes to prepare a "midnight snack" in the kitchen 30
minutes before retiring for the night, and could adjust the
temperatures of various zones based on an anticipated schedule, or
remaining family members in other zones. External inputs can also
be integrated into the decision-making process, as, for example,
factoring in the setting of an alarm clock or other wake-up device
to automatically raise the temperature of a bathroom in
anticipation of a morning shower.
[0017] Another option would be to apply different
rules/considerations based on a pre-defined "profile" for a
particular person. For example, a particular person may prefer to
keep the room they are occupying at a higher or lower temperature
than other potential occupants; in cases such as these, the system
may identify particular occupants by their size, heat signature, or
other methods of analysis and, based on their profile, define the
environmental parameters to be applied to the rooms they are
occupying at a particular time. When multiple occupants having
dissimilar profiles are in the same room, the system would derive
compromise settings based on pre-defined rules for factoring in the
profiles of each occupant.
[0018] In addition, some homes employ multiple heating systems
(either because of long duct runs, or for redundancy), and the
systems described herein are capable of interfacing multiple HVAC
units to manage their functionality as a single integrated system.
The resulting benefit could include alternating the use of the
units to prevent one unit from becoming overloaded, or using all
units simultaneously to speed the response to system-related
demands.
[0019] FIG. 1 is a simplified, schematic diagram illustrating the
basic operation of one embodiment of the invention. The drawing
shows three rooms, A, B, C, with the understanding that the
invention is not limited in terms of the number of areas
considered. Items labeled 140 and 142 are doors between the
rooms.
[0020] Item 102 represents a furnace, combined furnace/AC unit,
boiler, humidifier, dehumidifier, or any other unit associated with
heating, cooling or other faun of residential, commercial or
industrial environmental control. Assuming unit 102 is a furnace,
the furnace includes a hot air plenum 104 feeding registers 110,
112, 116, with a cold-air return coupled to plenum 106. Again, more
or fewer hot/cold vents may be accommodated
[0021] Each vent 110, 112, 114, 116 may include controlled louvers
120, 122, 124, 126. For example, louvers 120 are controlled by
motor 128. Each room A, B, C, in this case also includes an
Occupant Sensor/Thermostat Transmitter Unit (OSTTU) 130, 132, 134
described in further detail below. Each OSTTU is characterized by a
field of view (i.e., 131) used to detect persons entering, leaving,
or remaining within a respective room. In the preferred embodiment,
the OSTTUs include infrared sensors for this purpose. In practice,
these sensing means can be combined with motion sensors or other
detectors, and the sensitivities of these sensors can be adjusted,
so as to moderate the impact of some events (such as entering a
zone just for a few minutes before leaving again), or ignoring
other events (such as a pet roaming the zones).
[0022] The controlled louvers and OSTTUs are in communication with
a control unit 160 which, in turn, communicates and controls unit
102, whether a furnace or otherwise. In the preferred embodiment,
the OSTTUs are battery operated devices which communicate
wirelessly (i.e., RF or infrared) via broken lines 150 to the
control unit 160. This is preferred since an installer may wish to
locate the OSTTUs in various wall-mounted locations, including
locations having no continuous power supply available. In some
embodiments, however, the OSTTUs may be incorporated into wall
outlets, light fixtures, or the like and derive power through them
without the need for batteries, or alternatively through power
derived from batteries recharged by locally mounted solar-cells or
recharged by other means.
[0023] The louver controllers may also be battery operated and
wirelessly controlled. However, there are some disadvantages to
being battery operated, so they are more preferably hard-wired via
broken lines 152 to control unit 160 to ensure reliable operation.
Particularly as an after-market product, low-voltage wiring may be
oriented through existing ductwork to louvers 120, 122, 124, 126,
thereby forgoing the need for wiring nearby AC outlets, for
example.
[0024] By way of a simple example, in operation OSTTU "sees" that a
person is occupying room C. According, a signal is sent to control
unit 160, causing louver 116 to open. Depending upon the way in
which the system is programmed, as discussed in greater detail
below, louvers 120, 122 may be closed since the rooms are void of
occupants. Again depending upon the way in which the system is
programmed, cold-air return 124 may be partially open to circulate
at least a portion of the air from room C.
[0025] OSTTUs preferably include thermostats, which may be of the
programmable set-back type. Alternatively, a subset of the OSTTUs
may include thermostats, with the others simply including
thermometers, depending upon the operational environment. If
provided with thermostats, the OSTTUs may be set at the same
temperature or at different temperatures.
[0026] Continuing the simplified example of FIG. 1, assume that all
of the OSTTUs 130, 132, 134 include thermostats, that all are set
to 65.degree. F., and that the person just entered room C from room
B. If OSTTU 134 detects that room C is cold--say, 60.degree.
F.--the furnace 102 may be turned ON (if not already ON), and
louver 116 will be opened (again, if not already opened), until
OSTTU 134 detects that the room has been heated to 65.degree. F.,
at which time louver 126 may be closed and/or furnace 102 turned
OFF. Cold-air return 114 may also be opened and closed as desired
to attain the desired environmental condition(s).
[0027] The reason why louver 126 may be closed and/or furnace 102
turned OFF when a desired condition is met depends upon various
factors, including conditions in other rooms, time of day, movement
of occupants, and so forth. For instance, if the person just
entered room C from room B, and room B is at a desired temperature,
louver 116 may be opened and louver 122 may be closed, as shown,
with the furnace remaining ON, to favor heating room C over
previously heated room B. Generally speaking, in a heating
embodiment, the invention is used to open and close louvers, and
turn the furnace ON/OFF, so that occupied rooms are comfortable
while non-occupied rooms are allowed to cool down. For example, if
thermostats are set to 65.degree. F., occupied rooms may be heated
to that temperature, while non-occupied rooms are allowed to cool
to, say, 60.degree. F. or lower (depending upon programming).
[0028] In the preferred embodiments, the system is programmed to
make intelligent decisions regarding overall operation beyond room
occupancy, including number of occupants, occupant movement between
rooms, length of stay in a room, time of day, and so forth.
[0029] For example, if movement is detected to a previously
unheated room, heating that room may be delayed to determine if the
person(s) intend to stay in that room. The infrared sensors may be
used to detect activation of lights, televisions, and so forth for
additional evidence of intent. Similarly, if movement is detected
from a previously heated room, allowing that room to cool may be
delayed, to determine if the person(s) intend to return to that
room. Again, the infrared sensors may be used to detect
de-activation of the lights, televisions, and so forth for
additional evidence of intent.
[0030] If it is evident that one or more persons are continually
moving between the same two rooms, both may be favored in terms of
heating. If the person in room C just entered the room from work at
7 PM, and the entire dwelling is cold due to temperature set-back
programming, louver 116 may be open with one or more other louvers
being or remaining open to continue heating the rest of the house
(though probably not to 65.degree. F. for the reasons discussed
above). Those of skill in the art will appreciate that a complex
state diagram readily may be derived in accordance with the
invention to account for occupant movement, time of day/year,
heating versus cooling, etc.
[0031] FIG. 2 depicts an alternative embodiment of the invention
wherein the controlled vents 220, 222, 224, 226 are disposed at or
near the furnace 102. Whether for retrofit applications or new
construction, this embodiment allows all wiring and controls to be
located away from comfort zones such as in a basement, thereby
simplifying installation. The trade-off is that the ductwork within
which the controlled vents are placed may feed multiple registers
although this may actually be advantageous in some situations.
[0032] FIG. 3 is a simplified block diagram of a typical OSTTU
according to the invention. The device includes a microprocessor
302 providing overall control. The processor 302 receives occupant
presence signals from IR sensor 304 and temperature signals from
sensor 306. Other sensor(s) represented by unit 308 may include a
humidity sensor, etc. As discussed above, other occupant sensors
may be used such as video cameras, including IR video cameras.
Pattern recognition may be provided enabling the system to
determine the number, and movement of, occupants, and prevent pets
from exerting unintended influence on decision-making by the
system.
[0033] Continuing the reference to FIG. 3, a power supply 312
powers the various components. Block 312 is preferably a battery,
which may be rechargeable, with line 314 representing an auxiliary
power source such as line voltage or input from a solar cell. Item
310 is a wireless transmitter relaying conditions to control unit
160, which may utilize an RF signal, WiFi or any other suitable
communication. Each OSTTU is coded with an ID number so that the
signals received by the control unit 160 may be properly
interpreted in terms of the different zones being accommodated. A
wall-mounting adhesive film may be provided at 320.
[0034] In some of the embodiments, it may be desirable to draw air
from a zone or room after it becomes unoccupied (or even in some
cases while still occupied, but with a different group of
occupants. Depending on the configuration of the ductwork, it may
be advantageous or even necessary to implement additional vents or
fans (not shown) to facilitate the movement of air through
particular sections of ducts or zones. Control of these fans is
managed by the system and coordinated with the opening and closing
of the various vent openings, in order to supply or extract air
from any particular zone as desired.
[0035] While the invention has been described in terms of a
forced-air system in a residential setting, other environments,
including commercial and industrial may be readily accommodated.
Forced-air implementations are perhaps the most responsive in terms
of temperature or humidity adjustment; however, other systems,
including hot water (boiler), heated flooring, heat pumps and other
equipment are not precluded. In addition, other facilities (such as
humidifiers, de-humidifiers, heat exchangers, and air-filtration
units) may be integrated into and managed by the overall system, as
needed or desired. Further, other sources of information may be
integrated into the control system decision-making processes, such
as external sensors to detect outside temperature and humidity
changes, or external communication links to connect to the Internet
for receiving and interpreting programming information from the
users, or weather forecasts for advance planning of environmental
settings. Depending on these and other sources, the control system
may be programmed to store heat or "store" cold in unused rooms, so
that these sources of pre-conditioned air will be available for
later use, thereby improving the efficiency and response time of
the system.
* * * * *