U.S. patent application number 13/567523 was filed with the patent office on 2014-02-06 for hydrogen gas buildup prevention in hot water heaters.
The applicant listed for this patent is Michael Thomas Beyerle, Irena Jozie McDowell. Invention is credited to Michael Thomas Beyerle, Irena Jozie McDowell.
Application Number | 20140033993 13/567523 |
Document ID | / |
Family ID | 50024232 |
Filed Date | 2014-02-06 |
United States Patent
Application |
20140033993 |
Kind Code |
A1 |
McDowell; Irena Jozie ; et
al. |
February 6, 2014 |
HYDROGEN GAS BUILDUP PREVENTION IN HOT WATER HEATERS
Abstract
A hot water heater includes a controller, a hot water tank and a
sensor operatively coupled to the hot water tank and the
controller. The sensor is configured to detect use of hot water
from the hot water tank. The controller is operative to determine
an interval of non-use of hot water from the hot water tank; and
enable a drain cycle to withdraw a portion of water from the hot
water tank.
Inventors: |
McDowell; Irena Jozie;
(Louisville, KY) ; Beyerle; Michael Thomas;
(Louisville, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
McDowell; Irena Jozie
Beyerle; Michael Thomas |
Louisville
Louisville |
KY
KY |
US
US |
|
|
Family ID: |
50024232 |
Appl. No.: |
13/567523 |
Filed: |
August 6, 2012 |
Current U.S.
Class: |
122/14.3 ;
137/624.11; 392/441 |
Current CPC
Class: |
F24D 19/088 20130101;
F24D 17/0031 20130101; Y10T 137/86389 20150401; F24D 17/02
20130101; F24D 19/1051 20130101 |
Class at
Publication: |
122/14.3 ;
137/624.11; 392/441 |
International
Class: |
F24H 9/20 20060101
F24H009/20; F24H 1/18 20060101 F24H001/18 |
Claims
1. A hot water heater comprising: a controller; a hot water tank;
and a sensor operatively coupled to the hot water tank and the
controller, the controller being operative in response to the
sensor to detect use of hot water from the hot water tank to
determine an interval of non-use of hot water from the hot water
tank; and enable a drain cycle to withdraw a portion of water from
the hot water tank upon such determination.
2. The hot water heater of claim 1, wherein the sensor comprises a
water flow sensor and wherein the interval of non-use is determined
if a time interval of no water flow from the hot water tank exceeds
a predetermined time threshold.
3. The hot water heater of claim 1, wherein the sensor comprises a
water temperature sensor, wherein the interval of non-use is
determined if any change in temperature of the water in the hot
water tank during a pre-determined time interval does not exceed a
pre-determined temperature change threshold value.
4. The hot water heater of claim 1, further comprising a user
interface operatively coupled to the controller, the user interface
enabling a vacation mode of the hot water heater to be set, and
wherein the controller is configured to detect the vacation mode of
the hot water heater and enable the drain cycle to withdraw a
portion of water from the hot water tank at predetermined time
intervals.
5. The hot water heater of claim 4, further comprising a wireless
interface operatively coupling the user interface and the
controller.
6. The hot water heater of claim 1, further comprising a wireless
radio connection between the controller and the sensor.
7. The hot water heater of claim 1, further comprising an
electrically operated hot water using appliance operatively coupled
to the controller, wherein enabling the drain cycle comprises
enabling operation of the electrically operated appliance to
withdraw water from the water heater.
8. A hot water heater system comprising: a hot water heater; and a
controller coupled to the hot water heater, the controller
operative to: determine a stagnant state of the hot water heater;
and enable a drain cycle of the hot water heater.
9. The hot water heater system of claim 8, wherein the drain cycle
is enabled at predetermined time intervals during the stagnant
state.
10. The hot water heater system of claim 8, further comprising a
water flow sensor operatively coupled between the controller and
the hot water heater and wherein the controller is operative to:
detect a flow of hot water from the hot water heater; and determine
an elapsed time from the detection of the detected flow; and the
stagnant state being indicated when the elapsed time is greater
than the predetermined threshold time.
11. The hot water heater system of claim 8, further comprising a
water temperature sensor operatively coupled between the controller
and the hot water heater and wherein the controller is operative to
determine the stagnant state by monitoring a temperature of hot
water in the hot water heater; and wherein the stagnant state being
indicated when the temperature change does not exceed a
predetermined temperature change threshold value during a time
interval of predetermined duration.
12. The hot water heater system of claim 8, further comprising: an
appliance operatively coupled to the hot water heater and the
controller; wherein the controller is operative to enable the
appliance to withdraw water from the hot water heater upon
determination of a stagnant state.
13. The hot water heater system of claim 12, wherein the appliance
comprises a dishwasher, a washer, or an electronically controlled
hot water discharge valve.
14. The hot water heater system of claim 8, further comprising a
user interface operatively coupled to the controller, the user
interface enabling user selection of a vacation mode state of the
hot water heater, wherein the controller is operative during the
vacation mode to enable the drain cycle of the hot water heater at
predetermined time intervals.
15. The hot water heater system of claim 14, further comprising an
electrically operated appliance with a control panel operatively
coupled to the controller, the user interface comprising the
control panel.
16. The hot water heater system of claim 14, further comprising a
wireless interface operatively coupling the user interface and
controller.
17. The hot water heater system of claim 16, wherein the user
interface comprises a mobile communication device.
18. The hot water heater system of claim 8, further comprising a
home energy management system, the controller comprising a home
energy manager of the home energy system.
19. A hot water heater system comprising: a hot water heater; an
appliance coupled to the hot water heater and configured to
withdraw hot water from the hot water heater; and a home energy
manager coupled to the hot water heater and the appliance, wherein
the home energy manager is configured to enable the appliance to
withdraw hot water from the hot water heater at predetermined time
intervals.
20. The hot water heater system of claim 19, wherein the home
energy manager is configured to detect a stagnant state of the hot
water heater and enable the appliance to withdraw hot water from
the hot water heater upon detection of the stagnant state.
Description
BACKGROUND
[0001] The present disclosure generally relates to appliances, and
more particularly to preventing hydrogen gas buildup in a hot water
heater.
[0002] In a hot water heater system, hydrogen gas can form as a
byproduct of chemical reactions caused by the metals used in the
construction of the tanks, particularly when the water in the hot
water tank is stagnant. Since hydrogen gas is not soluble in water,
any hydrogen gas formed will remain in the water heater plumbing
system, tending to rise to the highest locations in the plumbing
system. The hydrogen gas can also be trapped in the lower levels of
the plumbing system.
[0003] During normal or regular operation of the hot water heater
system, the amount of hydrogen gas buildup will be minimal and will
tend to be vented from the plumbing system as hot water is
discharged from the hot water tank, either through the dispensing
of hot water from a tap, or the use of hot water by an appliance,
such as a dishwasher or washing machine. However, if the hot water
heater system is inactive for an extended period of time, there is
a potential for a buildup of hydrogen gas generated in the
tank.
[0004] In order to avoid problems associated with hydrogen gas
build up, it is generally recommended that when a hot water heater
system has been stagnant for a period of time, such as for example
two weeks, the hot water faucets be opened for several minutes to
vent any hydrogen gas that may have accumulated during the period
of non-use.
[0005] It would be advantageous to be able to automatically vent a
hot water heater system of any potential hydrogen gas buildup
during periods where the hot water heating system is not used
regularly.
[0006] Accordingly, it would be desirable to provide a hot water
heater system that addresses at least some of the problems
identified above.
BRIEF DESCRIPTION OF THE INVENTION
[0007] As described herein, the exemplary embodiments overcome one
or more of the above or other disadvantages known in the art.
[0008] One aspect of the exemplary embodiments relates to a hot
water heater. In one embodiment, the hot water heater includes a
controller, a hot water tank and a sensor operatively coupled to
the hot water tank and the controller. The sensor is configured to
detect withdrawal of hot water from the hot water tank. The
controller is operative in response to the sensor to detect the
occurrence of a stagnant state and initiate the withdrawal of hot
water from the tank in response to such detection. A stagnant state
results when the time interval between withdrawals of water from
the tank is greater than a predetermined interval selected to
prevent or limit the generation of hydrogen gas in the hot water
tank.
[0009] This and other aspects and advantages of the exemplary
embodiments will become apparent from the following detailed
description considered in conjunction with the accompanying
drawings. It is to be understood, however, that the drawings are
designed solely for purposes of illustration and not as a
definition of the limits of the invention, for which reference
should be made to the appended claims. Moreover, the drawings are
not necessarily drawn to scale and that, unless otherwise
indicated, they are merely intended to conceptually illustrate the
structures and procedures described herein. In addition, any
suitable size, shape or type of elements or materials could be
used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the drawings:
[0011] FIG. 1 is a schematic diagram of an exemplary hot water
heater system incorporating aspects of the present disclosure.
[0012] FIG. 2 is a flow chart illustrating an exemplary process
flow incorporating aspects of the present disclosure.
[0013] FIG. 3 is a schematic diagram of an exemplary hot water
heater system incorporating aspect of the present disclosure.
[0014] FIG. 4 is a schematic diagram of another exemplary hot water
heater system incorporating aspect of the present disclosure.
[0015] FIG. 5 is a flow chart illustrating an exemplary process
flow incorporating aspects of the present disclosure.
[0016] FIG. 6 is a flow chart illustrating another exemplary
process flow incorporating aspects of the present disclosure.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE
DISCLOSURE
[0017] Referring to FIG. 1, an exemplary hot water heater system
incorporating aspects of the disclosed embodiments is generally
designated by reference numeral 100. The aspects of the disclosed
embodiments are directed to a hot water heater system that detects
when the hot water heater has not been used for a period of time
and automatically drains enough hot water from the hot water tank
to prevent or satisfactorily limit the generation of hydrogen gas
in the tank. Although the embodiments disclosed herein will be
described with reference to the drawings, it should be understood
that the embodiments disclosed can be embodied in many alternate
forms. In addition, any suitable size, shape or type of elements or
materials could be used.
[0018] As shown in FIG. 1, the hot water heater system 100
generally includes a hot water heater 10 and a controller 20. In
the embodiment of FIG. 1, the hot water heater 10 includes a
reservoir or water storage tank 12 for storing water and a heat
source 14 for heating the water stored in the tank 12. The hot
water heater 10 includes an inlet 16 for receiving water into the
tank 12. The inlet 16 is typically connected to a water supply line
for a home or building. The hot water heater 10 also includes an
outlet 18 for supplying hot water from the tank 12 to the hot water
portions of the plumbing system 30 to which the hot water heater 10
is connected. The plumbing system 30 can be part of a residential,
commercial or other water plumbing system that incorporates a hot
water heater and is generally used to provide a connection between
the hot water heater 10 and one or more electrically operated
appliances 40 that use hot water. Although the plumbing system 30
is referred to in FIG. 1, in one embodiment, there can be a direct
connection from the hot water heater 10 to the appliance 40.
[0019] While the aspects of the disclosed embodiments can be
applied to any system that incorporates a hot water heater 10, for
the purposes of the description herein, such system will be
described as a "plumbing system" or "home." The hot water heater 10
can be any suitable hot water heater including an electric, gas or
hybrid hot water heater. In one embodiment, the heat source 14 can
comprise an electric heating element such as a resistive-type
heating element, a gas burner such as a propane or natural gas
burner, a heat pump type of heater, or any other type of heat
source.
[0020] As briefly mentioned in the Background, in hot water systems
including systems of the type illustrated in FIG. 1, when hot water
has not been dispensed or discharged from the hot water tank 12 for
an extended period of time, hydrogen gas can form as a byproduct of
chemical reactions caused by the metals used in the construction of
the tanks. If left unchecked, hydrogen gas can buildup in the hot
water heater system 100 to an undesirable level. The aspects of the
disclosed embodiments are configured to detect conditions conducive
to hydrogen generation, before any significant hydrogen gas buildup
has occurred. The time period for such conditions to develop or
occur in a hot water heater 10 can vary, depending on one or more
factors. Examples of such factors, can include, but are not limited
to the area of the world and the elevation. Many water heaters come
with a warning that hydrogen gas build up can occur after about two
weeks of inactivity.
[0021] In the embodiment shown in FIG. 1, the controller 20 is
provided for controlling aspects of the hot water heater system
100. In one embodiment, the controller 20 is configured to detect
the occurrence of condition of the water in the tank hereinafter
referred to as a stagnant state. A stagnant state is detected when
the interval of time between successive withdrawals or dispensing
of water from the tank exceeds a predetermined period which is
preferably selected to be of a duration that is long enough to
avoid short cycling or nuisance tripping, but short enough to
prevent the generation of such gas or at least limit the build up
of such gas in the plumbing system to an acceptable level. For
purposes of the examples herein, the pre-determined period is
selected to be not greater than fourteen days, although shorter or
longer time periods can be contemplated, depending upon the
particular hot water heater system application. When the controller
20 detects a stagnant state of the hot water heater 10, the
controller 20 is configured to automatically enable a drain cycle
of the hot water heater 10. A drain cycle of the hot water heater
10, as that term is used herein, generally refers to a cycle of the
hot water heater system 100 that causes hot water to be discharged
from the tank 12, and flow through the plumbing system so that
hydrogen gas build up cannot occur. A drain cycle can typically be
initiated by opening a hot water valve of the plumbing system 30 or
running an electrical appliance that is coupled to the plumbing
system 30 to withdraw water from the hot water heater. The aspects
of the disclosed embodiments are generally directed to
automatically flushing the hot water tank 12 and associated
plumbing lines when the hot water in the hot water heater tank 12
has not or will not be used for an extended period of time in order
to prevent hydrogen gas buildup.
[0022] In one embodiment, the controller 20 comprises or is coupled
to or is in communication with a processor(s) that is operable to
monitor and control the flow of hot water from the hot water tank
12, as well as execute the processes that are generally described
herein. In one embodiment the controller 20 is comprised of
machine-readable instructions that are executable by one or more
processors or other suitable processing device(s). The processor(s)
can include program code to perform particular tasks and/or data
manipulations, as are generally described herein. In one
embodiment, the processor(s) can include or be coupled to a memory
and input/output devices. The memory typically comprises both
non-volatile memory, such as semiconductor type random access
memory, and non-volatile memory such as a magnetic computer
disk.
[0023] As is shown in FIG. 1, in one embodiment, the controller 20
is coupled to a user interface 22. The user interface 22 can
comprise any suitable control or display that will allow a user to
program, set and adjust the functions and settings of the hot water
heater system 100, as are generally described herein. In one
embodiment, the user interface 22 comprises or includes a control
panel 26 that allows a user to program the system 100 and set the
hydrogen gas buildup prevention functions as are further described
herein. These functions can include, but are not limited to,
setting a hot water heater stagnation time period threshold,
setting a vacation mode and programming the system 100 to activate
an appliance 40 connected to the system 100 to enable a drain
cycle. In one embodiment, the user interface 22 can include a
display interface, such as a touch screen display. In alternate
embodiments, the user interface 22 can include buttons or switches
for manipulating and programming the settings of the system 100. In
one embodiment, the user interface 22 comprises or is part of a
control panel for the hot water heater 10. Alternatively, the user
interface 22 can be part of a control panel for an appliance 40.
The user interface 22 can also be located remotely from the hot
water heater 10, and can be accessible through a computing device
or a web based interface. For example, aspects of the disclosed
embodiments allow the controller 20 and control panel 26 to be
accessed and programmed using a mobile communication device 330, as
will be further described herein.
[0024] As is illustrated in FIG. 1, in one embodiment, the system
100 includes one or more sensors 24 for monitoring the state of the
hot water in the hot water tank 12. The sensor 24 is generally
configured to provide one or more signals or commands to the
controller 20 that will allow the controller 20 to detect a
stagnant state, because water has not been withdrawn from the hot
water tank 12 for an extended period of time. In one embodiment,
the sensor(s) 24 can comprises water flow monitors for detecting
the flow of water into, out of, or both into and out of the hot
water tank 12. In this example, the sensor(s) 24 can be coupled to
the tank 12 or one or both of the inlet 16 and outlet 18.
[0025] In another embodiment, the sensor(s) 24 can be configured to
sense the activation of one or more loads of the hot water heater
10. The loads of the hot water heater 10 generally include any
appliance 40 that utilizes hot water. In one embodiment, the
sensor(s) 24 can also comprise a temperature measuring device that
is configured to monitor and detect a temperature of the water in
the hot water tank 12.
[0026] The sensor 24 can be coupled to the controller 20 via a
wired or wireless communication connection or interface. For
purposes of the description herein, wireless communication
connections and interfaces can include, but are not limited to,
wireless radio, WiFi, Bluetooth, Zigbee and ethernet wireless type
devices and interfaces. In one embodiment, the sensor 24 can be
integrated with the controller 20.
[0027] In one embodiment, the controller 20 can include, or be
coupled to a clock/timer device 28. The clock/timer device 28 can
comprise any suitable timing device that is capable of monitoring
and providing real time data, providing an event clock or timing
mechanism, or providing both real time and event timing
capabilities. In one embodiment, the controller 20 is configured to
use the clock/timer 28 to determine a stagnant state of the hot
water heater 10, such as by determining an elapsed time since a
last use of the hot water from the hot water tank 12. Although the
clock/timer 28 will generally be referred to as a single clock or
timing device, the clock/timer 28 can also include multiple
clock/timer device. For example, the clock/timer 28 could include
one clock/timer for monitoring an elapsed time since a last use of
the hot water from the tank 12, and another clock/timer for
monitoring a time since a change in state of the sensor 24.
[0028] By providing information corresponding to the state of the
hot water in the hot water tank 12 to the controller 20, a stagnant
state of the hot water tank 12 can be determined FIG. 2 illustrates
one example of a process flow incorporating aspects of the
disclosed embodiments. In one embodiment, the controller 20
monitors 202 the state of the sensor(s) 24. Based on an indication
from the sensor 24, the controller 20 is configured to determine
204 the time or time interval since the last use or flow of hot
water from the tank 12, the use being one that is sufficient to
drain enough hot water from the hot water tank to prevent or
satisfactorily limit the generation of hydrogen gas in the tank.
Generally, a flow amounting to approximately 0.5 to 1 gallons, or
lasting approximately one to five minutes is a sufficient use.
[0029] In one embodiment, determining the time, or a time interval,
since the last use of the hot water from the tank 12 comprises
comparing a current clock time to a clock time of last use. A
difference between these two values can be used to determine if a
pre-determined time threshold or interval has been exceeded.
Alternatively, the clock/timer 28 can start a counter that is used
to determine an elapsed period since the last use. The controller
20 is configured to determine 206 whether a predetermined time
period or threshold time interval of non-use is met or exceeded.
Since it is generally understood that the potential for hydrogen
gas buildup in a typical domestic hot water heater system can occur
after approximately two weeks of non-use, the predetermined time
period or threshold time interval is selected to be not greater
than two weeks. For example, a period of a few days or one week can
be used as the threshold time interval. Alternatively, any suitable
time period can be used that will prevent hydrogen gas buildup in
the hot water heater 10 can be used as the predetermined time
period or threshold time interval.
[0030] If it is determined 206 that the predetermined time period
has not elapsed, in one embodiment, the controller 20 continues to
monitor 202 the state of the sensor(s) 24. If the predetermined
time period has elapsed, indicating that the hot water heater 10 is
in a stagnant state, the controller 20 is configured to enable 208
a drain cycle of the hot water tank 12. The drain cycle is
generally configured to allow a sufficient amount of hot water to
be drawn from the hot water tank 12 in order to prevent any
hydrogen gas buildup. In one embodiment, the amount of hot water
drained from the hot water tank 12 in a drain cycle is in the range
of approximately 0.5 to and including 1.0 gallons. In alternate
embodiments, any suitable amount of hot water can be dispensed from
the hot water tank 12 to ensure that any hydrogen gas that has
built up in the tank 12 and plumbing system 30 has been vented or
dispersed.
[0031] In one embodiment, the drain cycle can be an activation of
one or more of the appliances 40 coupled to the hot water heater
system 100 to withdraw water from the hot water heater. For
example, in one embodiment, when the controller 20 determines 206
that there has not been any use of hot water from the tank 12 for a
period of approximately one week, the controller 20, which is
communicatively coupled to the hot water consuming appliances 40,
can activate an appliance such as a dishwasher, to run through a
hot water cycle for a few minutes and then drain the water. The
cycle should be sufficient to drain an amount of water from the
tank 12 that will also flush any built-up hydrogen gas from the
tank 12. After the cycle is complete, the controller 20 continues
to monitor 202 and measure 204 the time period of inactivity.
[0032] One embodiment of a system 300 incorporating aspects of the
disclosed embodiments is illustrated in FIG. 3. In this example,
the controller 20 is communicatively coupled, via wired or wireless
connections, to the hot water heater 10, sensor 24, timer 28, the
one or more appliances 40 and communication gateway 320. In this
example, the appliances 40 include a dishwasher 42, a washer 44 and
an electronically controlled hot water discharge valve 46. In one
embodiment, the hot water discharge valve 46 is an electronically
controlled valve coupled to a hot water faucet or other outlet.
Activation of the valve 46 can allow hot water to be discharged
from the hot water tank 12. Each of the appliances 40 is a consumer
of hot water from the hot water heater 10, and when operated will
allow hot water to be discharged from the hot water tank 12 shown
in FIG. 1. The hot water is discharged from the hot water heater 10
to each of the appliances 40 through the plumbing system 30 that
fluidly couples the hot water heater 10 to each of the appliances
40 in a manner that will be generally understood.
[0033] In the embodiment shown in FIG. 3, the controller 20 is
communicatively coupled to a communication gateway or interface
320. The communication gateway 320 allows the homeowner or other
user to communicate with, program and operate the controller 20 and
hot water heater system 100 shown in FIG. 1 through one or both of
a computing device 324 and mobile communication device 330. The
communication connection between the device 324 and controller 20
can be via a wired or wireless connection, as is otherwise
described herein. When using a mobile communication device 330, the
communication gateway 320 allows the user to communicate with the
controller 20 through a remote connection and network. In this
example, the communication interface or gateway 320 includes a home
router 322, a computing or communication device 324, a broadband
communication interface or modem 326 and a communication network
328. The devices 324 and 330 can comprise any suitable computing or
communication devices, such as for example, a home computer, a
mobile phone, a smartphone, a pad or tablet type device. Generally,
the devices 324 and 330 will comprise any device that is capable of
communicating with the controller 20 over a wired or wireless
connection, as are generally known, in a suitable communication
format. The network 328 can comprise any suitable communication
network, such as for example the Internet or a cellular
communication network. In one embodiment, a user can utilize a
mobile communication device 330, such as a smartphone, to
communicate with the controller 20 to program the system 300 from a
remote location to monitor the hot water system 100, detect a
stagnation state of the hot water heater 10, and periodically cause
hot water to be discharged from the hot water tank 12 to prevent
hydrogen gas buildup.
[0034] In one embodiment, referring to FIG. 4, the hot water heater
system 100 includes, is part of, or is coupled to a home energy
gateway or manager (HEG) 50. The home energy manager 50 is
communicatively coupled to one or more of the exemplary appliances
40 to initiate or activate a hot water consumption cycle of one or
more of the appliances 40 to prevent hydrogen gas buildup. In one
embodiment, the home energy manager 50 is part of a home energy
management system. Home energy management (HEM) systems are
generally used to reduce energy consumption in homes and buildings.
A typical home energy management system is configured to
communicate with and control electrical appliances in homes and
buildings. These electrical appliances can include appliances 40
that make use of hot water from the hot water heater 10. Some
functions of a home energy management system, and the home energy
manager 50 are to create a network of appliances 40 in the home or
building, monitor the usage of such appliances, record and store
information, enable consumer interface with all appliances in the
home, and set preferences and operation modes for the appliances.
In the embodiment shown in FIG. 4, the home energy manager 50 is
coupled to the controller 20 in a suitable manner, including wired
or wireless connections. In alternate embodiments, the home energy
manager 50 can be integrated with or comprise the controller 20,
the user interface 22 or both the controller 20 and user interface
22, and include a connection to the sensor 24 as is generally
described herein.
[0035] In one embodiment, appliances 40 that are communicatively
coupled to the home energy manager 50 can be automatically
controlled to run hot water, which will create water movement in
the hot water tank 12. As an illustrative example, if a homeowner
is expecting to be away from the home for an extended period of
time, the homeowner can program the home energy manager 50 to
activate one or more of the appliances 40 to run hot water at
predetermined time intervals. At each time interval, an appliance
40, such as a dishwasher 42, can be controlled to withdraw a small
amount of hot water from the hot water heater and then drain it. If
the valves and drains of the appliances 40 cannot be separately
controlled, the dishwasher 42 can be controlled to run through a
suitable dish washing cycle(s) that uses hot water.
[0036] In one embodiment, the controller 20 and user interface 22
allow a user to program certain modes or states of the hot water
system 100 that indicate periods of non-use and enable the
automatic filling and draining of the hot water tank 12 to prevent
hydrogen gas buildup. For example, in one embodiment, referring to
FIG. 5, a vacation mode or state of the hot water heater system 100
can be detected or set 502. The term "vacation mode" generally
refers to a programmable state of the hot water heater 10 that
indicates that hot water from the hot water tank will not be
regularly used. The aspects of the disclosed embodiments allow the
hot water heater system 100 shown in FIG. 1, for example, to be
programmed as part of the vacation mode, to activate a drain cycle
of the hot water heater 10 at predetermined time intervals, without
first needing to determine that the hot water heater 10 is in a
stagnant state. In one embodiment, the vacation mode state can be
set using the user interface 22 of FIG. 1 to program one or more of
the hot water heater 10, an appliance 40 and controller 20. The
vacation mode state will be recognized or detected by the
controller 20. With reference to FIG. 3, in one embodiment, the
vacation mode state can be set using one or both of the computing
device 324 and mobile device 330.
[0037] In one embodiment, after the activation of the vacation mode
state is detected 502, the clock/timer 28 is activated 504. This
can include starting a counter that either counts up or counts
down. In one embodiment, the controller 20 is configured to monitor
506 the elapsed time and determine 508 if the elapsed time exceeds
a predetermined time interval. If yes, the controller 20 is
configured to enable 510 a drain cycle, such as by enabling the
activation of an appliance 40 to utilize hot water. In one
embodiment, before enabling 510 the drain cycle, the controller 20
can confirm that the vacation mode is still set. Once the drain
cycle is complete, the controller 20 can confirm that the vacation
mode is still set 502 and reset or restart 504 the timer 28. If it
is determined 508 that the elapsed time has not exceeded the
predetermined time interval, the controller 20 continues to monitor
506 the elapsed time. In one embodiment, if the elapsed time has
not exceeded the predetermined time interval, the controller 20 can
confirm that the vacation mode is still set before continuing to
monitor 506 the elapsed time.
[0038] Referring to FIG. 6, in an embodiment where the sensor 24
comprises a water temperature sensor, the controller 20 is
configured to monitor 602 the temperature of the water in the hot
water tank 12 in order to determine whether the hot water heater 10
is in a stagnant state. In this embodiment, the controller 20 can
be configured to detect deviations or changes of the temperature of
the hot water in the hot water tank 12. Temperature changes of the
water in the hot water tank 12 that exceed a nominal or
predetermined temperature deviation, generally referred to as
dramatic changes, can be indicative of withdrawal of hot water from
the hot water tank 12. A nominal deviation or change is generally
indicative of the natural drop in temperature of the water in the
hot water tank 12, which requires reheating of the water. For
example, in one embodiment, the controller 20 can be configured to
monitor the temperature of the water in the hot water tank every 10
minutes. If the detected temperature drop after 10 minutes is less
than approximately 5 degrees, it can be determined that there is no
water flow from the hot water tank 12, and the water is stagnant.
In another embodiment, in an exemplary hot water heater 10
operating in an energy efficient mode, if a drop in temperature of
the water on the order of approximately 0.2 degrees Fahrenheit
occurs over an approximately 2 minute time period, the controller
20 is configured to determine that there is normal or regular water
flow from the hot water tank 12, indicating that a stagnant state
has not occurred. A larger flow might be determined by a
temperature drop of approximately 8 degrees in approximately 10
minutes.
[0039] Alternatively, the controller 20 or home energy manager 50
can be configured to dynamically determine an average temperature
or temperature change of the hot water in the tank 12 during normal
or regular operation and use the dynamically determined average
temperature to determine a stagnant state. In one embodiment,
dynamically determining the average temperature or temperature
change can comprise taking temperature measurements over a
predetermined time interval and taking an average of the
temperature readings. In one embodiment, the vacation mode can be
used as an initial learning algorithm. For example, in one
embodiment, when the controller 20 first detects that a vacation
mode of the system has been set or such other suitable indication
that the hot water heater 10 will not be used for an extended
period, the controller 20 is configured to periodically read the
water temperature of the water in the water heater 10 and determine
how fast the water temp inside water heater decreases. In this
example, the controller 20 is configured to read the water
temperature approximately every minute. If the controller 20
determines that over a period of time such as approximately 10
minutes the water temperature drops only approximately 0.1 degrees
Fahrenheit, then this temperature/time change factor of 0.1 degrees
F./10 minutes, is set as the baseline for temperature change due to
environmental loss and not water usage. This baseline can be used
to determine a stagnant state. For example, if the controller 20
determines that over a period of time, such as one week, there has
been a temperature drop corresponding to the baseline
temperature/time change factor of 0.1 degrees F. in 10 minutes, the
controller 20 can be configured to identify a stagnant state and
automatically run some water through the dishwasher or washer.
Although this dynamic process can be run when a vacation or such
similar mode is first set, in one embodiment, the controller 10 can
be configured to determine when the hot water heater 10 has been
inactive for a predetermined period of time, and the initiate the
dynamic learning process. For example, while the vacation mode can
be used as the initial learning algorithm for dynamic learning
process, in a situation where a vacation mode is not set, the
aspects of the disclosed embodiments can detect that hot water is
not being used and initiate a learning mode or state. In this
embodiment, using dynamic process is used to determine the
temperature/time factor and monitor the hot water heater 10 for a
stagnant state. As another example of dynamically determining the
temperature of the hot water heater 10, the controller 20, which in
this example can include a real time clock, may read and store
water temperature readings every minute or so. Based on the
temperature readings, the controller 20 may determine that most
water usage occurs between 5 pm and 10 pm on weekdays, because of
large drops of water temperature over short periods of time. In
this example, the controller 20 uses the temperature changes during
the time period of midnight to 5 PM as the baseline of water
temperature loss due to the environment. The temperature changes
determined during this period of time can be set as the baseline or
temperature/time change factor determining when hot water is not
being used. For example, in one embodiment, the user manually
enters the time period(s) during which most of the water is used.
For instance, this could include one time period of 7 AM-8 AM and
another time period of 5 PM-10 PM. The controller 20 can use any of
the remaining time periods, such as 8 AM-5 PM and 10 PM-12 PM, to
determine the baseline temperature/time change factor. The
temperature drop or loss due to the environment can also be
different for different seasons of the year, such as for example
the seasons corresponding to the months of January-March,
April-June, July-September and, October-December. The controller 20
can be configured to determine baseline temperature/time change
factors for each of the seasons.
[0040] In one embodiment, the controller 20 is configured to
determine and record the time of the day, or periods of time, when
water draw from the hot water heater 10 is detected. As is
otherwise described herein, a default indication of hot water draw
from the hot water tank 10 is an approximate 0.2 degree temperature
drop in approximately 2 minutes, or an approximately 8 degree
temperature drop in approximately 10 minutes. The controller 20 can
records the times of water draw for a per-determined period of
time, such as one week. The controller 20 can determine the time
periods of no water draw and determine the average temperature drop
of water due to environment during these no water draw time
periods. The value of this new average temperature drop can be
designated as a maximum temperature loss per time period allowed to
establish a stagnant state.
[0041] In one embodiment, determining whether the hot water heater
10 is in a stagnant state can include determining 604 whether a
change in temperature of the hot water exceeds a predetermined
threshold temperature change value or range, such as the baseline
temperature/time change factor or maximum temperature loss per time
period.
[0042] If it is determined 604 that a temperature change of the hot
water exceeds the threshold value, this generally indicates that
the hot water heater 10 is not in a stagnant state and the
controller 20 can continue to monitor 602 the water temperature. In
one embodiment, monitoring 602 can include setting a timer. At the
expiration of a predetermined time period, the controller 20 can
determine 604 whether there has been a temperature change within
the predetermined time interval that exceeds the predetermined
temperature threshold change. If yes, indicating that the hot water
from the hot water tank 12 has been used, the controller 20 can
reset the timer and continue to monitor 602 the water
temperature.
[0043] If it is determined 604 that there has not been a change in
temperature of the water in the hot water tank 12 exceeding the
predetermined temperature threshold value, indicating a no-flow
state, in one embodiment, the controller 20 determines 606 whether
a predetermined time period since the last use of the hot water
from the hot water tank 12 has elapsed. The determining step 606
can use the elapsed time of the timer in step 602 to determine in
the predetermined time period has elapsed. In one embodiment, once
the no-flow state is determined in 604, or the vacation mode is
set, another timer can be started. The determining step 606 can use
an elapsed time of this other timer in determining whether the
predetermined time period has lapsed. In alternate embodiments, the
step of determining 606 can include any suitable method for
determining a time interval since the last use of hot water,
including the process described with respect to steps 204 and 206
in FIG. 2.
[0044] If it is determined 606 that the predetermined time value is
met or exceeded, in one embodiment, the controller 20 initiates 608
a hot water usage cycle of an appliance 40. Otherwise, the
controller 20 continues to monitor 602 the hot water temperature to
determine 604, 606 whether there is a change of temperature that
exceeds a nominal threshold value within a predetermined time
period, indicating use of the hot water.
[0045] In one embodiment, determining whether the hot water heater
10 is in a stagnant state can include monitoring the powering of
the heat source 14, such as the heating elements. If there is
limited or no power draw or consumption by the heat source 14 for a
predetermined time period, such as one week, the controller 20 is
configured to determine that the hot water heater 10 is in a
stagnant state. While the heat source 14 will consume some energy
in response to environmental heat loss of the hot water heater 10,
the amount of energy required to reheat the water due to
environmental heat loss will typically be distinguishable or less
than the amount of energy require to heat the water after a water
draw. For example, in one embodiment, the controller 20 is
configured to detect the time that a heating source 14 is powered
on. If the heat source 14 is on due to a water draw, the length of
time the heat source 14 is on, such as approximately 5-8 minutes
for example, will generally be greater than the period of time the
heat source 14 is on due to environmental heat loss, which can be
approximately in the range of 2 to 4 minutes. The controller 20 can
detect the time the heat source 14 is on, compare the detected time
value to a predetermined threshold, and determine if the hot water
heater 10 is in a stagnant state.
[0046] The system 100 and controller 20 of FIG. 1 are generally
configured to utilize program storage devices embodying
machine-readable program source code that is adapted to cause the
apparatus to perform and execute the method steps and processes
disclosed herein. The program storage devices incorporating aspects
of the disclosed embodiments may be devised, made and used as a
component of a machine utilizing optics, magnetic properties and/or
electronics to perform the procedures and methods disclosed herein.
In alternate embodiments, the program storage devices may include
magnetic media, such as a diskette, disk, memory stick or computer
hard drive, which is readable and executable by a computer. In
other alternate embodiments, the program storage devices could
include optical disks, read-only-memory ("ROM") floppy disks and
semiconductor materials and chips. The computer program or software
incorporating the processes and method steps incorporating aspects
of the disclosed embodiments may be stored in one or more computer
systems or on an otherwise conventional program storage device.
[0047] The exemplary embodiments described herein provide a system
for automatically determining when the hot water in a hot water
tank 12 has not been used or is stagnant. In order to prevent or
eliminate any hydrogen gas buildup in the hot water heater system
and associated plumbing, a fill and drain cycle of the hot water
heater can be run. This can include automatically operating an
electrically operated appliance fluidly coupled to the hot water
heater. The aspects of the disclosed embodiments can automatically
detect periods of non-use of the hot water heater based on times of
use of the hot water heater, changes in temperature of the water in
the hot water tank, or the setting of preprogrammed modes of the
hot water heater or appliances. The periodic operation of the hot
water heater system should prevent any buildup of hydrogen gas.
[0048] Thus, while there have been shown and described and pointed
out fundamental novel features of the invention as applied to the
exemplary embodiments thereof, it will be understood that various
omissions and substitutions and changes in the form and details of
devices illustrated, and in their operation, may be made by those
skilled in the art without departing from the spirit of the
invention. For example, it is expressly intended that all
combinations of those elements and/or method steps which perform
substantially the same function in substantially the same way to
achieve the same results are within the scope of the invention.
Moreover, it should be recognized that structures and/or elements
and/or method steps shown and/or described in connection with any
disclosed form or embodiment of the invention may be incorporated
in any other disclosed or described or suggested form or embodiment
as a general matter of design choice. It is the intention,
therefore, to be limited only as indicated by the scope of the
claims appended hereto.
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