U.S. patent application number 12/621492 was filed with the patent office on 2010-05-27 for system and method for on demand hot water distribution.
Invention is credited to William J. Lund, Dennis K. Metzger.
Application Number | 20100126604 12/621492 |
Document ID | / |
Family ID | 42195127 |
Filed Date | 2010-05-27 |
United States Patent
Application |
20100126604 |
Kind Code |
A1 |
Lund; William J. ; et
al. |
May 27, 2010 |
System and Method for On Demand Hot Water Distribution
Abstract
A demand type, multiple use, hot water distribution and freeze
protection system and method that responds to the user's desire for
hot water at a particular sink or fixture by delivering hot water
rapidly to that fixture, and only that fixture, without running
water down the drain is disclosed. The system requires only one
pump at the water heater, and does not require a dedicated hot
water return line, but works with a dedicated line in retrofit
applications. Circulating water in the plumbing system can also be
used to protect plumbing from freeze damage. Each valve and
activation device operates by transmitting a start command to the
valve controller which sends the pump controller a start signal,
the valve to open, hot water to circulate and the valve to close
when the hot water arrives at the fixture preventing heated water
from filling the cold water line.
Inventors: |
Lund; William J.; (Lake
Oswego, OR) ; Metzger; Dennis K.; (Sparks,
NV) |
Correspondence
Address: |
MANATT PHELPS AND PHILLIPS;ROBERT D. BECKER
1001 PAGE MILL ROAD, BUILDING 2
PALO ALTO
CA
94304
US
|
Family ID: |
42195127 |
Appl. No.: |
12/621492 |
Filed: |
November 18, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61115931 |
Nov 18, 2008 |
|
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|
Current U.S.
Class: |
137/565.01 |
Current CPC
Class: |
F24D 17/0078 20130101;
F24D 19/1051 20130101; Y10T 137/85978 20150401; F24D 19/0095
20130101 |
Class at
Publication: |
137/565.01 |
International
Class: |
E03B 11/16 20060101
E03B011/16 |
Claims
1. A high efficiency hot water demand delivery system comprising: a
pressurized cold water source; a pump having an inlet and an outlet
and a controller wherein the pump inlet is coupled to the cold
water source; a water heater having an inlet and an outlet wherein
the water heater is coupled to said pump outlet; a hot water
delivery conduit coupled to said water heater outlet; at least one
hot water faucets coupled to said water heater through said hot
water delivery conduit; a cold water delivery conduit coupled from
said cold water source to at least one cold water faucets; a valve
and controller coupled between each said at least one cold water
faucets and said at least one hot water faucets; said valve
controller having temperature sensing means and manual activation
means and said valve control being in communication with said pump
controller; and said pump controller capable of receiving start
commands from said valve controller, and having a fixed but
adjustable pump run time once started, to circulate hot water
through said hot water delivery conduit.
2. The hot water delivery system of claim, 1 further comprising
wireless communication to said valves and controllers from said
manual activation means.
3. The hot water delivery system of claim 1, further comprising
flow detection means in communications with said pump controller
for detecting water usage and in response to said detection
disabling the pumping means.
4. The hot water delivery system of claim 1 further comprising flow
detection means in communication with said valve controllers and in
response to flow causes activation of said valve controller.
5. The hot water delivery system of claim 1, further comprising
communication between said valve controller and said pump
controller wherein said communication causes said pump to shut off
upon receiving a stop command from said valve controller.
6. The hot water delivery system of claim 1 further comprising a
flow sensor or a current sensor in communication with said valve
controller for detecting operation of hot water consuming
appliances and at such time activating said valve controller.
7. The hot water delivery system of claim 1 wherein a pump means
runs for a pre-determined time after receiving a start command.
8. The hot water delivery system of claim 1, wherein said valve
controller is activated by a clock timer.
9. A high efficiency hot water demand delivery system comprising: a
pressurized cold water source; a pump having an inlet and an outlet
and a controller wherein the pump inlet is coupled to the cold
water source; a water heater having an inlet and an outlet wherein
said inlet is coupled to said pump outlet; a hot water delivery
conduit coupled to said water heater outlet; at least one hot water
faucet coupled to said water heater through said hot water delivery
conduit; a cold water delivery conduit coupled from said cold water
source to at least one cold water faucet; a valve and a controller
coupled between each said at least one cold water faucet and at
least one hot water faucet; said valve controller able to receive
wireless commands from remote switches; said valve controller
having temperature sensing means and manual activation means and
said valve controller being in communication with said pump
controller; said pump controller capable of receiving start
commands from said valve controllers, and having a fixed pump run
time once started to circulate hot water through said hot water
delivery conduit; and an outdoor temperature sensing means in
communication with valve/controllers wherein the valves are
activated when the outdoor temperature falls below freezing.
9. The hot water delivery system of claim 8, further comprising
flow detection means in communications with said pump controller
for detecting water usage and in response thereto disabling said
pump.
10. The hot water delivery system of claim 8, further comprising
flow detection means in communications with said valve controller
and in response to flow causing activation of said valve
controller.
11. The hot water delivery system of claim 8, further comprising
communication between said valve controller and said pump
controller causing the pump to shut off upon receiving a stop
command from the valve controller.
12. The hot water delivery system of claim 8, further comprising a
flow or current sensor in communication with the valve/controller
for detecting operation of hot water consuming appliances and at
such time activating said valve controller.
13. A high efficiency demand hot water delivery system comprising:
a pressurized cold water source; a water heater having an inlet and
an outlet wherein said inlet is coupled to said cold water source;
a hot water delivery conduit coupled to said water heater outlet
and looping past multiple hot water faucets and returning to said
water heater inlet; a pump having an inlet and an outlet and
controller with the pump inlet coupled between the return end of
the hot water distribution conduit and said water heater; at least
one hot water faucets coupled to said water heater through said hot
water delivery conduit; flow sensing means coupled between said
water heater inlet and said cold water conduit wherein said pump
controller starts said pump in response to water flow through said
water heater.
14. The hot water delivery system of claim 13, wherein said flow
sensing means detects flow and in response to flows lasting less a
brief time period starts said pump.
15. The hot water delivery system of claim 13, wherein said pump
controller having temperature sensor means for detecting hot water
at the end of the hot water distribution loop and in response
thereto shuts off the pump means.
16. The hot water delivery system of claim 6, wherein said hot
water consuming appliance is a dishwasher or a washing machine.
17. The hot water delivery system of claim 7, wherein said pump
means receives a stop command from one of said valve controllers
and in response to said stop command said pump means shuts off.
18. A high efficiency hot water demand delivery system comprising:
a pressurized cold water source; a pump having an inlet and an
outlet and a controller wherein the pump inlet is coupled to the
cold water source; a water heater having an inlet and an outlet
wherein the water heater is coupled to said pump outlet; a hot
water delivery conduit coupled to said water heater outlet; at
least one hot water faucets coupled to said water heater through
said hot water delivery conduit; a cold water delivery conduit
coupled from said cold water source to at least one cold water
faucets; a valve and controller coupled between each said at least
one cold water faucets and said at least one hot water faucets;
said valve controller having temperature sensing means and manual
activation means and said valve control being in communication with
said pump controller; and said pump controller capable of receiving
at least one start command and at least one program command from
said valve controller to circulate hot water through said hot water
delivery conduit. and capable of sending at least one stop command
to said valve controller.
Description
RELATED APPLICATIONS
[0001] The present application claims priority from U.S.
Provisional Application Ser. No. 61/115,931 filed Nov. 18, 2008,
which is incorporated herein by reference in its entirety for all
purposes.
BACKGROUND
[0002] 1. Field
[0003] The embodiments of the invention relates generally to
systems and methods for hot water distribution and more
particularly to systems and methods for on demand hot water
distribution to one or more specified fixtures.
[0004] 2. Background
[0005] In conventional residential hot water systems, a cold water
supply line is provided to the inlet of the water heater and a hot
water distribution line exits from the outlet of the water heater.
The hot and cold water distribution lines are then plumbed
throughout building to the various fixtures located throughout the
house.
[0006] While conventional systems operate well to distribute water,
conventional systems are not energy efficient and such systems
result in a tremendous waste of water. In a conventional system,
after each use the water in the hot water distribution line cools
off, consequently, when a faucet is turned on, the water is usually
cooler than desired and the user allows the water to run until the
cooled off hot water is purged from the line and hot water arrives
at the fixture. Waiting for the hot water to arrive is irritating
to the user, and it increases water consumption resulting in an
increase in the user's water bill.
[0007] A number of systems have been developed in an attempt to
solve this problem. For example, there are systems that circulate
hot water continuously through the hot water distribution piping,
and back to the water heater through a dedicated return line. These
types of systems provide nearly instant hot water and eliminate
water waste, but such systems waste significant energy. These
systems result in hot water being circulated throughout the
distribution system even if there is no demand for hot water.
Keeping the piping full of water that is higher in temperature than
the ambient temperature causes a large loss of heat energy, in
order to keep the temperature up, more energy is used which
increases the user's energy bill and greenhouse gas emissions.
[0008] In an attempt to curtail the energy use described in the
constant circulating hot water systems, many users put such systems
on a timer so that the system runs only during hours of normal use.
This creates an inconvenience when hot water is desired during off
hours, and still is very costly and wastes energy. Another problem
with this type of system is that if the home was not plumbed with a
hot water return line, it can be very expensive to add plumbing to
an existing home. Moreover, this type of system will not work with
a tankless water heater.
[0009] In an alternative to a designated hot water return line,
some conventional circulating systems use the cold water
distribution line as the hot water return line. One such system is
described in U.S. Pat. No. 5,829,467. The system discloses a pump
located at the water heater and special temperature sensing cross
over valves at the fixtures. The pump runs continuously, but can
only make water flow if one or more of the cross-over valves at the
fixtures is open. The valves are open if the water passing through
them is cold, and when the water reaches a preset temperature the
valve closes. This keeps warm water near the fixtures and thus
reduces the wait for hot water.
[0010] However, disadvantageously, this type of system results in
the hot water distribution piping being full of above ambient
temperature water all the time and much if not all of the cold
water distribution lines are also above ambient temperatures.
Consequently, there is a huge amount of energy wasted, greenhouse
gas emissions are increased and it is very costly to operate. This
type of system also does not work with tankless water heaters.
[0011] The reason these systems will not work with tankless water
heaters is because tankless water heaters are turned on when water
flows through them and activates a flow switch. These types of
circulating systems do not produce enough flow to turn on a
tankless water heater. Excess water flow voids the warranty on
tankless systems.
[0012] Furthermore, many homeowners don't like the above described
systems because lukewarm water as opposed to cold water is
distributed when a cold fixture is opened. These systems require
the line to be purged in order to get cold water, resulting in a
waste of energy and water.
[0013] Another type of system, for example the Laing System, uses a
small pump and valve at a fixture. The pump runs periodically to
keep the water at the fixture above ambient temperature. When the
water at the fixture cools to a preset temperature the pump turns
on and when the water reaches another preset elevated temperature
the pump turns off. Like the above described systems this system
results in the hot water piping and much of the cold water piping
to be at above ambient temperatures and thus wastes energy. In
addition, this system only serves the site where the pump and valve
are located and any fixtures directly between the pump/fixture and
the water heater. As with the previous system cold water is harder
to obtain, and the Laing systems do not work with tankless water
heaters.
[0014] Yet another type of system that uses the cold water line as
a hot water return line is a demand type system. With this type of
system the user needs to "demand" hot water by pressing a button or
otherwise activating the pump. The pump (and valve) is located at
the fixture where the user desires fast hot water. When the user
wants hot water he activates the pump, which begins pumping hot
water from the water heater to the fixture. When a sensor in the
pump detects an increase in temperature it shuts the pump off so
that no warm water enters the cold water line. When the user turns
on the faucet he only has to wait for a few seconds for hot water
(not warm). This system results in less water running down the
drain unused while waiting for hot water than other types of
non-demand systems. By using a powerful pump, the water can be
delivered very rapidly.
[0015] Another advantage of demand type systems is that they can be
used with tankless water heaters. In fact, because it takes longer
to get hot water with a tankless water heater than with a storage
type water heater, demand systems are particularly useful for
tankless installations.
[0016] However, with most installations a demand system provides
hot water to only one or two fixtures. To cover all of the fixtures
requires multiple pumps. Even in instances where one pump can
provide water to more than one fixture, it is not ideal situation
because it results in filling more of the distribution piping with
hot water than is needed to provide the hot water to a particular
fixture.
[0017] An optimally efficient system only fills the piping between
the water heater and the fixture being used with hot water, none of
the systems currently available have this advantage. Embodiments of
the present invention provide novel systems and methods of
efficiently delivering hot water to any fixture in a home without
running water down the drain, and without wasting energy.
Furthermore embodiments of the present invention eliminate the need
for multiple pumps, and provide novel systems that can be easily
and inexpensively retro-fitted to existing homes, even homes with
tankless water heaters.
SUMMARY
[0018] Embodiments of the present invention disclose systems and
methods for distributing hot water on demand or on a specified
schedule.
[0019] Further embodiments disclose a method of distributing hot
water using a distribution system which includes a water heater, a
pump with an electronic pump controller, one or more crossover
valves with controllers, a cold water conduit, a hot water conduit,
one or more hot and cold water outlets, with the cold water conduit
being coupled to the water heater inlet, a source of cold water,
any cold water outlets at the fixtures, and the outlets of any
crossover valves, the hot water conduit being coupled to the water
heater outlet, any hot water outlets at the fixtures, the inlets of
any crossover valves, and comprising the steps of: the user
activates a valve controller at a particular fixture the valve
controller checks the water temperature at the valve, and if the
water temperature is above a specified value, the valve controller
does nothing if the temperature is not above the value, the valve
controller at that fixture opens the valve and sends a start signal
to the pump controller the pump controller turns on the pump the
pump controller optionally looks for a turn off signal when the
valve controller detects an increase in temperature and sends a
turn off signal to the pump controller, shutting the pump off. If
the pump controller does not receive a turn off signal within a
specified time period the pump shuts off anyway.
[0020] Still other embodiments provide a method of distributing hot
water wherein the user activates a valve controller at a particular
fixture The valve controller checks the water temperature at the
valve, and if the water temperature is above a specified value, the
valve controller and optionally emits a sound or signal to indicate
to the user that hot water is available. If the water temperature
is not above a designated temperature, i.e., the water is not hot,
the valve controller at that fixture opens the valve, sends a start
signal to the pump controller, and emits a sound to indicate hot
water is on the way. The pump controller then turns on the pump and
the pump operates to dispense hot water through the distribution
system until an increase in temperature is detected. When the valve
controller detects an increase in temperature it shuts off the
valve, and optionally sends a stop signal to the pump controller,
and emits a sound or signal to indicate to the user that the hot
water has arrived. The pump controller shuts off the pump.
[0021] In an alternative embodiment, if the pump controller does
not receive a shut off signal within a specified time period, such
that hot water continues to flow through the distribution system,
the pump automatically shuts off when the specified period of time
has elapsed. However, if the none of the valves are open, the valve
will automatically shut down as there is be no water flowing in the
system.
[0022] In yet another embodiment, a system for distributing hot
water includes a water heater, a pump with an electronic pump
controller, one or more crossover valves with controllers, a cold
water conduit, a hot water conduit, one or more hot and cold water
outlets where the cold water conduit is coupled to the water heater
inlet, a cold water source, at least one cold water outlet at the
fixtures, and the outlets of any crossover valves, the hot water
conduit being coupled to the water heater outlet, at least one hot
water outlet at the fixtures, and the inlets of any crossover
valves. I
[0023] Embodiments of the present invention also provide a method
for distributing hot water including a user activating a valve
controller at a particular fixture, the valve controller or
automatic device sending a pump controller a function code, the
controller receiving the code and implementing a software program
identified by the function code, Upon completion of the program the
pump controller returning to the default program and awaits further
instructions.
[0024] In an alternative embodiment, an automatic device or sensor
activates a valve controller at a specified fixture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 depicts an embodiment of a system for hot water
distribution;
[0026] FIG. 2 depicts an embodiment of a basic system for hot water
distribution; and
[0027] FIG. 3 depicts an embodiment of a basic system for hot water
distribution when implemented with a dedicated return line.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0028] Various embodiments of the invention are described
hereinafter with reference to the figures. It should also be noted
that the figures are only intended to facilitate the description of
specific embodiments of the invention. The embodiments are not
intended as an exhaustive description of the invention or as a
limitation on the scope of the invention. In addition, an aspect
described in conjunction with a particular embodiment of the
invention is not necessarily limited to that embodiment and can be
practiced in any other embodiment of the invention.
[0029] Throughout the specification and claims, the following terms
take the meanings explicitly associated herein, unless the context
clearly dictates otherwise. The phrase "in one embodiment" as used
herein does not necessarily refer to the same embodiment, though it
may. Furthermore, the phrase "in another embodiment" as used herein
does not necessarily refer to a different embodiment, although it
may. Thus, as described below, various embodiments of the invention
may be readily combined, without departing from the scope or spirit
of the invention.
[0030] In addition, as used herein, the term "or" is an inclusive
"or" operator, and is equivalent to the term "and/or," unless the
context clearly dictates otherwise. The term "based on" is not
exclusive and allows for being based on additional factors not
described, unless the context clearly dictates otherwise. In
addition, throughout the specification, the meaning of "a," "an,"
and "the" include plural references. The meaning of "in" includes
"in" and "on." The term "coupled" implies that the elements may be
directly connected together or may be coupled through one or more
intervening elements.
[0031] The present invention discloses embodiments of systems and
methods for distributing hot water to a specified fixture. As will
be appreciated by one of skill in the art, the systems and methods
disclosed are equally applicable to residential, commercial and
industrial applications. The purpose of the embodiments is to
minimize the waste of water or energy in distributing hot
water.
[0032] As depicted in FIG. 1, embodiments of systems of the present
invention include a pump 3, a pump controller 4, a source of cold
water 1, a water heater 2 with an inlet and outlet 2B, 2A, one or
more fixtures 8, 12, 16 with hot and cold water outlets a cross
over valve 5, 11, 15 and controller 6, 13, 17, at each fixture 8,
12, 16, a conduit in fluid communication with the source of cold
water 9, the cold water outlets at the fixtures, the outlets of the
cross over valves 9A, 9B, 9C, and the water heater inlet 2B, a
conduit in fluid communication with the outlet 2A of the water
heater 10, the hot water outlets at the fixtures 8, 12, 16 and the
inlets of the cross over valves 9D, 9E, 9F. Embodiments of the
present invention further include a pump activation means
comprising at least one of a number of possible devices such as but
not limited to buttons, motion detectors, clock timers, and other
mechanical and electronic sensors.
[0033] When hot water is desired at a specified fixture, a pump
activation means communicates with pump controller conveying to the
controller at the outlet of the hot water heater that hot water is
desired. The valve controller checks the water temperature at the
cross over valve to make sure hot water is not already supplied to
the specified fixture. If hot water is not present at the specified
fixture, the valve controller sends the pump controller a start
signal and a function code that selects the software program to be
implemented by the pump controller.
[0034] The pump controller obtains a function code. The function
code is sent to the pump controller as a result of an initiating
action at a select fixture. The function code operates to select
the software program to be run by the pump controller. For example,
the function code may direct the pump controller to run a program
such that hot water is sent to a single fixture, it could direct
the pump controller to run a program for freeze protection, or any
other pre-established program for operating the hot water
distribution system.
[0035] If for example the device is a simple button to obtain hot
water from a fixture, the valve controller will first check the
temperature of the water at that location. If the temperature is
already high, the controller will beep twice which tells the user
the water is already hot. If the temperature is not too hot, the
controller beeps the activation device once telling the user that
the hot water is on the way, and sends a signal to the pump
controller requesting service and providing a function code. The
valve turns on if the water is not already hot when the button was
pressed.
[0036] The pump controller reads the function code and uses that to
determine which program to run. If it is the function to obtain hot
water, the pump turns on and pumps until it receives a stop signal
or if no stop signal is received in a specified amount of time it
shuts off. If it is a function to enter one of the other modes of
operation then it does so.
[0037] When a sensor in the valve senses an increase in temperature
the valve controller shuts the valve, communicates with the pump
controller telling it to shut off, then beeps to let the user know
that hot water has arrived at the fixture.
[0038] If the activating device is an outdoor freeze protection
temperature monitor, the pump controller would open all of the
valves; turn on the pump, and then when the last valve has closed
shuts the pump off, with the cycle repeating at regular intervals
until the danger is over.
[0039] A clock/timer device could be used to activate the system.
The pump controller and valve controllers would receive a function
code telling them to duplicate a temperature controlled type
circulating system at one or more specified locations that could be
programmed into the clock/timer device. This mode could last for a
period programmed into the clock/timer device.
[0040] The activation devices can be manually operated buttons,
motion detectors, proximity detectors, timers, clocks etc.
[0041] Turning now to the figure. FIG. 1 depicts a piping diagram
of a system for distributing hot water. The distribution system
includes: a pump, a pump controller, a source of cold water, a
water heater with an inlet and outlet, one or more fixtures with
hot and cold water outlets, a cross over valve and controller at
each fixture, a conduit in fluid communication with the source of
cold water, the cold water outlets at the fixtures, the outlets of
the cross over valves, and the water heater inlet, a conduit in
fluid communication with the outlet of the water heater, the hot
water outlets at the fixtures and the inlets of the cross over
valves. Embodiments of the present invention further include a pump
activation means comprising at least one of a number of possible
devices such as but not limited to buttons, motion detectors, clock
timers, and other mechanical and electronic sensors.
[0042] When hot water is desired at a sink 8, a user presses a
button 7. The user initiates the delivery process by pushing a
button or activating a sensor in some way. The button, motion
sensor, light beam, or whatever method is being employed to
activate the demand system as described below to turn the pump on
and open the valve associated with the fixture in question. The
button 7 is wired to a controller 6 for a valve 5 at the sink 8.
When the button 7 is depressed a program is initiated in the valve
controller at the sink 8. The controller 6 begins by sampling the
water temperature using a temperature sensor that is integral with
the valve and the controller 5. Although described as integral with
the valve and controller, it is contemplated within the scope of
the embodiments of the present invention that the temperature
sensor could be a separate device, could be integral with the
fixture, ideally located at the junction of the fixture and the hot
water inlet to the fixture, or positioned in any such way that the
temperature could be measured before dispensing the water through
the fixture. If the temperature is below a critical value (i.e., a
specified pre-designated temperature), the controller 6 opens the
valve 5, and turns on a pump 3. An audible or visual signal is
emitted to advise that a request for hot water has been made. The
temperature sensor monitors the temperature at the valve 5. When
the temperature sensor detects an increase in temperature of the
water, preferably in the range of 6 to 12 degrees, this range is
not intended to be a limitation on the embodiments of present the
invention, it sends a signal to the controller 6 to shut the valve
5 and pump 3 off. An alternate sound or signal is emitted to
indicate to the user that the hot water has arrived.
[0043] If when the button 7 is pushed, the temperature sensor 6
senses an already elevated temperature, then it may not open the
valve 5 or start the pump 3, but just emitted an alternate sound or
signal to indicate that the water is already hot. Alternatively, if
an elevated temperature is measured but the temperature is not
within the specified temperature range, the valve 5 may be opened
and the pump 3 run for a shorter period of time to result in hot
water at the desired temperature at the fixture.
[0044] The valve controller 6 may automatically, without user
intervention, send a shut-down signal to the pump controller 4
after a specified time period elapses, i.e. three minutes, so that
hot water ceases to be pumped through the distribution system.
[0045] In another alternative embodiment, a motion detector could
activate the demand feature as a user enters a bathroom or the
kitchen, in this embodiment, similarly an audible or visual signal
is emitted to signal hot water is on the way.
[0046] FIG. 1 also depicts the hot water distribution system
operating as a freeze protection system for the potable water
system. When operating as a freeze protection system the systems is
initiated when the temperature outside of the house drops to
freezing or below. When the external temperature drops, the
external temperature activation device 19 sends a function code to
the pump 3 which then sends commands to specified valves located
throughout the distribution system 5, 11, 15 directing the various
valves to open and emitting a sound or signal to alert potential
users that the freeze protection mode has been activated. When the
outside temperature rises above freezing or the system is not in
danger of freezing, the activation device 19 communicates to pump
controller 4 and the freeze protection system is deactivated. The
system then returns to its demand mode of operation.
[0047] In an alternate embodiment, a signal from a clock timer
activation device 20 instructs the pump controller 4 and designated
valve controllers 5, 11, 15 to enter a temperature controlled
circulating system mode. After a pre-programmed period of time, the
clock timer 20 sends a signal to the pump controller 4 to return to
demand system mode. When operating in this mode, the system
operates like a conventional demand system, but affording the
ability for hot water to be available at all fixtures in the
system. The clock timer activation device 20 can be user programmed
to provide hot water to one or more specified fixtures or even all
fixtures at once. The clock timer device 20 also provides for user
programming for any specified period of time that the system
remains in a timer/temperature mode.
[0048] In the systems described, the pump and valve controllers are
micro-controller based. The pump and valve controllers are
controlled with software programming with minimal interface
programs as is known to one of skill in the art. The pump may be
any suitable pump with the capability to be electrically
controlled. The more powerful the pump employed, the more quickly
the hot water will arrive at the selected fixture. Similarly, any
suitable electrically controlled valve or combination of valves may
be used in the above described embodiments.
[0049] In various embodiments the pump controller, valves, and
activation devices communicate with each other via hardwiring,
through power line signals, or via radio frequency links. The
valves and activation devices obtain power through the house wiring
alternatively, if the system is a retrofit battery power or
alternate power may be utilized. The utilization of battery power
makes the system very easy to install even in retrofit
applications.
[0050] The pump controller, valve controllers, and activation
devices may employ microcontrollers and associated circuitry to
provide the various functions.
[0051] By using a large powerful pump and high flow valves the
system may also be implemented in apartment buildings with central
water heaters and other commercial and industrial applications.
[0052] In another embodiment, the on demand system is initiated
without user interaction when a dishwasher is turned on, and the
motor operates to open the drain valve, the drain valve is wired to
a controller for a valve at the water inlet line. When the valve
opens a program is initiated in the valve controller at the water
inlet line. The controller begins by sampling the water temperature
using a temperature sensor that is integral with the valve and the
controller. Although described as integral with the valve and
controller, it is contemplated within the scope of the embodiments
of the present invention that the temperature sensor could be a
separate device, could be integral with the dishwasher, ideally
located at the water inlet of the dishwasher or positioned in any
such way that the temperature could be measured before dispensing
the water into the dishwasher. If the temperature is below a
critical value (i.e., a specified pre-designated temperature), the
controller opens the valve, and turns on a pump. In this
embodiment, it is not essential that an audible or visual signal is
emitted to advise that a request for hot water has been made as the
user is not waiting for hot water. The temperature sensor monitors
the temperature at the valve. When the temperature sensor detects
an increase in temperature of the water, preferably in the range of
6 to 12 degrees, this range is not intended to be a limitation on
the embodiments of the present the invention, it sends a signal to
the controller to shut the valve and pump off. Optionally an
alternate sound or signal is emitted to indicate to the user that
the hot water has arrived.
[0053] In yet another embodiment, a user may initiate a signal for
hot water to be delivered to the water inlet of the dishwasher by
depressing button in communication with the water inlet line to the
dishwasher in a manner similar as that described in conjunction
with hot water delivery at a faucet.
[0054] In still another embodiment, the dishwasher may initiate a
signal for hot water when the motor commences operation regardless
of whether or not the drain valve opens.
[0055] In another embodiment, the high efficiency hot water
delivery system is simplified such that the pump controller need
not know which valve is turned it on. This embodiment comprises of
a pump with controller at the water heater and a valve with
controller under the sink. The pump is coupled to the water heater
between the cold water supply and the water heater inlet, with the
cold water distribution plumbing connection on the inlet side of
the pump.
[0056] A valve with integral temperature sensing means is coupled
between the hot and cold supply lines at the fixture, and the valve
controller has terminals for a start button.
[0057] Pressing or otherwise engaging the start button causes the
valve controller to check the water temperature. If the water is
not already hot, the valve controller opens the valve and sends a
start command to the pump controller which starts the pump. When
hot water reaches the valve it closes, preventing heated water from
entering the cold water piping.
[0058] When the pump controller receives the start command from the
valve controller it turns on the pump for a pre-determined and
adjustable amount of time. The predetermined amount of time is
preferably 3 minutes. However, it may be a longer or shorter period
of time, preferably is it between 1 minute and 5 minutes.
[0059] Because the valve closes when the hot water reaches it, the
pump can keep running with no adverse effects, because with the
valve closed no flow will occur.
[0060] Pressing or otherwise engaging the button on any valve
starts the pump and sends the hot water to the fixture for with the
button was engaged and only that fixture. If multiple valves are
activated at the same time then hot water will flow to each of the
fixtures and only those fixtures where valves were activated.
[0061] The system also includes scald protection as there is the
chance that a user might activate a valve while another user is
taking a shower in another location. Such activity could result in
the pump causing a difference in pressure between the hot and cold
distribution conduits resulting in the possibility of a scalding
accident.
[0062] To prevent scalding, the pump controller may be connected to
a flow switch inserted into the cold water conduit or otherwise
placed to control flow. If water is flowing into the house
plumbing, the controller will not allow the pump to turn on. If the
pump is already running it shuts off. This eliminates the
possibility of scalding.
[0063] In another embodiment, the system may be operated using a
wireless or other remote system for activations. In such an
embodiment the valve controller is mounted under the sink and has
terminals to connect a start button. Alternatively it could also
have a built in RF receiver allowing it to be activated wirelessly.
the latter configuration allows for convenient night-stand
placement of switches etc.
[0064] In another embodiment, the hot water flow may be activated
without specific user intervention, i.e., proactively making a
request by depressing a button or taking other overt action. In
this configuration, the valve controller utilizes pressure or flow
sensing means for activation. For example; briefly turning on the
hot water faucet could be used for activation eliminating unsightly
buttons.
[0065] In another embodiment, the hot water is activated by
appliance use. Utilizing flow switches or current sensors,
appliances such as dishwashers and washing machines could activate
the valve controllers.
[0066] In still another embodiment, freeze protection is provided.
An outdoor temperature sensor sends the valves a turn-on signal
when the outside temperature drops below freezing. It then
periodically activates the valve/controllers until the outdoor
temperature reaches a safe level. The periodic circulation keeps
the piping warm and protected from freezing. In the case of
tankless water heaters this would also protect the heat exchanger
from freezing as well.
[0067] The various hot water distribution systems may also comprise
timer control. The valve/controllers can respond to start commands
from automatic timers or clocks via the start button terminals or
via other communication methods.
[0068] The systems may also comprise a dedicated return line. When
the system is used to replace a dedicated return line system a flow
switch is located at the water heater inlet or outlet to sense hot
water usage. When the flow switch detects hot water usage it turns
on the pump for a fixed time period. The fixed period of time may
be randomly set, alternatively it may be established or calculated
based on the size of the system or the length of pipe runs. For
example, it may be set to 2 minutes for a system with 100 feet of
pipe, or 4 minutes with a house with 200 feet of pipe. These
examples are however non-limiting and the time period could be
adjusted as necessary to ensure proper delivery of the hot water.
In addition, the fixed period of time may be preset and may vary
depending on the time of day and day of the week. In addition the
controller can differentiate between a very short usage of hot
water and a longer run, turning on the pump only if the hot water
is used very briefly. For example, if the hot water is turned on
for 1 second or less the pump would start, but over one second the
pump would do nothing.
[0069] In another embodiment the pump shuts off when it senses the
arrival of hot water at the pump, and if hot water never arrives,
the pump shut offs after a pre-set time period, for example but not
limited to 3 to 5 minutes
[0070] Other and further embodiments of systems of the present
invention include a pump, a pump controller, a source of cold
water, a water heater with an inlet and outlet, one or more
fixtures with hot and cold water outlets a cross over valve and
controller at each fixture, a conduit in fluid communication with
the source of cold water, the cold water outlets at the fixtures,
the outlets of the cross over valves, and the water heater inlet, a
conduit in fluid communication with the outlet of the water heater
the hot water outlets at the fixtures and the inlets of the cross
over valves.
[0071] Optionally embodiments of the system may include flow
sensing/detection means, including but not limited to paddle type
flow switches, and turbine type flow sensors, connected between the
cold water source and the pump inlet and in communication with the
pump controller, flow sensing means connected between the water
heater outlet and the hot water distribution conduit and in
communication with the pump controller, and flow sensing means
connected between the hot water distribution conduit and the hot
water faucet and in communication with the valve controller.
[0072] Embodiments of the present invention may further include
valve controller activation means including but not limited to
motion detectors, current sensors, photo electric beams, manual
switches, and proximity switches, comprising at least one of a
number of possible devices such as but not limited to buttons,
motion detectors, clock timers, flow sensors, current sensors and
other mechanical and electronic sensors.
[0073] When hot water is desired at a specified fixture, the valve
controller at that location is activated causing the valve
controller to check the water temperature, and if the water
temperature is below a set point, the controller opens the valve
and sends a start command to the pump which runs until the fixed
run time has elapsed. When the valve controller senses an increase
in temperature it closes the valve.
[0074] In another embodiment, FIG. 2 depicts an embodiment of a
basic system for hot water distribution 200. The system 200
includes a flow control means, i.e., a first flow switch 210, to
detect the consumption of water. The flow switch 210 prevents a
pump 220 from starting or if the pump 220 is already running a pump
controller 230 shuts it off, preventing the possibility of a
scalding injury.
[0075] As also shown in FIG. 2, a flow sensing means, i.e., a
second flow switch 240 (a . . . n), is located between a hot water
distribution conduit 250 and a hot water fixture 260 (a . . . n).
There may be multiple flow sensing means in a single system such
that a second flow switch 240 (a . . . n) is located at each hot
water fixture. When the flow sensing means senses flow it activates
a valve controller 270 (a . . . n) initiating the circulation of
hot water.
[0076] Another embodiment of the system includes flow sensing means
or current sensing means, such as series resistor sensing circuits,
transformer type current sensing circuits, and clamp on current
detectors in communication with the valve controller for activation
when an external appliance such as a washing machine or a
dishwasher begins operation.
[0077] Yet another embodiment of the system includes temperature
sensing means, including but not limited to thermisters,
thermocouples, bi-metallic contact sensors, and integrated circuit
sensors located outdoors and in communication with the valve
controllers to activate the valve controllers when the outdoor
temperature drops below freezing.
[0078] In another embodiment, FIG. 3 depicts a basic system 300 for
hot water distribution when implemented with a dedicated return
line 310. The dedicated return line employs a flow sensing means
320, i.e., a flow sensor, between a water heater outlet 330 and a
hot water distribution conduit 340 to activate a pump controller
350, which manages a pump 360.
[0079] As depicted, the dedicated return line 310 is used to
circulate unused water back to a water heater inlet 370. This
system employs a temperature sensing means 380 in communication
with the pump controller 350 and shuts off the pump 360 when a
temperature increase is detected. If no increase is detected the
pump 360 shuts off after a pre-set fixed time period, for example
but not limited to 3 to 5 minutes.
[0080] In the systems described above, the pump and valve
controllers are micro-controller based. The pump and valve
controllers are controlled with software programming with minimal
interface programs as known to one of skill in the art. The pump
may be any suitable pump with the capability to be electrically
controlled. The more powerful the pump employed, the more quickly
the hot water will arrive at the selected fixture. Similarly, any
suitable electrically controlled valve or combination of valves may
be implemented in the above described embodiments.
[0081] In various embodiments the pump controller, valves, and
activation devices communicate with each other via hardwiring,
through power line signals, or via radio frequency links or any
other system that enable communication. The valves and activation
devices may obtain power through the house wiring. Alternatively,
if the system is a retrofit, battery power or alternate power may
be utilized. The utilization of battery power makes the system very
easy to install even in retrofit applications.
[0082] Although the systems described above include a pump, any
pumping means, including but not limited to centrifugal pumps, gear
pumps, diaphragm pumps, piston pumps, and turbine pumps, are
contemplated within the scope of the embodiments of the present
invention.
[0083] Although described in conjunction with a single use or
single unit application, such description is not so limited and
further expansions and implementations are contemplated within the
scope of the embodiments of the present invention. The system is
equally applicable for large scale or multi-unit use. By using a
large powerful pump and high flow valves the system may be
implemented in apartment buildings with central water heaters and
other commercial and industrial applications.
[0084] As noted previously the forgoing descriptions of the
specific embodiments are presented for purposes of illustration and
description. They are not intended to be exhaustive or to limit the
embodiments of the invention to the precise forms disclosed and
obviously many modifications and variations are possible in view of
the above teachings. The embodiments were chosen and described in
order to explain the principles of the embodiments of the invention
and its practical applications, to thereby enable those skilled in
the art to best utilize the invention and various embodiments
thereof as suited to the particular use contemplated. It is
intended that the scope of the invention and embodiments thereof be
defined by the claims and their equivalents.
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