U.S. patent application number 10/710720 was filed with the patent office on 2006-02-02 for on-cue hot-water circulator.
Invention is credited to David L. Morris.
Application Number | 20060022062 10/710720 |
Document ID | / |
Family ID | 35731022 |
Filed Date | 2006-02-02 |
United States Patent
Application |
20060022062 |
Kind Code |
A1 |
Morris; David L. |
February 2, 2006 |
On-cue hot-water circulator
Abstract
The current invention is an on-cue hot-water circulator. This
device and method consists of an electronic control module, a
manifold containing a check valve and/or a normally closed solenoid
valve, a flow switch, and a high-performance pump (not a typical
circulation pump), that is also designed or selected for its
ability to allow water to pass through it with little or no
restriction, when not operating.
Inventors: |
Morris; David L.; (San
Antonio, TX) |
Correspondence
Address: |
JEFFREY FURR
253 N. MAIN STREET
JOHNSTOWN
OH
43031
US
|
Family ID: |
35731022 |
Appl. No.: |
10/710720 |
Filed: |
July 29, 2004 |
Current U.S.
Class: |
237/19 |
Current CPC
Class: |
F24D 17/0078
20130101 |
Class at
Publication: |
237/019 |
International
Class: |
F24D 3/08 20060101
F24D003/08 |
Claims
1. A method for having hot water through a plumbing system to a hot
water outlet, comprising the steps of: providing a hot water supply
line, a water heater, and a plurality of hot water outlets from
said hot water supply line; having a control module connected to a
manifold with a valve, a pump and flow switch; having said pump and
said flow switch connect to the water supply line between the line
and the water heater in connection for said water heater; and
having said pump move hot water through said hot water line for a
set run time with set time intervals.
2. The method of claim 1 including having said control panel having
an adjustment means to change said run time and said interval.
3. The method in claim 1 including having said control panel having
a display means to display said run time and said interval.
4. The method in claim 1 including having a hot water return line
connected to said hot water line at one end on said manifold with a
valve at the other end.
5. The method in claim 4 wherein said manifold with a valve is
connected to a T-fitting into the water supply line.
6. The method in claim 1 including having the hot water line purged
through the cold water line.
7. The method in claim 6 wherein said manifold with a valve is
between the hot water line and the cold water line.
8. The method in claim 1 wherein said flow switch determines if
there is no flow of hot water, if there is no flow of hot water
said control module will adjust the wait time interval.
9. The Method in claim 1 including having a user test to water flow
to find the optimum run time and interval time.
10. The Method in claim 1 including closing said solenoid valve on
a delay to prevent a water-hammer effect.
11. An apparatus for saving hot water through a plumbing system
through a hot water outlet, comprising of: a hot water supply line,
a water heater, and a plurality of hot water outlets from said hot
water supply line; a control module connected to a manifold with a
valve, a pump and flow switch; said pump and said flow switch
connect to the water supply line between the line and the water
heater in connection for said water heater; and said pump move hot
water through said hot water line for a set run time a at set
intervals.
12. An apparatus of claim 1 including said control panel having an
adjustment means to change said run time and said interval.
13. An apparatus in claim 1 including said control panel having a
display means to display said run time and said interval.
14. An apparatus in claim 1 including a hot water return line
connected to said hot water line at one end on said manifold with a
valve at the other end.
15. An apparatus in claim 4 wherein said manifold with a valve is
connected to a T fitting into the water supply line.
16. An apparatus in claim 1 including having the hot water line
purged through the cold water line.
17. An apparatus in claim 6 wherein said manifold with a valve is
between the hot water line and the cold water line.
18. An apparatus in claim 1 wherein said flow switch determines if
there is no flow of hot water, if there is no flow of hot water
said control module will adjust the wait time interval.
19. The Method in claim 1 including the user testing to water flow
to find the optimum run time and interval time.
20. The Method in claim 1 including said solenoid valve closing on
a delay to prevent a water-hammer effect.
Description
BACKGROUND OF INVENTION
[0001] This invention relates to a hot-water circulator, and more
specifically to a hot-water circulator that provides on-cue hot
water and serves as a water-conservation device.
[0002] 1. Background
[0003] A common problem with potable water systems which have an
associated water heater is that once the tap, valve or faucet
controlling the flow of the water from the heater is turned off,
the water which is left in the line between the valve and the
heater container gradually cools over time making a user wait until
the cooled water within the line is purged from the line and
through the drain and the line is once again filled with warm
water. This causes water and energy to be wasted as it can require
up to several minutes for the line to be purged and again filled
with warm water.
[0004] This problem can be particularly troublesome for large,
single story homes, which tend to be more spread out than
multilevel homes, where the water heater can be great distances
from the farthest hot water tap.
[0005] There are several known proposed solutions to this problem
but they each have their own problems and issues.
[0006] The first one is called Hot-Water Re-Circulation, which is
also referred to as hot-water circulation. This method of
conserving water wasted when purging cold water from the hot water
plumbing system works well, but it is very expensive to operate. It
consists of a closed loop in the hot-water plumbing system, looping
through the water heater, with the introduction of a circulation
pump located next to the water heater, with its intake connected to
the hot-water return line and its output connected to a water pipe
that returns the re-circulated, cooler hot water directly into the
bottom of the water heater holding tank to be re-heated.
[0007] This system circulates and "re-circulates" hot water in the
hot-water plumbing system, maintaining hot water throughout the
system. Each faucet or hot-water appliance will have access to
"instant" hot water. Often, as an energy saving addition, a timer
is used to provide re-circulation only during times when hot water
use is anticipated.
[0008] The problem with this system is the fact that heating water
in the water heater and the hot-water plumbing system is very
expensive. The water heater is forced to cycle often to maintain
the heat. If the system re-circulates the water and hot water is
not used or is seldom used, the energy consumed to keep the water
hot is wasted. Even with a timer, constant re-circulation of water
through the hot-water system causes the water heater to cycle more
often, using large amounts of energy. Also, if the hot water is
requested at a time not anticipated, when water is allowed to cool
in the hot-water system, the original problem exists; water is
wasted purging cooled water from the hot-water system, from the
water heater to the point-of-request.
[0009] Another proposed solution is a Hot-Water Circulation system.
This is a method of conserving water wasted when purging cold water
from the hot water plumbing system which is similar to the system
above, except it is used where a closed-loop in the hot-water
plumbing system is not available where there is no dedicated
hot-water line back to the water heater. This can be considered as
a retrofit to an existing plumbing system, where re-circulation was
not considered. This system consists of a circulation pump that is
located above the water heater, with its intake coming from the hot
water outlet of the water heater, and its output returning hot
water into the hot-water system. The pump is designed to allow
water to pass through it with little or no restriction, when not
operating, and it also has an integrated timer to provide
circulation only during periods when hot water usage is
anticipated. The key to this system is a manifold valve with
fittings to allow its location beneath a sink, or co-located with
another suitable fixture, which must have both hot and cold-water
outlets, and for being installed between the respective hot and
cold water supply valves and their corresponding faucets. One end
of the manifold valve has an intake and an outlet for the hot water
supply line and is installed between the standard hot-water supply
valve and the hot-water faucet using two standard flexible hoses.
The other end of the manifold valve has an intake and an outlet for
the cold water supply line and is installed between the standard
cold-water supply valve and the cold-water faucet, also using two
standard flexible hoses. The manifold valve body connects and mixes
the hot-water system with the cold-water system through a
temperature-actuated valve that is normally opened. This system is
designed for the valve to be co-located with a suitable fixture,
located farthest from the water heater.
[0010] With this method, during periods of anticipated use, the
circulation pump runs continually. When the circulation pump is
operating, water passes from the hot-water system into the
cold-water system, for return to the water heater. During this
time, the water in the cold-water plumbing system flows in the
opposite direction from normal operation, from the plumbing fixture
back to the water heater. Because the water in the hot-water system
is cold until purged, the manifold with the normally opened,
temperature-actuated valve allows the water to pass freely from the
hot-water system into the cold-water system. Once the cold water is
purged and hot water begins to pass through the
temperature-actuated valve, the valve closes and prevents further
mixture between the hot and cold-water systems, even though the
circulation pump continues to operate. Thus, water is circulated,
but not re-circulated. In a "properly" designed plumbing system,
all fixtures will now have "instant" hot water. When the water, and
the media of the manifold valve, cools to a preset temperature, the
temperature-actuated valve reopens allowing the water to pass from
the hot-water system into the cold-water system again, maintaining
hot water throughout the hot-water plumbing system.
[0011] Few thermal-actuated valves are able to immediately register
a temperature change (up or down) and close before passage of hot
water into the cold-water system. Turning on cold water, at the
fixture where the manifold valve is installed, may result in
warm-to-hot water being provided from the cold-water system, until
that water is purged from the cold-water system. It is assumed that
this condition will be acceptable at that fixture.
[0012] If this system really worked as well as the idea wished, it
would only have the same problems as the re-circulation system
described above, i.e.: if the water is not used during periods of
anticipated use, the energy used to heat the water is wasted, or if
hot water is desired during periods when use is not anticipated,
purged water is wasted (original problem). However, there are a few
other problems: a) Use of cold water, during a non-circulating
period, at the fixture where the manifold valve is installed, or
from an adjacent cold-water fixture, such as a toilet, will draw
water from the hot-water system through the manifold valve (which
is always opened when cold), causing the water heater to cycle
needlessly. b) The temperature-actuated valve may allow an
indeterminate amount of warm-to-hot water to pass into the
cold-water system at the fixture where the temperature-actuated
valve is installed. A request for "cold" water at that fixture may
result in water being wasted down the drain, waiting for the hot
water to be purged from the cold-water system. c) The
temperature-actuated valve will retain heat much better than the
water throughout the rest of the hot water system, resulting in the
valve remaining closed after the water in the hot-water system has
cooled below an acceptable temperature. As such, when hot water is
desired, it will not be available, without manually purging the
system with water down the drain, even if the circulation pump is
operating. At best, this system can only provide part-time
"instant" hot water during periods when hot water use is
anticipated and this with no reliability for when the water will
actually be hot.
[0013] Another method is the On-demand hot-water circulator. This
method of conserving water wasted when purging cold water from the
hot-water system consists of an electronic control module, a
thermal sensor, a normally closed solenoid valve, a momentary-on
actuation switch or button (wired or wireless), and a
high-performance pump (not a typical low-speed circulation pump),
all constructed in modular fashion for installation beneath a sink,
or it may be similarly co-located with another suitable plumbing
fixture, which has both hot and cold-water fixtures. Installation
also requires the replacement of the hot and cold-water supply
valves for the plumbing fixture, with proprietary "T-fittings,"
wherever the device is installed. The device is meant to be
installed at the plumbing fixture farthest from the water heater.
This device has an inlet, which is connected to an outlet provided
on the newly installed hot-water supply valve, or "T-fitting," and
an outlet, which is connected to an inlet provided on the newly
installed cold-water supply valve, or "T-fitting." This
installation connects and mixes the hot-water system with the
cold-water system, which are separated by the electrically
actuated, normally closed, solenoid valve.
[0014] When hot water is desired, a counter-top or wall-mounted
button is depressed, sending a signal to the control module. As
long as the thermal sensor detects cold temperature water, as
measured in the device, the solenoid valve opens and the
high-performance pump begins circulating the water through the
device, purging cooled water from the hot-water system into the
cold-water system, and back to the water heater in reverse-flow
fashion. When the control module detects a preset temperature, as
signaled from the thermal sensor, the pump stops and the solenoid
valve closes, preventing further mixture of water between the hot
and cold-water systems. In a "properly" designed plumbing system,
all fixtures will now have hot water. Because the pump is
high-performance, and because the water does not pass through any
water-restriction valves or outlets (often found in faucets and
shower heads), hot water is delivered to the point-of-demand much
more quickly than if the water was allowed to run out of the faucet
at full volume.
[0015] Few thermal sensors are able to immediately register a
temperature change, therefore turning on cold water at the fixture
where the device is installed, immediately after a demand for hot
water, may result in warm-to-hot water being provided from the
cold-water system, until that water is purged from the system. It
is assumed that this condition will be acceptable, because hot
water was originally desired.
[0016] The problem with this method is the difficulty of
installation. Because few sinks in bathrooms (if any) have 110-volt
access available beneath them, the services of a licensed
electrician (most areas) will be required to complete the
installation. Use of an extension cord could present safety and
cosmetic concerns. The required replacement of the hot and
cold-water supply valves with the required proprietary "T-fittings"
necessitates shutting off the water for the complete system, both
hot and cold-water. Further, most consumers would have to employ
the services and skill of a plumber to use an open flame torch to
sweat the old valves off and sweat the new valves on, and then test
for leaks. There is never enough space under a sink, even less with
this device installed. The noise the system would make, even though
relatively quiet, could be an annoyance, especially if installed
adjacent to a bedroom. The button required for operating the system
poses another problem. A button would have to be placed near each
point-of-demand. Wireless buttons are available, but these could be
considered unsightly (cosmetic detraction), and would require
batteries from time-to-time (low-level annoyance). A casual user
may not know to push the button for hot water, without signage
(another cosmetic detraction), so guests in the facility where the
system is installed my not take advantage of it.
[0017] There are two problems anticipated with operation of this
method: a) the thermal sensor will retain heat longer than the
water throughout the hot-water system, which will create instances
when the consumer "demands" hot water, but the system will not
operate to provide it. During these instances, the consumer must
manually purge the system by allowing the cooled water from the
hot-water system to pour down the drain (original problem). b) If
the water heater fails, providing cold water in both systems (hot
and cold), the circulation may continue for an extended period of
time before the system shuts itself down. With wireless actuation
buttons, it is possible that a water heater failure could occur
when no one is present (work-day or holidays) and a stray RF signal
(garage door opener for example) could initiate a false demand.
[0018] 2. Prior Art
[0019] U.S. Pat. No. 6,164,307 by Byles and issued on Dec. 26, 2000
is for a non-circulating, rapid, hot tap water apparatus and
method. It discloses a plumbing system having a warm water outlet
for rapidly delivering hot water through the plumbing system to the
warm water outlet and is comprised of a diverter valve attachable
to a building water pipe upstream of the warm water outlet for
purging cold water from the water pipe, a diverter pipe section
extending from the diverter valve, a back flow preventer in flow
relationship with the diverter pipe section, and a flow control
regulator in flow relationship with the diverter pipe section,
whereby a small controlled flow of cold water may be diverted from
the water pipe to thereby cause rapid delivery of warm water to the
warm water outlet when actuated.
[0020] U.S. Pat. No. 5,603,344 by Hall, Jr. and issued on Feb. 18,
1997 is for an apparatus for recovering and saving chilled water in
hot water lines having adjustable thermostatic control. It
discloses a water saving device for use with domestic hot water
systems of the noncirculating storage tank heater type and uses a
hydraulic motor to drive a water pump, to pump water from the hot
water pipe to a cold water pipe.
[0021] U.S. Pat. No. 5,323,803 by Blumenauer and issued on Jun. 28,
1994 is for an instant hot water device. It discloses an
instantaneous hot water device comprised of a gate valve means
connected to a hot water line and having a gate valve and a gate
valve seat providing a controlled flow of hot water from the hot
water line into a ball valve means having a ball check and a first
ball valve seat having slot cooperating with the ball check to
provide a small, controlled flow of hot water into a cold water
line and a second ball valve seat cooperating with the ball check
to prevent flow of cold water into the gate valve means and the hot
water line.
[0022] U.S. Pat. No. 5,277,219 by Lund and issued on Jan. 11, 1994
is for a hot water demand system suitable for retrofit. A control
system causes the pump to circulate water from the hot water line
into the cold water line and back to the hot water source when a
hot water valve on said plumbing fixture is turned on. A
temperature sensor stops the pump, via the control system, to
prevent heated water from being circulated through the cold water
delivery lines.
[0023] U.S. Pat. No. 5,183,029 by Ranger and issued on Feb. 2, 1993
discloses a supply system including at least one user terminal such
as a shower head to which blended hot and cold water are supplied
at a selected temperature, the cold water of the blend is supplied
via a check valve which responds to changes in hydrodynamic
pressure so as to regulate the volumetric flow of cold water and
thereby compensate for changes of water demand in other parts of
the system.
[0024] U.S. Pat. No. 5,105,846 by Britt and issued on Apr. 21, 1992
discloses a purge line to return cooled water in a hot water line
directly to a cold water line to avoid wasting water by draining
the cooled water while awaiting arrival of hot water at a hot water
outlet valve. The purge line is connected in near adjacency to a
hot water outlet valve to minimize the amount of cooled water still
in the hot water line between the purge line and the valve.
[0025] U.S. Pat. No. 5,009,572 by Imhoff, et al. and issued on Apr.
23, 1991 discloses a compact and self-contained circular water
conservation device having a source of pressurized water, a hot
water supply line, a cold water supply line, a hot water heater,
and outlet fixtures coupled to the hot and cold water supply lines.
The water conservation device includes essentially an electric
water pump for pumping water from the hot water supply line into a
solenoid valve.
[0026] U.S. Pat. No. 4,945,942 by Lund and issued on Aug. 7, 1990
is for an accelerated hot water delivery system. It discloses a
plumbing system for accelerated hot water delivery to a plurality
of plumbing fixtures from a hot water source. Flow switch means are
provided to enable a pump to circulate hot water to the plumbing
fixtures in response to water being withdrawn from a plumbing
fixture. In addition, the hot water source may include a hot water
recovery apparatus for withdrawing hot water from circulation pipes
subsequent to cessation of water flow from a plumbing fixture.
[0027] U.S. Pat. No. 4,750,472 by Fazekas and issued on Jun. 14,
1988 discloses a control means and process for a recirculating hot
water system having a hot water supply pipe and a hot water return
pipe connected in a loop between a hot water outlet of a hot water
tank and a return inlet to that tank, and having an electrically
controlled recirculating pump in the loop, for keeping sufficient
circulation in the loop as to assure substantially instant
dispensing of water of a desirably high temperature.
[0028] U.S. Pat. No. 4,201,518 by Stevenson and issued on May 6,
1980 discloses a recirculating hot water system includes a hot
water supply pipe and a hot water return pipe connected in a loop
between a hot water outlet of a hot water tank and a return inlet
to that tank. An electrically controlled recirculating pump is
placed in the return pipe between the inlet to the hot water tank
and the supply pipe, which has hot water taps located at various
points along it.
[0029] There is still room for improvement in the art.
SUMMARY OF INVENTION
[0030] The present invention relates to a water-conservation device
which saves potable water that is most often allowed to pour out of
the hot-water faucet of a sink, tub, or shower, or out of the valve
of a washing machine, dish-washer, or other hot-water-using
appliance, to be wasted down the drain, while waiting for the
desired hot water to arrive from the water heater.
[0031] The current invention is an on-cue hot-water circulator.
[0032] This device and method consists of an electronic control
module, a manifold containing a check valve and/or a normally
closed solenoid valve, a flow switch, and a high-performance pump
(not a typical circulation pump), that is also designed or selected
for its ability to allow water to pass through it with little or no
restriction, when not operating.
[0033] The object of this invention is to provide a way to conserve
water and energy that is easy to operate and automatic in its use,
and that can be easily installed by most do-it-yourselfers, with no
need to interrupt a complete water system.
BRIEF DESCRIPTION OF DRAWINGS
[0034] Without restricting the full scope of this invention, the
preferred form of this invention is illustrated in the following
drawings:
[0035] FIG. 1 shows the basic components of the invention;
[0036] FIG. 2 shows the system in operation;
[0037] FIG. 3 shows a flow chart of how the system works;
[0038] FIG. 4 displays a Retrofit connection; and
[0039] FIG. 5 shows the retrofit hook up.
DETAILED DESCRIPTION
[0040] The following description is demonstrative in nature and is
not intended to limit the scope of the invention or its application
of uses.
[0041] There are a number of significant design features and
improvements incorporated within the invention.
[0042] The current invention is an on-cue hot-water circulator. As
shown in FIG. 1, this device 1 and method consists of an electronic
control module 10, a manifold 20 containing a check valve 25,
and/or a normally closed solenoid valve 30, a flow switch 40, and a
high-performance pump 50 (not a typical circulation pump), that is
also designed or selected for its ability to allow water to pass
through it with little or no restriction, when not operating.
[0043] In the current invention there is no temperature-sensing
device. This distinguishes it from other devices and methods. There
are two separate installation types, depending on whether the
plumbing system is "on-cue-ready," or if the plumbing system
requires a retrofit installation, where no hot-water return line is
available.
[0044] In the preferred embodiment all components of the device are
located on or within close vicinity of the water heater 60. A
high-performance pump 50 is mounted above the water heater 60 with
its outlet connected to the inlet (cold-water supply) of the water
heater. The flow switch 40 is connected to the inlet of the pump 50
and the water supply is connected to the flow switch. The outlet of
the hot-water system return line 220 connects to the inlet end of
the manifold 20. The manifold 20 outlet connects to the inlet of a
standard T-fitting 70 in the water supply line 80, which supplies
system water from one direction and provides water to the water
heater 60 in the other direction, which has an outlet connected to
the inlet of the flow switch 40. The control module 10 mounts on a
wall 90 near the water heater 60, and is attached to a power
source, which in the preferred embodiment is provided by a 110-volt
standard grounded outlet through a 110-volt service cord with a
standard 3-prong, grounded plug. The high performance pump 50 plugs
into a switched receptacle provided on the control module 10. The
flow switch 40 operates on low-voltage and is attached to terminals
provided on the control module 10. The solenoid valve 30 in the
manifold 20 is also low voltage and connects to the control module
through a 1 pair, appropriate gage wire, which attaches to the
manifold 20 and to the control module 10 by terminals provided.
[0045] The control module 10 operation is the same for both the
standard and retrofit installations. In the preferred embodiment,
besides the 110 volt switched plug, low-voltage flow switch
terminals, and low-voltage solenoid terminals already mentioned, it
also has two flush-mounted, screwdriver-type adjustment receptacles
110 for adjustment of "run-time" (from 10 seconds to 5 minutes) and
"wait-time" (1 to 10 minutes). Indicator LEDs (light-emitting
diodes) are provided to indicate activation of "run-time" and
activation of "wait-time", for set up procedures.
[0046] The device 1 and how it is connected is shown in FIG. 2.
[0047] The control module 10 is connected to a power source such as
an outlet plug. In the preferred embodiment, it also provides power
to the flow switch 40, solenoid valve 30 and the pump 50. The water
supply line 80 provides water to the water heater 60 and to the
cold outlets such as faucets in the plumbing fixtures 300 through
the cold water line 210. Before reaching the water heater 60 the
water supply line 80 runs through the T-fitting 70 into the flow
switch 40 to the pump 50 and then into the water heater 60. The
water heater 60 supplies heated water through the hot water line
250 to the plumbing fixtures 300. The return line 220 is connected
to the hot water line 250 at the furthest fixture 300 from the
water heater 60, through the manifold 20 with the check valve 25
and/or the solenoid valve 30 into the T-fitting 70 where it
connects to the water supply line 80. This allows the hot water
line 250 to be purged of cooled water and refilled with hot water,
with no waste.
[0048] Operation
[0049] FIG. 3 shows the flowchart for the control module. The user
turns the water on. If it's hot, they use it; if it's not hot, they
turn the water off and wait a minute. Turning the water on is the
control module's 10 cue that hot water is requested. The control
module 10, through the flow switch, detects hot-water flow. When
hot water is requested from any hot water faucet 300 or appliance
(by water flow), the high-performance pump 50 begins to operate and
the solenoid valve 30 opens simultaneously. Water circulates at
high velocity, quickly purging cooled water from the hot-water
system. Circulation continues for the adjusted period of "run-time"
(approximately one minute in the test water system), at which time
the pump 50 stops, and approximately 1.5 seconds later; the
solenoid valve 30 closes, discontinuing the flow of water from the
hot-water system into the cold-water system. The delay in solenoid
30 operation prevents "water-hammer effect." When the control
module 10 senses there is no flow of hot water, it begins timing
the adjusted "wait-time." The control module 10 will not begin
circulation until the "wait-time" has expired. If flow is detected
before expiration of the "wait-time," the timer resets and waits
for the next "no-flow" condition before timing begins again. The
system design assumes that cool water is purged from the hot-water
system if flow was detected inside the "wait-time." The "wait-time"
prevents hot water from circulating through the cold-water system.
"Wait-time" must correspond with the length of time it takes water
to cool to an unacceptably cool temperature in the hot-water
system. "Wait-time" will vary greatly depending upon each water
system and user preferences.
[0050] In setting up the device 1 at the specific fixture where the
manifold valve 20 is to be installed, the user needs to use a
stop-watch or other suitable timing device and time how long it
takes for hot water to "begin" to arrive, before it is actually
hot. Divide that time period by two (2). This is the beginning
"run-time." Next, the hot water is turned on at the same fixture
and is left on until the water is hot (as hot as it will get). Then
the water is turned off and the user waits for two (2) minutes. The
water temperature is then tested to see if it has cooled down to an
undesirably cool temperature. The water flows for a few moments to
allow the cooler water to purge the hotter water. If the water is
too hot, the user continues to run the water until it is as hot as
it will get. Again, the water is turned off for a wait of three (3)
minutes. The water is re-tested again, as instructed above. If the
temperature is cooled sufficiently at three (3) minutes, this is
the device's "wait-time." If not, the test is continued until a
desired "wait-time" is established. The "run-time" and the
"wait-time" are recorded for reference.
[0051] An LED labeled "Run Time" or "RT" indicates the duration of
the pump "run-time." In the preferred embodiment the default is
approximately 45 seconds. Another LED labeled "Wait Time" or "WT"
indicates the duration of the "wait-time." In the preferred
embodiment the default is approximately 4 minutes. The wait-time is
adjusted by turning the adjustment receptacles 110 clock-wise to
increase the time and counter-clock-wise to decrease the "run-time"
and the "wait-time" to correspond with the times recorded. A
"run-time" that is too long, or a "wait-time" that is too short
could result in delivering completely hot water to all cold-water
outlets.
[0052] To act as a fail-safe, in the preferred embodiment, during a
"no-hot water condition," the maximum amount of time the device 1
will operate the high-performance pump 60 is approximately one
minute, or the "run-time." The device 1 does not rely on a specific
temperature condition for any action. In the event of a significant
leak in the hot-water system, the system will still only operate
for approximately one minute, or the "run-time."
Alternative Embodiments
[0053] As shown in FIG. 4, a retrofit installation is similar to a
standard device installation as far as the pump 50, flow switch 40,
and control module 10 are concerned. As shown in FIG. 5, because
there is no dedicated hot-water return line, the manifold 20 is
fitted with two additional T-fittings 75, one on each end for
in-line installation between the water supply lines (cold 210 and
hot 250), and faucets of a suitable plumbing fixture 300, having
both hot and cold water, and located the farthest from the water
heater 60. In a retrofit installation, the cold-water supply line
220 is used for returning purged water to the water heater 60. The
T-fittings 75 have appropriate fittings for installation using two
3/8'' standard plumbing flexible hoses 100 for each line, hot and
cold water. The solenoid valve 40 is connected electrically in
similar fashion as in the non-retro installation with terminals at
module 10, except that the wire is longer to span the greater
distance between the control module 10 and the manifold 20.
[0054] Improper set-up and adjustment of the "run-time" and
"wait-time" control module settings will result in wasted resources
(energy or water). In a retro fit, it is preferable to use the
farthest plumbing fixture, preferably a tub faucet, for initial
"run-time." Divide that time by two (2) for beginning "run-time."
Use the same "wait-time" procedure as described above from the same
faucet to determine "wait-time." To optimize: Over time, reduce the
"run-time" a small amount and test each time until water at the
farthest fixture does not reach "fully hot," then return the
"run-time" setting to the next previous setting. Similarly,
increase the "wait-time" until the water in the hot-water system
has cooled to an undesirable temperature, and then return the
"wait-time" setting to the next previous setting.
[0055] Advantages
[0056] The previously described version of the present invention
has many advantages. The device 1 is easily installed by most
do-it-yourselfers. No licensed electrician is required because
110-volt service is usually available near a water heater,
low-voltage electrical wiring for the flow switch 40 and solenoid
switch 30 do not require a licensed electrician for installation.
There is no need to interrupt a complete water system. Installation
of the pump and flow switch can be done by turning localized water
off with the water heater cut-off valve (during which time cold
water will still be available through the rest of the system), and
most plumbing fixtures have separate cut-off valves for both the
hot and cold water lines, for installation of the retrofit
manifold, which will only interrupt water at the
installation-fixture. The device 1 auto-starts circulation for
appliances, such as washing machines and dishwashers with multiple
cycles or that start unattended, with remote timers. The device 1
does not compete for space. There's always enough room over and
next to the water heater for component installation, and the
retrofit valve fits above the water supply valves, in an area that
is not utilized. The adjustment of pump "run-time" is superior to
temperature sensing, because temperature-sensing systems typically
delay on providing a signal. Timing the length of flow time ("run
time") and the length of cool time ("wait time") is superior to
temperature sensing, because it provides quick resets and allows
consumers to customize their preference. Mounting the
high-performance pump and flow switch on the cold-water side of the
water heater extends the life of the pump and switch, because they
do not experience extreme temperature changes the water is cold as
it enters the water heater.
[0057] Although the present invention has been described in
considerable detail with reference to certain preferred versions
thereof, other versions are possible. Therefore, the point and
scope of the appended claims should not be limited to the
description of the preferred versions contained herein.
[0058] As to a further discussion of the manner of usage and
operation of the present invention, the same should be apparent
from the above description. Accordingly, no further discussion
relating to the manner of usage and operation will be provided.
[0059] With respect to the above description, it is to be realized
that the optimum dimensional relationships for the parts of the
invention, to include variations in size, materials, shape, form,
function and manner of operation, assembly and use, are deemed
readily apparent and obvious to one skilled in the art, and all
equivalent relationships to those illustrated in the drawings and
described in the specification are intended to be encompassed by
the present invention.
[0060] Therefore, the foregoing is considered as illustrative only
of the principles of the invention. Further, since numerous
modifications and changes will readily occur to those skilled in
the art, it is not desired to limit the invention to the exact
construction and operation shown and described, and accordingly,
all suitable modifications and equivalents may be resorted to,
falling within the scope of the invention.
* * * * *