U.S. patent application number 12/826523 was filed with the patent office on 2010-10-21 for water heater with passive automatic hot water circulation through a home or building.
Invention is credited to John Funk, Raymond G. Ziehm.
Application Number | 20100263604 12/826523 |
Document ID | / |
Family ID | 38918047 |
Filed Date | 2010-10-21 |
United States Patent
Application |
20100263604 |
Kind Code |
A1 |
Ziehm; Raymond G. ; et
al. |
October 21, 2010 |
WATER HEATER WITH PASSIVE AUTOMATIC HOT WATER CIRCULATION THROUGH A
HOME OR BUILDING
Abstract
A water heater unit is described for providing convective water
flow through a water circulatory system. In one embodiment, the
water heater unit has an outer housing, a water tank disposed
within the housing, and a first cold water inlet coupled to the
tank and connectable to a cold water supply line. A hot water
outlet is coupled to the tank and connectable to a hot water supply
line. A connection chamber adjacent to the tank has a second cold
water inlet connectable to the cold water line, and a chamber
outlet connected to the first cold water inlet of the tank. The
connection chamber has at least one return inlet connectable to the
hot water return line at a position to allow a substantially
continuous flow of return hot water driven by convection forces
without the benefit of a recirculation pump.
Inventors: |
Ziehm; Raymond G.;
(Littleton, CO) ; Funk; John; (Evergreen,
CO) |
Correspondence
Address: |
PERKINS COIE LLP;PATENT-SEA
P.O. BOX 1247
SEATTLE
WA
98111-1247
US
|
Family ID: |
38918047 |
Appl. No.: |
12/826523 |
Filed: |
June 29, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11742472 |
Apr 30, 2007 |
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12826523 |
|
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60819687 |
Jul 9, 2006 |
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Current U.S.
Class: |
122/19.1 |
Current CPC
Class: |
Y10T 137/85962 20150401;
F24D 17/0078 20130101; F24H 9/124 20130101 |
Class at
Publication: |
122/19.1 |
International
Class: |
F24H 9/12 20060101
F24H009/12 |
Claims
1-23. (canceled)
24. A continuous hot water supply system connectable to a water
supply line and to a flow circuit having a hot water supply line,
and a hot water return line connected to the hot water supply line,
comprising: a water heating assembly coupled to the water supply
line, wherein at least a portion of the water supply line extends
from the water heating assembly; a reservoir remote from the water
heating assembly and positioned to receive heated water from the
water heating assembly, the reservoir having a first inlet and a
first outlet, the first outlet being connectable to the hot water
supply line; and a circulation device in fluid communication with
the reservoir, the circulation device having a second inlet
connectable to the water supply line to receive water therefrom,
the circulation device having a second outlet in fluid connection
with at least one of the water heating assembly and the reservoir,
the circulation device having at least one return inlet connectable
to the hot water return line and configured to allow a
substantially continuous flow of return hot water therethrough
driven by convection forces without the benefit of a recirculation
pump, and a valve connected to the return inlet and being moveable
between open and closed positions, the valve in the open position
allowing recirculated hot water to flow into the chamber from the
return line, and the valve in the closed position blocking water
from flowing from the chamber through the return line.
25. The continuous hot water supply system of claim 24 wherein the
water heating assembly is a tankless water heater.
26. The continuous hot water supply system of claim 24 wherein the
reservoir includes a heating element activatable to heat water
contained in the reservoir.
27. The continuous hot water supply system of claim 24 wherein the
circulation device is positioned immediately adjacent to the
reservoir.
28. The continuous hot water supply system of claim 24 wherein the
circulation device is positioned immediately adjacent to and
upstream from the water heating assembly.
29. The continuous hot water supply system of claim 24 wherein the
second inlet of the circulation device is connected to the portion
of the water supply line, and the second outlet of the circulation
device is connected to the first inlet of the reservoir.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to U.S. Provisional
Patent Application No. 60/819,687, filed Jul. 9, 2006, the
disclosure of which is incorporated herein by reference in its
entirety.
TECHNICAL FIELD
[0002] The present invention is directed toward water distribution
systems, and more particularly to hot water supply and circulatory
systems.
BACKGROUND
[0003] Conventional water heaters are often positioned in basements
or utility/mechanical rooms of homes or office buildings. Typical
use of hot water in residential or commercial settings involves
non-continuous water flow from a remote water heater to a water
outlet assembly (e.g., a faucet, shower, dishwasher, etc.). While
hot water flows through the pipes, the pipe wall becomes heated and
the hot water is delivered to the water outlet assembly. When flow
ceases, water trapped within the piping cools to the ambient
temperature. For subsequent water usage, this mass of cool water
must be expelled from the piping and the cool pipe must be heated
before hot water can arrive at the faucet site.
[0004] This delay in hot-water delivery leads to water losses as a
user waits for hot water to arrive and watches the once-hot, but
now cold, water go down the drain. It may take up to several
minutes for a user to receive hot water at a faucet, which can
waste large quantities of water, as well as be inconvenient to the
user. It is estimated that a typical home wastes more than 10,000
gallons of water a year in this manner; a substantial effect
particularly in geographic regions where water is scarce.
[0005] Another consequence of cooled water in the hot water supply
lines is a negative effect on performance in regard to washing
appliances, particularly dishwashers. If the dishwasher operates
with water less than the recommended temperature, dissatisfactory
results occur.
[0006] One conventional approach includes the use of additional
heaters that are placed proximate a particular faucet in the home
or building. These additional heaters require electricity or gas to
keep the water heated at the desired temperature near the faucet,
and it may be problematic to maintain a relatively constant
temperature of hot water.
[0007] Another conventional solution to this problem includes the
use of electric pumps that actively pump hot water through the home
or building. However, as recognized by the present inventor, such
pumps require electricity and maintenance as these pumps are
expensive and complicated and can fail over time. Moreover, if the
flow rate through the pump is too high, the pump can erode and
prematurely degrade water pipes, which can lead to breakages and
water damage in the home or building.
[0008] Water recirculation valves have been developed to help
provide instant hot water at remote faucets through a home or
building. Examples of such recirculation valves include those
described in U.S. Pat. Nos. 5,331,996; 5,918,625; and 6,161,567,
invented by Raymond G. Ziehm, the inventor of the present
invention. The valves disclosed in these patents are used in
conjunction with hot water return lines that are installed in a
home or building, and these valves are generally adapted to be
fluidly coupled with a conventional water heater, wherein the valve
is positioned externally to the conventional water heater, such as
is shown in the figures of these patents. As recognized by the
present inventor, such an arrangement of a recirculation valve
connected externally to a conventional water heater can consume
excessive space, requires additional time for installation due to
custom fittings and additional plumbing.
[0009] Accordingly, as recognized by the present inventor, what is
needed is a water heater that can provide, in operation, passive
automatic circulation of hot water through a home or building and
thereby provide hot water nearly instantaneously to remote faucets
throughout the house or building.
[0010] It is against this background that various embodiments of
the present invention were developed. The features, utilities and
advantages of the various embodiments of the invention will be
apparent from the following more particular description of
embodiments of the invention as illustrated in the accompanying
drawings.
SUMMARY
[0011] The present invention provides a water heater unit for a
water circulatory system that overcomes drawbacks experienced in
the prior art and provides additional benefits. In one embodiment a
water heater unit is connectable to a water flow circuit having a
hot water supply line, a hot water return line connected to the hot
water supply line, and a cold water supply line. The water heater
unit has an outer housing, a water tank disposed within the
housing, and a first cold water inlet coupled to the tank and
connectable to the cold water supply line. A hot water outlet is
coupled to the tank and connectable to the hot water supply
line.
[0012] A connection chamber is provided adjacent to the tank. The
connection chamber has a second cold water inlet connectable to the
cold water line, and a chamber outlet connected to the first cold
water inlet of the tank. The connection chamber has at least one
return inlet connectable to the hot water return line to allow a
substantially continuous flow of return hot water driven by
convection forces without the benefit of a recirculation pump. A
valve is connected to the return inlet and is moveable between open
and closed positions. The valve in the open position allows
recirculated hot water to flow into the chamber from the return
line for return into the tank, and the valve in the closed position
blocks water from flowing from the chamber through the return line
to an open, remote water assembly that is calling for water.
[0013] In another embodiment, a pumpless hot water recirculation
kit is provided for installation in a dwelling having a water flow
circuit with a hot water supply line and a cold water supply line.
The hot water supply line is connected to a water outlet assembly,
and at least one hot water return line is connected to the hot
water supply line adjacent to the water outlet assembly. The
pumpless hot water recirculation kit has a water heater remote from
the water outlet assembly. The water heater has a housing and a
tank disposed within the housing. A first cold water inlet is
coupled to the tank and is connectable to the cold water supply
line. A hot water outlet is coupled to the tank and is connectable
to the hot water supply line.
[0014] A recirculation device is provided adjacent to the tank. The
recirculation device has an interior chamber, a second cold water
inlet coupled to the chamber connectable to the cold water supply
line, and a chamber outlet connected to the first cold water inlet
of the tank. A return inlet is connectable to the hot water return
line to allow a substantially continuous flow of return hot water
driven by convection forces without the benefit of a recirculation
pump. The connection chamber is accessible to connect to the cold
water line and the hot water return line at or through the
housing.
[0015] In another embodiment, a pumpless water recirculation
assembly is provided for convective recirculation of water through
a water circuit to a water heater. The water heater has a cold
water inlet and a hot water outlet. The water circuit has a hot
water supply line, a cold water supply line, and a hot water
recirculation line connected to the hot water supply line. The
water recirculation assembly has a body having an interior chamber
and an outlet portion coupled to the interior chamber. The outlet
portion is threadably connectable to the cold water inlet of the
tank. A first inlet portion is coupled to the chamber and sealably
connectable to the cold water line.
[0016] A plurality of hot water return inlets are coupled to the
chamber and sealably connectable to the recirculation line such
that at least a segment of the recirculation line is disposed
vertically above the water heater. Each hot water return inlet has
a flow control valve therein configured to allow hot water to flow
in one direction from the recirculation line into the chamber and
to block water flow in a reverse direction from the chamber through
the hot water return inlet. A cover member is connectable to the
tank to define an interior area and configured to contain at least
a portion of the body within the interior area. The cover has a
fist opening in alignment with the first inlet and a second opening
in alignment with the hot water inlet. The water recirculation
assembly is installable in the water circuit to provide a
substantially continuous flow of return hot water driven by
convection forces in the water circuit without the benefit of a
recirculation pump.
[0017] In another embodiment, a continuous hot water supply system
is connectable to a water supply line and to a flow circuit. The
flow circuit has a hot water supply line and a hot water return
line connected to the hot water supply line. The continuous hot
water supply system has a water heating assembly coupled to the
water supply line, wherein at least a portion of the water supply
line extends from the water heating assembly. A reservoir is remote
from the water heating assembly and is positioned to receive heated
water from the water heating assembly. The reservoir has a first
inlet and a first outlet, wherein the first outlet is connectable
to the hot water supply line. A circulation device is in fluid
communication with the reservoir.
[0018] The circulation device has a second inlet connectable to the
water supply line to receive water therefrom. The circulation
device has a second outlet in fluid connection with at least one of
the water heating assembly and the reservoir. The circulation
device has at least one return inlet connectable to the hot water
return line and configured to allow a substantially continuous flow
of return hot water therethrough driven by convection forces
without the benefit of a recirculation pump. A valve is connected
to the return inlet and is moveable between open and closed
positions. The valve in the open position allows recirculated hot
water to flow into the chamber from the return line, and the valve
in the closed position blocking water from flowing from the chamber
through the return line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a schematic view of a water flow circuit with a
water heater in accordance with an embodiment of the present
invention.
[0020] FIG. 2 illustrates an example of a water heater having
automatic recirculation in accordance with one embodiment of the
present invention.
[0021] FIG. 3 illustrates a portion of a sectional view of the
example water heater of FIG. 2 in accordance with one embodiment of
the present invention.
[0022] FIG. 4 illustrates an example of a check valve that may be
used in a water heater in accordance with one embodiment of the
present invention.
[0023] FIG. 5 illustrates an example of a faucet, return line, and
water heater coupled together in accordance with one embodiment of
the present invention.
[0024] FIG. 6 illustrates an example of a circulation device
attached to a conventional water heater in accordance with one
embodiment of the present invention.
[0025] FIG. 7 illustrates an example of a circulation device in
accordance with one embodiment of the present invention.
[0026] FIG. 8 is an isometric view of a circulation device in
accordance with another embodiment of the present invention.
[0027] FIG. 9 is an enlarged cross-sectional view of the
circulation device taken substantially along line 9-9 of FIG.
8.
[0028] FIG. 10 is a front elevation view of a circulation device in
accordance with yet another embodiment of the present
invention.
[0029] FIG. 11 is a front elevation view of a water heater unit
with a side-mounted circulation device in accordance an embodiment
of the present invention.
[0030] FIG. 12 is an enlarged front elevation view of the
side-mounted circulation device of FIG. 11.
[0031] FIG. 13 illustrates an example of a shell for attachment to
a conventional water heater, the shell for enclosing a circulation
device, in accordance with one embodiment of the present
invention.
[0032] FIG. 14 illustrates a fluid circuit with a tankless water
heater and a circulation device in accordance with another
embodiment of the present invention.
[0033] FIG. 15 illustrates a fluid circuit with a tankless water
heater and a circulation device in accordance with yet another
embodiment of the present invention.
DETAILED DESCRIPTION
[0034] Embodiments of the present invention relate to a water flow
circuit and components thereof having a capability or feature of
providing instant or substantially instant delivery of hot water to
faucets, including remote faucets, located throughout a home or
building, without the need for water recirculation pumps or
localized extra water heaters positioned near faucets of the home
or building.
[0035] In one example, a water heater is provided with a
circulation device integral within the water heater assembly. The
water heater thereby automatically circulates hot water through the
home or building while the hot water faucets are closed. When a
user (i.e., a person or machine) needs hot water and opens a hot
water faucet or valve, hot water is instantly available at the
faucet because the water heater was automatically circulating hot
water through the water flow circuit of a home or building while
the faucets were closed. One or more convective circulation loops
are established from the water heater outlet to the remote faucets
and back to the heater through return lines in the water heater
that contain valves so as to prevent reverse flow and to ensure
reliable operation on a small pressure differential.
[0036] In one embodiment, the water heater may have the circulation
device positioned inside the top surface of the water heater
encased between the heating tank and the top portion of the housing
of the water heater. Insulating material may be added around or
about the body of the circulation device within the housing of the
water heater. This configuration will normally be assembled in this
fashion during the manufacturing process.
[0037] In another embodiment, a circulation device may be provided
as part of a kit that may be added externally to a conventional
water flow circuit and/or water heater so as to add the instant hot
water functionality to a conventional water flow circuit and/or
water heater in a compact fashion. Various embodiments of the
present invention are described herein.
[0038] FIG. 1 is a schematic view of a water flow circuit 1 with a
water heater 10 in accordance with one embodiment of the present
invention. The water flow circuit 1 includes the water heater 10
coupled to a plurality of water outlet assemblies 3 by a plurality
of water lines 4. In the illustrated embodiment, the water outlet
assemblies 3 can be faucets or other controllable water outlet
devices. The water heater 10 has a pumpless circulation device 6
connected to the water lines 4 so as to provide a continuous flow
of hot water past the water outlet assemblies 3 via convection
forces, thereby providing instant hot water at any time to the
water outlet assembly.
[0039] In the illustrated embodiment, the water lines 4 include a
cold water supply line 16 connected to the circulation device 6 so
as to provide water to the water heater 10. A hot water supply line
19 is connected to the water heater 10 and to one or more of the
water outlet assemblies 3, and hot water return lines 22 are
connected to the hot water supply line 19 adjacent to the water
outlet assemblies 3. The hot water return lines 22 are also
connected to the pumpless circulation device 6. As discussed in
greater detail below, the circulation device 6 is configured with
the water lines 4 to provide the continuous hot water flow through
the water flow circuit 1 without requiring a recirculation pump to
generate the water flow.
[0040] FIGS. 2-3 illustrate an example of a water heater 10 having
the pumpless circulation device 6 for automatically circulating hot
water through a home or building in accordance with one embodiment
of the present invention. In one example, the water heater 10 has a
tank 12, a cold water inlet 14 for receiving water from the cold
water supply line 16, and a hot water outlet 18 (FIG. 2) for
delivering hot water to the home or building through the hot water
supply lines 19 (FIG. 2). The water heater 10 also includes one or
more return inlets 20 adapted to be coupled with the one or more
hot water return lines 22 that are provided in the water flow
circuit in a home or building.
[0041] The return inlets 20 are in fluid communication with the hot
water supply lines 19 at one end and with the cold water inlet 14
of the water heater 10 at the other end. The pumpless circulation
device 6 includes a chamber 24 configured to accommodate the hot
water return inlets 20 and the cold water inlet 14 and to interface
with the heater tank 12. Water in the chamber 24 enters the water
heater tank 12.
[0042] The chamber 24 can take any form desired. The chamber 24
provides a fluid entry point for fluid from the return inlets 20
and the cold water inlet 14. The chamber 24 may be provided as an
input port to fluidly couple the return lines 22 with the cold
water inlet 14 or water heater tank 12. In this example, the
chamber 24 establishes a transverse orientation of the return lines
22 relative to the cold water inlet 14. In another embodiment, the
chamber 24 can establish an angled orientation or a parallel
orientation between the return lines 22 and the cold water inlet
14. In one example, the chamber 24 may be formed from plastic,
chlorinated PVC plastic, metal, brass, or any other conventional
material.
[0043] The return inlets 20 must be provided with check valves 30
(FIG. 3) or other conventional valves that permit water flow into
the water heater 10 through the return inlets 20 but prevent water
flow in the opposite direction. For instance, FIG. 4 illustrates an
example of a check valve 30 having a moveable poppet 32 in a
passageway 34. The poppet 32 has a specific gravity at or near 1.0
(the specific gravity of water) to provide the sensitivity to
reliably open when in the convective mode. The poppet 32 has a body
36 whose cross section will allow water to flow through the
passageway 34 when in the open position, terminating at one end
with a nose 38 that interfaces with a valve seat 40 to terminate
flow. An opposing end 42 of the poppet 32 may be flat.
[0044] In this example, the check valve 30 includes a cylindrical
passageway 34 adapted to receive a square poppet 32 and provide
limited lateral movement of the poppet within the passageway. The
passageway 34 may be provided at a first end with a fluid opening
46 into the chamber 24 of the water heater 10. At this first end,
the passageway 34 may be provided with a ridge or shoulder 44 to
limit the travel of the poppet 32. On the opposing second end of
the check valve 30, the passageway 34 may be terminated by a valve
seat 40 defining a fluid opening, the seat adapted to mate with the
end of the poppet 32 when the poppet is in the closed position
within the check valve 30. When the poppet 32 is in the closed
position, water is prevented from flowing in the opposing
direction. In the illustrated embodiment, the check valve 30 moves
automatically in response to the differences in water pressure,
such that the check valve is not adjustable. In other embodiments,
the chamber 24 can include one or more adjustable valve assemblies
in the return inlets 20. The adjustable valve assemblies can be
manually adjustable, automatically adjustable, or both to help
control the water flow rate through the chamber.
[0045] In one embodiment, the chamber 24 includes a filter 35
(shown schematically in FIG. 3) in each return inlet 20 just
upstream from the check valve 30. The filters 35 allow the water to
flow therethrough without negatively impacting the flow rate. The
filters 35, however, is positioned and sized to capture any solid
impurities, such as sand, dirt, rust particles, or other solids,
that may be flowing through the return lines 22 and that may clog
or jam the check valves 30. The filters 35 can be made of a screen
or mesh material, or other suitable filtering material or
materials. In one embodiment, the chamber 24 is configured so the
filters 35 are easily removable for cleaning or replacement.
[0046] If desired, the water heater 10 (FIG. 2) may be sized and
shaped in a manner similar to the general shape of water heaters,
such as generally cylindrical with a flat top surface 48, and
insulating material may be placed around and above the heater tank
12, although other shapes could be used if desired. The water
heater 10 of the illustrated embodiment has the chamber 24 and the
water inlet 14 adjacent to the top of the tank 12, although other
embodiments can have the chamber and water inlet adjacent to the
side or bottom portion of the tank. As shown in FIG. 3, the water
heater 10 has an outer shell 52 that preferably encloses the tank
12, portions of the return lines 22, the chamber 24, and the check
valves 30, in one example. The outer shell 52 is provided with an
opening for the cold water inlet 14 as well as openings for the
return inlets 20. Insulation 50 may be provided about the chamber
24 and the return inlets 20.
[0047] In operation, the water heater 10 provides for natural and
constant convective flow of water through a closed fluid circuit 56
(FIG. 5) formed by the chamber 24, hot water tank 12, hot water
supply lines 19, and return lines 22. The convective flow will be
described with respect to the system of FIG. 5 having one hot water
supply line 19, one faucet 54 and one return line 22, although it
is understood that the same principles apply if more than one of
these elements is used.
[0048] In particular, the fluid circuit 56 is formed through the
fluid connections between the following: the water heater tank 12;
the hot water outlet 18 of the water heater 10 being fluidly
coupled with the hot water supply line 19; the hot water supply
line fluidly coupled with one or more faucets 54; the return line
22 fluidly coupled with the hot water supply line proximate one of
the faucets, preferably the farthest from the heater on any hot
water branch; the return line also being fluidly coupled with the
chamber 24 of the water heater 10, the chamber 24 being fluidly
coupled with the cold water inlet 14 to the tank 12, thereby
closing the fluid circuit 56.
[0049] The chamber 24 is also coupled with the cold water supply
line 16, although for purposes of describing the convective fluid
flow, the cold water supply line is not part of the circuit during
convective fluid flow.
[0050] Convective fluid flow occurs constantly without the need for
pumps or additional localized water heaters in the fluid circuit 56
by virtue of the water heater 10 of the present invention. During
normal operation, a user opens the faucet 54, and that open faucet
allows water from the water heater 10 to exit the hot water outlet
of the water heater and travel through the hot water supply line 19
up to and out of the faucet. While the faucet 54 is open, cold
water from the cold water supply line 16 enters the chamber 24 and
travels into the heater tank 12 to replace the volume of water
exiting the faucet. When the faucet 54 is open, the check valve 30
in the return inlet 20 closes, due to the low pressure in the hot
water supply line 19, to prevent water from the cold water supply
line 16 flowing through the return lines 22 to the faucet.
[0051] Once the faucet 54 is closed, the check valve 30 in the
return inlet 20 opens due to convective pressure, permitting
convective fluid flow from the return line 22, into the chamber 24,
and back into the tank 12. Fluid will circulate through the fluid
circuit 56 (including through the water heater 10) constantly while
the faucet is closed. Because cold water is denser than hot water,
and because pressure is proportional to density, the temperature
differences of water within the fluid circuit 56 will create
pressure differences within the circuit, and the pressure
differences will induce fluid flow via convection through the fluid
circuit. As the distance from the water heater 10 increases, the
water in the circuit will be cooler due to ambient temperatures
cooling the water over time. Hence, the natural convective flow of
water through the fluid circuit 56 will cause the cooler water in
the return line 22 to constantly return towards the water heater 10
without requiring the aid of a pump or other mechanical assist
device. Hence, in accordance with embodiments of the present
invention, the water heater 10 automatically circulates hot water
towards the faucets 54 and through the return line 22 back through
the fluid circuit to the chamber 24 in a home or building while the
faucets are closed.
[0052] In another embodiment of the present invention and as shown
in FIGS. 5-6, a circulation device 60 may be attached to a water
heater assembly 61 (FIG. 6), and a cap 64 may be attached to the
top of the water heater assembly over the circulation device. In
one embodiment, the circulation device 60 and the cap 64 can be
sold along with or for use with a water heater assembly 61, so that
the water heater assembly can provide automatic hot water
circulation.
[0053] In one example, a circulation device 60 can be provided as
shown in the example of FIG. 7. In this example, the circulation
device 60 has a main body 62 that is generally rectangular or
square in shape with planar top and bottom surfaces 66 and 67 and
an arcuate or curved side 68 to match a curved perimeter of the
water heater assembly 61. In another example shown in FIGS. 8 and
9, the main body 62 has a short, cylindrical puck shape. The top
surface 66 has an inlet 70 for cold water which may be provided as
a round or tubular stub 72 extending upwardly from the top surface
of the circulation device 60. A standard compression coupling or
fitting 74 may be placed about the stub so that a standard copper
or PEX pipe can be coupled with the stub 72 and secured to the stub
so as to provide a water tight fluid coupling between the cold
water supply and inlet stub.
[0054] The circulation device 60 may also be provided with an
outlet stub 76 or tube extending outwardly and downwardly from the
bottom surface 67 of the circulation device. In one example, the
outlet stub 76 may be generally cylindrical with a threaded outer
surface adapted to mate with a standard water heater inlet
connection, such as using standard 3/4 inch threaded fittings. In
another embodiment, a compression fitting 78 can be connected to
the outlet stub 76, and the compression fitting can have a threaded
outer surface 79 adapted to mate with the standard water heater
inlet connection.
[0055] One or more water return inlet members 80 may extend
outwardly from the curved side 68 of the circulation device 60. In
one example, three return inlet members 80 are provided along the
curved side 68 of the circulation device 60. Each return inlet
member 80 has a check valve 30 integrated therewith that permits
water flow from a return line 84 (external to the circulation
device) into the circulation device 60 through the return inlet
members 80 and through the check valve 30, but does not permit
water flow in the opposing direction (i.e., from within the
circulation device out through the return inlet members). A
standard compression coupling or fitting 81 may be placed about the
return inlet member 80 so that a standard copper pipe or PEX tubing
can be coupled with the member and secured to the member so as to
provide a watertight fluid coupling between the pipe carrying
recirculated hot water and the return inlet member.
[0056] In one embodiment, the circulation device 60 can include one
or more quick-release, water-tight fittings that allow the
circulation device to be quickly and easily connected to the
associated water lines. For example, the inlet stub 72, the outlet
stub 76, and/or the return inlet members 80 can include quick
release fittings that releasably, yet sealably, engage the cold
water supply line 16, the water heater inlet 14, and/or the return
lines 22, respectively. Accordingly, a user can quickly install the
circulation device 60, such as in a retrofit process. The
quick-release fittings also allow the user to temporarily remove
and reinstall the circulation device 60, such as to clean or
inspect the device.
[0057] FIG. 10 is a front elevation view of a circulation device
100 in accordance with yet another embodiment of the present
invention. In this embodiment, the circulation device 100 has a
main body 102 that has a cylindrical, generally barrel shape with
top and bottom surfaces 104 and 106 and an arcuate sidewall 108.
The circulation device 100 has a plurality of hot water return
inlets 110 projecting from the top surface and in fluid
communication with an interior chamber 112 within the body 102.
Each return inlet 110 is connectable to a respective hot water
return line 22. The circulation device 100 also has a cold water
inlet 114 projecting from the sidewall on one side 116 of the body,
and an outlet 118 projecting from the sidewall on the other side
117 of the body. The cold water inlet 114 is connectable to the
cold water supply line 16 and is in fluid communication with the
interior chamber 112. The outlet 118 is also in fluid communication
with the interior chamber 112 and is configured to direct a flow of
water from the interior chamber via the cold water inlet 114 and/or
the return inlets 110 into the tank 12 (not shown).
[0058] FIG. 11 is a front elevation view of a water heater unit 120
with a side-mounted circulation device 122 mounted on the side of a
water heater 124 toward the bottom portion of the water heater as
certain water heaters are now designed with cold water inlets in
this location. In this embodiment, a cold water inlet 126 of the
water heater 124 is provided at the bottom portion of the water
heater's tank 128. The circulation device 122 is connected to the
water heater 124 adjacent to the cold water inlet 126 and further
connected to hot water return lines 22.
[0059] FIG. 12 is an enlarged front elevation view of the
side-mounted circulation device 122 of FIG. 11. In this embodiment,
the circulation device 122 has a main body 130 that has a
cylindrical, generally barrel shape with top and bottom surfaces
132 and 134 and an arcuate sidewall 136. The circulation device 122
has three hot water return inlets 138 radially spaced about the
main body 130 and projecting outwardly from the sidewall 136. The
return inlets 138 are in fluid communication with an interior
chamber 140 within the body 130. Each return inlet 138 is
connectable to a respective hot water return line 22, as discussed
above.
[0060] The circulation device 122 also has a cold water inlet 142
projecting from the sidewall 136 below one of the return inlets
138. The cold water inlet 142 in other embodiments can be
positioned at a different location on the main body 130 relative to
the sidewall 136 and the return inlets 138. The cold water inlet
142 is connectable to the cold water supply line 16 and is in fluid
communication with the interior chamber 140. The circulation device
122 also has an outlet 144 projecting from the sidewall 136 in
axial alignment with one of the return inlets 138. The outlet 144
connects to the inlet of the water tank 128 (not shown).
[0061] The return inlet members 80 are adapted to be fluidly
coupled with the return line plumbing provided throughout the home
or building. Although a particular shape of circulation device 60
has been illustrated and described herein, the circulation device
60 could take other shapes depending upon the particular
implementation, for instance in connection with systems as shown
and described in U.S. Pat. Nos. 5,331,996, 5,918,625, and
6,161,567, the disclosures of which are hereby incorporated by
reference herein in the entirety.
[0062] In one example, the return inlet members 80 are generally
cylindrical or tubular and can be sized to match the dimensions of
the plumbing that they are adapted to be coupled with, for instance
1/2-inch copper pipe or 1/2 inch PEX tubing. In one example, the
circulation device 60 may be formed from plastic, chlorinated PVC
plastic, metal, brass, or any other conventional material. The
circulation device may be formed by any conventional process,
including stamping, injection molding, sheet metal formation, or
any other known process for forming a fluid device.
[0063] FIG. 13 illustrates an example of a shell or cap 64 that can
be used to enclose the region about the top of a water heater 10
having a circulation device 60 attached thereto. The cap 64 is
adapted to be attached to the top of a conventional water heater
10. In one example, the shell is generally cylindrical with a solid
top, curved sides, and a hollow interior so that the shell forms an
extended cylindrical cap which may be placed over the top surface
of the water heater 10. The cap 64 may have an opening 90 along its
top surface 92, such as a round opening, which permits the cold
water inlet stub 72 of the circulation device to upwardly protrude
therefrom. Along a curved side 94 of the cap 64, a set of openings
96 may be provided to permit the return inlet members 80 of the
circulation device 60 to outwardly extend therefrom, in one
example. The shape of the cap 64 and the positioning and number of
the openings will vary depending upon the implementation. For
instance, if a circulation device 60 is provided that orientates
the cold water inlet stub 72 and the return inlet members 80 in an
upward orientation relative to the top of the water heater 10, then
the openings 90 and 96 in the cap 64 for the return lines 22 (not
shown) may be positioned along the top surface 92 of the cap and
not along the side of the cap.
[0064] Insulating material 50, such as fiberglass insulation or any
conventional insulation, may be provided about or around the
circulation device 60 and the top surface 92 of the cap 64, and can
be encased within the shell attached to the top of the water
heater.
[0065] FIG. 14 illustrates a fluid circuit 200 with a tankless
water heater 202 and a circulation device 204 in accordance with
another embodiment of the present invention. The tankless water
heater 202 is a conventional unit that receives and "instantly"
heats a flow of cold water from the cold water supply line 16.
Although the tankless water heater 202 can heat water very quickly,
the conventional tankless water heater systems can experience a
delay in providing hot water to the faucet 206 due to cooled water
in the hot water supply pipes as discussed above. The fluid circuit
200 of the present embodiment that includes the tankless water
heater 202 avoids the hot water delay so a user will not experience
the wait for hot water.
[0066] In the illustrated embodiment, the tankless water heater 202
is connected at an inlet to the cold water supply line 16, and is
connected at its outlet to a hot water line 208 that carries heated
water away from the tankless water heater. The hot water line 208
provides the heated water to a small reservoir 210 through an inlet
portion 212. The reservoir 210 is configured to hold a small volume
of water (e.g., 1-5 gallons), although larger or smaller reservoirs
can be used in other embodiments. The illustrated reservoir 210
includes a heating element 214, such as a gas or electric heater,
configured to maintain the water temperature within the reservoir
within a selected range. The reservoir functions in a manner
similar or identical to a traditional water heater.
[0067] The reservoir 210 provides hot water to a supply line 218,
which in turn provides the hot water to one or more faucets 206.
One or more return lines 220 are connected to the hot water supply
line 218 adjacent to the faucet(s) 206. Each return line 220 is
also connected to a return inlet 222 of a circulation device 204
positioned adjacent to the reservoir 210. The circulation device
204 of the illustrated embodiment has an inlet 226 connected to the
hot water line 208, an outlet 228 connected to the inlet portion
212 of the reservoir 210, and one or more return inlets 222
connected to the return lines 220. Each return inlet 222 contains a
check valve 230 that operates in substantially the same manner as
the check valve 30 discussed above. The circulation device 204 can
also include adjustable valves, filters, compression fittings,
quick release connectors, and/or other features discussed above in
connection with the other embodiments. In another embodiment, the
circulation device 204 could be located adjacent to the tankless
water heater 202 and inlet 226 is connected to the cold water
supply line 16 with the outlet 228 connected to the tankless water
heater inlet 201. Alternately, circulation device 204 could be
located adjacent to the tankless water heater 202 via with inlet
226 connected to hot water outlet 203 of the tankless water heater
202 and outlet 228 connected to the hot water line 208.
[0068] In operation, the tankless water heater 202 heats a flow of
water from the cold water supply line 16 and directs the heated
water to the small reservoir 210. The heated water continuously
flows through the fluid circuit under the convection forces
discussed above. Accordingly, the hot water flows from the small
reservoir 210, through the supply lines, past the closed faucet(s)
206, through the return line 220, into the circulation device 204
and back into the small reservoir. As the small reservoir 210 has a
heating element, the convection currents are maintained and the
convection flow is continuous regardless of how long the faucet(s)
206 are closed. When a faucet 206 is open to instantly draw the hot
water drawn, the tankless water heater is automatically activated
to provide additional heated water into the fluid circuit 200.
Accordingly, the fluid circuit 200 with the tankless water heater
202 and the circulation device 204 provides the instant hot water
to the faucet(s) 16 and any other hot water outlets in a home or
building at all times without the delay suffered by the prior
art.
[0069] FIG. 15 illustrates a fluid circuit 200 with a tankless
water heater 202 and a circulation device 204 in accordance with
another embodiment of the present invention. The fluid circuit 200
is similar to the circuit described above in connection with FIG.
14, such that only the primary differences are discussed. In the
illustrated embodiment, the small water reservoir 210 does not
include a heating element. Instead, a return loop is 250 is formed
by a water line connected at one end 252 to the hot water supply
line 218 and connected at the other end 254 to the cold water
supply line 16 just upstream of the tankless water heater 202.
[0070] The return loop 250 is configured to provide a flow of water
from reservoir back into the cold water supply line for re-entry
into the tankless water heater 202 to be reheated. In the
illustrated embodiment, a thermostatically-controlled pump 256 is
coupled to the reservoir 210 and is connected to the return loop
250. When the water temperature in the reservoir drops below a
selected temperature, the thermostatically-controlled pump is
activated to move the cooled water from the reservoir back to the
tankless water heater 202 through the return loop. The
thermostatically-controlled pump 256 is configured to create a
sufficient pressure drop or other selected condition to
simultaneously activate the tankless water heater 202. When the
water temperature in the reservoir rises to a selected temperature,
the thermostatically controlled pump shuts off and the tankless
water heater also shuts off.
[0071] It is noted that the thermostatically-controlled pump 256
does not drive the water flow through the fluid circuit 200.
Instead, the continuous hot water flow as discussed above through
the hot water supply line 218, the return line 220, and the
circulation device 204 is maintained via the convection forces and
the circulation device 204 independent of whether the
thermostatically controlled pump is on or off.
[0072] In the illustrated embodiment, the circulation device 204 is
positioned adjacent to the top of the small water reservoir 210. In
other embodiments, the circulation device 204 can be provided
adjacent to the inlet of the tankless water heater 202. In this
embodiment, the water flow from the return line 220 passes through
the circulation device and into the tankless water heater 202.
Accordingly, the continuous flow of water can be instantly heated
by the tankless water heater 202 as needed if the water temperature
in the fluid circuit drops below a selected temperature. As a
result, nearly instantaneous hot water is provided at the faucet
and any other hot water outlets in a home or building at all
times.
[0073] It can be seen that embodiments of the present invention can
provide a fluid circuit and/or a water heater 10 (electric or gas)
with automatic recirculation of water in order to provide hot water
to faucets and any other hot water outlets in a home or building at
all times. While the components and methods disclosed herein have
been described and shown with reference to particular operations
performed in a particular order, it will be understood that these
operations may be combined, subdivided, or reordered to form
equivalent methods without departing from the teachings of the
present invention. Accordingly, unless specifically indicated
herein, the order and grouping of the operations is not a
limitation of the present invention.
[0074] It should be appreciated that reference throughout this
specification to "one embodiment" or "an embodiment" or "one
example" or "an example" means that a particular feature,
structure, or characteristic described in connection with the
embodiment may be included, if desired, in at least one embodiment
of the present invention. Therefore, it should be appreciated that
two or more references to "an embodiment" or "one embodiment" or
"an alternative embodiment" or "one example" or "an example" in
various portions of this specification are not necessarily all
referring to the same embodiment.
[0075] It should be appreciated that in the foregoing description
of exemplary embodiments of the invention, various features of the
invention are sometimes grouped together in a single embodiment,
figure, or description thereof for the purpose of streamlining the
disclosure and aiding in the understanding of one or more of the
various inventive aspects. Inventive aspects lie in less than all
features of a single foregoing disclosed embodiment, and each
embodiment described herein may contain more than one inventive
feature. While the invention has been particularly shown and
described with reference to embodiments thereof, it will be
understood by those skilled in the art that various other changes
in the form and details may be made without departing from the
spirit and scope of the invention.
* * * * *