U.S. patent application number 10/800142 was filed with the patent office on 2005-09-15 for fireplace hydronic heating.
Invention is credited to Bachinski, Thomas J., Butler, Gary Lee, Lyons, David Charles.
Application Number | 20050199233 10/800142 |
Document ID | / |
Family ID | 34920652 |
Filed Date | 2005-09-15 |
United States Patent
Application |
20050199233 |
Kind Code |
A1 |
Butler, Gary Lee ; et
al. |
September 15, 2005 |
Fireplace hydronic heating
Abstract
A hydronic heating system that includes a liquid-filled conduit
and a combustion chamber enclosure having a plurality of panels
that define a combustion chamber for the combustion of fuel to
generate heat. At least one of the panels and a portion of the
liquid-filled conduits are integrally formed together. The at least
one panel absorbs heat generated in the combustion chamber and
transfers the absorbed heat to the liquid in the conduit. The
heated liquid may be transferred to a remote location where the
heat is removed from the liquid using a heat exchanger. The at
least one panel and the portion of the liquid-filled conduit may be
integrally formed using a moldable material such as a ceramic fiber
and a binder, and molded using such processes as compression
molding or vacuum molding. The use of moldable may reduce
condensation in or around the combustion chamber enclosure.
Inventors: |
Butler, Gary Lee; (Silver
Lake, MN) ; Bachinski, Thomas J.; (Lakeville, MN)
; Lyons, David Charles; (Red Wing, MN) |
Correspondence
Address: |
Merchant & Gould P.C.
P.O. Box 2903
Minneapolis
MN
55402-0903
US
|
Family ID: |
34920652 |
Appl. No.: |
10/800142 |
Filed: |
March 12, 2004 |
Current U.S.
Class: |
126/523 ;
237/56 |
Current CPC
Class: |
Y02B 10/70 20130101;
F24D 2220/2081 20130101; F24D 2200/18 20130101; F24D 2200/10
20130101; F24B 1/1881 20130101 |
Class at
Publication: |
126/523 ;
237/056 |
International
Class: |
F24B 001/188; F24D
003/00 |
Claims
We claim:
1. A hydronic heating system, comprising: a conduit configured to
carry a heat conductive liquid; and a panel integrally formed
together with a portion of the conduit; wherein the panel is
configured to absorb heat from a heat source and transfer the
absorbed heat to the liquid in the conduit.
2. The system of claim 1, wherein the at least one panel is formed
from a material that is configured to resist formation of
condensation on a primary surface of the panel.
3. The system of claim 1, wherein an outer surface along a portion
of the conduit length is encapsulated with a material that is
configured to resist formation of condensation.
4. The system of claim 1, wherein the panel is formed from a high
temperature material using a vacuum molding, compression molding,
or casting process.
5. The system of claim 1, wherein the heat source is a combustion
chamber enclosure having a plurality of chamber panels defining a
combustion chamber for the combustion of fuel to generate heat, and
the system panel is configured as one of the chamber panels.
6. The system of claim 1, further comprising a heat exchanger that
removes heat from the liquid in the conduit at a location remote
from the combustion chamber enclosure.
7. The system of claim 6, wherein a portion of the conduit extends
through the heat exchanger.
8. The system of claim 1, further comprising a pump configured to
move the liquid in the conduit.
9. The system of claim 5, wherein the combustion chamber enclosure
includes a molded material, and the system panel and the portion of
the conduit are integrally formed into a panel of the combustion
chamber enclosure.
10. The system of claim 1, wherein the system is adapted and
configured for removable engagement with a heat generating device
that is configured as a heat source.
11. The system of claim 4, wherein the high temperature material is
a moldable material that includes a ceramic fiber and a binder.
12. The system of claim 1, wherein a portion of the liquid-filled
conduit is integrally formed together with two or more panels of
the combustion chamber enclosure.
13. The system of claim 5, wherein the combustion chamber enclosure
is part of a fireplace.
14. A hydronic heating system for a fireplace, the system
comprising: a liquid-filled conduit; a combustion chamber enclosure
having a plurality of panels defining a combustion chamber for the
combustion of fuel to generate heat, the panels being integrally
formed from a ceramic moldable material using a molding process, a
portion of the liquid-filled conduit being integrally formed within
at least one of the panels.
15. The system of claim 14, wherein the molding process includes a
compression molding or a vacuum molding process.
16. The system of claim 14, wherein the moldable material includes
a ceramic fiber and a binder.
17. The system of claim 14, wherein the moldable material resists
formation of condensation on the panels.
18. The system of claim 14, wherein the panels of the combustion
chamber enclosure are integrally formed as a single piece.
19. A method of manufacturing a hydronic heating system that
includes a panel and a liquid-filled conduit, the method comprising
the steps of: forming the panel from a heat conductive moldable
material; and encapsulating a first portion of the conduit in the
panel.
20. The method of claim 19, wherein the panel is formed using a
vacuum molding, compression molding, or casting process.
21. The method of claim 19, wherein forming the panel includes
forming the panel as panel of a combustion chamber enclosure, the
combustion chamber enclosure defining a combustion chamber for the
combustion of fuel to generate heat.
22. The method of claim 21, further comprising encapsulating a
second portion of the conduit in a moldable material configured to
resist formation of condensation on an outer surface of the
moldable material.
23. The method of claim 19, wherein the moldable material includes
a ceramic fiber and a binder.
24. The method of claim 21, wherein the encapsulating step includes
encapsulating the first portion of the conduit in two or more
panels of the combustion chamber enclosure.
25. The method of claim 21, wherein the panels of the combustion
chamber enclosure are integrally formed as a single piece.
26. The method of claim 19, further comprising mounting the system
to an outer surface or an inner surface of a heat generating
device.
27. A hydronic heating system for a fireplace, the system
comprising: a combustion chamber enclosure having a plurality of
panels defining a combustion chamber for the combustion of fuel to
generate heat; and a heat exchanger, including: a molded panel; and
a liquid-filled conduit, a portion of the liquid-filled conduit
being integrally formed within the molded panel; wherein the molded
panel is positioned adjacent to the combustion chamber
enclosure.
28. The system of claim 27, further comprising an outer enclosure
configured to enclose the combustion chamber enclosure and being
spaced apart from the combustion chamber enclosure to define a
plenum there between, wherein the heat exchanger is positioned
adjacent to the outer enclosure.
29. The system of claim 28, wherein the heat exchanger is coupled
to an outer surface of the outer enclosure.
30. The system of claim 28, wherein the heat exchanger is
positioned within the plenum.
31. The system of claim 27, wherein the molded panel extends along
two or more panels of the combustion chamber enclosure.
32. The system of claim 27, wherein the molded panel is positioned
adjacent to a panel of the combustion chamber enclosure within the
combustion chamber.
33. The system of claim 27, wherein the molded panel defines at
least one panel of the combustion chamber enclosure.
34. The system of claim 27, wherein the molded panel includes a
ceramic fiber and a binder.
35. The system of claim 27, wherein the liquid-filled conduit is
defined by a pipe member, wherein a portion of the pipe member is
molded into the molded panel.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to hydronic heating
systems, and more particularly relates to hydronic heating systems
that include a fireplace as a source of heat.
[0003] 2. Related Art
[0004] The use of closed loop liquid systems for the purpose of
transferring heat generated within a heating appliance to a remote
location for radiant convection of a surrounding area is well-known
in the art. Liquid-based heating systems can be more efficient than
air-based heating systems in many cases and may be particularly
useful for scavenging otherwise lost heat from an existing
air-based heating system. Liquid-based heating systems are often
referred to as hydronic heating systems and typically include a
liquid-filled conduit positioned next to a source of heat whereby
the heat is absorbed into the liquid, the heated liquid is
transferred to a remote location, and the heat is removed from the
liquid at the remote location.
[0005] One common hydronic heating system includes a boiler as the
source of heat. Boilers are designed specifically for heating the
liquid to a predetermined temperature and pumping the liquid to a
heat exchanger, such as a radiator, that is positioned somewhere in
living space to be heated. Other hydronic heating systems utilize a
fireplace as a source of heat. In one example fireplace hydronic
system, the liquid-filled conduit extends through the fireplace
grate, and the liquid is heated by heat generated by burning a
combustible fuel on or around the grate. The heated liquid is then
pumped to a suitable heat exchanger that is part of a forced-air
heating system or mixed with a cold water supply that feeds a hot
water heater. In another known fireplace hydronic heating system,
the liquid passes through a fireplace jacket that extends around
the combustion chamber enclosure of the fireplace. The water heated
in the jacket is then transferred to a remote location where the
heat is removed in a heat exchanger.
[0006] A common problem associated with fireplace hydronic heating
systems is undesired condensation buildup on the structure holding
the liquid due to the temperature differential between the cool
liquid and the heated air generated by the fireplace. Typically, a
metal or metal alloy material is used for the conduit or jacket
that holds the liquid to be heated in or around the fireplace
combustion chamber enclosure. When heat is initially generated in
the fireplace, humidity in the fireplace collects as condensation
on the structure holding the liquid because the structure is being
cooled by the cool liquid. This condensation is aesthetically
undesirable and may adversely effect functions of the fireplace.
Further, if the condensation occurs on the outside of the
combustion chamber enclosure, for example within an interior wall
of the building in which the fireplace is mounted, the condensation
may result in damage to the building structure.
[0007] A hydronic heating system that addresses these and other
shortcomings of known hydronic heating systems would be an advance
in the art.
SUMMARY OF THE INVENTION
[0008] The present invention generally relates to hydronic heating
systems, and more particularly relates to fireplace hydronic
heating systems that are designed to eliminate condensation and
improve manufacturability of the hydronic heating system.
[0009] One aspect of the invention relates to a hydronic heating
system that includes a conduit configured to carry a heat
conductive liquid, and a panel integrally formed together with a
portion of the conduit. The panel is configured to absorb heat from
a heat source and transfer the absorbed heat to the liquid in the
conduit. The heated liquid may be transferred to a remote location
where the heat is removed from the liquid using, for example, a
heat exchanger. The panel and the portion of the liquid-filled
conduit may be integrally formed using a moldable material such as
a ceramic fiber and a binder, and using such processes as
compression and vacuum molding. The use of some moldable materials
may substantially eliminate condensation in or around the
combustion chamber enclosure.
[0010] Another aspect of the invention relates to a method of
manufacturing a hydronic heating system that includes a panel and a
liquid-filled conduit. The method includes the steps of forming the
panel from a heat conductive moldable material, and encapsulating a
first portion of the conduit in the panel. The method may also
include forming the system panel in a panel of a combustion chamber
enclosure and encapsulating a portion of the conduit in a panel of
the combustion chamber enclosure. The method may also include
generated heat in the combustion chamber, absorbed the generated
heat into system panel, and transferring the absorbed heat into the
liquid in the conduit. The method may also include encapsulating a
portion of the conduit in two or more panels of the combustion
chamber enclosure.
[0011] A yet further aspect of the invention relates to a hydronic
heating system for a fireplace that includes a combustion chamber
enclosure having a plurality of panels defining a combustion
chamber for the combustion of fuel to generate heat, and a heat
exchanger. The heat exchanger includes a molded panel and a
liquid-filled conduit. A portion of the liquid-filled conduit is
integrally formed within the molded panel and the molded panel is
positioned adjacent to the combustion chamber enclosure.
[0012] The above summary of the present invention is not intended
to describe each disclosed embodiment or every implementation of
the present invention. Figures in the detailed description that
follow more particularly exemplified embodiments of the invention.
While certain embodiments will be illustrated and described, the
invention is not limited to use in such embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention may be more completely understood in
consideration of the following detailed description of various
embodiments in the invention and in connection with accompanying
drawings, in which:
[0014] FIG. 1 is a schematic representation of an example hydronic
heating system according to principles of the invention;
[0015] FIG. 2 is a top view of an example fireplace hydronic
heating system according to principles of the present
invention;
[0016] FIG. 3 is a cross-sectional view of the fireplace hydronic
heating system shown in FIG. 2 taken along cross-sectional
indicators 3-3;
[0017] FIG. 4 is a rear view of another example fireplace hydronic
heating system having liquid-filled conduits included in the top,
side and rear panels of the fireplace;
[0018] FIG. 5 is a side view of the example fireplace hydronic
heating system shown in FIG. 4;
[0019] FIG. 6 is a cross-sectional view of the example fireplace
hydronic heating system shown in FIG. 4 taken along cross-sectional
indicators 6-6;
[0020] FIG. 7 is a cross-sectional view of another example
fireplace hydronic heating system with the liquid-filled conduits
positioned on an exterior of a heated air plenum of the fireplace;
and
[0021] FIG. 8 is a cross-sectional view of another example
fireplace hydronic heating system with the liquid-filled conduits
positioned adjacent to an interior surface of the combustion
chamber enclosure.
[0022] While the invention is amenable to various modifications and
alternate forms, specifics thereof have been shown by way of
example in the drawings and will be described in detail. It should
be understood, however, that the invention is not limited to the
particular embodiments described. On the contrary, the invention is
to cover all modifications, equivalents, and alternatives falling
within the spirit and scope of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] The present invention generally relates to hydronic heating
systems, and more particularly relates to an improved fireplace
hydronic heating system that is capable of eliminating condensation
and improve manufacturability of the hydronic heating system. While
the example embodiments of the present invention provided below are
described in conjunction with example fireplaces, the present
invention is equally applicable to other heating systems or
appliances that generate heat for the purpose of heating a living
space. Some example fireplaces that may be used in accordance with
principles of the present invention include a direct vent, a
universal vent, a B-vent, a horizontal/vertical-vent, a dual direct
vent, and a multi sided unit having two or three glass panels as
combustion chamber side panels.
[0024] As used herein, the phrase "combustion chamber enclosure"
may include any structure that at least partially encloses a space
in which heat is generated from combusting a material, solid, or
gas, activating an electric heating element, or a flame is
simulated. The phrase "transferring heat" may include either
convection or conduction heat transfer. A "heat source" may
include, for example, an electric or gas (e.g., natural gas or
hydrogen gas) heater or a combustible solid fuel such as wood or
wood pellets. The term "hydronic" is generally defined as referring
to any liquid and is not limited to the use of water as the liquid.
The term "conduit" is generally defined as a passage having an
inlet and an outlet and is capable of carrying a fluid between the
inlet and the outlet.
[0025] FIG. 1 is a schematic representation of an example hydronic
heating system 10 according to principles of the invention. System
10 includes a heating appliance 12, a first heat exchanger 14, a
pressure regulating tank 16, first and second pumps 18, 20, a
pressure release valve 22, and second and third heat exchangers 24,
26. The heating appliance 12 is shown as a fireplace that includes
a combustion chamber enclosure 30 having top and bottom panels 32,
34, first and second side panels 36, 38, and a rear panel 40 that
define a combustion chamber 42. The heating appliance 12 also
includes a fuel input 44, an exhaust vent 46, and a combustion air
inlet 48. The first heat exchanger 14 includes a plurality of
liquid-filled conduits 50 associated with the top panel 32 of the
combustion chamber enclosure 30. The liquid-filled conduits may be
defined by a pipe member having any desired cross-sectional shape.
The pipe member may be formed into the top panel 32 during a
molding process, or may be a defined by forming a channel in the
top panel 32 during a molding process.
[0026] The second heat exchanger 24 includes a blower 52 and a set
of cooling fins 54 through which the heated liquid passes and the
blower forces air against to heat the blown air. The third heat
exchanger 26 includes a flooring 56, such as a cement floor of a
home, and liquid-filled conduit coils 58 embedded in the flooring
56. The passage of liquid from the first heat exchanger through the
second heat exchanger 24 defines a first heat exchanging loop 28,
and the flow of liquid between the first heat exchanger 14 and the
third heat exchanger 26 defines a second heat exchanging loop
29.
[0027] When using the hydronic heating system 10 for the purpose of
transferring heat generated in the heating appliance 12 to a remote
location, heat is generated in combustion chamber 42 and the heat
is transferred to the liquid within conduit coils 50 of the first
heat exchanger 14. The heated liquid is then moved into the
pressure regulating tank 16 and the pressure release valve 22
directs the heated liquid to either the first or the second heat
exchanging loop 28, 29.
[0028] When the heated liquid is directed into the first heat
exchanging loop 28, the first pump 18 pumps the heated liquid
through the second heat exchanger 24 where the blower 52 moves air
across the cooling fins 54 to transfer the heat held by the heated
liquid to the air that is passing over the cooling fins 54. The
heated air may be injected into a central heating system or may be
used for other heating purposes. The cooled liquid is then pumped
back to the heating appliance 12 where it is again heated by heat
produced in combustion chamber 42.
[0029] When the heated liquid is directed into the second heat
exchanging loop 29, the second pump 20 pumps the heated liquid
through the third heat exchanger 26. Heat carried by the heated
liquid is exchanged between the heated liquid and the flooring 56
as the liquid-filled conduit coils 58 travel through or adjacent to
the flooring 56. The heated flooring 56 absorbs heat from the coils
58 and radiates the absorbed heat into the living space. The cooled
liquid in second heat exchanging loop 29 is then pumped back to the
first heat exchanger 14 where the liquid is again heated by heat
generated in the combustion chamber 42.
[0030] Although two common heat exchanger structures are shown in
the example of FIG. 1 as heat exchangers 24, 26, other types of
heat exchangers may be used and alternative features may be added
to the hydronic heating system 10. For example, the heat
transferred by the hydronic heating system 10 may be used for
heating hot water in a hot water heater, a hot tub, a humidifier,
or other appliances that require a heated liquid.
EXAMPLE
[0031] In an example hydronic heating system application, the
heating system is used to heat a 1,500 square foot room having 8
foot ceilings and a cement floor. Liquid-filled conduits are
embedded in the cement floor and coupled to liquid-filled conduits
embedded in a panel of a combustion chamber enclosure of the
heating appliance. The liquid being heated in the hydronic heating
system is a mixture of about 50% water and 50% glycol and is
carried in half-inch HEPEX.TM. tubing between the heating appliance
and the cement floor. The desired temperature of the air in the
room is 70.degree. F. and the temperature outside of the room is
11.degree. F. In order to heat the room to the desired temperature,
the heating appliance generates about 13,300 BTUs/hour to generate
a liquid temperature in the liquid-filled conduits of the
combustion chamber enclosure of about 80.degree. F. The heated
liquid is pumped to the liquid-filled conduits of the cement floor
at a flow rate of about 2.9 gal/min to heat the cement floor to
about 73.degree. F. Heat radiating from the cement floor raises the
air temperature in the room to the desired temperature of about
70.degree. F.
[0032] Referring now to FIGS. 2 and 3, an example hydronic heating
system 100 is shown including a heating appliance 112 and a heat
exchanger 114. The heating appliance 112 includes a combustion
chamber enclosure 130 that includes top and bottom panels 132, 134,
first and second side panels 136, 138, and a rear panel 140 that
define a combustion chamber enclosure 142. A heat generating device
such as a burner 148 is positioned within the combustion chamber
enclosure 130, and an exhaust 146 is provided for exhausting out
combustion gases or other unwanted by-products of generating heat
in the combustion chamber enclosure 130.
[0033] The heat exchanger 114 includes a plurality of liquid-filled
conduit coils 150 that are embedded within the top panel 132 of the
combustion chamber enclosure 130. The conduit 150 includes an inlet
151 and an outlet 151 to move cooled liquid into the heat exchanger
114 and move heated liquid out of the heat exchanger 114.
[0034] Referring now to FIGS. 4-6, another example hydronic heating
system 200 is shown including a heating appliance 212 and a heat
exchanger 214. The heating appliance 212 includes a combustion
chamber enclosure 230 having top and bottom panels 232, 234, first
and second side panels 236, 238, and a rear panel 240 that define a
combustion chamber 242. Heating appliance 212 includes an exhaust
246 and a burner 248 that functions as a heat generating unit. The
heat exchanger 214 includes a plurality of liquid-filled conduit
coils 250 having an inlet 251 and an outlet 252. The conduit coils
are embedded within the top, first and second side, and rear panels
232, 236, 238, 240. Positioning conduit coils in more than one
panel of the combustion chamber enclosure may increase the ability
of the heat exchanger 214 to absorb heat from the combustion
chamber 242 as compared to the heat exchanger 114 of the system 100
that includes embedded conduits in a single panel.
[0035] Referring now to FIG. 7, another example hydronic heating
system 300 is shown. System 300 including a heating appliance 312
that includes a combustion chamber enclosure 330, an outer
enclosure 370, and a heat exchanger 314. The combustion chamber
enclosure 330 includes top and bottom panels 332, 334, at least one
side panel 336, and a rear panel 340 that define a combustion
chamber 342. A burner 348 is positioned in the combustion chamber
342 and functions as a heat generating unit. A co-axial vent 345
provides an exhaust vent 346 for exhausting combustion gases out of
the combustion chamber 342, and a combustion air vent 347 that
provides a fresh combustion air flow B into the combustion chamber
enclosure 342 for combustion of fuel at the burner 348.
[0036] The outer enclosure 370 includes top and bottom panels 372,
374 and a rear panel 378, and may further include first and second
side panels (not shown). A plenum 380 defined between the
combustion chamber panels 332, 334, 340 and the outer enclosure
panels 372, 374, 376 is designed for the movement of an air flow A
around the combustion chamber enclosure to heat the air when
combustion is occurring in the combustion chamber 342. A blower
(not shown) may be positioned in the plenum 380 to draw cool air
into the plenum and expel the heated air out of the plenum.
[0037] The heat exchanger 314 includes a plurality of liquid-filled
conduit coils 350 embedded within a panel 360 that is coupled to an
exterior surface of top panel 372 of the outer enclosure 370. In
other embodiments (not shown), the heat exchanger 314 may be
positioned within the plenum 380 or may be coupled to other panels
of the outer enclosure 370. The heat exchanger 314 may be used to
absorb heat generated in the combustion chamber 342 that passes
through the combustion chamber enclosure panels 332, 334, 336, 340.
In other embodiments, separate heat exchangers that each include a
set of fluid-filled conduit coils embedded in a panel distinct from
the combustion chamber enclosure may be positioned at various
locations around the combustion chamber 330, the plenum 380, and
the outer enclosure 370. The heat exchanger(s) of the heating
appliance 300 is configured to absorb heat generated in the
combustion chamber 342 into the liquid-filled conduits 350 for
transport to a remote heat exchanger.
[0038] Referring now to FIG. 8, another example hydronic heating
system 400 is shown and includes a heating appliance 412 and a heat
exchanger 414. The heating appliance 412 includes a combustion
chamber enclosure 430 having top and bottom panels 432, 434, first
and second side panels 436, 438, and a rear panel 440 that define a
combustion chamber 442. Heating appliance 412 includes an exhaust
446 and a burner 448 that functions as a heat generating unit. The
heat exchanger 414 includes a plurality of liquid-filled conduit
coils 450 embedded within a panel 460 that is coupled to the top
panel 432 within the combustion chamber 442. In other embodiments,
the heat exchanger 414 may be coupled to any of the combustion
chamber enclosure panels 432, 434, 436, 440 within the combustion
chamber 442, or two or more heat exchangers may be coupled to
separate panels of the combustion chamber enclosure 430 within the
combustion chamber 442. The heat exchanger of the heating appliance
400 is configured to absorb heat generated in the combustion
chamber 442 into liquid held in the liquid-filled conduits 450 for
transport to a remote heat exchanger.
[0039] The heating system 400 may also include another heat
exchanger 415 that includes a plurality of liquid-filled coils 451
embedded within a panel 461. The heat panel 461 is shaped to extend
around at least a portion of exhaust 446 and configured to absorb
heat emanating from exhaust 446 into the liquid held in coils
451.
[0040] Although not show, the heating systems described above may
include heat exchanger having panels and coils that are configured
for mounting at other locations relative to the source of heat. For
example, a heat exchanger panel may be mounted below a bottom panel
of a combustion chamber enclosure or below a burner plate within a
combustion chamber enclosure. In another example, the heat
exchanger panel may be integrated into an outdoor fire pit or fire
pit surround.
[0041] It is a well known physical property of gaseous substances
to rise when heated. This principle applies in heating appliances
that include a combustion chamber enclosure, such as the device
shown in FIGS. 1-6, wherein heated air and hot combustion gases
rise toward the top portion of the combustion chamber. As a result,
it is common that some of the highest temperatures in a combustion
chamber enclosure exist near the top part of the combustion
chamber. However, high temperatures also occur adjacent to the
source of heat in the combustion chamber, for example, adjacent a
flame emitted from a burner in a gas fireplace, which results in
high temperatures at certain locations on the side and rear panels
of a combustion chamber enclosure that are adjacent to the heat
source. These heating principles may be exploited for maximizing
heat transfer in a hydronic heating system, for example the
hydronic heating systems described above. The liquid-filled
conduits of the heat exchanger associated with the heating
appliance may be embedded within one or more panels of the
combustion chamber enclosure or in independently mounted panels in
areas of the combustion chamber enclosure that coincide with the
highest heating areas.
[0042] In the hydronic heating systems 10, 100, 200, 300, 400
described above, the liquid-filled conduits of the heat exchanger
associated with the heating appliance are described as being
embedded within at least one panel of the combustion chamber
enclosure of the heating appliance. More generally, such conduits
of the heat exchanger are integrally formed with at least one panel
of the combustion chamber enclosure so as to be a single unit. In
yet other embodiments, the conduits are defined by material of the
combustion chamber enclosure, wherein the combustion chamber
enclosure material includes insulating properties, or at least
properties that promote a substantially linear temperature
transition across the material thickness between the liquid in the
conduits and the heated air of the combustion chamber so as to
reduce the possibility of condensation forming in association with
the heating appliance.
[0043] One way in which the combustion chamber enclosure panels and
the conduits of the heat exchanger may be constructed includes
forming those features using a moldable material, for example, a
moldable material that includes an inorganic ceramic fiber and a
binder or other type of high temperature moldable material or
fiber. A molded feature of the heating appliance may be formed
using any known molding process, such as, for example, compression
molding, vacuum molding, or casting processes. Exemplary molding
compositions and forming techniques are described in pending U.S.
Patent Application Publication No. 2003/0049575 and U.S. Pat. Nos.
5,941,237; 5,996,575; and 6,170,481, which patents and patent
application are incorporated herein by reference in their
entirety.
[0044] The use of moldable material may provide several advantages
over other types of materials. For example, when using moldable
materials for a combustion chamber enclosure, all panels of the
enclosure may be formed simultaneously as a single, unitary piece.
Another important advantage of using such moldable materials is
that the conduits may be directly and integrally formed within
panels of the combustion chamber enclosure during the molding
process. This provides many design options including intricate
conduit designs and positioning arrangements relative to the panels
to help position the conduits at the regions of highest temperature
within the combustion chamber enclosure. An advantage of using an
inorganic ceramic fiber material is the fiber's resistance to the
formation of condensation when a cool liquid is in contact with the
molded material on one side of the molded piece while a high air
temperature condition exists on an opposing side of the molded
material piece due to heat within the combustion chamber. Reducing
and/or eliminating such condensation provides a more aesthetically
pleasing heating appliance, in particular when the heating
appliance is a fireplace that is viewable through a front surface
thereof for viewing within the combustion chamber. Condensation
within a combustion chamber is typically out of character with a
heating appliance and may cause stains or discoloring of the
heating appliance and may ultimately cause damage to the heating
appliance.
[0045] Other types of material besides moldable materials may be
useful for providing a condensation resistant barrier between the
liquid-filled conduits and the combustion chamber or other features
associated with the fireplace. Such material may be positioned
adjacent to the liquid-filled conduits or between the liquid-filled
conduits and the combustion chamber so as to provide a desired
condensation barrier.
[0046] In some embodiments, portions of the liquid-filled conduits
may be at least partially encapsulated in a condensation resistant
material, and the encapsulated conduits positioned inside or
outside of the combustion chamber enclosure or the outer enclosure
of the fireplace, or within a panel of one of those enclosures. In
other embodiments, the liquid-filled conduits may be encapsulated
with different materials along different portions of the conduit
length, or may have multiple layers of encapsulation with different
material defining separate encapsulating layers.
[0047] The present invention should not be considered limited to
the particular examples or materials described above, but rather
should be understood to cover all aspects of the invention as
fairly set out in the attached claims. Various modifications,
equivalent processes, as well as numerous structures to which the
present invention may be applicable will be readily apparent to
those of skill in the art to which the present invention is
directed upon review of the instant specification.
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