U.S. patent application number 15/347207 was filed with the patent office on 2017-05-11 for residential outdoor heat exchanger unit.
The applicant listed for this patent is Carrier Corporation. Invention is credited to James Amick, Kevin Mercer.
Application Number | 20170130974 15/347207 |
Document ID | / |
Family ID | 58663516 |
Filed Date | 2017-05-11 |
United States Patent
Application |
20170130974 |
Kind Code |
A1 |
Mercer; Kevin ; et
al. |
May 11, 2017 |
RESIDENTIAL OUTDOOR HEAT EXCHANGER UNIT
Abstract
An outdoor coil unit of a residential heating, ventilation, and
air conditioning system includes a frame and a heat exchanger
assembly mounted within the frame. The heat exchanger assembly
includes at least one heat exchanger coil having a first header, a
second header, and a plurality of heat exchange tube segments
extending between and fluidly coupling the first header and the
second header. The heat exchanger assembly is formed into a shape
including at least one apex. A fan assembly is mounted to the frame
and includes at least one fan operable to draw air into the outdoor
coil unit through the at least one heat exchanger coil and
discharge the a qr outside of the outdoor coil unit.
Inventors: |
Mercer; Kevin; (Danville,
IN) ; Amick; James; (Coatesville, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Carrier Corporation |
Jupiter |
FL |
US |
|
|
Family ID: |
58663516 |
Appl. No.: |
15/347207 |
Filed: |
November 9, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62253034 |
Nov 9, 2015 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F 1/16 20130101; F24F
1/50 20130101; F24F 1/56 20130101 |
International
Class: |
F24F 1/16 20060101
F24F001/16; F24F 13/20 20060101 F24F013/20 |
Claims
1. An outdoor coil unit of a residential heating, ventilation, and
air conditioning system, comprising: a frame; a heat exchanger
assembly mounted within the frame, the heat exchanger assembly
including at least one heat exchanger coil having a first header, a
second header, and a plurality of heat exchange tube segments
extending between and fluidly coupling the first header and the
second header, the heat exchanger assembly being formed into a
shape including at least one apex; and a fan assembly mounted to
the frame and including at least one fan operable to draw air into
the outdoor coil unit through the at least one heat exchanger coil
and discharge the air outside of the outdoor coil unit.
2. The outdoor coil unit according to claim 1, wherein the heat
exchanger assembly is generally V-shaped.
3. The outdoor coil unit according to claim 1, wherein the heat
exchanger assembly is generally W-shaped.
4. The outdoor coil unit according to claim 1, wherein the first
header and the second header are oriented generally horizontally,
and the plurality of heat exchange tube segments is oriented
generally vertically.
5. The outdoor coil unit according to claim 1, wherein the first
header and the second header are oriented generally vertically, and
the plurality of heat exchange tube segments is oriented generally
horizontally.
6. The outdoor coil unit according to claim 1, wherein the heat
exchanger assembly formed into a shape including at least one apex
includes a first heat exchanger coil and a second heat exchanger
coil fluidly coupled via an intermediate header.
7. The outdoor coil unit according to claim 1, wherein the heat
exchanger assembly formed into a shape including at least one apex
includes a first heat exchanger coil and a second heat exchanger
coil, the first heat exchanger coil and second heat exchanger coil
being fluidly separate from one another.
8. The outdoor coil unit according to claim 1, wherein the heat
exchanger assembly is oriented vertically within the frame.
9. The outdoor coil unit according to claim 1, wherein the heat
exchanger assembly is oriented horizontally within the frame.
10. The outdoor coil unit according to claim 1, wherein the at
least one heat exchanger coil is a microchannel heat exchanger coil
such that each heat exchange tube segment includes a plurality of
discrete flow channels.
11. The outdoor coil unit according to claim 1, further comprising
a base pan positioned within the frame, wherein an interface
between the heat exchanger assembly and the base plan stabilizes a
position of the heat exchanger assembly within the frame.
12. The outdoor coil unit according to claim 11, wherein the base
pan includes a raceway having a contour generally complementary to
a portion of the heat exchanger assembly such that when the portion
of the heat exchanger is mounted therein, the heat exchanger is
offset from a floor of the base pan.
13. The outdoor coil unit according to claim 11, wherein one or
more openings are formed in a portion of the base pan.
14. The outdoor coil unit according to claim 13, wherein the one or
more openings are positioned adjacent an area of the heat exchanger
assembly where condensate accumulates.
15. The outdoor coil unit according to claim 13, wherein at least
one of a size and location of the one or more openings is optimized
to provide maximum drainage during a defrost cycle of the outdoor
coil unit.
16. The outdoor coil unit according to claim 13, wherein the one or
more openings are positioned adjacent an area of the heat exchanger
assembly to provide an optimized airflow path.
17. The outdoor coil unit according to claim 1, wherein the fan
assembly includes a first fan and a second fan, the first fan and
the second fan being operably independent.
18. The outdoor coil unit according to claim 1, wherein a plurality
of heat exchanger fins are mounted to the plurality of heat
exchange tube segments and the plurality of heat exchanger fins do
not extend beyond a leading edge or a trailing edge of the
plurality of heat exchange tube segments.
19. The outdoor coil unit according to claim 1, wherein a plurality
of heat exchanger fins are mounted to the plurality of heat
exchange tube segments and the plurality of heat exchanger fins
extend beyond at least one of a leading edge and a trailing edge of
the plurality of heat exchange tube segments.
20. The outdoor coil unit according to claim 1, wherein the
residential heating, ventilation, and air conditioning system has a
capacity of less than or equal to 65,000 Btuh.
21. The outdoor coil unit according to claim 1, wherein the apex of
the heat exchanger assembly includes an opening to define a flow
path there between.
22. The outdoor coil unit according to claim 1, wherein at least a
portion of the heat exchanger assembly is sealed with a cover such
the fan assembly draws air through only an intended portion of the
heat exchanger assembly.
23. An outdoor coil unit, comprising: a frame; and a heat exchanger
assembly mounted within the frame, the heat exchanger assembly
including a first heat exchanger coil and a second heat exchanger
coil, each heat exchanger coil having a first header, a second
header, and a plurality of heat exchange tube segments extending
between and fluidly coupling the first header and the second
header, the first heat exchanger coil and the second heat exchanger
coil are angled relative to one another to such that a first end of
the first heat exchanger coil and a first end of the second heat
exchanger coil form an apex, the first end of the first heat
exchanger coil and the first end of the second heat exchanger coil
being separated from one another by a distance to allow a flow path
for at least one of debris, airflow, and condensate there between;
and a fan assembly including at least one fan being mounted to the
frame, the fan assembly being located adjacent a second end of the
first heat exchanger coil and a second end of the second heat
exchanger coil.
24. An outdoor coil unit comprising: a frame; a heat exchanger
assembly mounted within the frame, the heat exchanger assembly
including at least one heat exchanger coil having a first header, a
second header, and a plurality of heat exchange tube segments
extending between and fluidly coupling the first header and the
second header, the heat exchanger assembly being formed into a
shape including at least one apex; a fan assembly mounted to the
frame and including at least one fan operable to draw air into the
outdoor coil unit through the at least one heat exchanger coil and
discharge the air outside of the outdoor coil unit; and at least
one cover positioned adjacent a portion of the heat exchanger
assembly to seal the portion of the heat exchanger assembly against
air flow there through.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/253,034, filed Nov. 9, 2015, the contents of
which are incorporated by reference in their entirety herein.
BACKGROUND
[0002] This disclosure relates generally to outdoor units for air
conditioners and heat pumps and, more particularly, to a heat
exchanger configured for use in a residential outdoor unit.
[0003] Air cooled condensers, commonly used in residential air
conditioning systems, employ a fin tube construction to transfer
heat from the refrigerant to the outdoor air. As hot, high pressure
refrigerant passes through the coil, heat from the compressed
refrigerant is transferred through the tubes to the attached fins.
An electrically powered fan is used to draw outside air across the
fin heat transfer surfaces to remove heat from the refrigerant so
that it will condense and partially sub-cool prior to reaching an
expansion valve.
[0004] The heat exchanger coil of an outdoor unit is usually round,
rectangular, or square in form, and the compressor is normally
disposed within the coil. A fan and its drive motor is commonly
mounted above the heat exchanger such that the fan draws outdoor
air inwardly through the coil and then upwardly to be discharged
into the atmosphere.
SUMMARY
[0005] According to a first embodiment, an outdoor coil unit of a
residential heating, ventilation, and air conditioning system
includes a frame, and a heat exchanger assembly mounted within the
frame. The heat exchanger assembly includes at least one heat
exchanger coil having a first header, a second header, and a
plurality of heat exchange tube segments extending between and
fluidly coupling the first header and the second header. The heat
exchanger assembly is formed into a shape including at least one
apex. A fan assembly is mounted to the frame and includes at least
one fan operable to draw air into the outdoor coil unit through the
at least one heat exchanger coil and discharge the air outside of
the outdoor coil unit.
[0006] In addition to one or more of the features described above,
or as an alternative, in further embodiments the heat exchanger
assembly is generally V-shaped.
[0007] In addition to one or more of the features described above,
or as an alternative, in further embodiments the heat exchanger
assembly is generally W-shaped.
[0008] In addition to one or more of the features described above,
or as an alternative, in further embodiments the first header and
the second header are oriented generally horizontally, and the
plurality of heat exchange tube segments is oriented generally
vertically.
[0009] In addition to one or more of the features described above,
or as an alternative, in further embodiments the first header and
the second header are oriented generally vertically, and the
plurality of heat exchange tube segments is oriented generally
horizontally.
[0010] In addition to one or more of the features described above,
or as an alternative, in further embodiments the heat exchanger
assembly formed into a shape including at least one apex includes a
first heat exchanger coil and a second heat exchanger coil fluidly
coupled via an intermediate header.
[0011] In addition to one or more of the features described above,
or as an alternative, in further embodiments the heat exchanger
assembly formed into a shape including at least one apex includes a
first heat exchanger coil and a second heat exchanger coil. The
first heat exchanger coil and the second heat exchanger coil are
fluidly separate from one another.
[0012] In addition to one or more of the features described above,
or as an alternative, in further embodiments the heat exchanger
assembly is oriented vertically within the frame.
[0013] In addition to one or more of the features described above,
or as an alternative, in further embodiments the heat exchanger
assembly is oriented horizontally within the frame.
[0014] In addition to one or more of the features described above,
or as an alternative, in further embodiments the at least one heat
exchanger coil is a microchannel heat exchanger coil such that each
heat exchange tube segment includes a plurality of discrete flow
channels.
[0015] In addition to one or more of the features described above,
or as an alternative, in further embodiments a base pan is
positioned within the frame. An interface between the heat
exchanger assembly and the base plan stabilizes a position of the
heat exchanger assembly within the frame.
[0016] In addition to one or more of the features described above,
or as an alternative, in further embodiments the base pan includes
a raceway having a contour generally complementary to a portion of
the heat exchanger assembly such that when the portion of the heat
exchanger is mounted therein, the heat exchanger is offset from a
floor of the base pan.
[0017] In addition to one or more of the features described above,
or as an alternative, in further embodiments one or more openings
are formed in a portion of the base pan.
[0018] In addition to one or more of the features described above,
or as an alternative, in further embodiments the one or more
openings are positioned adjacent an area of the heat exchanger
assembly where condensate accumulates.
[0019] In addition to one or more of the features described above,
or as an alternative, in further embodiments at least one of a size
and location of the drainage holes is optimized to provide maximum
drainage during a defrost cycle of the outdoor coil unit.
[0020] In addition to one or more of the features described above,
or as an alternative, in further embodiments the one or more
openings are positioned adjacent an area of the heat exchanger
assembly to provide an optimized airflow path.
[0021] In addition to one or more of the features described above,
or as an alternative, in further embodiments the fan assembly
includes a first fan and a second fan. The first fan and the second
fan are operable independently.
[0022] In addition to one or more of the features described above,
or as an alternative, in further embodiments a plurality of heat
exchanger fins are mounted to the plurality of heat exchange tube
segments. The plurality of heat exchanger fins does not extend
beyond a leading edge or a trailing edge of the plurality of heat
exchange tube segments.
[0023] In addition to one or more of the features described above,
or as an alternative, in further embodiments a plurality of heat
exchanger fins are mounted to the plurality of heat exchange tube
segments and the plurality of heat exchanger fins extend beyond at
least one of a leading edge and a trailing edge of the plurality of
heat exchange tube segments.
[0024] In addition to one or more of the features described above,
or as an alternative, in further embodiments the residential
heating, ventilation, and air conditioning system has a capacity of
less than or equal to 65,000 Btuh.
[0025] In addition to one or more of the features described above,
or as an alternative, in further embodiments the apex of the heat
exchanger assembly includes an opening to define a flow path there
between.
[0026] In addition to one or more of the features described above,
or as an alternative, in further embodiments at least a portion of
the heat exchanger assembly is sealed with a cover such the fan
assembly draws air through only an intended portion of the heat
exchanger assembly.
[0027] According to another, an outdoor coil unit is provided
including a frame and a heat exchanger assembly mounted within the
frame. The heat exchanger assembly includes a first heat exchanger
coil and a second heat exchanger coil. Each heat exchanger coil has
a first header, a second header, and a plurality of heat exchange
tube segments extending between and fluidly coupling the first
header and the second header. The first heat exchanger coil and the
second heat exchanger coil are angled relative to one another such
that a first end of the first heat exchanger coil and a first end
of the second heat exchanger coil form an apex. The first end of
the first heat exchanger coil and the first end of the second heat
exchanger coil are separated from one another by a distance to
allow a flow path for at least one of debris, airflow, and
condensate there between. A fan assembly including at least one fan
is mounted to the frame. The fan assembly is located adjacent a
second end of the first heat exchanger coil and a second end of the
second heat exchanger coil.
[0028] According to another, an outdoor coil unit is provided
including a frame and a heat exchanger heat exchanger assembly
mounted within the frame. The heat exchanger assembly includes at
least one heat exchanger coil having a first header, a second
header, and a plurality of heat exchange tube segments extending
between and fluidly coupling the first header and the second
header. The heat exchanger assembly is formed into a shape
including at least one apex. A fan assembly is mounted to the frame
and includes at least one fan operable to draw air into the outdoor
coil unit through the at least one heat exchanger coil and
discharge the air outside of the outdoor coil unit. At least one
cover is positioned adjacent a portion of the heat exchanger
assembly to seal the portion of the heat exchanger assembly against
air flow there through.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The subject matter, which is regarded as the present
disclosure, is particularly pointed out and distinctly claimed in
the claims at the conclusion of the specification. The foregoing
and other features, and advantages of the present disclosure are
apparent from the following detailed description taken in
conjunction with the accompanying drawings in which:
[0030] FIG. 1 is a schematic diagram of an example of a
conventional vapor compression cycle;
[0031] FIG. 2 is a perspective view of an outdoor coil unit
according to an embodiment;
[0032] FIG. 3 is a front view of an outdoor coil unit according to
an embodiment;
[0033] FIG. 4 is a perspective view of an outdoor coil unit
according to an embodiment;
[0034] FIG. 5 is a perspective view of a heat exchanger assembly of
an outdoor coil unit according to an embodiment;
[0035] FIG. 6 is a perspective view of another heat exchanger
assembly of an outdoor coil unit according to an embodiment;
[0036] FIG. 7 is a perspective view of another heat exchanger
assembly of an outdoor coil unit according to an embodiment;
[0037] FIGS. 8a and 8b are cross-sectional views of a heat
exchanger coil of the heat exchanger assembly according to an
embodiment;
[0038] FIG. 9 is a cross-sectional view of a portion of the heat
exchanger assembly of the outdoor coil unit according to an
embodiment; and
[0039] FIG. 10 is a cross-sectional view of a portion of the heat
exchanger assembly of the outdoor coil unit according to another
embodiment.
[0040] The detailed description explains embodiments of the present
disclosure, together with advantages and features, by way of
example with reference to the drawings.
DETAILED DESCRIPTION
[0041] Referring now to FIG. 1, a conventional vapor compression or
refrigeration cycle 10 of an air conditioning system is
schematically illustrated. Exemplary air conditioning systems
include split, packaged, and rooftop systems, for example. A
refrigerant R is configured to circulate through the vapor
compression cycle 10 such that the refrigerant R absorbs heat when
evaporated at a low temperature and pressure and releases heat when
condensed at a higher temperature and pressure. Within this cycle
10, the refrigerant R flows in a counterclockwise direction as
indicated by the arrows. The compressor 12 receives refrigerant
vapor from the evaporator 18 and compresses it to a higher
temperature and pressure, with the relatively hot vapor then
passing to the condenser 14 where it is cooled and condensed to a
liquid state by a heat exchange relationship with a cooling medium
such as air or water. The liquid refrigerant R then passes from the
condenser 14 to an expansion valve 16, wherein the refrigerant R is
expanded to a low temperature two phase liquid/vapor state as it
passes to the evaporator 18. The low pressure vapor then returns to
the compressor 12 where the cycle is repeated.
[0042] Referring now to FIG. 2, an outdoor coil unit 20, for
example configured as an air-cooled condenser 14 of the vapor
compression cycle 10 of FIG. 1, is illustrated in more detail. The
outdoor coil unit 20 illustrated and described herein is intended
for use in any residential HVAC system, which generally includes
any system having a capacity of about 5 Tons or less (i.e. capacity
less than or equal to 65,000 Btuh). The outdoor coil unit 20
includes a frame 22 and a heat exchanger assembly 24 arranged
within the frame 22. In one embodiment, the heat exchanger assembly
24 is arranged completely within the frame 22. A compressor 26,
fluidly coupled to the heat exchanger assembly 24 may be positioned
within the interior of the outdoor coil unit 20 and is configured
to pump refrigerant through a vapor compression cycle 10.
[0043] The outdoor coil unit 20 additionally includes a fan
assembly 28 having at least one fan 30 configured to draw ambient
air inward through the heat exchanger coils 25, and then discharge
the air outward through an opening. A solid cover 32, such as
formed from sheet metal for example, may be positioned about one or
more portions of the frame 22 to seal between the heat exchanger
assembly 24 and the fan assembly 28 to prevent air flow there
through bypassing the heat exchanger assembly 24. For example, the
opposing ends of the heat exchanger assembly 24 are sealed with
side plates 33 in FIG. 2 such that the fan 30 draws air only
through an intended portion of the heat exchanger assembly 24. As
shown in FIG. 2, the fan assembly 28 is positioned at the uppermost
surface (top) of the outdoor coil unit 20 such that air is
discharged vertically upward there through. However, in other
embodiments, the fan assembly 28 may be mounted to a side surface
of the frame 22, within a vertical plane as shown in FIG. 4. When
the fan assembly 28 is mounted at a side of the outdoor coil unit
20, the fan 30 is configured to draw air horizontally, such as
through an opposing side 34 of the outdoor coil unit 20 for
example.
[0044] As previously described, the fan assembly 28 may include one
or multiple fans. Although the coil units illustrated have either
one or two fans 30, embodiments including any number of fans are
within the scope of the disclosure. In embodiments including a
plurality of fans 30, such as shown in FIG. 2, each fan 30 of the
fan assembly 28 may be independently operable. In such instances,
the heat exchanger assembly 24 of the outdoor coil unit 20 may
include a plurality of heat exchanger coils 25 such that each fan
30 is operatively associated with one or more of the plurality of
heat exchanger coils 25. As a result, the outdoor coil unit 20 may
be operated at a reduced capacity. In one embodiment, a partition
plate or side plate 33, such as including a one way louver for
example, may be positioned between the heat exchanger coils 25 to
prevent air from being drawn through the non-operational portion of
the of the heat exchanger assembly 24.
[0045] As best shown in FIG. 2, a base pan 36 may be configured to
hold the heat exchanger assembly 24 in place relative to the frame
22. A raceway 37 generally complementary to a portion of the heat
exchanger assembly 24, such as an apex thereof for example, may be
formed in the base pan 36. When the portion of the heat exchanger
assembly 24 is positioned within the raceway 37, the raceway 37
stabilizes the heat exchanger assembly 24. In addition, the portion
of the heat exchanger assembly 24 positioned within the raceway 37
may be generally offset from the floor of the base pan 36. The
raceway 37 may be located at any position on the base pan 36
corresponding to the heat exchanger assembly 24. In one embodiment,
one or more openings 38 may be formed in a portion of the base pan
36 adjacent the heat exchanger assembly 24 to aid in drainage of
condensate from the exterior surface of the heat exchanger assembly
24, or for other reasons, not limited to condensate drainage, such
as airflow for example. In embodiments where the fan assembly 28 is
configured to draw air vertically through the coil unit 20, the
plurality of openings 38 may be located adjacent an apex, bend, or
other region of the heat exchanger assembly 24 where condensate is
likely to accumulate or for desirable airflow. Alternatively, in
embodiments where the fan assembly 28 is configured to draw air
horizontally through the coil unit 20 as in FIG. 4, the one or more
openings 38 may be positioned at any location underneath the heat
exchanger assembly 24. In one embodiment, at least one of a size,
shape and location of the openings 38 is determined to provide
optimal condensate drainage during a defrost cycle of the outdoor
coil unit 20, or optimal airflow for same outdoor coil unit 20.
[0046] With reference now to FIGS. 3-7, various examples of the
heat exchanger assembly 24 of the outdoor coil unit 20 are
illustrated in more detail. As previously suggested, the outdoor
coil unit 20 includes one or more heat exchangers coils 25. For
example, the embodiment of the outdoor coil unit 20 illustrated in
FIG. 3, includes one heat exchanger coil 25. Though shown having a
single tube bank 27, a heat exchanger coil 25 having any number of
tube banks is within the scope of the disclosure. Alternatively,
the non-limiting embodiments illustrated in FIGS. 4-7 include a
heat exchanger assembly 24 having a first heat exchanger coil 25a
and a second heat exchanger coil 25b arranged at an angle to one
another within the frame 22. In embodiments including multiple heat
exchanger coils 25, although a portion of the coils may be
positioned near one another, the coils 25 remain fluidly separate.
In such embodiments, the adjacent portions of the heat exchanger
coils 25, for example the apex formed when two heat exchanger coils
25 are arranged in a V-shaped configuration, may be separated from
one another by a distance sufficient to allow debris or other
particles that collect within the coil unit 20 to pass between the
coils 25. In one embodiment, the distance between the first and
second heat exchanger coils 25a, 25b is between about 0 and 12
inches.
[0047] FIG. 3 shows the at least one coil 25 of the heat exchanger
assembly 24 includes a first manifold or header 40, a second
manifold or header 42 spaced apart from the first manifold 40, and
a plurality of heat exchange tubes 44 extending in a spaced
parallel relationship between and fluidly connecting the first
manifold 40 and the second manifold 42. In the illustrated,
non-limiting embodiment of FIG. 5, the first manifold or header
40a, 40b and the second manifold or header 42a, 42b of each heat
exchanger coil 25a, 25b are oriented generally vertically. By
arranging the tubes 44a, 44b vertically, as shown in FIG. 5, water
condensate collected on the tubes 44a, 44b is drained from the heat
exchanger assembly 24. However, a heat exchanger coil 25 having
another configuration, for example where the manifolds or headers
40, 42 are arranged vertically and the plurality of heat exchanger
tubes 44 extend horizontally, as shown in FIG. 6, are also within
the scope of the disclosure.
[0048] In the non-limiting embodiments illustrated in the FIGS.,
the manifolds or headers 40, 42 comprise hollow, closed end
cylinders having a circular cross-section. However, manifolds or
headers 40, 42 having other configurations, such as a
semi-elliptical, square, rectangular, hexagonal, octagonal, or
other cross-sectional shapes for example, are within the scope of
the disclosure. The heat exchanger assembly 24 may be used as
either a condenser 14 or an evaporator 18 in a vapor compression
cycle 10, such as a heat pump system or air conditioning system for
example.
[0049] In embodiments including a plurality of heat exchanger coils
25, the plurality of heat exchanger coils 25 may be fluidly coupled
to or fluidly separate from one another. In embodiments where at
least a portion of the plurality of heat exchanger coils 25 are
fluidly coupled, the coils 25 may be coupled via an intermediate
manifold or header 46, as shown in FIG. 7. Regardless of how many
heat exchanger coils 25 are included, the heat exchanger assembly
24 may have any desired shape, including, but not limited to a "V",
"A", "W", "C", "U", or "L" for example.
[0050] Each coil 25 of the heat exchanger assembly 24 may be
configured with a single (FIG. 8a) or multi-pass flow configuration
(FIG. 8b). To form a multi-pass flow configuration, at least one of
the first manifold 40 and the second manifold 42 includes two or
more fluidly distinct sections or chambers. In one embodiment, the
fluidly distinct sections are formed by coupling separate manifolds
together to form the first or second manifold 40, 42.
Alternatively, a baffle or divider plate 45 known to a person of
ordinary skill in the art may be arranged within at least one of
the first header 40 and/or the second header 42 to define a
plurality of fluidly distinct sections therein.
[0051] In one embodiment, at least one coil 25 of the heat
exchanger assembly 24 is a microchannel heat exchanger. In such
embodiments, each heat exchange tube 44 comprises a flattened heat
exchange tube having a leading edge 50, a trailing edge 52, a first
surface 54, and a second surface 56. The leading edge 50 of each
heat exchanger tube 44 is upstream of its respective trailing edge
52 with respect to an airflow A through the heat exchanger assembly
24. The interior flow passage of each heat exchange tube 44 may be
divided by interior walls into a plurality of discrete flow
channels 58 that extend over the length of the tubes 44 from an
inlet end to an outlet end and establish fluid communication
between the respective first and second manifolds 40, 42. The flow
channels 58 may have a circular cross-section, a rectangular
cross-section, a trapezoidal cross-section, a triangular
cross-section, or another non-circular cross-section. The heat
exchange tubes 44 including the discrete flow channels 58 may be
formed using known techniques and materials, including, but not
limited to, extrusion or folding.
[0052] As known, a plurality of heat transfer fins 60 (FIGS. 9 and
10) may be disposed between and rigidly attached, e.g., by a
furnace braze process, to the heat exchange tubes 44, in order to
enhance external heat transfer and provide structural rigidity to
the heat exchanger coil 25. The fins 60 may be configured with any
of a plurality of configurations, in the illustrated, non-limiting
embodiment, each fin 60 is formed from a plurality of connected
strips or a single continuous strip of fin material tightly folded
in a ribbon-like serpentine fashion thereby providing a plurality
of closely spaced fins 62 that extend generally orthogonal to the
flattened heat exchange tubes 44. In one embodiment, such as when
the outdoor coil unit 20 is configured as a heat pump and as shown
in FIG. 9, the fins 60 of the heat exchanger assembly 24 do not
extend beyond the leading edge 50 or trailing edge 52 of the heat
exchange tubes 44. Alternatively, as shown in FIG. 10, the fins 60
may extend beyond at least one of the leading edge 50 and trailing
edge 52 of the heat exchange tubes 44, for example when the outdoor
coil unit 20 is configured as a portion of an air conditioning
system. When the fins 60 extend beyond at least one of the leading
edge 50 and trailing edge 52, the fins 60 not only provide an
additional heat transfer surface, but also protect the adjacent
tubes 44 from damage. However, the reduced ability of these
extended fins 60 to drain condensate makes them more beneficial,
but not limited to use in air conditioning applications. Heat
exchange between the fluid within the heat exchanger tubes 44 and
the air flow A, occurs through the outside surfaces 54, 56 of the
heat exchange tubes 44 collectively forming a primary heat exchange
surface, and also through the heat exchange surface of the fins 60
which form a secondary heat exchange surface.
[0053] The outdoor coil unit 20 illustrated and described herein
has a new configuration that is both easier to manufacture and
typically lower in cost. In addition, a larger fan 30 may be used
in the fan assembly 28 resulting in decreased noise and increased
fan efficiency. In some embodiments, unlike conventional outdoor
coil units where a heat exchanger is positioned at an exterior
surface of the unit, the heat exchanger assembly 24 is located at a
recessed position, wholly contained within the frame 22 of the unit
20. As a result, the additional paneling commonly used to protect
one or more surfaces of the heat exchanger is no longer necessary
or may be greatly reduced.
[0054] While the present disclosure has been particularly shown and
described with reference to the exemplary embodiments as
illustrated in the drawings, it will be recognized by those skilled
in the art that various modifications may be made without departing
from the scope of the present disclosure. Therefore, it is intended
that the present disclosure not be limited to the particular
embodiment(s) disclosed as, but that the disclosure will include
all embodiments falling within the scope of the appended
claims.
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