U.S. patent application number 11/337107 was filed with the patent office on 2007-07-26 for condensate pan internal corner design.
This patent application is currently assigned to United Technologies Corporation. Invention is credited to Arturo Rios.
Application Number | 20070169501 11/337107 |
Document ID | / |
Family ID | 38283440 |
Filed Date | 2007-07-26 |
United States Patent
Application |
20070169501 |
Kind Code |
A1 |
Rios; Arturo |
July 26, 2007 |
Condensate pan internal corner design
Abstract
An internal corner design of a condensate pan is configured to
prevent condensation blow-off in an evaporator assembly. The
condensate pan comprises a first rib and a second rib, the first
rib and the second rib defining a first groove configured to
receive a delta plate.
Inventors: |
Rios; Arturo; (Avon,
IN) |
Correspondence
Address: |
KINNEY & LANGE, P.A.
THE KINNEY & LANGE BUILDING
312 SOUTH THIRD STREET
MINNEAPOLIS
MN
55415-1002
US
|
Assignee: |
United Technologies
Corporation
Hartford
CT
|
Family ID: |
38283440 |
Appl. No.: |
11/337107 |
Filed: |
January 20, 2006 |
Current U.S.
Class: |
62/286 ; 62/285;
62/291 |
Current CPC
Class: |
F24F 13/222 20130101;
F28D 2021/0071 20130101; F28F 17/005 20130101; F28D 1/0477
20130101; F25D 21/14 20130101 |
Class at
Publication: |
062/286 ;
062/285; 062/291 |
International
Class: |
F25D 21/14 20060101
F25D021/14 |
Claims
1. A condensate pan comprising: a first pan member for receiving a
lower end of a first coil slab; a second pan member for receiving a
lower end of a second coil slab; a third pan member coupled to the
first and second pan members; and a first groove configured to
receive a delta plate, wherein the first groove includes a first
rib and a second rib, and wherein the first groove is disposed at a
first internal corner defined by the first and third pan
members.
2. The condensate pan of claim 1, wherein the condensate pan is
formed from a plastic.
3. The condensate pan of claim 2, wherein the plastic comprises
polystyrene.
4. The condensate pan of claim 1, and further comprising a second
groove configured to receive the delta plate, wherein the second
groove includes a third rib and a fourth rib, and wherein the
second groove is disposed at a second internal corner defined by
the second and third pan members.
5. The condensate pan of claim 4, and further comprising a delta
plate support disposed between the first groove and the second
groove for aligning the delta plate with respect to the condensate
pan.
6. The condensate pan of claim 5, and further comprising a
plurality of delta plate supports disposed between the first and
second grooves.
7. The condensate pan of claim 6, wherein the plurality is equal to
five.
8. The condensate pan of claim 1, wherein the condensate pan
further comprises an aperture configured to receive a tab member of
the delta plate for securing the delta plate to the condensate
pan.
9. The condensate pan of claim 8, wherein the condensate pan
further comprises a second aperture configured to receive a second
tab member of the delta plate for securing the delta plate to the
condensate pan.
10. An evaporator assembly comprising: a condensate pan comprising:
a first rib; and a second rib, the first rib and the second rib
defining a first groove configured to receive a delta plate; a
delta plate at least partially disposed within the first
groove.
11. The evaporator assembly of claim 10, wherein the condensate pan
further comprises: a third rib; and a fourth rib, the third rib and
the fourth rib defining a second groove configured to receive the
delta plate.
12. The evaporator assembly of claim 11, wherein the condensate pan
further comprises a delta plate support disposed along an inner
wall of the condensate pan between the first and second
grooves.
13. The evaporator assembly of claim 12, and further comprising a
plurality of delta plate supports disposed along the inner wall of
the condensate pan between the first and second grooves.
14. The evaporator assembly of claim 12, wherein the inner wall
includes an aperture configured to receive a tab member of the
delta plate to secure the delta plate to the inner wall.
15. A condensate pan comprising: a generally rectangular outer
wall; a generally rectangular inner wall disposed within the outer
wall, the inner and outer walls defining a first internal corner
comprising: a first rib; and a second rib, the first and second
ribs defining a first groove configured to receive a first delta
plate.
16. The condensate pan of claim 15, wherein the outer and inner
walls further define a second internal corner comprising: a third
rib; and a fourth rib, the third and fourth ribs defining a second
groove configured to receive the first delta plate.
17. The condensate pan of claim 16, wherein the outer and inner
walls further define a third internal corner comprising: a fifth
rib; and a sixth rib, the fifth and sixth ribs defining a third
groove configured to receive a second delta plate.
18. The condensate pan of claim 17, wherein the outer and inner
walls further define a fourth internal corner comprising: a seventh
rib; and an eighth rib, the seventh and eighth ribs defining a
fourth groove configured to receive the second delta plate.
19. The condensate pan of claim 18, wherein the condensate pan
further comprises: a first delta plate support disposed between the
first and second grooves; and a second delta plate support disposed
between the third and fourth grooves.
20. The condensate pan of claim 18, wherein a first section of the
inner wall includes an aperture configured to receive a tab member
of the first delta plate, and wherein a second section of the inner
wall includes an aperture configured to receive a tab member of the
second delta plate.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] The following application is filed on the same day as the
following co-pending applications: "METHOD AND SYSTEM FOR
HORIZONTAL COIL CONDENSATE DISPOSAL" by inventors Arturo Rios,
Floyd J. Frenia, Jason Michael Thomas, Michael V. Hubbard, and
Thomas K. Rembold (attorney docket number U75.12-003); "CASING
ASSEMBLY SUITABLE FOR USE IN A HEAT EXCHANGE ASSEMBLY" by inventors
Floyd J. Frenia, Arturo Rios, Thomas K. Rembold, Michael V.
Hubbard, Jason Michael Thomas, and Stephen R. Carlisle (attorney
docket number U75.12-004); "CONDENSATE PAN INSERT" by inventors
Jason Michael Thomas, Floyd J. Frenia, Thomas K. Rembold, Arturo
Rios, Michael V. Hubbard, and Dale R. Bennett (attorney docket
number U75.12-005); "METHOD AND SYSTEM FOR VERTICAL COIL CONDENSATE
DISPOSAL" by inventors Thomas K. Rembold, Arturo Rios, Jason
Michael Thomas, and Michael V. Hubbard (attorney docket number
U75.12-006); "CASING ASSEMBLY SUITABLE FOR USE IN A HEAT EXCHANGE
ASSEMBLY" by inventors Arturo Rios, Thomas K. Rembold, Jason
Michael Thomas, Stephen R. Carlisle, and Floyd J. Frenia (attorney
docket number U75.12-007); "LOW-SWEAT CONDENSATE PAN" by inventors
Arturo Rios, Floyd J. Frenia, Thomas K. Rembold, Michael V.
Hubbard, and Jason Michael Thomas (attorney docket number
U75.12-008); "VERTICAL CONDENSATE PAN WITH NON-MODIFYING SLOPE
ATTACHMENT TO HORIZONTAL PAN FOR MULTI-POISE FURNACE COILS" by
inventor Arturo Rios (attorney docket number U75.12-010);
"CONDENSATE SHIELD WITH FASTENER-FREE ATTACHMENT FOR MULTI-POISE
FURNACE COILS" by inventor Arturo Rios (attorney docket number
U75.12-011); and "SPLASH GUARD WITH FASTENER-FREE ATTACHMENT FOR
MULTI-POISE FURNACE COILS" by inventor Arturo Rios (attorney docket
number U75.12-012), which are incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to a condensate pan for an
evaporator assembly. More particularly, the present invention
relates to a condensate pan design that is configured to prevent
condensation blow-off in an evaporator assembly.
[0003] In a conventional refrigerant cycle, a compressor compresses
a refrigerant and delivers the compressed refrigerant to a
downstream condenser. From the condenser, the refrigerant passes
through an expansion device, and subsequently, to an evaporator.
The refrigerant from the evaporator is returned to the compressor.
In a split system heating and/or cooling system, the condenser may
be known as an outdoor heat exchanger and the evaporator as an
indoor heat exchanger, when the system operates in a cooling mode.
In a heating mode, their functions are reversed.
[0004] In the split system, the evaporator is typically a part of
an evaporator assembly coupled with a furnace. However, some
cooling systems are capable of operating independent of a furnace.
A typical evaporator assembly includes an evaporator coil (e.g., a
coil shaped like an "A", which is referred to as an "A-frame coil")
and a condensate pan disposed within a casing. An A-frame coil is
typically referred to as a "multi-poise" coil because it may be
oriented either horizontally or vertically in the casing of the
evaporator assembly.
[0005] During a cooling mode operation, a furnace blower circulates
air into the casing of the evaporator coil assembly, where the air
cools as it passes over the evaporator coil. The blower then
circulates the air to a space to be cooled. Depending on the
particular application, an evaporator assembly including a
vertically oriented A-frame coil may be an up flow or a down flow
arrangement. In an up flow arrangement, air circulated upwards,
from beneath the evaporator coil assembly, whereas in a down flow
arrangement, air is circulated downward, from above the evaporator
coil assembly.
[0006] Refrigerant is enclosed in piping that is used to form the
evaporator coil. If the temperature of the evaporator coil surface
is lower than the dew point of air passing over it, the evaporator
coil removes moisture from the air. Specifically, as air passes
over the evaporator coil, water vapor condenses on the evaporator
coil. The condensate pan of the evaporator assembly collects the
condensed water as it drips off of the evaporator coil. The
collected condensation then typically drains out of the condensate
pan through a drain hole in the condensate pan.
BRIEF SUMMARY
[0007] The present invention is an internal corner design of a
condensate pan that is configured to prevent condensation blow-off
in an evaporator assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1A is a perspective view of an evaporator assembly,
which includes an evaporator coil and condensate pan disposed
within a casing.
[0009] FIG. 1B is an exploded perspective view of the evaporator
assembly of is FIG. 1A.
[0010] FIG. 2A is an exploded perspective view of an evaporator
coil slab and the condensate pan of FIG. 1A.
[0011] FIG. 2B is a perspective view of an alternative embodiment
of an evaporator coil slab exploded from the condensate pan.
[0012] FIG. 3 is a cross-sectional view of the evaporator assembly
of FIGS. 1A and 1B.
[0013] FIG. 4 is a top view of the condensate pan.
[0014] FIG. 5 is a cross-sectional view of a corner section of the
evaporator assembly shown in FIG. 3.
[0015] FIG. 6 is a perspective view of a bottom side of the
condensate pan.
[0016] FIG. 7A is a perspective view of a shield.
[0017] FIG. 7B is a side view of the shield of FIG. 7A.
[0018] FIGS. 8A-8B illustrate a first step of attaching the shield
onto a bottom of a coil slab. FIGS. 9A-9B illustrate a second step
of attaching the shield onto the bottom of the coil slab.
[0019] FIGS. 10A-10B illustrate a third step of attaching the
shield onto the bottom of the coil slab.
[0020] FIG. 11A is a perspective view of an alternative embodiment
of a shield.
[0021] FIG. 11B is a side view of the shield of FIG. 11A.
[0022] FIGS. 12A-12B show the shield of FIG. 11A attached onto a
bottom of a coil slab.
[0023] FIG. 13 is a cross-sectional view of the shield of FIG. 11A
attached to a coil slab having three rows of coils.
[0024] FIG. 14 is a perspective view of a condensate pan insert for
the evaporator assembly.
[0025] FIG. 15A is an enlarged perspective view of the evaporator
assembly showing the condensate pan and pan insert.
[0026] FIG. 15B is a sectional view showing the condensate pan
insert secured to a front pan member of the condensate pan.
[0027] FIG. 16 is a perspective view of a corner section of the
evaporator assembly showing a delta plate prior to insertion into a
first corner groove of the condensate pan.
[0028] FIG. 17 is a side view of a corner portion of the delta
plate coupled to a coil slab.
[0029] FIG. 18 is a side view of the corner section of the
evaporator assembly shown and described above in reference to FIG.
16 after the delta plate has been inserted into the first corner
groove.
[0030] FIG. 19A is a front view of a vertical condensate pan.
[0031] FIG. 19B is a front view of the vertical condensate pan of
FIG. 19A coupled to a horizontal condensate pan.
[0032] FIG. 20 is a perspective view of a corner portion of the
vertical condensate pan coupled to the horizontal condensate
pan.
DETAILED DESCRIPTION
The Evaporator Assembly (FIGS. 1A-1B)
[0033] FIG. 1A is a perspective view of evaporator assembly 2,
which includes casing 4, A-frame evaporator coil ("coil") 6, coil
brace 8, first delta plate 10, second delta plate 12, horizontal
condensate pan 14, drain holes 15, vertical condensate pan 16,
drain holes 17, first cover 18, input refrigerant line 20, and
output refrigerant line 22. When evaporator assembly 2 is
integrated into a heating and/or cooling system, evaporator
assembly 2 is typically mounted above an air handler. The air
handler includes a blower that cycles air through evaporator
assembly 2. In a down flow application, the blower circulates air
in a downward direction (indicated by arrow 24) through casing 4
and over coil 6. In an up flow application, the blower circulates
air in an upward direction (indicated by arrow 26) through casing
4.
[0034] Coil 6, condensate pan 14, and condensate pan 16 are
disposed within casing 4, which is preferably a substantially
airtight space for receiving and cooling air. That is, casing 4 is
preferably substantially airtight except for openings 4A and 4B
(shown in FIG. 1B). In a down flow application, air is introduced
into evaporator assembly 2 through opening 4A and exits through
opening 4B. In an up flow application, air is introduced into
evaporator assembly 2 through opening 4B and exits through opening
4A. In the embodiment shown in FIGS. 1A and 1B, casing 4 is
constructed of a single piece of sheet metal that is folded into a
three-sided configuration, and may also be referred to as a
"wrapper". In alternate embodiments, casing 4 may be any suitable
shape and configuration and/or formed of multiple panels of
material.
[0035] Coil 6 is a multi-poise A-frame coil, and may be oriented
either horizontally or vertically. The vertical orientation is
shown in FIGS. 1A and 1B. In a horizontal orientation, casing 4 is
rotated 90.degree. in a counterclockwise direction. Coil brace 8 is
connected to air seal 28 and helps support coil 6 when coil 6 is in
its horizontal orientation.
[0036] Coil 6 includes first slab 6A and second slab 6B connected
by air seal 28. A gasket may be positioned between air seal 28 and
first and second slabs 6A and 6B, respectively, to provide an
interface between air seal 28 and slabs 6A and 6B that is
substantially impermeable to water. First and second delta plates
10 and 12, respectively, are positioned between first and second
slabs 6A and 6B, respectively. First slab 6A includes multiple
turns of piping 30A with a series of thin, parallel plate fins 32
mounted on piping 30A. Similarly, second slab 6B includes multiple
turns of piping 30B with a similar series of thin, parallel fins
mounted on piping 30B. Tube sheet 29A is positioned at an edge of
slab 6A, and tube sheet 29B is positioned at an edge of slab 6B.
Delta plates 10 and 12, and air seal 28, may be attached to tube
sheets 29A and 29B.
[0037] In the embodiment shown in FIG. 1A, coil 6 is a two-row
coil. However, in alternate embodiments, coil 6 may include any
suitable number of rows, such as three, as known in the art.
Refrigerant is cycled through piping 30A and 30B, which are in
fluidic communication with one another (through piping system 62,
shown in FIG. 1B). As FIG. 1A illustrates, coil 6 includes input
and output lines 20 and 22, respectively, which are used to recycle
refrigerant to and from a compressor (which is typically located in
a separate unit from evaporator assembly 2). Refrigerant input and
output lines 20 and 22 extend through first cover 18. Evaporator
assembly 2 also includes access cover 38 (shown in FIG.1B) adjacent
to first cover 18, and together, first cover 18 and access cover 38
fully cover the front face of evaporator assembly 2 (i.e., the face
which includes first cover 18). Access cover 38 will be described
in further detail in reference to FIG. 1B.
[0038] As discussed in the Background section, if the temperature
of coil 6 surface is lower than the dew point of the air moving
across coil 6, water vapor condenses on coil 6. If coil 6 is
horizontally oriented, condensation from coil 6 drips into
condensate pan 14, and drains out of condensate pan 14 through
drain holes 15, which are typically located at the bottom of
condensate pan 14. If coil 6 is vertically oriented, condensate pan
16 collects the condensed water from coil 6, and drains the
condensation through drain holes 17, which are typically located at
the bottom of condensate pan 16.
[0039] Because evaporator assembly 2 includes horizontal condensate
pan 14 and vertical condensate pan 16, evaporator assembly 2 is
configured for applications involving a horizontal or vertical
orientation of coil 6. In an alternate embodiment, evaporator
assembly 2 is modified to be applicable to only a vertical
orientation of coil 6, in which case horizontal condensate pan 14
and brace 8 are absent from evaporator assembly 2. In another
alternate embodiment, evaporator assembly 2 excludes vertical
condensate pan 16 such that evaporator assembly 2 is only
applicable to horizontal orientations of coil 6.
[0040] FIG. 1B is an exploded perspective view of evaporator
assembly 2 of FIG. 1A. Front deck 39 and upper angle 40 are each
connected to casing 4 with screws 41. Another suitable method of
connecting front deck 39 and upper angle 40 to casing 4 may also be
used, such as welding, an adhesive, or rivets. Front deck 39 and
upper angle 40 provide structural integrity for casing 4 and
provide a means for connecting front cover 18 and access cover 38
to casing 4. Screw 43 attaches brace 8 (and thereby, air seal 28)
to condensate pan 14. Of course, other suitable means of attachment
may be used in alternate embodiments. In addition to air seal 28,
air splitter 44 is positioned between first slab 6A and second slab
6B of coil 6 and is attached by tabs on tube sheets 29A and 29B of
coil 6.
[0041] Horizontal and vertical condensate pans 14 and 16 are
typically formed of a plastic, such as polyester, but may also be
formed of any material that may be casted, such as metal (e.g.,
aluminum). Horizontal condensate pan 14 slides into casing 4 and is
secured in position by pan supports 46. Tabs 46A of pan supports 46
define a space for condensate pan 14 to slide into. When coil 6 is
in a horizontal orientation (and casing 4 is rotated about
90.degree. in a counterclockwise direction), coil 6 is positioned
above horizontal condensate pan 14 so that condensation flows from
coil 6 into horizontal condensate pan 14. Air splitter 44 and
splash guards 45A and 45B also help guide condensation from coil 6
into horizontal condensate pan 14.
[0042] Condensation that accumulates in horizontal condensate pan
14 eventually drains out of horizontal condensate pan 14 through
drain holes 15. Gasket 52A is positioned around drain holes 15
prior to positioning first cover 18 over drain holes 15 in order to
help provide a substantially airtight seal between drain holes 15
and first cover 18. First cover 18 includes opening 53A, which
corresponds to and is configured to fit over drain holes 15 and
gasket 52A. The substantially airtight seal helps prevent air from
escaping from casing 4, and thereby increases the efficiency of
evaporator assembly 2. Caps 56A may be positioned over one or more
drain holes 15, such as when evaporator assembly 2 is used in an
application in which coil 6 is vertically oriented.
[0043] Vertical condensate pan 16 slides into casing 4 and is
supported, at least in part, by flange 48, which is formed by
protruding sheet metal on three-sides of casing 4 and top surface
39A of front deck 39. Specifically, bottom surface 16A of
condensate pan 16 rests on flange 48 and top surface 39A of front
deck 39. Condensate pan 16 includes outer perimeter 49, insert 50,
drain holes 17, which are sealed by gasket 52, and plurality of
ribs 54.
[0044] One or more channels are positioned about outer perimeter 49
of vertical condensate pan 16 for receiving condensation from coil
6. In the vertical orientation of coil 6 illustrated in FIGS. 1A
and 1B, coil 6 is positioned above vertical condensate pan 16 to
allow condensation to flow along one slab 6A or 6B and eventually
into one or more of the channels along outer perimeter 49 of
vertical condensate pan 16. In this way, condensation collects in
condensate pan 16. In some applications, such as when coil 6
includes three rows of coils, insert 50 is positioned in condensate
pan 16 to help shield coil 6 from condensate blow-off from
condensate pan 16.
[0045] Evaporator assembly 2 includes features, such as ribs 54 and
shield 58, that are configured to help direct condensation into the
one or more channels along outer perimeter 49 of vertical
condensate pan 16 (when coil 6 is vertically oriented). Shield 58
is attached to tube sheet 29A and is configured to both guide
condensation into a channel along outer perimeter 49 of condensate
pan 16 and help protect coil 6 from condensation blow-off, which
occurs when condensation that is collected in condensate pan 16 is
blown into the air stream moving through evaporator assembly 2. A
similar shield is attached to tube sheet 29B.
[0046] Condensation that accumulates in vertical condensate pan 16
eventually drains out of vertical condensate pan 16 through drain
holes 17. Gasket 52B is positioned around drain holes 17 prior to
positioning first cover 18 over drain holes 17 in order to help
provide a substantially airtight seal between drain holes 17 and
first cover 18. First cover 18 includes opening 53B, which
corresponds to and is configured to fit over drain holes 17 and
gasket 52B. The airtight seal helps prevent air from escaping from
casing 4, and thereby increases the efficiency of evaporator
assembly 2. Cap 56B may be positioned over one or more drain holes
17.
[0047] Piping system 62 fluidically connects piping 30A of first
slab 6A and piping 30B of second slab 6B. Refrigerant flows through
piping 32 and 30B, and is recirculated from and to a compressor
through inlet and outlet tubes 20 and 22, respectively.
Specifically, refrigerant is introduced into piping 30A and 30B
through inlet 20 and exits piping 30A and 30B through outlet 22. As
known in the art, refrigerant inlet 20 includes rubber plug 64, and
refrigerant outlet 22 includes strainer 66 and rubber plug 68.
Inlet 20 protrudes through opening 70 in first cover 18 and outlet
22 protrudes through opening 72 in first cover 18. By protruding
through first cover 18 and out of casing 4, inlet 20 and outlet 22
may be connected to refrigerant lines that are fed from and to the
compressor, respectively. Gasket 74 is positioned around inlet 20
in order to provide a substantially airtight seal around opening
70. Similarly, gasket 76 is positioned around outlet 22.
[0048] First cover 18 is attached to casing 4 with screws 78.
However, in alternate embodiments, other means of attachment are
used, such as welding, an adhesive, or rivets. Further covering a
front face of evaporator assembly 2 is access cover 38, which is
abutted with first cover 18. Again, in order to help increase the
efficiency of evaporator assembly 2, it is preferred that joint 81
between first cover 18 and access cover 38 is substantially
airtight. A substantially airtight connection may be formed by, for
example, placing a gasket at joint 81.
[0049] Access cover 38 is attached to casing 4 with screws 82.
However, in alternate embodiments, any means of removably attaching
access cover 38 to casing 4 are used. Access cover 38 is preferably
removably attached in order to provide access to coil 6, condensate
pan 16, and other components inside casing 4 for maintenance
purposes. One or more labels 84, such as warning labels, may be
placed on first cover 18 and/or access cover 38.
The Condensation Collection Process (FIGS. 2A and 2B)
[0050] FIG. 2A is an exploded perspective view of evaporator coil 6
and condensate pan 16 of FIG. 1A in a vertical orientation. As
shown in FIG. 2A, coil slab 6B is removed for purposes of clarity
and discussion. FIG. 2A also includes shield 58A and tube sheet
29A, which is attached to an edge of slab 6A. A similar tube sheet
is also attached on an opposing edge of slab 6A.
[0051] When the temperature of coil slab 6A is lower than the dew
point of the air moving across slab 6A, water vapor will condense
on slab 6A. The condensation flows in a downward direction, due to
gravity, along coil slab 6A toward shield 58A, as indicated by
arrow 86. Shield 58A includes a plurality of apertures 88 aligned
to be offset from a plurality of primary channels 90 disposed
between ribs 54 of condensate pan 16. Apertures 88 are configured
to help direct the condensation from coil slab 6A onto ribs 54 and
then into primary channels 90. A similar plurality of primary
channels 92 are located on an opposing side of condensate pan 16.
The condensation in primary channels 90 is then directed into one
of the channels along outer perimeter 49 of condensate pan 16, and
eventually drained out of condensate pan 16 through drain holes
17.
[0052] In the embodiment shown in FIG. 2A, there are eight ribs 54
on each side of condensate pan 16. However, a condensate pan that
includes more or less ribs is possible.
[0053] Although the above discussion focused on condensation
draining from coil slab 6A, coil slab 6B is positioned within
evaporator assembly 2 to allow condensation formed on slab 6B to
drain in a similar manner. Thus, FIG. 2A refers to coil slab 6A
merely for purposes of example.
[0054] FIG. 2B is a perspective view of an alternative embodiment
of an evaporator coil exploded from condensate pan 16. As shown in
FIG. 2B, coil slab 6A' has three rows of coils, and shield 58A' is
configured to engage with the wider three row coil slab. However,
condensation formed on coil slab 6A' is collected in condensate pan
16 in a similar manner as described above in reference to FIG. 2A.
It should be understood that an evaporator coil slab having any
number of coils may be incorporated into evaporator assembly 2.
Low-Sweat Condensate Pan 16 (FIGS. 3-6)
[0055] FIG. 3 is a cross-sectional view of evaporator assembly 2
showing coil 6 coupled to condensate pan 16. In FIG. 3, shield 58A
is coupled to tube sheet 29A, and shield 58B (which is similar to
shield 58A) is coupled to tube sheet 29B. First coil slab 6A and
second coil slab 6B engage with and are supported by ribs 54 of
condensate pan 16 such that slabs 6A and 6B form an angle A with
condensate pan 16. The angled position of coil 6 allows
condensation to drip down a side of a slab, as indicated by arrow
94 on first slab 6A. As discussed above, shields 58A and 58B are
configured to catch and drain the condensation as it drips or flows
down slabs 6A and 6B. Shields 58A and 58B will be discussed in more
detail below, starting with reference to FIG. 7A.
[0056] Condensate pan 16 is supported by flanges 48 of casing 4. In
addition to providing support for condensate pan 16, flanges 48
create an air pocket P to prevent streams of unconditioned air
flowing in direction 26 (an upflow direction) from coming into
contact with one or more channels located along outer perimeter 49,
as will be discussed in more detail below.
[0057] FIG. 4 is a top view of vertical condensate pan 16 shown and
described above in reference to FIGS. 1A and 1B. Condensate pan 16
includes right pan member 100, left pan member 102, front pan
member 104, and rear pan member 106. As shown in FIG. 4, right pan
member 100 and left pan member 102 are positioned substantially
parallel to each other. Furthermore, right pan member 100 and left
pan member 102 are substantially perpendicular to both front pan
member 104 and rear pan member 106. Thus, pan members 100-106 form
a generally rectangular structure with an open center portion. In
addition, right pan member 100 and front pan member 104 intersect
to form first internal corner 101; left pan member 102 and front
pan member 104 intersect to form second internal corner 103; right
pan member 100 and rear pan member 106 intersect to form third
internal corner 105; and left pan member 102 and rear pan member
106 intersect to form fourth internal corner 107.
[0058] Outer perimeter 49 of condensate pan 16 includes secondary
channel 108 disposed along outer wall 110 of right pan member 100,
secondary channel 112 disposed along outer wall 114 of left pan
member 102, and drain channel 116 disposed along front side 118 of
front pan member 104. Secondary channels 108 and 112 are configured
to receive condensation from primary channels 90 and 92,
respectively. Furthermore, secondary channels 108 and 112 are
connected to drain channel 116, which allows condensation collected
in secondary channels 108 and 112 to flow into drain channel 116
for disposal through condensate drain holes 17. To direct the flow
of condensation from secondary channels 108 and 112 into drain
channel 116, secondary channels 108 and 112 are sloped toward front
pan member 104. As shown in FIG. 4, drain holes 17 are positioned
along front side 118 of front pan member 104, although drain holes
17 may be positioned anywhere that enables condensation to exit
condensate pan 16.
[0059] Although placing a secondary or drain channel in rear pan
member 106 is not necessary to properly drain the condensation in
evaporator assembly 2, a rear pan member may be designed to also
include a channel to catch condensation from coil 6. Rear pan
member 106 shown in FIG. 4 is an example of such a pan member.
However, even though a rear pan member may not include a channel,
it is still an important component of a condensate pan for other
reasons including, but not limited to, providing rigidity to the
pan and providing a surface capable of receiving and supporting a
delta plate.
[0060] As shown in FIG. 4, condensate pan 16 also includes first
corner groove 120, second corner groove 122, third corner groove
124, and fourth corner groove 126. First corner groove 120 and
second corner groove 122 are each configured to receive a portion
of delta plate 12, while third corner groove 124 and fourth corner
groove 126 are each configured to receive a portion of a second
delta plate similar to delta plate 12. In addition, condensate pan
16 includes a first plurality of delta plate supports 125A disposed
within front pan member 104, and a second plurality of delta plate
supports 125B disposed within rear pan member 106. Delta plate
supports 125A and 125B help to align and provide support for their
respective delta plates when inserted into condensate pan 16.
Although FIG. 4 shows condensate pan 16 with five delta plate
supports 125A and five delta plate supports 125B, a condensate pan
with any number of delta plate supports is possible.
[0061] Typically, sweat from the cold condensation forms on an
underside of a condensate pan because streams of unconditioned air
being blown through an evaporator assembly are at a higher
temperature than the cool condensation collected in the condensate
pan. If the unconditioned air is allowed to contact a surface of
the pan that contains the cool condensation (such as the secondary
channels), heat will transfer from the warmer unconditioned air to
the cool pan surface, causing sweat to form on the condensate pan.
Thus, in order to reduce sweat from an underside of the condensate
pan, condensation must be quickly re-directed away from streams of
unconditioned air that are contacting the underside of the pan.
[0062] FIG. 5 is a cross-sectional view of a corner section of the
evaporator assembly shown in FIG. 3. As shown in FIG. 5, right pan
member 100 further includes inner wall 127, outer air pocket wall
128, and inner air pocket wall 130. Outer air pocket wall 128 and
inner air pocket wall 130 extend in a downward direction from
bottom side 132 of right pan member 100 along a longitudinal length
of right pan member 100. When condensate pan 16 is removed from
evaporator assembly 2, such as in FIG. 1B, secondary channel 108 is
open to streams of unconditioned air U. However, when properly
positioned within casing 4 as shown in FIG. 5, flange 48 mates with
outer air pocket wall 128 and inner air pocket wall 130 to create
air pocket P. Thus, flange 48 creates a barrier between streams of
unconditioned air U and secondary channel 108.
[0063] In the embodiment shown in FIG. 5, primary channels 90 are
sloped toward secondary channel 108 from inner wall 127 to outer
wall 110 of right pan member 100. As condensation from first coil
slab 6A drips in a downward direction toward condensate pan 16, the
condensation is directed into right pan member 100 by shield 58A.
As discussed above in reference to FIG. 2A, the apertures in shield
58A are configured to provide a path for the condensation into
primary channels 90. The sloped primary channels 90 quickly direct
the condensation toward outer wall 100 and into secondary channel
108, as indicated by a condensation path depicted by arrows 134. As
a result, a pool of cold condensation C is created in secondary
channel 108. As discussed above in reference to FIG. 4, secondary
channel 108 is sloped toward front pan member 104 to quickly direct
cold condensation into drain channel 116. Furthermore, drain
channel 116 is also sloped in a downward direction from right pan
member 100 to left pan member 102 to direct the condensation toward
drain holes 17. By providing a series of sloped channels, the
condensation may be quickly removed from condensate pan 16.
[0064] The design of condensate pan 16 reduces the formation of
sweat on an underside of condensate pan 16 by quickly re-directing
the condensation toward secondary channel 108 along outer wall 100,
and providing air pocket P between streams of unconditioned air U
and the pool of cold condensation C. In particular, flange 48 of
casing 4 prevents streams of unconditioned air U from reaching
secondary channel 108. Air pocket P prevents (or at least slows
down) the transfer of heat from the warmer streams of unconditioned
air to the cooler surface of secondary channel 108 caused by cold
condensation C present in channel 108. As a result of quickly
directing condensation toward an outer portion of condensate pan 16
that is shielded from warm streams of unconditioned air, the
formation of sweat on condensate pan 16 is reduced.
[0065] Although the above discussion in reference to FIG. 5 focused
on right pan member 100, left pan member 102 includes similar
features to reduce the formation of sweat on condensate pan 16.
Thus, it should be understood that the discussion above applies in
the same manner (except for the element numbers) to left pan member
102 as well.
[0066] FIG. 6 is a perspective view of a bottom side of one
embodiment of condensate pan 16. In the embodiment shown in FIG. 6,
the bottom side of right pan member 100 further includes a
plurality of support members 138 perpendicular to and extending
between inner air pocket wall 130 and outer wall 110. A bottom side
of left pan member 102 includes a similar plurality of support
members. Support members 138 provide rigidity to right pan member
100, and are configured to mate with flange 48 in casing 4 to
support condensate pan 16 and prevent a stream of unconditioned air
from contacting a bottom side of secondary channel 108.
[0067] Although the above discussion has focused on a condensate
pan for use with coil slabs containing two rows of coils, the
condensate pan may also be used with coil slabs containing more
than two rows of coils. Furthermore, although a preferred material
for the construction of condensate pan 16 is a plastic, such as
polyester, other materials such as metals may also be used.
Shields 58A and 58B (FIGS. 7A-13)
[0068] Shields 58A and 58B are useful in both down flow and up flow
arrangements of evaporator assembly 2; however, shields 58A and 58B
are of particular benefit in a down flow arrangement in which air
is circulated downward (indicated by arrow 24 in FIG. 1A) from
above evaporator assembly 2. Water (i.e., condensate) blow-off from
coil 6 is more likely in a down flow arrangement of evaporator
assembly 2. Shields 58A and 58B are configured to help address
potential problems attributable to water blow-off by substantially
enclosing condensation that drips off of coil 6, and directing the
condensation into condensate pan 16.
[0069] FIG. 7A is a perspective view of shield 58A of FIG. 2A.
Shield 58A is configured to wrap around a bottom of coil slab 6A
and couple with tube sheet 29A. Shield 58A includes bottom member
150 having inside bottom portion 151 and outside bottom portion
152, inside extension member 154, and outside extension member 156.
Inside bottom portion 151 includes apertures 88 described above in
reference to FIG. 2A. Outside extension member 156 includes lip 158
having tabs 159A and 159B extending from opposing ends. When shield
58A is coupled to a bottom of coil slab 6A, slab 6A and shield 58A
are angled such that, as the condensation drains into shield 58A,
it is directed toward inside extension member 154 and drains
through apertures 88.
[0070] Apertures 88 are spaced apart along inside bottom portion
151, and are configured to allow the condensation to drain through
bottom member 150 of shield 58A. In the embodiment shown in FIG.
7A, apertures 88 are slots that extend across inside bottom portion
151; however, it is recognized that shield 58A could be designed
with various other types of apertures or openings formed on bottom
member 150 of shield 58A. As shown in FIG. 7A, shield 58A has nine
apertures 88. However, shield 58A may be designed with more or less
apertures.
[0071] Bottom portion 150 is configured to be positioned under a
bottom end of coil slab 6A. Inside extension member 154 is
configured to be positioned on an inside surface of coil slab 6A.
Outside extension member 156 is configured to be positioned on an
outside surface of coil slab 6A. Tabs 159A and 159B, extending from
lip 158 of outside extension member 156, are configured to engage
with tube sheet 29A and a similar tube sheet on an opposing edge of
coil slab 6A.
[0072] FIG. 7B is a side view of shield 58A of FIG. 7A showing
bottom member 150, inside extension member 154 and outside
extension member 156 including lip 158. As shown in FIG. 7B, inside
bottom portion 151 is oriented at a slight angle relative to
outside bottom portion 152, such that inside bottom portion 151
slopes downward toward inside extension member 154. FIGS. 8A-10B
illustrate general steps in one system and method for attaching
shield 58A onto a bottom of coil slab 6A. FIG. 8A shows tube sheet
29A, which is attached to an edge of coil slab 6A, and positioned
above shield 58A. FIG. 8B is a rotated view of FIG. 8A showing coil
slab 6A (including fins 32A and piping 30A) and shield 58A
(including outside extension member 156 and tabs 159A and
159B).
[0073] Specifically, FIGS. 8A and 8B depict a first step of
attaching shield 58A onto a bottom surface of coil slab 6A. As
shown in FIGS. 8A and 8B, shield 58A is initially positioned below
a bottom of coil slab 6A. Shield 58A is then moved upward toward
coil slab 6A, as indicated by arrows 164.
[0074] FIGS. 9A and 9B depict a second step of attaching shield 58A
onto coil slab 6A. As shown in FIGS. 9A and 9B, shield 58A has
moved upward such that inside extension member 154 is slid onto an
inner side of coil slab 6A, and outside extension member 156 has
moved upward such that lip 158 is near notch 166 on tube sheet 29A.
Notch 166 on tube sheet 29A is configured to receive tab 159A
extending from lip 158. A similar notch on the opposing tube sheet
is similarly configured to receive tab 159B extending from the
other end of lip 158.
[0075] FIGS. 10A and 10B depict a third step of attaching shield
58A onto coil slab 6A. As shown in FIGS. 10A and 10B, shield 58A
has been moved upward such that the bottom surface of coil slab 6A
is resting on outside bottom portion 152 of shield 58A. Outside
extension member 156 is positioned such that lip 158 contacts fins
32A and tab 159A of lip 158 is received through notch 166 on tube
sheet 29A. Similarly, tab 159B is received through the notch on the
opposing tube sheet. Inside extension member 154 is contacting a
set of fins, similar to fins 32A, on the inside surface of coil
slab 6A. As described above in reference to FIG. 7B, inside bottom
portion 151 is angled relative to outside bottom portion 152. Thus,
inside bottom portion 151 is angled relative to the bottom surface
of slab 6A, as shown in FIG. 10A. As such, apertures 88 of shield
58A are visible in FIG. 10B.
[0076] Inside extension member 154 and outside extension member 156
are configured to flex during attachment onto coil slab 6A,
particularly during steps two and three described above under FIGS.
9A-9B and 10A-10B. Shield 58A is designed to spring-fit onto coil
slab 6A such that inside extension member 154 and outside extension
member 156 open up and then spring back toward their original
configuration once shield 58A is attached on coil slab 6A.
[0077] In the preferred embodiment of shield 58A described above,
shield 58A is attachable to coil slab 6A without requiring any
fasteners. However, it is recognized that shield 58A and coil slab
6A may be designed to incorporate other suitable means of attaching
shield 58A to coil slab 6A using, for example, screws, rivets or
other types of fasteners.
[0078] Referring back to FIG. 5, coil slab 6A and shield 58A are
shown coupled to condensate pan 16. As explained above in reference
to FIG. 3, coil slab 6A and shield 58A are supported by ribs 54 of
condensate pan 16 such that coil slab 6A and shield 58A are
oriented at an angle relative to condensate pan 16. As explained
above in reference to FIG. 2A, apertures 88 on inside bottom
portion 151 of shield 58A are aligned with ribs 54 of condensate
pan 16. In FIG. 5, bottom member 150 is substantially flat, despite
inside bottom portion 151 being originally configured at a slight
angle relative to outside bottom portion 152, as shown in FIG. 7B.
When coil slab 6A and shield 58A are coupled to pan 16, inside
bottom portion 151 is brought closer into alignment with outside
bottom portion 152 due to contact with ribs 54.
[0079] Due to the angle of coil slab 6A and shield 58A relative to
condensate pan 16, as the condensation drips down slab 6A and into
shield 58A, the condensation is directed toward inside extension
member 154 and then through apertures 88. After the condensation
drains through apertures 88 of inside bottom portion 151, the
condensation flows onto ribs 54 and into primary channels 90.
[0080] Primary channels 90 are sloped downward such that the
condensation will automatically flow into secondary channel 108
disposed along outer wall 110 of right pan member 100. Shield 58A
is typically formed from a thin, single sheet of metal. In one
embodiment, shield 58A is made from aluminum to prevent corrosion.
However, other materials may be used without diminishing the
functionality of shield 58A.
[0081] Shield 58B, shown in FIG. 3, is similar to shield 58A and is
attachable to second coil slab 6B in a similar manner to how shield
58A is attachable to coil slab 6A. Shield 58B is configured to
drain condensation from second coil slab 6B into primary channels
92 on an opposing side of condensate pan 16 (see FIG. 4).
[0082] FIG. 11A is a perspective view of shield 58A', which is an
alternative embodiment of shield 58A of FIG. 7A. Shield 58A' is
shown in FIG. 2B and is configured to engage with coil slab 6A'
which is a wider three row coil slab. Shield 58A' similarly
includes bottom member 150' having inside bottom portion 151' and
outside bottom portion 152', inside extension member 154', and
outside extension member 156'. Lip 158' is connected to outside
extension member 156' and includes tabs 159A' and 159B' extending
from opposing ends.
[0083] Similar to shield 58A, bottom member 150' of shield 58A'
includes apertures 88'. Apertures 88' are spaced apart along inside
bottom portion 151' and each aperture 88' extends across inside
bottom portion 151'. However, in shield 58A', a different type of
aperture is used, as compared to shield 58A, to direct the
condensation toward inside extension member 154' and then out
through bottom member 150'.
[0084] In this embodiment, apertures 88' formed on inside bottom
portion 151' of shield 58A' comprise a plurality of shield
channels. As shown in FIG. 2B, when shield 58A' is assembled on
coil slab 6A', the shield channels are aligned with primary
channels 90 of condensate pan 16 and are configured to drain the
condensation out of shield 58A' and into condensate pan 16. It
should be understood that shield channels are merely one example of
an aperture design that may be used to direct condensation from a
coil slab into a condensate pan. Moreover, shield 58A' of FIG. 1A
is shown with eight shield channels formed on inside bottom portion
151; however, it is recognized that more or less shield channels
may incorporated into shield 58A'.
[0085] FIG. 11B is a side view of shield 58A' of FIG. 11A showing
bottom member 150', inside extension member 154', outside extension
member 156', and lip 158'. As described above, apertures 88' are
shield channels and are configured to extend below bottom member
150'.
[0086] FIGS. 12A and 12B show shield 58A' attached onto a bottom
surface of coil slab 6A'. Shield 58A' is attached onto coil slab
6A' in a similar manner as described above under FIGS. 8A-10B in
reference to attachment of shield 58A onto coil slab 6A.
[0087] As shown in FIGS. 12A and 12B, tab 159A' on lip 158' is
inserted through notch 166' on tube sheet 29A'. Tab 159B' is
inserted through a similar notch on an opposing tube sheet. When
shield 58A' is attached on coil slab 6A, a bottom surface of coil
slab 6A' rests on bottom portion 150'. Apertures 88' are configured
to extend below bottom member 150' of shield 58A'. FIG. 13 is a
cross-sectional view of shield 58A' of FIG. 11A attached to coil
slab 6A' and coupled to condensate pan 16. Again, shield 58A' is
configured such that the condensation that drains into shield 58A'
is directed toward inside extension portion 154' and then through
apertures 88'. Apertures 88' are aligned with primary channels 90
of condensate pan 16 such that the condensation drains is through
apertures 88' into primary channels 90. The condensation is then
drained out of condensate pan 16 in the same manner as described
above.
[0088] A shield similar to shield 58A' is attachable to a second
coil slab of evaporator assembly 2 in a similar manner.
[0089] In the preferred embodiments described above, shield 58A is
configured to be attached to a coil slab with two rows of coils,
and shield 58A' is configured to be attached to a coil slab with
three rows of coils. Moreover, apertures 88 of shield 58A are
described as being configured to align with ribs 54 of condensate
pan 16, whereas apertures 88' of shield 58A' are described as being
configured to align with primary channels 90 of condensate pan 16.
However, it is recognized that either embodiment of shields 58A and
58A' could be used with a coil having any suitable number of rows.
Similarly, either shield design could be configured to align with
either ribs 54 or primary channels 90 of condensate pan 16.
Additionally, the shields described above are configured to be used
with multiple coil sizes.
Condensate Pan Insert 50 (FIGS. 14, 15A, and 15B)
[0090] FIG. 14 is a perspective view of a representative embodiment
of condensate pan insert 50, which includes cover member 170, pan
wall member 172, snap member 174, first wing member 176, and second
wing member 178. Cover member 170 has first end 180, second end
182, front side 184, and rear side 186. As shown in FIG. 14, pan
wall member 172 is positioned at front side 184, first wing member
176 is positioned at first end 180, and second wing member 178 is
positioned at second end 182 of cover member 170.
[0091] When inserted into condensate pan 16 as shown in FIG. 1B,
condensate pan insert 50 is configured to cover an open top of
drain channel 116, thereby enclosing drain channel 116 to prevent a
stream of air from contacting the condensation collected in
condensate pan 16. Without condensate pan insert 50 positioned
within condensate pan 16, evaporator assembly 2 is more susceptible
to condensation blow-off. Condensation blow-off occurs when
condensation that is collected in condensate pan 16 is blown into
the air stream moving through evaporator assembly 2. As a result,
condensation may be blown into the furnace or surrounding
duct-work, potentially leading to problems such as moisture
build-up or mold.
[0092] Although FIGS. 1A and 1B depict evaporator assembly 2 having
coil 6 with only two rows of coils, condensate pan insert 50 is
particularly useful in an embodiment where coil 6 has three or more
rows of coils. In general, when evaporator assembly 2 is operating
in a down flow application, a larger number of coil rows correlates
with a larger velocity of a stream of air circulated by the blower
in the downward direction (as indicated by arrow 24 in FIG. 1A). As
a result of the increased velocity, there is a greater chance that
the stream of air will hit drain channel 116 and prevent
accumulated condensation from flowing properly from secondary
channels 108 and 112 into drain channel 116, thereby leading to
condensation blow-off.
[0093] A first air gap is formed between first coil slab 6A and
secondary channel 108 when evaporator assembly 2 is fully
assembled. Similarly, a second air gap is formed between second
coil slab 6B and secondary channel 112 when evaporator assembly 2
is fully assembled. When condensate pan insert 50 is properly
secured to front pan member 104, first wing member 176 and second
wing member 178 are configured to be inserted into the first and
second air gaps, respectively. Once inserted into the air gaps,
first wing member 176 and second wing member 178 function with
cover member 170 to prevent a stream of air from entering secondary
channel 108, secondary channel 112, or drain channel 116 during a
down flow application of evaporator system 2. Thus, in the
embodiment shown in FIG. 14, first wing member 176 and second wing
member 178 act together with cover member 170 to prevent
condensation blow-off during a down flow application of evaporator
system 2.
[0094] In other embodiments of evaporator system 2, the coil slabs
and the secondary channels may couple with each other in such a way
that the first and second air gaps are eliminated, thereby
preventing a stream of air from entering the secondary channels
without the need for the wing members. Therefore, in such
embodiments, first wing member 176 and second wing member 178 are
not a necessary part of condensate pan insert 50.
[0095] As shown in FIG. 15A, front side 118 of front pan member 104
includes a recess 192 along a top edge 194. When properly secured
to front pan member 104 of condensate pan 16, pan wall member 172
mates with recess 192 in front pan member 104 to form a portion of
front side 118. In particular, angled contour 188 of pan wall
member 172 mates with an angled contour of recess 192 to create a
substantially smooth and continuous top edge 194 on front side 118
of front pan member 104.
[0096] Furthermore, condensate pan insert 50 may include one or
more raised arch portions 190 as shown in FIG. 14. In some
embodiments of condensate pan 16, drain holes 17 may extend higher
(closer toward top edge 194 of front pan member 104) along front
side 118 than drain channel 116. As a result, a portion of drain
holes 17 would not be protected by cover member 170 of condensate
pan insert 50. Thus, raised arch portions 190 are positioned along
front side 184 of cover member 170 and are configured to receive
and provide a cover for drain holes 17.
[0097] FIG. 15B is a side view of condensate pan insert 50 secured
to front pan member 104. As shown in FIG. 15B, when properly
positioned within condensate pan 16, cover member 170 extends
between front side 118 and surface 196 of front pan member 104 to
enclose an otherwise open side of drain channel 116. Condensate pan
insert 50 thus forms a barrier between a stream of air A above
cover member 170 and condensation C collected in drain channel 116
below cover member 170.
[0098] Snap member 174 further comprises lip 198 that engages with
bottom edge 200 of front side 118 to secure condensate pan insert
50 to front pan member 104. Lip 198 ensures that condensate pan
insert 50 remains securely fastened to front pan member 104 during
shipment and operation of evaporator assembly 2. In other
embodiments, lip 198 engages with another feature of front side 118
other than bottom edge 200. For example, front pan member 104 may
include a slot configured to receive lip 198 to securely fasten
condensate pan insert 50 to condensate pan 16. Other means of
attachment are also available for securing condensate pan insert 50
to condensate pan 16.
[0099] Cover member 170 of condensate pan insert 50 may include top
surface 202 that is sloped in a downward direction between front
side 118 and rear side 204 of front pan member 104. A sloped top
surface 202 directs condensation that drips onto cover member 170
during the operation of evaporator assembly 2 (such as from
blow-off as discussed above) toward rear side 204 of front pan
member 104, as indicated by arrow 205. Additionally, cover member
170 may be designed such that when cover member 170 engages with
surface 196 of front pan member 104, gap 206 is formed. Gap 206
allows condensation that dripped onto cover member 170 and was
directed toward rear side 204 (as shown by arrow 205) to be
re-directed onto surface 196, which may be sloped in a downward
direction toward drain channel 116. As a result, the condensation
eventually flows into drain channel 116, as indicated by arrow 208.
Although sloped top surface 202 and gap 206 are not a necessary
component of condensate pan insert 50, they provide an additional
benefit that increases the effectiveness of the insert. For
instance, in an embodiment that does not incorporate sloped top
surface 202 and gap 206, condensation that drips onto cover member
170 may end up being blown into the furnace or duct-work, resulting
in problems such as those previously discussed.
[0100] A preferred material for manufacturing condensate pan insert
50 is a plastic, such as polycarbonate. However, condensate pan
insert 50 may be formed from other materials, such as various types
of metal including sheet metal or aluminum. In addition, condensate
pan insert 50 is preferably injection molded to form a single part.
Alternatively, the various components of condensate pan insert 50
(such as right pan member 100, left pan member 102, front pan
member 104, and rear pan member 106) may be formed as separate
parts and secured together by means such as welding or gluing.
Internal Corner Feature of Condensate Pan 16 (FIGS. 16-18)
[0101] In typical evaporator assemblies, a gap is formed on the
four internal corners of the condensate pan where the delta plate
and the coil slab engage with the condensate pan. These gaps are
generally due to round radii on the internal corners of the
condensate pan to improve strength. In down flow applications,
streams of high velocity air pass by the gap, with some of these
high velocity streams entering the gap. This poses a problem
because the air streams may get in between the coil slab and the
condensate pan. As a result, condensation on the coil slab or
condensate pan may get caught-up in the streams of high velocity
air between the slab and the pan and end up being blown-off of
those surfaces. Condensation blow-off due to high velocity air
entering these gaps is undesirable because the condensation that is
blown-off of the coil slab or condensate pan cannot be controlled,
and as a result, it may be carried into the furnace or duct-work by
the air streams. Among other things, blown-off condensation may
harm the furnace components or result in moisture build-up or mold
formation in the furnace or duct-work. The design of condensate pan
16 reduces condensation blow-off by placing a corner groove member
in each of the internal pan corners in order to eliminate the gap
and prevent streams of high velocity air from getting in between
the coil slab and condensate pan.
[0102] FIG. 16 is a perspective view of a corner section of
evaporator assembly 2 showing delta plate 12 prior to insertion
into first corner groove 120. First corner groove 120 includes
first rib 220 and second rib 222. First rib 220 and second rib 222
are spaced apart and configured to receive delta plate 12. As shown
in FIG. 16, first corner groove 120 forms a portion of one of ribs
54 near first internal corner 101. Once evaporator assembly 2 is
assembled as shown in FIG. 1A, a portion of delta plate 12 will be
positioned within first corner groove 120, thereby preventing the
formation of a gap near first internal corner 101.
[0103] As shown in FIG. 16, condensate pan 16 includes aperture 224
configured to receive tab 226 of delta plate 12. Tab 226 of delta
plate 12 is configured to be inserted into aperture 224 to secure
delta plate 12 to condensate pan 16. Delta plate supports 125A are
configured to align delta plate 12 within condensate pan 16 and
provide support so that tab 226 is not inadvertently removed from
aperture 224. Furthermore, delta plate supports 125A may be
configured to support delta plate 12 so that an inner surface of
delta plate 12 remains substantially flush with inner wall 204.
[0104] Although FIG. 16 focuses on first corner groove 120, the
other corner grooves of condensate pan 16 also include a pair of
ribs spaced apart and configured to receive a portion of a delta
plate to reduce condensation blow-off. For instance, third corner
groove 124 and fourth corner groove 126 each include a pair of ribs
configured to receive a delta plate similar to delta plate 12. In a
preferred embodiment, all of the corner grooves are constructed
from the same material as condensate pan 16. However, in the
alternative, other materials may be used to create corner grooves
120-126.
[0105] FIG. 17 is a side view of a corner portion of delta plate 12
and coil slab 6A. Delta plate 12 further includes bottom edge 228
and corner 230. As shown in FIG. 17, bottom edge 228 of delta plate
12 extends below a bottom edge 232 of coil slab 6A. Positioning
bottom edge 228 below coil slab 6A allows corner 230 and a portion
of bottom edge 228 to be inserted into first corner groove 120
between first rib 220 and second rib 222, as will be shown in the
following figure.
[0106] FIG. 18 is a side view of the corner section of evaporator
assembly 2 shown and described above in reference to FIG. 16. As
shown in FIG. 18, coil 6 has been coupled to condensate pan 16 such
that coil slab 6A is resting on and being supported by ribs 54, and
a portion of delta plate 12 is positioned within first corner
groove 120. In particular, first corner groove 120 is configured to
receive delta plate 12 in such a way that corner 230 and a portion
of bottom edge 228 are disposed within first corner groove 120, as
indicated by the broken lines within rib 54. When delta plate 12 is
properly positioned within first corner groove 120, all major gaps
or openings are eliminated in first internal corner 101 of
condensate pan 16. Thus, because the gaps and openings are
eliminated, streams of high velocity air are no longer able to
bypass delta plate 12 and get in between coil slab 6A and
condensate pan 16. As a result, condensation blow-off from the
internal corners of condensate pan 16 is reduced or eliminated.
Non-Modifying Slope Attachment of Condensate Pan 14 to Condensate
Pan 16 (FIGS. 19A, 19B, and 20)
[0107] In a multi-poise A-coil such as that shown and described
above in reference to FIGS. 1A and 1B, a horizontal condensate pan
is used to collect condensation coming off of an evaporator coil
during a horizontal application of an evaporator assembly, and a
vertical condensate pan is used to collect condensation coming off
of the coil during a vertical application of the evaporator
assembly. In general, the horizontal and vertical condensate pans
form an "L" when they are assembled together within a casing of the
evaporator assembly. Although evaporator assemblies may be
assembled to include only a horizontal or a vertical condensate pan
(as discussed in reference to FIG. 1A), assembling the evaporator
assembly with both condensate pans makes the assembly more
universal by allowing use in both vertical and horizontal
applications.
[0108] FIG. 19A is a front view of vertical condensate pan 16 of
evaporator assembly 2 resting on surface S. As shown in FIG. 19A, a
bottom side of left pan member 102 includes notch 240. Notch 240
extends along the bottom side of left pan member 102, and is
configured to receive a bottom wall of horizontal condensate pan 14
when evaporator assembly 2 is assembled to include both pans 14 and
16 within casing 4. In a preferred embodiment of condensate pan 16,
notch 240 is about 3 millimeters wide, which correlates with a
typical thickness of a condensate pan wall.
[0109] FIG. 19B is a front view of vertical condensate pan 16
coupled to horizontal condensate pan 14. As shown by the broken
lines within bottom portion 242 of condensate pan 14, pan 14 is
configured to receive condensate pan 16 such that a portion of left
pan member 102 is resting on an inner pan wall within bottom
portion 242 of condensate pan 14. Recess 244 is configured to allow
condensate pan 16 to nest within condensate pan 14 in such a way
that right side 246 of pan 14 does not interfere with drain holes
17.
[0110] As shown in FIG. 19B, when condensate pans 14 and 16 are
coupled together, pan 16 remains in the exact same position
relative to surface S as it did prior to being coupled with pan 14
(FIG. 19A). This is an improvement over prior art designs in which
coupling a vertical condensate pan with a horizontal condensate pan
results in a bottom surface of the vertical condensate pan being
angled relative to a surface below. An angled position of the prior
art condensate pan modifies the slopes of channels within the pan,
potentially creating drainage problems such as stagnation or
accumulation of the collected condensation.
[0111] Evaporator assembly 2 is designed in such a way that
horizontal condensate pan 14 and vertical condensate pan 16 may be
coupled together without changing the slope of any condensate pan
channels. As discussed previously in reference to FIGS. 3-6,
vertical condensate pan 16 is designed for minimum condensation
retention and quick drainage in vertical applications of coil 6. In
particular, primary channels 90 and 92 are configured to direct
condensation into secondary channels 108 and 112, respectively,
which are then sloped toward front pan member 104 to direct the
condensation into drain channel 116. Drain channel 116 is sloped in
a downward direction from right pan member 100 to left pan member
102 to direct the condensation toward drain holes17. These sloped
channels are designed to optimize the flow of condensation through
condensate pan 16 and out of drain holes 17. Therefore, by allowing
condensate pan 14 to couple with condensate pan 16 without changing
the slope of any channels, condensate pan 16 functions to properly
drain condensation when evaporator assembly 2 is operating in a
vertical configuration regardless of whether both pans are coupled
together within casing 4.
[0112] In addition, since condensate pan 16 remains in the exact
same position relative to surface S whether or not it is coupled
with condensate pan 14, the position of drain holes 17 also remains
constant. Thus, unlike prior art designs, it is not necessary to
enlarge opening 53B of first cover 18 in order to accommodate
changing locations of drain holes 17. As a result, opening 53B is
designed to provide a tighter fit around drain holes 17 which, when
combined with gasket 52B (as described above in reference to FIG.
1B), provides an improved airtight seal that increases the
efficiency of evaporator assembly 2. In addition, the tighter fit
of opening 53B around drain holes 17 is beneficial in shipping
because first cover 18 is also configured to secure condensate pan
16 in position within casing 4, thereby decreasing movement of pan
16 during shipping and handling of evaporator assembly 2.
[0113] FIG. 20 is a perspective view of horizontal condensate pan
14 coupled with vertical condensate pan 16. As shown in FIG. 20,
horizontal condensate pan 14 includes support member 250 on rear
side 252. Support member 250 is configured to rest on top edge 254
of rear pan member 106 when horizontal condensate pan 14 is coupled
with vertical condensate pan 16. Support member 250 functions to
provide many important benefits to evaporator assembly 2. One
benefit provided by support member 250 is a tight and rigid
connection between condensate pans 14 and 16. Another benefit
provided by support member 250 is a means for securing condensate
pan 14 to condensate pan 16 such that the bottom wall of pan 14
remains within notch 240, as shown and described above in reference
to FIG. 19B. It should be understood that notch 240 is merely one
example of a support feature that may help provide a secure and
rigid connection between horizontal condensate pan 14 and vertical
condensate pan 16.
[0114] The terminology used herein is for the purpose of
description, not limitation. Specific structural and functional
details disclosed herein are not to be interpreted as limiting, but
merely as bases for teaching one skilled in the art to variously
employ the present invention. Although the present invention has
been described with reference to preferred embodiments, workers
skilled in the art will recognize that changes may be made in form
and detail without departing from the spirit and scope of the
invention.
* * * * *