US3839880A

US3839880A - Fan and coil arrangement

Info

Publication number: US3839880A
Application number: US00422476A
Authority: US
Inventors: G Premaza
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1973-12-06
Filing date: 1973-12-06
Publication date: 1974-10-08
Anticipated expiration: 1991-10-08
Also published as: CA995897A; JPS5148214Y2; JPS5081641U

Abstract

A shielding arrangement is provided for the end bends of a fin and tube coil where the end bends are located closely adjacent a fan creating a relatively high velocity of air flow, the coil including at least some tube rows unoccupied by tubes to provide passages for an induced air flow through such tube rows and then out the open side of the shielded space facing in the downstream direction of air flow created by the fan.

Description

United @tates Patet 1 1 Premaza 1 51 on. s, Wm

1 1 FAN Ahlll) COlllL ARRANGEMENT [75] lnventor: George .1. ll remaza, Columbus, Ohio [731 Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

[22] Filed: Dec. 6, 1973 [21 1 App]. No; 422,476

[51 1 lat. Cl. lFZSd 23/12 1581 Field of Search 62/262, 428, 426

[56] References Cited UNITED STATES PATENTS 1,870.460 8/1932 Lambert 62/426 1.991.897 2/1935 Higgins 62/426 2,088,254 7/1937 Wolfert 62/428 2.323,]76 6/1943 Ashley v t v i i 4, 62/426 2,959,031) 11/1960 Mehalick 62/262 Primary Examiner-William J Wye Attorney, Agent, or Firm -E. C. Arenz ['57] ABSTRACT A shielding arrangement is provided for the end bends of a tin and tube coil where the end bends are located closely adjacent a fan creating a relatively high velocity of air flow, the coil including at least some tube rows unoccupied by tubes to provide passages for an induced air flow through such tube rows and then out the open side of the shielded space facing in the down stream direction of air flow created by the fan.

5 Claims, 4 Drawing Figures FAN AND COIIL ARRANGEMENT BACKGROUND OF THE INVENTION 1. Field of the Invention The invention pertains to the art of fan and coil arrangements, and in particular to a fan and coil arrangement for a self-contained room air conditioner in which the condenser coil and fan are arranged in generally side-by-side relation on a single face of the room air conditioner.

2. Description of the Prior Art The closest prior art of which I am aware is the construction of room conditioners manufactured by the assignee of this patent application and in which the end bends at one end of the condenser coil are substantially totally enclosed and isolated by a shield or baffle which is of U-shape in horizontal section and extends for the entire height of the condenser coil. Further reference will be made to this prior art baffle arrangement in connection with the description of this invention.

The type of room air conditioner to which the invention is particularly applicable is one in which the condenser coil and the condenser air flow fan are arranged in generally side-by-side relation, but with the condenser fan offset inwardly into the cabinet sufficiently that the end bracket on'the coil and the end bends overlap the fan ring. With that particular arrangement, in certain environments the end bends are subject to corrosion and erosion from air-borne particles (such as sand and salt) drawn past the end bends at'a relatively high velocity due to the proximity of the end bends to the fan. To eliminate this problem the baffle referred to previously, which substantially totally isolated the end bends from the air flow path, was provided. While the baffle provides the protection for the end bends that is desired, the performance of the room air conditioner is hampered by the restriction to condenser air flow provided by the baffle.

The arrangement according to my invention provides adequate protection of the end bends, and also yields improved performance relative to the prior art baffle arrangement.

SUMMARY OF THE INVENTION In accordance with the invention, a fan and coil arrangement is provided including an extended surface plate-fin coil of the type having a number of closely spaced fins provided with tube collars forming a plurality of tube rows through which a number of tubes, less than the number of tube rows, extend transversely and terminate in end bends, and in which a fan for creating a main flow of air between said fins and over said tubes is arranged with the fan located such that a portion of its cross-sectional area through which air flow passes is closely adjacent an end of the coil provided with the end bends, and shield means is provided on the end of the coil having the end bends to form a shielded space having a side facing in the upstream direction of air flow created by the fan being closed, and with the side of the shielded space facing in the downstream direction of the air flow created by the fan being open, the end of the coil opposite the fan being open to the main air flow created by the fan so that a minor flow of air is induced through those tube rows in the coil which are unoccupied by the tubes.

DRAWING DESCRIPTION FIG. l is a top plan view, partly broken away, of a room air conditioner provided with an arrangement ac cording to the invention;

FIG. 2 is an elevational view of a face of the room air conditioner having the condenser and condenser fan arranged in generally side-by-side relation;

FIG. 3 is a vertical sectional view corresponding to one taken along the line IIIlII of FIG. 2; and

FIG. 4 is an enlarged face view of a fragmentary portion of the condenser.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, the room air conditioner includes an outer wrapper 10 which, with the base 12, generally forms the cabinet for the air conditioner. The interior of the cabinet is separated into a room-side space 14 and an outside-side space 16 by a generally vertically disposed partition 18.

The refrigeration and air moving system is generally conventional and basically includes an evaporator 20 and room air fan 22 in the'room-side space, and a refrigerant compressor 24, condenser 26, and condenser air fan 28 in the outside-side space. The usual refrigerant lines connect the various components of the system.

As is perhaps best seen in FIG. 2 the fan 28 and condenser 26 are arranged in generally side-by-side relation adjacent the outwardly-facing face of the cabinet. The air for cooling the condenser is drawn in through the fan ring 30 into the outside-side space 12 and flows generally as indicated by the solid line directional arrows out through the condenser 26 by passing between the multitude of closely spaced, vertically disposed fins 32 and over the tubes 34. The condenser coil 26 as a whole is conventional and includes the usual fins 32 (FIGS. 3 and 4) with a large number of openings 36 therein. The material around each of the openings is displaced out of the plane of the fin in the usual manner to form tube hole flanges or collars 37 which provide the spacing between adjacent fins. In the manufacturing process the fins are stacked with each other with the holes 36 in registry, and the tubes 34 are inserted through selected ones of the tube rows formed by the flanged openings 36. Typically, a number of the tubes are hairpin shaped and the open ends of various of these tubes are connected to open ends of various of the other tubes by end bends 38 which are then soldered. As a result, one or more circuits for the flow of refrigerant fluid through the condenser coil is provided. Since the capacity of a coil is in part dependent upon the number of tubes therein, it is common practice to provide fins with the number of openings 36 required for the maximum capacity of a coil, and in manufacturing those coils requiring lesser capacity some of the openings 36 forming the tube rows are unoccupied by the tubes so that passages 39 parallel to the tubes are formed. As noted before, the described construction of the coil is well known and conventional.

In the room air conditioner shown in FIGS. 1 and 2, the condensing capacity required, coupled with the fan size for the required air flow, and the size of the cabinet 7 and arrangement of components therein dictates that the coil 26 and fan 28 be arranged as shown adjacent theone face of the cabinet so that there is a degree of overlapping relation of the end bends 38 on the left end of the condenser coil relative to the fan ring 30 through which air is drawn by the fan 28. With that overlapping relationship, difficulty is experienced with erosion and corrosion of end bends at the end of the coil adjacent the fan, due to airborne particles being moved against and past the end bends at a high velocity. Particular difficulty is experienced in those areas in which sand and- /or salt was present in the air. The prior art solved this difficulty by providing a baffle which was U-shaped in horizontal cross-section and which enclosed the entire space containing the end bends and outboard of the end brackets 40 of the coil. This prior art baffle extended for the total height of the coil. As will be apparent from FIG. 1, that leg of such a U-shaped baffle closest to the fan ring obstructed part of the air flow. In that connection it is noted that while overlap of the end bends and the fan ring as illustrated in FIGS. 1 and 2 is relatively slight, in some instances the overlap may be significantly greater and the side of the fan ring adjacent the coil end may be chordal rather than circular.

In accordance with my invention, shielding means for the end bends adjacent the fan is provided by a baffle 42 which is of generally L-shape in horizontal crosssection and which is also of a height corresponding generally to the height of the coil. Additionally, in accordance with the invention, the space 44 containing the end bends at the end of the coil opposite that end adjacent the fanis placed in communication with the interior of the outside side space 12 to permit the flow of air from the discharge side of the fan into that space 44.

With the arrangement as described, a shielded space 46 is provided behind the baffle 42 with the side of the shielded face facing in the upstream direction of air flow created by the fan being closed, while the side of the space facing in the downstream direction of air flow created by the fan is open. Thus, with the main air flow created by the fan 28 being in the direction indicated by the solid line arrows in FIG. 1, a minor flow of air is induced to pass from the space 44 at the right end of the coil through passages 39'formed by the tube rows which are unoccupied by tubes and in a direction transverse to the main flow of air. This minor flow of air indicated by the dash-line arrows passes into the shielded space 46 and back into the main air flow stream.

It has been found that with an arrangement according to the invention, as contrasted with the prior art isolating baffle arrangement, reduced condenser temperatures are achieved under the same operating conditions. As a result, the greater effectiveness of the arrangement permits the removal of some of the tubes and end bends from the condenser with a concomitant cost savings. For example, in a condenser with the prior art baffle arrangement having 66 tubes in a nominal 10,000 B.T.U. unit, the new arrangement permitted the removal of eight of these tubes from the'condenser.

I claim as my invention:

1. A self-contained room air conditioner including:

a cabinet having a room side portion and an outside side portion;

a refrigerating system in said cabinet including a refrigerant condensing coil of the plate-fin type and having tube end bends on opposite ends of said coil, said coil being disposed to occupy a part of the outwardly facing face of said cabinet;

a condenser fan having an inlet opening arranged in generally side-by-side relation with said coil to substantially occupy the remaining part of said outwardly facing face of said cabinet, said fan being offset inwardly sufficiently to accommodate an overlap of said'end bends on one end of said coil relative to said inlet opening;

means forming a shielded space for said end bends on said one end of said coil to prevent the direct impingement of air-borne particles against said end bends in the passage of air into said inlet opening. the side of said shielded space facing said inlet opening being open;

said coil including a plurality of tube rows formed by said plate fins having tube collars thereon, a part of said tube rows being unoccupied by tubes whereby open-ended air passages extending parallel to said tubes are formed;

the end of said coil opposite said one end being open to the interior of said cabinet so that a part of the air being forced by said fan toward said coil will pass through said unoccupied tube rows from said end opposite said one end to said shielded space at said one end.

2. In a room air conditioner having a condenser fan and a condenser coil arranged so that a part of the ambient air for condenser cooling is drawn by said fan past one end bend portion of said condenser coil and is then forced by said fan through said condenser coil, an arrangement comprising:

baffle means forming a space at the end of said condenser coil shielding said one end bend portion from ambient air being drawn directly across said end bend portion from exteriorly of said air conditioner, the side of said shielded space facing the suction side of said fan being open thereto;

open ended passage means extending through said condenser coil from the end of said condenser coil opposite said one end bend portion to said shielded space, said opposite end of said passage means being in communication with the pressure side of said fan so that a flow of air is induced from said opposite end to said one end bend portion of said condenser coil during operation of said fan.

3. In an arrangement according to claim 2 wherein:

said condenser coil is of plate-fin and tube construction including tube collars on said fins; and

said passage means is formed of tube collars in registry and unoccupied by tubes.

4. In an arrangement according to claim 2 wherein:

said baffle means comprises an L-shaped member in transverse section located at said one end bend portion of said condenser coil.

5. In a fan and coil arrangement in a housing and in which the fan and coil are arranged so that air flow both into and out of the housing is through a single face of the housing;

a plate-fin coil having a number of closely spaced fins provided with tube collars forming a plurality of tube rows through which a number of tubes, less than the number of tube rows, extend transversely and terminate in end bends at opposite ends of said coil;

a fan for creating a main flow of air between said tins and over said tubes, said fan being arranged with a tion of air flow created by said fan being open, the end of said coil opposite said end adjacent said fan being open to the interior of the housing. so that a minor flow of air is induced through those tube rows unoccupied by said tubes and exits out of said shielded space into the main air flow.

* l l l

Claims

1. A self-contained room air conditioner including: a cabinet having a room side portion and an outside side portion; a refrigerating system in said cabinet including a refrigerant condensing coil of the plate-fin type and having tube end bends on opposite ends of said coil, said coil being disposed to occupy a part of the outwardly facing face of said cabinet; a condenser fan having an inlet opening arranged in generally side-by-side relation with said coil to substantially occupy the remaining part of said outwardly facing face of said cabinet, said fan being offset inwardly sufficiently to accommodate an overlap of said end bends on one end of said coil relative to said inlet opening; means forming a shielded space for said end bends on said one end of said coil to prevent the direct impingement of air-borne particles against said end bends in the passage of air into said inlet opening, the side of said shielded space facing said inlet opening being open; said coil including a plurality of tube rows formed by said plate fins having tube collars thereon, a part of said tube rows being unoccupied by tubes whereby open-ended air passages extending parallel to said tubes are formed; the end of said coil opposite said one end being open to the interior of said cabinet so that a part of the air being forced by said fan toward said coil will pass through said unoccupied tube rows from said end opposite said onE end to said shielded space at said one end.

2. In a room air conditioner having a condenser fan and a condenser coil arranged so that a part of the ambient air for condenser cooling is drawn by said fan past one end bend portion of said condenser coil and is then forced by said fan through said condenser coil, an arrangement comprising: baffle means forming a space at the end of said condenser coil shielding said one end bend portion from ambient air being drawn directly across said end bend portion from exteriorly of said air conditioner, the side of said shielded space facing the suction side of said fan being open thereto; open ended passage means extending through said condenser coil from the end of said condenser coil opposite said one end bend portion to said shielded space, said opposite end of said passage means being in communication with the pressure side of said fan so that a flow of air is induced from said opposite end to said one end bend portion of said condenser coil during operation of said fan.

3. In an arrangement according to claim 2 wherein: said condenser coil is of plate-fin and tube construction including tube collars on said fins; and said passage means is formed of tube collars in registry and unoccupied by tubes.

4. In an arrangement according to claim 2 wherein: said baffle means comprises an L-shaped member in transverse section located at said one end bend portion of said condenser coil.

5. In a fan and coil arrangement in a housing and in which the fan and coil are arranged so that air flow both into and out of the housing is through a single face of the housing; a plate-fin coil having a number of closely spaced fins provided with tube collars forming a plurality of tube rows through which a number of tubes, less than the number of tube rows, extend transversely and terminate in end bends at opposite ends of said coil; a fan for creating a main flow of air between said fins and over said tubes, said fan being arranged with a portion of its cross-sectional area through which air flow passes being closely adjacent one end of said coil provided with said end bends; shield means on said one end of said coil forming a space having a side facing in the upstream direction of air flow created by said fan being closed, and the side of said space facing in the downstream direction of air flow created by said fan being open, the end of said coil opposite said end adjacent said fan being open to the interior of the housing, so that a minor flow of air is induced through those tube rows unoccupied by said tubes and exits out of said shielded space into the main air flow.