US3213936A

US3213936A - Air conditioning apparatus

Info

Publication number: US3213936A
Application number: US289195A
Authority: US
Inventors: Robert H Tull
Original assignee: Westinghouse Electric Corp
Current assignee: McQuay Perfex Inc
Priority date: 1963-06-20
Filing date: 1963-06-20
Publication date: 1965-10-26
Anticipated expiration: 1982-10-26
Also published as: JPS4213360B1

Description

Oct. 26, 1965 R. H. TULL AIR CONDITIONING APPARATUS 3 Sheets-Sheet 1 Filed June 20, 1963 Q if Oct. 26, 1965 R. H. TULL 3,213,936

AIR CONDITIONING APPARATUS Filed June 20, 1963 5 Sheets-Sheet 2 INVENTOR Robert H. Tull Oct. 26, 1965 R. H. TULL 3,213,936

AIR CONDITIONING APPARATUS Filed June 20, 1963 5 Sheets-Sheet 5 mun.

This invention relates to air conditioning apparatus, and particularly to means for controlling air flow through such apparatus.

In air conditioning apparatus in which heating is provided as one of the functions, a problem exists in providing a gravity rating for the system.

The so-called gravity rating is a measure of the heating capacity of the unit due to natural circulation of air over the heating coils when the blower is not operating. This is a feature desired by many who prefer to shut down the blower while the heating means remains functioning, to provide a quieter operating unit during the night. However, in most air conditioning units the remote location of the air inlet from the heating unit together with the location of the blower in the duct tend to prevent the natural flow of air over the heater and thereby lessen the gravity rating of the unit.

It is therefore an object of the invention to provide air conditioning apparatus having air flow over the conditioning means when the blower is not operating.

Another object of the invention is to provide a damper arrangement for providing air flow over the conditioning means due to gravity flow, which arrangement is operated in response to air flow caused by the blower.

Another object of the invention is to provide a damper arrangement for providing gravity flow in an air conditioning unit, which arrangement is simple in construction and may be inexpensively manufactured.

These objects, and other objects which will become apparent as the description proceeds, are achieved by providing an air conditioning unit having an inlet for drawing air from the enclosure to be conditioned, and an outlet for discharge of conditioned air to the enclosure. Walls of the unit housing define a duct etween the air inlet and the air outlet and disposed in the duct are a blower, heating coils and any additional conditioning means which are desired.

The in ention further provides an opening in the duct disposed upstream of the heating coils, considered in the direction of air flow therethrough, and in spaced relation below the heating coils. The opening communicates with the enclosure and is provided with a damper which opens into the duct serving to cover the opening when in the closed position. The damper is so located, and so constructed, that the pressure in the duct caused by the blower forcing air therethrough is sufficient to maintain the damper in the closed position. When the blower is shut down, the damper returns to an open position and air flows from the enclosure, through the opening and over the heating element due to natural gravity flow.

For a better understanding of the invention reference should be had to the accompanying drawings, wherein:

FIGURE 1 is a front elevational view of a curtainwall type air conditioner having the invention employed therein;

FIG. 2 is a top plan view of the air conditioning unit shown in FIG. 1 having the upper panels removed to better show the arrangement of the components;

FIG. 3 is a longitudinal sectional view taken along line lIlIII of FIG. 2;

FIG. 4 is an enlarged fragmentary transverse sectional view taken along line IV-IV of P16. 2;

ates Patent FIG. 5 is an enlarged fragmentary perspective view showing a portion of the unit in detail; and

FIG. 6 is a fragmentary view similar to FIG. 5, but showing an alternate embodiment of the invention.

Although the principles of the invention are broadly applicable to air conditioning units in general, the invention has been herein illustrated as employed in an air conditioning unit suitable for installation in the outside wall of a building, and will be so described.

Referring to the drawings, especially FIGS. 1 and 2, there is shown an air conditioning unit 1% installed adjacent a building wall 11 having an opening provided to accommodate the fresh air side of the cooling system.

The cooling system contained in the conditioning unit 10 is a conventional compressor-condenser-expander type refrigerating circuit, and only those components deemed necessary for a complete explanation of the present invention have been shown in the drawings.

The fresh air side of the unit it contains an electric motor-compressor unit 12, a refrigerant condenser 13, and a mixed flow fan and motor assembly 14. The fan and motor assembly 14 operates in the usual manner to draw fresh air into the unit 10 and discharge the air over the refrigerant condenser 13, as illustrated by the arrows shown in FIG. 2.

The room air side of the unit 10 contains the refrigerant evaporator 16, finned heating coils 17 which may receive steam or hot water, and centrifugal blower assembly 18 which operates to draw air from the enclosure and to cause the flow of air over the refrigerant evaporator 16 and the heating coils 17 prior to being discharged into the enclosure.

As best shown in FIGS. 3 and 4, air from the en- H closure is drawn into the unit 18 through the inlet opening 19 and the centrifugal blower assembly 18 from where it flows into a duct formed by walls of the unit 10. The air then passes over the evaporator 16 and flows upwardly past the heating coils 17, after which it is discharged through an outlet opening 21 which is located adjacent the front of the unit 16 and directly above the heating coils.

Referring now to FIGS. 1 and 4, there is shown an opening 22 adjacent the lower portion of the unit 10 communicating with the enclosure. The opening 22 is provided with a damper 23 which is pivotally supported adjacent the lower side of the opening as by a pair of hinge members 24 and 26. The damper 23 opens inwardly, and is biased toward the open position shown in solid lines of FIG. 4, where it is supported by the

cover plates

27 and 28 of the evaporator 16.

As best shown in FIG. 5, each of the hinges 24 and 26 have a spring 29 disposed between the damper 23 and the unit 14}, tending to lightly force the damper away from the opening 22.

In operation, when the unit is calling for heating or cooling, air from the enclosure is drawn through the inlet opening 19, into the duct of the unit 10 and over the

conditioning elements

16 and 17. After being heated or cooled the air is discharged to the enclosure at the outlet opening 21. The spring member 29 is so designed that the pressure caused by air flowing through the duct overcomes the spring pressure and causes the damper 23 to remain in the closed position as shown in phantom lines in FIG. 4. When the blower is not operating, the drop in pressure caused by insufficient air flow in the duct eliminates the force overcoming the spring pressure, and the damper moves to the open position.

With the damper 23 in the opened position as shown in FIG. 4, air from the enclosure will be caused to enter through the opening 22 and flow through the duct between the opening and the heating coils 17. The heat of the coils 17 causes the Warm air to rise through the opening 21 and the air flows through the unit 10, as shown by the arrows in FIG. 4, due to gravity flow or natural convection.

Although the damper 23 is shown biased toward an open position in the duct by the spring members 29, the damper may be designed in a manner whereby the center of gravity of the damper would cause the damper to open, thus eliminating the use of a spring member.

Referring to FIG. 6 wherein such arrangement is shown, it will be noted that a damper 23a is disposed in the structure in a manner similar to the damper 23 of the prior embodiment, but with the springs 29 omitted.

The damper 23a has a pair of inwardly sloping surfaces 31 and 32 comprising the greater mass of the damper. By constructing the damper 23a as shown, the center of gravity is located inwardly of the duct with respect to the pivotal axis 33 of the hinges 24 and 26. The resultant unbalance force causes the damper 23a to be biased toward an open position when the blower 18 is not operating, but is of a magnitude which is overcome by pressure caused by air flow in the duct when the blower is operating. The damper 23a thereby functions similar to the damper 23 of the prior described embodiment, but without use of the springs 29 to create the biasing force.

In addition to the advantage obtained by having gravity flow caused by the heating elements 17, it is obvious that a reverse flow could taken place when the cooling cycle is terminated. That is, cool air flowing from the evaporator 16 would flow downwardly in the duct and cause a reverse flow, whereby air would enter at the outlet opening 21 and would be discharged through the opening 22 by gravity flow or convection.

An additional feature of the invention is evident in installations where the outer casing of the unit is installed in a building together with the heating coils 17, and the cooling unit and blower 19 are to be added at some later time. Such an instance often occurs in new buildings where only the heating coils are installed to maintain the interior of the building at a warm temperature during construction. By incorporating the invention as employed in the unit 10, the damper 23 remains open at all times when the blower in inoperative, and therefore the flow of air over the heating units would take place without installation of the blower 18.

It should therefore be evident from the foregoing that the invention provides air conditioning apparatus which has air flow over the conditioning means when the blower is not operating. Further, the invention provides air flow by a damper arrangement which is operated in response to air flow caused by the blower of the air conditioning unit. The invention therefore provides gravity flow in an air conditioning unit by employing an arrangement which is simple in construction and may be inexpensively manufactured.

While the invention has been shown in but two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various additional changes and modifications without departing from the spirit thereof.

What is claimed is:

1. Air conditioning apparatus comprising:

a housing including a first room air inlet, an air outlet adjacent the top of said housing, and means defining a passage connecting said first inlet with said outlet;

blower means selectively operable for forcing air through said passage from said inlet to said outlet;

heating means in said passage;

a second room air inlet for said passage, said second inlet being located upstream from said heating means, relative to the direction of air flow through said passage, and generally below said heating means; and

a damper for said second inlet biased toward an open position to permit gravity convection of air through said second inlet and upwardly past said heating means to said outlet when said blower means is inoperative, and operable to close said second inlet in response to a pressure condition in said passage arising from operation of said blower means.

2. Apparatus according to claim 1 including:

spring means for biasing said damper toward said open position.

3. Apparatus according to claim 1 wherein:

said damper is pivotally supported along its lower edge and has its center of gravity vertically offset from said pivotal support to gravity bias said damper toward said open position.

4. Air conditioning apparatus comprising:

a cabinet including a central portion containing selectively operable, separate, heating and cooling coils, and an end compartment containing blower means;

a first room air inlet in said end compartment for said blower means;

an air outlet adjacent the top of said central portion, said heating coil being disposed closely below said outlet;

means defining a passage for air flow forced by said blower means from said first room air inlet to said outlet, said passage including, in sequence, said blower, said cooling coil, said heating coil, and said outlet;

a second room air inlet in the central portion of said cabinet, said second inlet being disposed generally below said heating coil, and on the downstream side of said cooling coil;

a damper for said second room air inlet; and

means biasing said damper to an open position in the absence of blower operation and yieldable to permit said damper to move to a closed position in response to the pressure created in said passage by operation of said blower means.

References Cited by the Examiner UNITED STATES PATENTS 1,876,547 9/32 Ashley 53 X 2,191,224 2/40 Adair 165-126 X 2,552,396 5/51 Brandecker 62426 X 2,723,616 11/55 Gannon 98-38 2,775,188 12/56 Hubbard 98-38 2,884,228 4/59 Jor-gensen 62-426 X FOREIGN PATENTS 823,497 12/ 51 Germany.

ROBERT A. OLEARY, Primary Examiner. CHARLES SUKALO, Examiner,

Claims

1. AIR CONDITIONING APPARATUS COMPRISING: A HOUSING INCLUDING A FIRST ROOM AIR INLET, AN AIR OUTLET ADJACENT THE TOP OF SAID HOUSING, AND MEANS DEFINING A PASSAGE CONNECTING SAID FIRST INLET WITH SAID OUTLET; BLOWER MEANS SELECTIVELY OPERABLE FOR FORCING AIR THROUGH SAID PASSAGE FROM SAID INLET TO SAID OUTLET; HEATING MEANS IN SAID PASSAGE; A SECOND ROOM AIR INLET FOR SAID PASSAGE, SAID SECOND INLET BEING LOCAXTED UPSTREAM FROM SAID HEATING MEANS, RELATIVE TO THE DIRECTION OF AIR FLOW THROUGH SAID PASSAGE, AND GENERALLY BELOW SAID HEATING MEANS; AND A DAMPER FOR SAID SECOND INLET BIASED TOWARD AN OPEN POSITION TO PERMIT GRAVITY CONVECTION OF AIR THROUGH SAID SECOND INLET AND UPWARDLY PAST SAID HEATING MEANS TO SAID OUTLET WHEN SAID BLOWER MEANS IS INOPERATIVE, AND OPERABLE TO CLOSE SAID SECOND INLET IN RESPONSE TO A PRESSURE CONDITION IN SAID PASSAGE ARISING FROM OPERATION OF SAID BLOWER MEANS.