US2900891A - Room air conditioning system - Google Patents

Description

Aug. 25, 1959 L. J. SCHUTTE 2,900,891

I RQOM AIR CONDITIONING SYSTEM Filed April 30, 1956 2 Sheets-Sheet 1 INVENTOR.

LA URENT J; SCHUTTE Aug. 25, 1959 sc 2,900,891

ROOM AIR CONDITIONING SYSTEM Filed April 30, 1956 Q V 2 Sheets-Sheet 2 MAN;WWW...

%@M a e/M ROOM AIR CONDITIONING SYSTEM Laurent J. Schutte, Elm Grove, Wis., assignor to Super- Stcel Products Company, Milwaukee, Wis., a corporation of Wisconsin Application April 30, 1956, Serial No. 581,528

' 3 Claims. (31. 98-40 This invention relates to a room air conditioning system to be employed particularly for rooms having large wall expanses along one or more sides thereof and exposed to outside temperatures substantially different from that desired in the room.

The invention has been employed in the construction of school classrooms having one side composed principally of glass windows in northern climates where the windows may be exposed to sub-zero temperatures on the outside and tend to produce a cold downward draft of air that unbalances the heating of the room. In such rooms it is desired to avoid temperature differences between occupied areas in the room exceeding about 2 F., and to prevent both drafts and stagnation. For this purpose it is desired to maintain an air movement in all occupied areas of the room corresponding to a velocity of from about 15 to about 65 feet per minute. These requirements generally apply to the entire area of the room from the floor level to a height of approximately six feet.

Attempts to solve the problem. and to provide the desired uniformity in temperature and ventilation have been varied and have included systems in which heated air is forced across the room toward the windows from spaced registers near the ceiling, a construction found to enhance drafts and non-uniformity in temperatures. Another system employed spaced registers in the window sill generally of a width of several inches and through which hot air was discharged upwardly either by convection or at low velocities. The last system did not provide the uniform room temperature and air movement desired.

The difiiculty will be more appreciated from the fact that tests indicate that in some instances the cold air moving downwardly on the inside of the window by convection may reach a velocity as high as 250 feet per minute.

The present invention is based upon a new principle in air distribution in a room wherein the incoming air is introduced in the form of a high velocity quiet upward jet of continuous length for the full length of the exposed wall or window panels and whereby the incoming air thoroughly mixes with any convection currents adjacent the wall or window and then travels completely across the room near the ceiling and down into the occupied portion of the room on the opposite side of the room and from thence returns toward the exposed wall or windows.

the ceiling to the opposite side of the room Without being objectionably disturbed by mixing with the room air, and will depend upon the height and size of the room and upon the air volumes necessary for proper room ventilation.

According to the invention the air is discharged upwardly through a very narrow grille near the window sill, generally less than one inch in Width, and extending continuously without substantial interruption for the full length of the window or other outside wall panel for The velocity of discharge of air should be sufficiently high to force the air curtain to continue across nited States Patent ICC the room. The velocity of air discharge is generally several times the maximum possible convection current velocity created by the window temperature and should be capable of fully counteracting such convection current or of thoroughly mixing the jet of air with the convection air before the discharged air passes across the ceiling into the room.

In carrying out the invention the air for ventilating the room is supplied to the narrow grille uniformly throughout its length by employing a distributing or plenum chamber beneath the grille and which supports the latter. The air enters the distributing chamber from one or more ducts at the bottom of the chamber and is distributed throughout the length of the chamber as it rises toward the grille. Where the height of the chamber as proportioned to its length is insufficient to obtain adequate uniformity of air discharge from the grille throughout its length, a partition may separate the chamber into an upper plenum chamber and a lower feed chamber and bafiles may be employed within the chamber to assure adequate distribution of air flow for the purpose.

The distribution chamber and its top grille is generally constructed in separate sections or lengths which are secured end to end in multiples to make up a complete system extending for the full length of the adjacent wall or window. Each section or unit will have a horizontal partition therein with baffled openings therein for directing the air upwardly and longitudinally to effect the desired uniform distribution of air flow to and through the top grille.

The sections or units are supported on the floor and are generally constructed of sheet metal which may be covered with a vinyl resin providing added rigidity therefor. Each unit has a top with a front panel supporting the forward edge of the top at the height of the window sill so that the top forms an extension of the sill into the room.

For school classrooms the top of each unit may extend farther into the room, beyond the front panel of the distributing chamber to provide open or closed bookshelf space therebeneath and facing the room. In such construction a center bookshelf is generally provided at a level where it adds rigidity to the front panel. A bottom shelf is provided raised from the floor. Each bookshelf is flanged downwardly at its edges and the rear flanges are secured as by bracket hooks from the front panel of the distributing chamber. The bookshelf space may have end panels for each unit to which the end flanges of the bookshelves are secured as by bracket hooks to add rigidity to the structure. Front doors may be provided to close the space if desired.

The construction is designed to avoid noise from the high velocity of air passing therethrough. Tests have shown a surprisingly low noise level even with velocities of air discharge at the top in excess of 800 feet per minute. By making the top grille less than two inches in width and in many instances as narrow as five-eighths of an inch, the width of the distributing chamber can be kept within practical limits, generally less than six inches, without undue noise from the air flow. Where vibrations of the panels tend to magnify the noise, the baffle partition and the front bookshelf construction tends to reduce the amplitude and lower the noise level.

The bafile and the top grille should be, constructed to provide the desired directional influence for the air with a minimum of noise. In counteracting the down draft on a cold window it has been found desirable to direct the jet of air from the top grille toward the window which will cause the air to engage the window at the top of the latter. With most construction an angle of about 5 from the vertical, toward the Window is satisfactory.

By minimizing or avoiding spaces between the ends of the grille at the joints between the sections or'units; the air is discharged in a continuous sheet without interruptions that produce what may be termed eddy currents along the window. Byhaving a high velocity continuoussheet of' airdischarged' from the grille, the air fi'ow domihates the Windowdrafts and effectively controls the air movement in the room.

The accompanying drawings illustrate the best mode presently contemplated of carrying out the invention as applied to a school classroom having one wall essentiallyof window panes for the full length thereof.

In the drawings:

Figure 1' is a front elevation of the inside window wall of theclassroom showing the air conditioning system with parts broken away and sectioned;

Fig; 2 is a transverse section through the room: showing the airflow from the system;

Fig. 3 is a top plan: view of the air conditioning system with parts broken awayand sectioned;

Fig. 4 is anenlarged detail section showing the end joints between the sections;

Fig. 5 is an enlarged detail section showing the balfle construction; and

Fig. 6 isv an enlarged detailed section showing the flanged grille opening.

In. the drawings, the room illustratedis a typical school classroom having a floor 1, an outside wall 2' with a window 3, end walls. 4 and 5, an inside wall. 6 and a ceiling 7. The window 3 extends. for nearly the full distance between the end walls 4 and 5, and from a sill 8 up to the ceiling 7.

The heated air from the furnace in the basement is brought upwardly through the floor 1 by duct 9 which opens into the feed portion of the air distributing chamber 10 beneath the sill 8 and adjacent the wall- 2. Where the room does not exceed about thirty feet in length and the Window sill 8 is at. a substantial height, a single duct. 9 opening centrally of the length of the room into chamber 10 will be satisfactory. For longer rooms or for substantially lower sills it will be advisable to employ more than one duct 9 and to space the inlet openings into chamber 10 provided by the ducts, longitudinally of the room.

In the. construction shown, the chamber 10 is provided by a plurality of sections or units 11. extending. from a suitable support 12 on the floor 1. to the level of the sill 8 and joined end to end to extend for the length of the wall 2.

Each unit 11 comprises a vertical front panel. 13. of sheet metal or other suitable material, and atop sill panel 14 supported thereby. The panel 13 is spaced from the wall 2 preferably about five inches and. is supported on the floor 1 by means of the riser 12. The top panel 14 extends horizontally rearwardly from panel cover 13 to sill 8 where it is secured to. provide a smooth. topextension thereof.

Where the top panel 14 extends into the room beyond front. panel 13, as illustrated, the upper edge of the front panel has a flange 15 which supports. top panel-.14 and the ends of the front. panel are bent forwardly to provide partitions 16. for the bookshelves at the joints between the sections.

The joints betweenthe sections or unit 11 may comprise downward flanges. 17; on the adjacent end edges of the tops 14 and which overlie the partitions: 16 and; may

bev suitably bolted or otherwise secured in assembly by bolts 18 passing through the adjacent partitions.

The top panel 14 of each unit 11 contains anarrow opening having a [flanged grille 19 extending centrally for the full length of the unit. The flanges of grille 19- may be set to direct the air vertical, or. as has been found preferable, toward the window 3 at an angle of about 5 from the vertical; The grille 19' should be less than one.

inch in width and is shown as having a width of about five-eighths of an inch.

The flanges 17 at the ends of each top panel 14 extend across the narrow opening for the grille 19 and tie the rear portion of the top panel to the front portion of the panel.

The air distributing baffle comprises a horizontal metal sheet 20 extending from the front panel 13 to the Wall 2 for the full length of each unit 11, and a central opening havinga grille 21 above it and vanes 22 below it adapted to pick up air from the. lower feed portion of, chamber 16 and to direct it upwardly through the grille into the upper plenum portion of chamber 10 where the air flow spreads out as indicated in Figure l for the full length of each unit as it approaches the top. grille 19' in top panel 14.

The forward edge of baffle partition 20 has a downward flange 23 which is secured to the back of front panel .13 by suitable bracket books 24. The. rear edge. of each partition 20' may be suspended from the correspond ing top panel 14 by means of metal straps 25 near the ends of the units and which hold the partitions inplace.

-In the construction illustrated, an open bookcase is provided in front of. each unit. For this. purpose the top panel 14 extends into the room beyond front panel 13 for a distance of about fourteen inches and the front edge is flanged downwardly and inwardly to simulate the thickness of a board and avoid danger of cuts as fromv an exposed sheetmetal edge.

A. central sheet metal bookshelf 26 is provided with its rear edge flanged downwardly and secured to the front panel 13 by suitable bracket books 27. The front edge. of shelf 26 is flanged downwardly similar to the front edge of top 14 previously described.

A bottom sheetv metal shelf 28 is provided for the book.- case and may be formed integral with the front panel 13. The front edge of shelf 28 is flanged downwardly similar to shelf 26 and top 14 and is supported on a second riser 29 recessed from the front of the bookcase.

In operation in winter the hot air from the furnace is.

forced by a suitable circulating fan, not. shown, through duct 9 into chamber 10 near the center of the latter. Turning vanes 30 are provided at the mouth of the duct 9 to direct air therefrom toward the opposite ends of chamber 10.

As air flows toward the ends of the chamber, a certain amount of air is directed by'angular vanes 22 through each grille 21 into the upper plenum chamber where it spreads out. evenly as it flows to the top grille 19. The

air is discharged upwardly in the form of a thin sheet jet ejected from the plenum chamber through. grille 19 at a velocity generally inv excess of five hundred feet per minute and preferably at about eight hundred feet per minute. The-flanges of grille 19 direct the sheet of air at a slight angle toward the window 3, as shown by arrows in Fig. 2.

The sheet of air moves so fast that it counteracts all window drafts and transient air currents and hits, the ceiling 7 where it is forced completely across the room to the opposite side and where it is turned by the inside. wall 6 downwardly toward the floor 1. When the air stream reaches the occupied portion of the room, it has reduced in velocity to the sixty-five or seventy feet per minute considered desirable.

As the air stream reaches the pupil section of the classroom, it mixes with room air and movesv in a return path toward the wall 2. Tests have shown that the air mixing is so continuous and uniform as to effect an even temperature throughout the occupied portion of the. room, it being possible to maintain a temperature which does not varymore than 1 between any two portions of the occupied section. The air velocity in this portion of the room is less than about sixty-five feet per minute and exceeds fifteen feet per minute.

The initial velocity of air. from. grille 19 should be. adjusted according to. the height. and. width of the room.

to be heated thereby. In general, a velocity of about eight hundred feet per minute will be satisfactory for a room that is feet high and 20 feet wide. Where the height is reduced about two feet, the velocity should be reduced by about fifty feet per minute. Where the width of the room is reduced by about four or five feet, the velocity should be reduced by about fifty feet. Similarly, an increase in height or an increase in width will require an increase in velocity accordingly.

The invention is applicable to summertime cooling of rooms with cold air. Where cold or refrigerated air is supplied through duct 9 and ejected through grille 19 at the velocities described above, the air jet thoroughly mixes with the upward hot air current adjacent the window and thereafter travels across the ceiling, gradually lowering into the room proper to mix with the air and cool it. In general, somewhat lower velocities may be employed for cooling than for heating, depending upon the temperature differentials inside and outside the room.

The system of the invention with its high velocity and uniform'air mixing is sensitive to rapid changes in heat requirements as when a class of pupils enters or leaves the room thereby substantially altering the required heat input to maintain a given room temperature. The temperature in all occupied parts of the room can be maintained substantially constant regardless of such changes in occupancy.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. A room air conditioning system adapted to be disposed on the inside of a wall containing a series of windows and a window sill therefor, comprising a plurality of open ended like casing units, each unit comprising a top panel adapted to be disposed as an extension of the window sill, a front panel adapted to be spaced from the wall and to support said top panel from the floor with the top panel extending into the room from said front panel, a horizontally disposed partition secured to said front panel and adapted to extend to the wall therefrom and to separate the space between said front panel and the wall and beneath said top panel into an upper plenum chamber and a lower air distributing chamber, a horizontal shelf secured on the front side of said front panel to provide a rigid support for storage purposes beneath said extended top panel, said partition having an opening to transmit from said distributing chamber to said plenum chamber, a narrow slot in the top panel extending substantially for the full length thereof and adapted to discharge air upwardly from the plenum chamber at high velocities without noise, said casing units being joined end to end and having end walls cooperating with the partition and the top, front and room walls to provide continuous air distribution and plenum chambers and an air discharge slot for substantially the full length of the room wall, and duct means to supply air to said air distribution chamber at a rate effecting air discharge through said slot at velocities in excess of five hundred feet per minute.

2. A room air conditioning system adapted to be disposed on the inside of a wall containing a series of windows and a window sill therefor, comprising a plurality of open ended like casing units, each unit comprising a top panel adapted to be disposed as an extension of the window sill, a front panel adapted to be spaced from the wall and to support said top panel from the floor at the heighth of the window sill, a horizontally disposed partition secured to said front panel and adapted to extend to the wall therefrom and to separate the space between said front panel and the wall and beneath said top panel into an upper plenum chamber and a lower air distributing chamber, said partition having an opening to transmit air from said distributing chamber to said plenum chamber, a narrow slot in the top panel extending substantially for the full length thereof and adapted to discharge air upwardly from the plenum chamber at high velocities without noise, said casing units being joined end to end with the end units having end walls cooperating with the partition and the top and front panels and the room wall to provide continuous air distribution and plenum chambers and an air discharge slot for substantially the full length of the room wall, and duct means to supply air to said distribution chamber at a rate effecting air discharge through said slot at velocities in excess of five hundred feet per minute.

3. A room air conditioning system adapted to be disposed on the inside of a wall containing a series of windows and a window sill therefor, comprising a sheet metal top panel adapted to be disposed as an extension of the window sill, a front panel adapted to be spaced from the wall and to support said top panel from the floor with the top panel extending into the room from said front panel, a horizontally disposed partition secured to said front panel and adapted to extend to the wall therefrom and to separate the space between said front panel and the wall and beneth said top panel into an upper plenum chamber and a lower air distributing chamber, a horizontal shelf secured on the front side of said front panel to provide a rigid support for storage purposes beneath said extended top panel, said partition having an opening to transmit air from said distributing chamber to said plenum chamber, a narrow slot in the top panel extending substantially for the full length thereof and adapted to discharge air upwardly from the plenum chamber at high velocities without noise, and duct means to supply air to said air distribution chamber at a rate effecting air discharge through said slot at velocities in excess of five hundred feet per minute.

References Citedin the file of this patent UNITED STATES PATENTS 587,373 Parker et al Aug. 3, 1897 2,235,500 Kitchen Mar. 18, 1941 2,395,233 Richardson Feb. 19, 1946 2,723,616 Hubbard Nov. 15, 1955 2,727,455 Miller et a1. Dec. 20, 1955 2,775,188 Gannon Dec. 25, 1956 2,796,016 De Roo June 18, 1957 FOREIGN PATENTS 525,222 Great Britain Aug. 23, 1940 112,969 Sweden Jan. 23, 1945

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