US3669349A

US3669349A - Air flow control system

Info

Publication number: US3669349A
Application number: US636748A
Authority: US
Inventors: William K Hall Jr
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-05-08
Filing date: 1967-05-08
Publication date: 1972-06-13
Anticipated expiration: 1989-06-13

Abstract

Environmental temperatures are controlled by selectively proportioning air flow from a pair of air flow paths by generation of a force proportional to temperature and dependent solely upon temperature for oppositely and proportionally changing registration of small openings in pairs of perforated plates laterally disposed in the air flow paths.

Description

United States Patent Hall, Jr.

[ 1 June 13, 1972 [54] AIR FLOW CONTROL SYSTEM [72] Inventor: William K. Hall, Jr., 1221 Frito-Lay Tower, Dallas, Tex. 75235 [22] Filed: May 8, 1967 [21] App1.No.: 636,748

Related [1.8. Application Data [63] Continuation-impart of Ser. No. 577,298, Sept. 6,

1966, abandoned.

[52] us. c1. ..236/13, 98/38, 98/40 D, 165/16, 236/49 51 1111.01 ..G05d 11/16, F.24r 13 04 [58] Field ot'Search ..98/38, 40, 38 E; 236/13, 49; 165 22, 16

[56] References Cited UNITED STATES PATENTS 1,455,846 5 1923 Lewis ..98/40 x 3,367,407 2/1968 Warren,.|r ..165/22 3,376,916 4/1968 Gressett ..98/38 2,266,217 12/1941 Kings1and.. ..236/13 2,430,759 11/1947 Crise ..236/13 X 2,835,449 5/1958 Joesting ..236/13 2,936,123 5/1960 Kreuttner .....236/13 2,971,450 2/1961 Millman ..98/38 3,114,505 12/1963 Kennedy.... ...98/38 X 2,976,884 3/1961 Kurth et a1.. ..98/38 2,987,982 6/1961 Wilson 1 ..98/38 3,179,338 4/1965 Ostrander ..98/38 Primary Examiner-William E. Wayner Attorney-Rogers, Ezell, Eilers & Robbins [57] ABSTRACT Environmental temperatures are controlled by selectively proportioning air flow from a pair of air flow paths by generation of a force proportional to temperature and dependent solely upon temperature for oppositely and proportionally changing registration of small openings in pairs of perforated plates laterally disposed in the air flow paths.

10 Claims, 17 Drawing Figures PATENTEDJUN 13 I972 SHEET 2 OF 6 88 FIG. 3 g

INVENTOR WILLIAM K. HALL, JR.

FIG. 4

ATTORNEY PATENTEDJUH13 I972 3, 669 349 sum 3 or e INVENTOR WILLIAM K. HALL, JR.

'Axww ATTORNEY PATENTEDJUH 1 3 I972 3 669 349 SHEET u 0F 6 l'I'I'I'I'I'I'l Ir INVEN'TOR WILLIAM K. HALL, JR. A). QM M FIG. I3

ATTORNEY PATENTEDJUH 1 3 i972 SHEET 8 BF 6 INVENTOR WILLIAM K. HALL, JR.

ATTORNEY AIR FLOW CONTROL SYSTEM RELATED APPLICATIONS This application is a continuation-in-part of application Ser. No. 577,298, filed Sept. 6, 1966, now abandoned.

FIELD OF THE INVENTION This invention relates to environmental control systems and more particularly to the control of air flow from warm and cool sources. In a more specific aspect, the invention relates to a flow control system which includes pairs of relatively slidable perforated plates positioned transversely of the flow paths leading from the sources. In a still further aspect, the invention relates to the development and direct use of forces produced solely in response to change in temperature for varying relative positions of such perforated plates.

PRIOR ART A wide variety of systems has been heretofore employed in the delivery of air to one or more zones where individual con trol of the temperature for each zone is desired. In the past, heat exchange units have been supplied for each zone with temperature sensing means for controlling the heat supplied to, or extracted from, air flowing to such zone. In air flow systems, motor-driven mechanically-actuated dampers have been widely employed. Further, in high pressure systems, the flow of supercooled air under high pressure to a particular area has been employed for inducing circulation.

The practical utilization of many of these previously developed temperature control systems has been limited by several factors. Many of the prior systems have not only required complex and expensive control and actuation devices for each temperature control unit, but have often required a separate control unit for each zone for which temperature control is desired. In addition to the economic limitations thus imposed upon many previously developed systems, the complex motor-operated construction of some systems has often not been entirely satisfactory with respect to maintenance requirements or operating efficiency. Further, many of the systems previously employed for zone temperature control have not been responsive to the temperature of air in the desired zone.

SUMMARY In accordance with the present invention, conduit means is mounted adjacent to a supply opening leading to a zone to be temperature controlled. Structure is provided which forms a -pair of air supply paths which lead to the conduit means. A

THE DRAWINGS Other objects and intended advantages of this invention will be more readily appreciated as they become better understood by reference to the following detailed description in connection with the accompanying drawings wherein:

FIG. 1 illustrates a system according to the present invention for individually controlling the temperature in a plurality of adjacent rooms;

FIG. 2 illustrates a system for conditioning the temperature in a plurality of vertically disposed room zones;

FIG. 3 illustrates a system utilizing common returned air to temperature condition adjacently disposed room zones;

FIG. 4 is a perspective view, partially cut away, of one embodiment of the present invention;

FIG. 5 is a cross-sectional view of the sensing unit of the device shown in FIG. 4;

FIG. 6 is another perspective view of the device shown in FIG. 4;

FIG. 7 is a perspective sectional view of a portion of the perforated plates shown in FIGS. 4 and 5;

FIG. 8 is a sectioned view of another embodiment of the perforated plates of the present invention;

FIG. 9 is a cross-sectional view of another embodiment of the perforated plates of the present invention;

FIG. 10 is a schematic diagram of a temperature conditioning system utilizing the present invention;

FIG. 11 is a perspective sectional view of the system embodying the device shown in FIG. 4;

FIG. 12 is a somewhat schematic view, partially in cross section, of the system shown in FIG. 1 1;

FIG. 13 is a cross-sectional view of another embodiment of a sensing unit of the present invention;

FIGS. 14-17 are perspective views, partially. cut away, of four different temperature control systems utilizing perforated plate control according to the present invention.

THE PREFERRED EMBODIMENTS FIGS. l-3 illustrate air temperature control systems wherein warm air or cool air reservoirs common to a plurality of individual zones to be temperature controlled may be utilized with the application of the present invention. FIG. 1 discloses a control system wherein the temperature of air in several adjacently disposed rooms may be maintained individually in accordance with their separate requirements. A warm air reservoir or plenum 10, which may, for example, be an attic space fed by return air from rooms therebelow, is commonly disposed to each of the rooms l2, l4, l6, and 18. Cool air is supplied from a suitable source through a duct 20 which forms a cool air supply path leading to a first control section 22 in a flow control unit 24 constructed in accordance with the present invention. Warm air is returned from the room 12 through the opening 26 to combined with the warm air in the reservoir 10 to form a warm air supply path leading to a second control section 28 on the control unit 24. The control sections each comprise pairs of perforated plates, one slidable with respect to the other, and so actuated as to proportion the air flowing therethrough in dependence upon temperature, as will be described in greater detail. A fan is' located in the control unit 24 to pull air through the

control sections

22 and 28 in such proportions as required to control the temperature of room 12. The air from the warm and the cool supply paths is mixed and then supplied to room 12 through

conduits

30 and 32 and through

supply openings

34 and 36, respectively.

Also illustrated in FIG. 1 is another embodiment of a system utilizing the present invention, wherein cool air from aduct 38 supplies a portion of air through openings 40 into room 14, opening 42 into room 16, and opening 44 into room 18 in such proportions as determined by the

control units

46 and 48, constructed in accordance with the present invention. Warm air is. returned through opening 50 from room 14 into the reservoir 10 for mixture with the cool air supplied by the duct 38 in such proportions as is determined by the control unit 46. In a somewhat similar manner, warm air is supplied to an opening 52 from room 18 to be mixed with the cool air supplied by the duct 38 in such proportions as is determined by the control unit 48. The proportions of warm air and cool air are accurately controlled in response to sensing devices exposed to air of the temperature of the air in the individual rooms, thus allowing individual temperature control of each of the adjacently disposed rooms. 7

FIG. 2 illustrates the use of the present invention in a temperature control system for a plurality of vertically disposed rooms in a building. A cool air reservoir or plenum 54, common to a plurality of vertical rooms, contains cool air supplied by a blower 55 in a conventional cooling unit 56, which may utilize conventional dampers 58 to control the inlet of outside air. A warm air return plenum 60 contains warm exhaust air supplied by the rooms and from the cool air reservoir 54 through the grille 62. The plenum 60 is connected through conduit 63 and suitable dampers to the cooling unit 56.

As may be seen, a system utilizing the present invention may take any one of a variety of forms. For instance, the system for independently controlling the temperature of room 64 supplies conditioned air to the inlets 66 through conduits 67, the conditioned air being mixed by the control unit 68 from the warm air returned through the outlets 69 and the cool air supplied through the path 70. A similar system is shown for conditioning the air of room 72 wherein rigid ductwork 74 is utilized instead of flexible conduits. If desired, a plurality of control units may be utilized for conditioning a single room, as shown by the three

units

76, 78, and 80, which selectively proportion the amount of cool air from the reservoir 54 and the warm air from the attic plenum 82 mixed and provided to the room.

FIG. 3 illustrates a conditioning system for a pair of

rooms

84 and 86 which are commonly disposed to a warm air attic reservoir 88 and a cool air reservoir 90. Warm air from

rooms

84 and 86 flows to a common plenum 92 and a conduit 93 and thence into a conventional cooling system 94. A blower unit 95 supplies a continuous supply of cool air to the reservoir 90. Warm air also flows from the

rooms

84 and 86 into the attic reservoir 88 through

openings

85 and 87, respectively. A pair of

control units

96 and 98, constructed in accordance with the present invention, are mounted between the warm air reservoir 88 and the cool air reservoir 90 in order to selectively proportion the mixture of the two air supplies which is fed into

rooms

84 and 86, respectively.

While refrigeration units have been illustrated in conjunction with the embodiments described, it will be appreciated that, if desired, cold air could be provided from an outside environment and heating means could be provided to supply a source of warm air.

The construction of a control unit in accordance with the present invention may be best understood by reference to FIGS. 46, wherein the unit 100 is enclosed by a main housing 102. Housing 102 is an elongated rectangular polyhedron conveniently formed of sheet metal. Housing 102 may have one or more removable panels 104 for repair or maintenance access.

A pair of conventional

blower fan units

106 and 108 include rotatable vaned cages 109 and 1 l driven by an electric motor 111. The operation of electric motor 111 is controlled by a suitably placed wall switch 112 connected through cable 113 which controls the application of power from a suitable source (not shown) to the motor. Rotation of the

cages

109 and 110 induces flow of supply air through a first perforated plate unit 1 l4 and a second perforated plate unit 116.

Perforated plate units 114 and l 16, as shown in FIG. 6, are disposed relative to one another at an angle corresponding with the junction of warm and cool air supply paths.

Rectangular flanges

117 and 118 may be provided about the outer openings of the plate sections in order to enable connection with air conduits. As shown in FIG. 7-, plate unit 114 comprises a fixed plate 122 adjacent to a slidable plate 128.

Plates

122 and 128 have perforations therein which may be brought into registration or moved out of registration to open or close the air flow path and thus proportion the air passing through the housing 102. Plate unit 1 16 includes slidable plate 139 and fixed plate 134. Air flowing through

plate units

114 and 1 16 is expelled by the fan units through their

respective outlets

119 and 120.

Referring again to FIG. 7, plate unit 114 comprises a first plate 122 which is fixedly connected at one edge to a bracket member 124 which is in turn connected to the main housing 102 of the unit. The other edge of the plate 122 is connected to housing 102 by means of a folded flange 125 (FIG. 4). Plate 122 includes a plurality of elongated perforations 126 defined therethrough in a predetermined alternating pattern. A second plate 128, comprising one-half of an integral plate having a central right angle bend, is slidable adjacent to the plate section 122. Plate 128 is connected to the rod 130, as by welding, for slide movement relative to plate 122.

Plate 128 includes a plurality of elongated perforations 132 disposed in the same pattern as the perforations 126 in the plate 122, so that the perforations in the adjoining plates may be selectively brought into registration or moved out of registration in order control the flow of air therethrough. In FIG. 7, the

perforations

126 and 132 are disposed in exact registration so that the passage of air therethrough is substantially unimpeded. Upon a slight vertical movement of the rod 130, the perforations may be moved out of registration in order to accurately adjust the magnitude of the air flow therethrough.

The second plate unit 116 comprises a first plate 134 rigidly secured to the bracket member 136 and having a plurality of elongated perforations 138 disposed therethrough in a predetermined pattern. The plate 134 is offset with respect to the plate 122 so that the perforations through the two plates are not aligned. The second half of the bent plate, plate 139, has a plurality of perforations 140 and is adjacent to the plate 134. Because the perforation patterns of

plates

122 and 134 are offset, when the perforations of the plate unit 1 14 are exactly aligned, the perforations of the second plate unit 116 are unaligned. In such case, the flow of air through the second plate unit 1 16 is thus totally obstructed.

Upon movement of the rod 130, however, the plates I28 and 139 would be moved relative to both the

plates

122 and 134, thereby decreasing the proportion of air allowed to pass through the first plate unit 1 14, while concurrently increasing the proportion of air allowed to pass through the second plate unit 116. It will be understood that fine control of the passage of air, and similar control of mixing of air from two different air supply paths, may be accomplished by the present device. Only a very small mechanical movement is required to change one pair of plates from open to closed. The elongated slot configuration shown in FIG. 7 has the distinct advantage of not requiring extremely accurate manufacturing dimensioning to provide substantial registration of the perforations while maintaining at a minimum the travel necessary to open and close a pair of plates.

FIG. 5 discloses means for moving rod 130 to adjust the positions of the perforated plates. A fluid filler sensor 141 is connected in fluid communication with a fluid chamber 142 by means of a line 144. An insert 146 within the chamber 142 limits the upward movement of the end 148 of an elongated linkage 150. A housing 152 provides a fluid-tight seal about the linkage 150, and a bias spring 154 is disposed between the end 148 and the housing 152. A threaded portion 158 on the linkage provides for connection to an extension 156 on the rod 130 in order to allow initial adjustment of the position of the rod 130 for proper alignment of the perforations.

A fluid conduit 160 connects the chamber 142 in fluid communication with an adjustment mechanism 162 comprising a hollow chamber 164 also filled with the fluid. A slidable piston 166 is biased against the fluid in the chamber 164 by a spring 168. A dial 170 may be manually turned to selectively increase or decrease the tension applied by the piston 166 against the fluid. The variance of pressure on the fluid acts on the end 148 to move the linkage 150 vertically. By suitable adjustment of dial 170, therefore, the static position of the rod 130 and the

outer plate sections

128 and 139 may be adjusted to provide either warmer or cooler air flow. I

In operation of the present unit, the dial 170 is set to the desired operating temperature. The sensor 141 senses air of the temperature of air in a room. If the temperature increases, the fluid inside the sensor 14] tends to expand, overcoming the bias pressure of the spring 154 and moving the linkage 150 downwardly. This causes the'rod 130 and thus the

perforated plate sections

128 and 139 to be moved downwardly, thereby changing the registration of the perforations. This movement concurrently increases the amount of cool air and decreases the amount of warm air supplied to the room.

Conversely, if the temperature of the room air drops, the volume of the fluid inside the sensor 141 and the chamber 142 will decrease. Spring 154 moves the

perforated sections

128 and 139 upward. The change causes the temperature of the air in the room to be raised. The novel construction of the present invention thus allows very accurate control of the air supply to a room in response to only a very slight mechanical movement. This movement is within the capabilities of the expandable fluid sensing device 141.

Other configurations of perforations may be employed in the perforated plates. For example, FIG. 8 illustrates a plurality of substantially circular perforations 171 distributed in predetermined patterns through fixed

plates

172 and 173. A movable outer plate 174 is connected, as by welding, to the rod 176 for movement relative to the fixed

plates

172 and 173. The plate 174 includes a plurality of circular perforations 175 which may be moved into registration with the openings of only one of the fixed

plates

172 or 173 at a time.

FIG. 8 illustrates a position of the plate 174 such that the perforations 175 are in registration with the perforations in plate 172. In this position, the perforations in plate 174 are out of registration with the openings of the plate 173, thereby preventing the passage of air therethrough. It will be understood that other configurations of perforations may also be employed for the plates, as, for example, square, rectangular, and the like.

The plates above described may advantageously be constructed of rigid material, preferably of stainless steel. Plate sections of other metals, such as aluminum or the like, may also be used when corrosion will not adversely affect operatron.

It may be found advantageous to construct one or more of the plates from a flexible material, in the manner illustrated in FIG. 9. In this embodiment, the perforated plate 178 is constructed from stainless steel, while the perforated plate 180 is constructed from a flexible material, such as neoprenecovered canvas or the like. By placing the flexible plate upstream of the rigid plate section, the pressure of the air flow against the flexible plate will press it against the rigid plate, thereby minimizing the loss of air through the space between the plates. Alternatively, a felt-like material may be bonded to one side of two stainless steel plates of a pair, and between them, in order to cut down air loss and to resist corrosion.

FIG. illustrates another embodiment of a sensing apparatus for use with the present control unit 181 above described for control of the temperature in room 184. A bimetallic circuit controller 185 is mounted on the wall 187 or in some other suitable place in order to sense the temperature of air in room 184. Such a bimetallic controller conventionally changes from one position to another in order to open or close an electrical contact (not shown). The controller 185 serves to energize and de-energize a servo motor 186 which is connected through a mechanical linkage 188 to the movable

perforated plate sections

182 and 183. Energization of the servo motor 186, also of a conventional construction, selectively varies the alignment of the perforations in the plate sections in order to control the content of the air being supplied to room 184.

FIGS. 11 and 12 illustrate a system utilizing the sensing device shown in FIG. 5. In this application, the control unit 190 has perforated

plate sections

191 and 192 operated in dependence upon an expandable fluid sensor 193. Sensor 193 is disposed in an air conduit 194. The conduit 194 is connected at one end to a wall panel box 196 having a perforated front panel 198 to allow the passage of air from a room therethrough. The other end of the air conduit 194 is connected to a junction box 200 mounted on the unit 190. Electric power from a suitable source may be provided to energize the blower fans in the unit 190 through

cables

204 and 206.

An electrical switch 208 is remotely disposed from the unit 190 and is mounted on the perforated panel 198 in order to allow remote adjustment of the speed of the blower in unit 190. Similarly, a temperature selector mechanism 210, similar to that shown in FIG. 5, in fluid communication with the expandable liquid sensor 193, is mounted on the perforated panel 198 in order to allow remote adjustment of the temperature of the air of the room.

The wall panel box 196 ordinarily will be mounted in the space between

room wall panels

212 and 214. The end of the air conduit 194 connected to the junction box 200 is disposed upstream of the blower of the unit so that room air passes through the conduit 194 and flows over the sensor 193. If desired, the remote end of the conduit 194 may be disposed between the

wall panels

212 and 214 in order to sample warm air from the room being returned to a warm air reservoir. Alternatively, the sensor 193 may be disposed in a region downstream from the blower fans of the unit 190 in order to sample the air flow to a given room.

FIG. 13 illustrates another embodiment of a suitable temperature sensor for mechanically moving perforated plates relative to one another. A housing 216 includes an inlet port 218 for entry of air whose temperature is to be sampled and further includes an annular ring 221 having outlet ports 220 for exhausting air.

A temperature sensitive device 222 contains an expandable material and may be of the type manufactured by American- Standard Controls Division, Detroit, Michigan, and sold under the name Vernatherm Valve. Unit 222 is mounted on a bracket 224. A piston 226 is movable into and out of unit 222 in response to expansion of the material therein in response to temperature changes. A pin 228 is connected to the piston 226 and includes a threaded portion 230 adapted to connect to a rod 232. Rod 232 is to be connected to the movable perforated plates above described. A sleeve 234 abuts a cup 236 which is biased by a spring 238. A base cup 240 abuts the lower end of spring 238 and has a central opening through which pin 228 passes.

The base cup 240 includes a threaded section 242 which threadedly mates with threads in the annular ring 221. Ring 221 also includes a threaded portion 244 which mates with threads in the housing 216. The threaded

portions

242 and 244 may be provided with threads of different pitch to allow for initial adjustment of the static position of the sensing device. A coarse adjustment may be made by rotation of the annular ring 221. A fine adjustment may be made by rotation of the base member 240 relative to the ring 221.

The sensor illustrated in FIG. 13 preferably is mounted on or near a control unit and is mechanically linked to movable perforated plates through the rod 232. The unit of FIG. 13 may be mounted in the conduit opening into a room in order to sense the temperature of the air being supplied to the room. Alternatively, it may be mounted in or near the return paths from a room. In each of these embodiments, a mechanical linkage may connect the cup 240 to a manually operable wallmounted actuator or control knob to allow adjustment of the set point.

Other applications of the present invention will be apparent upon consideration of FIGS. 14-17, wherein perforated plate control according to the present invention is utilized in four different types of temperature control systems. FIG. 14 illustrates a supply grille or conduit 246 which has a rectangular frame 248 adapted to be releasably mounted in a supply opening leading to a room. A warm air supply path 250 is partially defined by a duct collar 252 having insulation 254 installed therein. A cool air supply path 256 is located beneath the warm air supply path 250 and is defined by the collar 252and an insulated divider partition 258.

The two

air supply paths

250 and 256 are fed into the room from suitable sources through pairs of perforated plates constructed in accordance with the present invention. More particularly, an integral perforated plate 260 is rigidly mounted between the frame 248 and a bracket 262 connected to the duct collar 252. A pair of movable

perforated plates

264 and 266 are slidably disposed in a groove in the bracket 262 and are connected to the horizontally movable bar 268. Thus, a first pair of perforated plates comprising the upper portion of plate 260 and the movable plate 264 is transversely disposed in the warm air path 250. Similarly, a second pair of perforated plates comprising the lower portion of the fixed perforated plate 260 and the movable plate 266 is transversely disposed in the cool air supply path. The plate section pairs may thus be relatively moved, in the manner previously described, to selectively adjust the registration of the perforations in adjacent plates to control the mixture of warm and cool air which is supplied to the room.

The force for moving bar 268 is provided by the power unit 270, which may, for instance, be of the expandable fluid or material type previously described. Pressure resulting from fluid expansion in the power unit 270 acts upon the head 272 of a rod 274. A spring 276 biases the head 272 against the bottom of the lower housing 278 of the power unit. The lower end of rod 274 is connected to a threaded member 280 by adjusting nut 282 in order to allow initial adjustment of the position of the perforated plates. The threaded member 280 is connected to a projection 284 from bar 268 by a plurality of screws 286. The frame 248 and the fixed perforated plate 260 are thus made to be easily removed for maintenance purposes. More particularly, screws 286 are disposed to be easily accessible upon the removal of frame 248 and plate 260 to allow the

movable plates

264 and 266 to be removed for servicing.

FIG. illustrates the use of perforated plates in a temperature control system wherein cool air is forced into a room through a nozzle 288 and a duct 290. Return air from a warm air plenum may be selectively mixed with the cool air by means of a venturi type action created by the flow of air through the nozzle 288. This venturi action induces flow of warm air into the duct 290 through the perforated plate pairs 292 and 294.

The perforated plate pairs include a horizontally slidable plate 296 which is transversely disposed across both of the warm return air paths and also across the cool air supply path. Plate 296 is connected to a guide bracket 298 which is horizontally slidably mounted upon a frame member 300 which rigidly connects nozzle 288 to the front duct frame 301. A power unit 302 is connected to move the rod 304, which in turn moves a projecting member 306 and bar 298.

A perforated plate 308 is mounted in the duct 290 adjacent to the movable perforated plate 296. The fixed perforated plate 308 may comprise a unitary plate having a predetermined pattern of aligned perforations at the top and the bottom portions of the plate which are disposed adjacent the

movable plates

292 and 294, and a pattern of horizontally offset perforations in the middle portion of the plate which is disposed transversely across the opening of the nozzle 288.

Alternatively, the movable plate 296 may comprise three sheets mounted adjacent to each other, with the perforations of the top and bottom plate sections being aligned and the perforations of the middle plate being horizontally offset. In either embodiment, it will now be apparent that when the movable perforated plate 296 is horizontally translated in response to changes of air temperature in the room to be conditioned, the proportion of cool air supplied through the duct 290 may be selectively modulated in one sense while the proportion of warm return air is concurrently modulated in the opposite sense.

FIG. 16 illustrates another type of temperature control system 310, generally known as a double duct constant volume system. Warm air under a high pressure is fed through the supply inlet 312 into the housing 314, while cool air under high pressure is supplied through the inlet 316. A partition 318 divides the air supply paths inside the front portion of the housing 314. The warm and the cool air are then mixed in the back portions of the housing 314 in proportions determined by transversely disposed

perforated plates

320 and 322. The plate 322 is rigidly connected to the housing 314. Plate 320 is movable in response to movements of the temperature sensitive power unit 324. The power unit 324 moves the movable plate 320 by means of a projection 326 mounted on a transversely disposed bar 328 rigidly connected to plate 320. The bar 328 is slidable through a slot 330 in the partition 318.

The perforated plates are supported by a spacer member 332 which has provisions to allow a sliding movement of the plate 320. The perforations in the movable plate disposed in the warm air supply path are horizontally offset with respect to the perforations in the movable plate disposed in the cool air supply path. This allows the proportion of air supplied to the room by the warm air supply path to be selectively increased while concurrently the proportion of air supplied to the room by the cool air supply path is decreased, or vice versa.

FIG. 17 illustrates the use of the present invention in a temperature control system commonly termed a high velocity induction unit. In this system, a bypass control simultaneously modulates the amount of return room air which passes over heating or cooling coils and theamount of return room air bypassed around the coils. For example, in the illustrated system of FIG. 17, return room air is induced to flow through a grille 333 and then through

perforated plate units

334 and 336. Air flow through plates 334 bypasses the heating or cooling coils in zone 337. A bafile 338 separates the two flows of air. Air passing through plates 336 contacts the heat exchange elements in zone 337. The perforated plate pairs are constructed in a manner similar to the units previously described, with a slidable plate 340 being connected to a bracket 342 which is horizontally moved by a power unit 343. The bracket 342 slides along an edge portion of the baffle 338. A fixed plate 344 is connected to the frame 346.

It will be understood from the embodiments previously described that the perforations of one perforated plate section in each of the perforated plate pairs 334 and 336 are horizontally offset with respect to one another so that the proportion of room air return supplied through one path may be concurrently increased while the proportion of room air return supplied through the second path is concurrently decreased.

Whereas the present specification has been described in considerable detail with respect to several embodiments, it is to be understood that this description is merely for purposes of illustration and that changes or variations in the described embodiments may be made by persons skilled in the art without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. In a system for control of air in a room having a supply opening leading thereto, the combination which comprises:

a. a powered mixing box adapted to be mounted adjacent to said supply opening for directing air through said supply opening into said room;

b. said powered mixing box having a first inlet opening, a

second inlet opening, and an outlet opening,

c. a first structure forming a warm air supply path leading to said first inlet opening of said powered mixing box;

d. a second structure forming a cool air supply path leading to said second inlet opening of said powered mixing box;

e. a first pair of plates, at least one of which is perforated;

f. said first pair of plates being mounted so they are always immediately adjacent said first inlet opening and are transversely disposed in, and substantially normal to, said warm air supply path;

g. a second pair of plates, at least one of which is perforated;

h. said second pair of plates being mounted so they are always immediately adjacent said second inlet opening and are transversely disposed in, and substantially normal to, said cool air supply path;

i. means interconnecting one plate of each pair for moving one plate of said first pair relative to the other in a first sense while moving one plate of said second pair relative to the other in a second sense to increase the proportion of air supplied to said powered mixing box through one air supply path while concurrently decreasing the proportion of air supplied to said powered mixing box through the other air supply path;

j. said outlet opening being located in one wall of said powered mixing box and both of said inlet openings being displaced short distances from said one wall of said powered mixing box to define a space which is wholly within said powered mixing box and which is bounded by said outlet opening and by said pairs of perforated plates, and

k. a fan that is mounted in said space within said powered mixing box and that is immediately adjacent to said pairs of plates;

1. said fan being disposed within said space within said powered mixing box but being located downstream from said plates of said first pair of plates and also being located downstream from said plates of said second pair of plates,

m. said fan receiving warm air from said warm air supply path via said first inlet opening and said first pair of plates and receiving cool air from said cool air supply path via said second inlet opening and said second pair of plates and mixing said warm air and cool air and then moving said mixed air through said outlet opening and into said room through said supply opening.

2. The combination set forth in claim 1 wherein said first inlet opening is located in a second wall of said powered mixing box, wherein said second inlet opening is located in a third wall of said powered mixing box, wherein said second and said third walls abut each other to subtend an angle of substantially ninety degrees, whereby said pairs of plates are disposed relative one to another at an angle of substantially ninety degrees, and wherein three sides of said space within said powered mixing box are defined and delimited by said one and said second and said third walls of said powered mixing box.

3. A system for controlling the temperatures within a plurality of rooms which comprises:

a. a plenum forming a cold air reservoir common to said plurality of rooms, means including an air unit having the outlet thereof connected to said plenum for supplying and creating flow of cold air into said cold air reservoir,

c. a second plenum common to said plurality of rooms,

d. structure connecting each of said rooms with said second plenum to permit return air from said rooms to enter said second plenum,

said air unit having the inlet thereof connected to said second plenum to receive said return air from said rooms via said second plenum,

f. a plurality of separate air drive means opening into said rooms,

g. each of said air drive means having a first inlet for receiving warm air, a second inlet connected to the first said plenum for receiving cold air from said cold air reservoir, a fan, a proportioning damper between said inlets and said fan, and an outlet for mixed air,

h. said proportioning damper varying the proportions of warm air and cold air which said fan draws through said first and second inlets, respectively, and then discharges through said mixed air outlet,

'. the first said plenum being substantially larger in cross section than the discharge outlet of said air unit, and being substantially larger in cross section than the second inlet of any of said separate air drive means, whereby the first said plenum holds a large volume of cold air im mediately available to said separate air drive means,

j. said second plenum being substantially larger in cross section than said inlet of said air unit, whereby said second plenum holds a large volume of return air immediately available to said air unit, and

k. means responsive to the temperature of air in a given room for control of the position of said proportioning damper, in said air drive means for said room, to determine the relative proportions of warm and cold air introduced into said room by its air drive means.

4. A system for controlling the temperatures within a plurality of rooms which comprises:

a. a plenum forming a cold air reservoir common to said plurality of rooms,

b. means including an air unit having the outlet thereof connected to said plenum for supplying and creating flow of cold air into said cold air reservoir,

c. a second plenum common to said plurality of rooms,

e. said air unit having the inlet thereof connected to said second plenum to receive said return air from said rooms via said second plenum,

. a plurality of separate air drive means opening into said rooms,

. the first said plenum being substantially larger in cross section than the discharge outlet of said air unit, and

being substantially larger in cross section than the second inlet of any of said separate air drive means, whereby the first said plenum holds a large volume of cold air immediately available to said separate air drive means,

j. said second plenum being substantially larger in cross section than said inlet of said air unit, whereby said second plenum holds a large volume of return air immediately available to said air unit,

k. means responsive to the temperature of air in a given room for control of the position of said proportioning damper, in said air drive means for said room, to determine the relative proportions of warm and cool air introduced into said room by its air drive means,

. the first said plenum and said second plenum being horizontally directed,

in. one of said plenums being located immediately above the other of said plenums,

n. the lower limit of said one plenum and the upper limit of said other plenum being defined and delimited by a horizontally-directed partition means,

0. the return air flow through said second plenum being in one direction relative to said rooms, and

p. the cold air flow through said one plenum being in the opposite direction relative to said rooms.

5. A system for controlling the temperatures within a plurality of rooms which comprises:

a. a plenum forming a cold air reservoir common to said plurality of rooms, I

means including an air unit having the outlet thereof connected to said plenum for supplying and creating flow of cold air into said cold air reservoir,

. a second plenum common to said plurality of rooms,

structure connecting each of said rooms with said second plenum to permit return air from said rooms to enter said second plenum,

a plurality of separate air drive means opening into said rooms,

i. the first said plenum being substantially larger in cross section than the discharge outlet of said air unit, and being substantially larger in cross section than the second inlet of any of said separate air drive means, whereby the first said plenum holds a large volume of cold air immediately available to said separate air drive means,

said second plenum being substantially larger in cross section than said inlet of said air unit, whereby said second plenum holds a large volume of return air immediately available to said air unit,

. means responsive to the temperature of air in a given in. connecting means for permitting warm air flow from said warm air reservoir into said first inlets of said air drive means through said connecting means.

An atmosphere control system for a building having a plurality of rooms which comprises:

a cooling unit that includes a blower which can supply quantities of cooled air,

structural elements of said building which define and delimit parts of rooms of said building and which also define and delimit part of a large cross section plenum that extends from a point adjacent said cooling unit to the immediate proximity of said rooms,

. the outlet of said blower of said cooling unit being connected to said plenum for feeding cool air into said plenum from said cooling unit, and said plenum conducting said cool air to the immediate proximity of said rooms,

a plurality of air-mixing boxes,

said air-mixing boxes being disposed adjacent said rooms,v

and each of said air-mixing boxes having structure forming two inlet ports, a fan mounted between said inlet ports and a discharge port leading to a room,

said fan in said air-mixing box acting to move air from said inlet ports to and through said discharge port and thence into said room,

. a cool air flow path between said plenum and one'of said inlet ports of each said air-mixing box to conduct cool air from said plenum to said one inlet port,

. further structural elements of said building which define and delimit parts of rooms of said building and which also define and delimit part of a second large cross section plenum that extends from the immediate proximity of said rooms to a point adjacent said cooling unit,

. the inlet of said blower of said cooling unit being connected to said second plenum,

. a warm air flow path from each said room to a second of said inlet ports of said air-mixing boxfeeding said room to conduct air from said room to said second inlet port,

structure forming flow paths from said rooms to said second plenum to include return air from said rooms in the air flowing through said second plenum,

. said second plenum conducting return air from said rooms to said cooling unit and thereby enabling said cooling unit to cool return air from said rooms and to include the cooled return air in the air which said cooling unit supplies to the first said plenum,

m. temperature responsive means in said rooms, and

proportioning damper means in each said air-mixing box between the inlet ports thereof and the fan therein to vary the relative amounts of cooled air entering each air-mixing box from the first said plenum and the amounts of air entering each air-mixing box from the room.

a powered cooler for supplying quantities of cool air,

means which define and delimit an air-distributing passage that extends from a point adjacent said powered cooler to the immediate proximity of said rooms,

. the outlet of said powered cooler being connected to said air-distributing passage for feeding cool air into said airdistributing passage from said powered cooler, and said air-distributing passage conducting said cool air to the immediate proximity of said rooms,

. a plurality of air-mixing boxes,

said air-mixing boxes being disposed adjacent to said rooms and each of said air-mixing boxes having structure fonning two inlet ports, a fan mounted between said inlet ports and a discharge port leading to a room, said fan in said air-mixing box acting to move air from said inlet ports to and through said discharge port and thence into said room,

a cool air flow path between said air-distributing passage and one of said inlet ports of each said air-mixing box to conduct cool air from said air-distributing passage to said one inlet port,

a warm air flow path from each said room to a second of said inlet ports of said air-mixing box feeding said room to conduct air from said room to said second inlet port, structure forming a return flow path from said rooms to the inlet of said powered cooler to enable said powered cooler to receive and cool return air from said rooms and to incorporate the cooled return air in the air which said powered cooler supplies to said air-distributing passage,

j. temperature responsive means in said rooms,

a proportioning damper in each said air-mixing box between the inlet ports thereof and the fan therein to vary the relative amounts of air entering each air-mixing box from said air-distributing passage and the amounts of air entering each air-mixing box from the room, and means providing a continuously-open path which extends from the outlet of said powered blower to the inlet of said powered blower,

in. said continuously-open path means conducting substantially all of the air, supplied by said powered blower, from said outlet of said powered blower to said inlet of said powered blower whenever all of said proportioning dampers in all of said air-mixing boxes are closed and act to prevent air in said air-distributing passage from entering said air-mixing boxes,.

. thereby preventing any build-up of pressure within said air-distributing passage,

said continuously-open path means conducting progressively less of the air, supplied by said powered blower, from said outlet of said powered blower to said inlet of said powered blower as said proportioning dampers in said air-mixing boxes respond, to said temperature responsive means in said rooms, to progressively permit air from said air-distributing passage to enter said air-mixing boxes.

a powered cooler for supplying quantities of cool air,

. a plurality of powered air-mixing boxes,

said air-mixing boxes being disposed adjacent to said rooms and each of said air-mixing boxes having structure forming two inlet ports, a fan mounted between said inlet ports and a discharge port leading to a room,

. a warm air flow path from each said room to a second of said inlet ports of said ainmixing box feeding said room to conduct air from said room to said second inlet port,

. structure forming a return flow path from said rooms to said powered cooler to enable said powered cooler to cool return air from said rooms and to include the cooled return air in the air which said powered cooler supplies to said airrdistributing passage,

j. temperature responsive means in said rooms,

k. a proportioning damper in each said air-mixing box between the inlet ports thereof and the fan therein to vary the relative amounts of air entering each air-mixing box from said air-distributing passage and the amounts of air entering each air-mixing box from the room,

I. continuously-open passages interconnecting said rooms with said return air structure,

in. means providing a continuously-open path between said air-distributing passage and said return air structure,

n. said continuously-open passages between said rooms and said return air structure and said continuously-open path means coacting to connect said rooms with said air-distributing passage via said return air structure,

. whereby said rooms are connected to said air-distributing passage both by said air-mixing boxes and by said continuously-open path means and the continuously-open passages which interconnect said air return structure with said rooms.

9. An atmosphere control system for a building having a plurality of rooms which comprises:

a. a cooling unit that includes a blower which can supply quantities of cooled air,

b. structural elements of said building which define and delimit parts of rooms of said building and which also define and delimit part of a large cross section plenum that extends from a point adjacent said cooling unit to the immediate proximity of said rooms, the outlet of said blower of said cooling unit being connected to said plenum for feeding cool air into said plenum from said cooling unit, and said plenum conducting said cool air to the immediate proximity of said rooms,

a plurality of air-mixing boxes, said air-mixing boxes being disposed adjacent said rooms,

a cool air flow path between said plenum and one of said inlet ports of each said air-mixing box to conduct cool air from said plenum to said one inlet port,

j. a warm air flow path from each said room to a second of said inlet ports of said air-mixing box feeding said room to conduct air from said room to said second inlet port,

k. structure forming flow paths from said rooms to said second plenum to include return air from said rooms in the air flowing through said second plenum,

m. temperature responsive means in said rooms,

n. proportioning damper means in each said air-mixing box between the inlet ports thereof and the fan thereinto vary the relative amounts of cooled air entering each air-mixing box from the first said plenum and the amounts of air entering each air-mixing box from the room,

0. the first said plenum and said second plenum being horizontally-directed,

p. one of said plenums being located immediately above the other of said plenums, q. the lower limit of said one plenum and the upper limit of said other plenum being defined and delimited by a horizontally-directed partition means,

r. the return air fiow through said second one direction relative to said rooms, and

s. the cold air flow through said one plenum being in the opposite direction relative to said rooms.

10. An atmosphere control system for a building having a plurality of rooms which comprises:

a. a cooling unit that includes a blower which can quantities of cooled air,

b. structural elements of said building which define and delimit parts of rooms of said building and which also define and delimit part of a large cross section plenum that extends from a point adjacent said cooling unit to the immediate proximity of said rooms,

c. the outlet of said blower of said cooling unit being connected to said plenum for feeding cool air into said plenum from said cooling unit, and said plenum conducting said cool air to the immediate proximity of said rooms,

d. a plurality of air-mixing boxes,

e. said air-mixing boxes being disposed adjacent said rooms,

f. said fan in said air-mixing box acting to move air from said inlet ports to and through said discharge port and thence into said room,

g. a cool air flow path between said plenum and one of said inlet ports of each said air-mixing box to conduct cool air from said plenum to said one inlet port,

h. further structural elements of said building which define and delimit parts of rooms of said building and which also define and delimit part of a second large cross section plenum that extends from the immediate proximity of said rooms to a point adjacent said cooling unit,

i. the inlet of said blower of said cooling unit being connected to said second plenum,

. said second plenum conducting return air from said rooms to said cooling unit and thereby enabling said cool-ing unit to cool return air from said rooms and to include the cooled return air in the air which said cooling unit supplies to the first said plenum,

m. temperature responsive means in said rooms,

n. proportioning damper means in each said air-mixing box between the inlet ports thereof and the fan therein to vary the relative amounts of cooled air entering each air-mixing box from the first said plenum and the amounts of air entering each air-mixing box from the room,

0. the first said plenum being located between said rooms,

p. the first said structural elements being the upper portions of confronting walls of said rooms plus a horizontallydirected ceiling extending between said upper portions of said confronting walls, and

q. a lower ceiling defining the bottom of the first said plenum.

plenum being in pp y

Claims

1. In a system for control of air in a room having a supply opening leading thereto, the combination which comprises: a. a powered mixing box adapted to be mounted adjacent to said supply opening for directing air through said supply opening into said room; b. said powered mixing box having a first inlet opening, a second inlet opening, and an outlet opening, c. a first structure forming a warm air supply path leading to said first inlet opening of said powered mixing box; d. a second structure forming a cool air supply path leading to said second inlet opening of said powered mixing box; e. a first pair of plates, at least one of which is perforated; f. said first pair of plates being mounted so they are always immediately adjacent said first inlet opening and are transversely disposed in, and substantially normal to, said warm air supply path; g. a second pair of plates, at least one of which is perforated; h. said second pair of plates being mounted so they are always immediately adjacent said second inlet opening and are transversely disposed in, and substantially normal to, said cool air supply path; i. means interconnecting one plate of each pair for moving one plate of said first pair relative to the other in a first sense while moving one plate of said second pair relative to the other in a second sense to increase the proportion of air supplied to said powered mixing box through one air supply path while concurrently decreasing the proportion of air supplied to said powered mixing box through the other air supply path; j. said outlet opening being located in one wall of said powered mixing box and both of said inlet openings being displaced short distances from said one wall of said powered mixing box to define a space which is wholly within said powered mixing box and which is bounded by said outlet opening and by said pairs of perforated plates, and k. a fan that is mounted in said space within said powered mixing box and that is immediately adjacent to said pairs of plates; l. said fan being disposed within said space within said powered mixing box but being located downstream from said plates of said first pair of plates and also being located downstream from said plates of said second pair of plates, m. said fan receiving warm air from said warm air supply path via said first inlet opening and said first pair of plates and receiving cool air from said cool air supply path via said second inlet opening and said second pair of plates and mixing said warm air and cool air and then moving said mixed air through said outlet opening and into said room through said supply opening.

3. A system for controlling the temperatures within a plurality of rooms which comprises: a. a plenum forming a cold air reservoir common to said plurality of rooms, b. meanS including an air unit having the outlet thereof connected to said plenum for supplying and creating flow of cold air into said cold air reservoir, c. a second plenum common to said plurality of rooms, d. structure connecting each of said rooms with said second plenum to permit return air from said rooms to enter said second plenum, e. said air unit having the inlet thereof connected to said second plenum to receive said return air from said rooms via said second plenum, f. a plurality of separate air drive means opening into said rooms, g. each of said air drive means having a first inlet for receiving warm air, a second inlet connected to the first said plenum for receiving cold air from said cold air reservoir, a fan, a proportioning damper between said inlets and said fan, and an outlet for mixed air, h. said proportioning damper varying the proportions of warm air and cold air which said fan draws through said first and second inlets, respectively, and then discharges through said mixed air outlet, i. the first said plenum being substantially larger in cross section than the discharge outlet of said air unit, and being substantially larger in cross section than the second inlet of any of said separate air drive means, whereby the first said plenum holds a large volume of cold air immediately available to said separate air drive means, j. said second plenum being substantially larger in cross section than said inlet of said air unit, whereby said second plenum holds a large volume of return air immediately available to said air unit, and k. means responsive to the temperature of air in a given room for control of the position of said proportioning damper, in said air drive means for said room, to determine the relative proportions of warm and cold air introduced into said room by its air drive means.

4. A system for controlling the temperatures within a plurality of rooms which comprises: a. a plenum forming a cold air reservoir common to said plurality of rooms, b. means including an air unit having the outlet thereof connected to said plenum for supplying and creating flow of cold air into said cold air reservoir, c. a second plenum common to said plurality of rooms, d. structure connecting each of said rooms with said second plenum to permit return air from said rooms to enter said second plenum, e. said air unit having the inlet thereof connected to said second plenum to receive said return air from said rooms via said second plenum, f. a plurality of separate air drive means opening into said rooms, g. each of said air drive means having a first inlet for receiving warm air, a second inlet connected to the first said plenum for receiving cold air from said cold air reservoir, a fan, a proportioning damper between said inlets and said fan, and an outlet for mixed air, h. said proportioning damper varying the proportions of warm air and cold air which said fan draws through said first and second inlets, respectively, and then discharges through said mixed air outlet, i. the first said plenum being substantially larger in cross section than the discharge outlet of said air unit, and being substantially larger in cross section than the second inlet of any of said separate air drive means, whereby the first said plenum holds a large volume of cold air immediately available to said separate air drive means, j. said second plenum being substantially larger in cross section than said inlet of said air unit, whereby said second plenum holds a large volume of return air immediately available to said air unit, k. means responsive to the temperature of air in a given room for control of the position of said proportioning damper, in said air drive means for said room, to determine the relative proportions of warm and cool air introduced into said room by its air drive means, l. the first said plenum and said second plenum being horizontally directed, m. one of said plenums being located immediately above the other of said plenums, n. the lower limit of said one plenum and the upper limit of said other plenum being defined and delimited by a horizontally-directed partition means, o. the return air flow through said second plenum being in one direction relative to said rooms, and p. the cold air flow through said one plenum being in the opposite direction relative to said rooms.

5. A system for controlling the temperatures within a plurality of rooms which comprises: a. a plenum forming a cold air reservoir common to said plurality of rooms, b. means including an air unit having the outlet thereof connected to said plenum for supplying and creating flow of cold air into said cold air reservoir, c. a second plenum common to said plurality of rooms, d. structure connecting each of said rooms with said second plenum to permit return air from said rooms to enter said second plenum, e. said air unit having the inlet thereof connected to said second plenum to receive said return air from said rooms via said second plenum, f. a plurality of separate air drive means opening into said rooms, g. each of said air drive means having a first inlet for receiving warm air, a second inlet connected to the first said plenum for receiving cold air from said cold air reservoir, a fan, a proportioning damper between said inlets and said fan, and an outlet for mixed air, h. said proportioning damper varying the proportions of warm air and cold air which said fan draws through said first and second inlets, respectively, and then discharges through said mixed air outlet, i. the first said plenum being substantially larger in cross section than the discharge outlet of said air unit, and being substantially larger in cross section than the second inlet of any of said separate air drive means, whereby the first said plenum holds a large volume of cold air immediately available to said separate air drive means, j. said second plenum being substantially larger in cross section than said inlet of said air unit, whereby said second plenum holds a large volume of return air immediately available to said air unit, k. means responsive to the temperature of air in a given room for control of the position of said proportioning damper, in said air drive means for said room, to determine the relative proportions of warm and cool air introduced into said room by its air drive means, l. a warm air reservoir located above, but common to, said rooms, and m. connecting means for permitting warm air flow from said warm air reservoir into said first inlets of said air drive means through said connecting means.

6. An atmosphere control system for a building having a plurality of rooms which comprises: a. a cooling unit that includes a blower which can supply quantities of cooled air, b. structural elements of said building which define and delimit parts of rooms of said building and which also define and delimit part of a large cross section plenum that extends from a point adjacent said cooling unit to the immediate proximity of said rooms, c. the outlet of said blower of said cooling unit being connected to said plenum for feeding cool air into said plenum from said cooling unit, and said plenum conducting said cool air to the immediate proximity of said rooms, d. a plurality of air-mixing boxes, e. said air-mixing boxes being disposed adjacent said rooms, and each of said air-mixing boxes having structure forming two inlet ports, a fan mounted between said inlet ports and a discharge port leading to a room, f. said fan in said air-mixing box acting to move air from said inlet ports to and through said discharge port and thence into said room, g. a cool air flow path between said plenum and one of said inlet ports of each said air-mixing box to conduct cool air from said plenum to said one inlet port, h. further structural elements of said building wHich define and delimit parts of rooms of said building and which also define and delimit part of a second large cross section plenum that extends from the immediate proximity of said rooms to a point adjacent said cooling unit, i. the inlet of said blower of said cooling unit being connected to said second plenum, j. a warm air flow path from each said room to a second of said inlet ports of said air-mixing box feeding said room to conduct air from said room to said second inlet port, k. structure forming flow paths from said rooms to said second plenum to include return air from said rooms in the air flowing through said second plenum, l. said second plenum conducting return air from said rooms to said cooling unit and thereby enabling said cooling unit to cool return air from said rooms and to include the cooled return air in the air which said cooling unit supplies to the first said plenum, m. temperature responsive means in said rooms, and n. proportioning damper means in each said air-mixing box between the inlet ports thereof and the fan therein to vary the relative amounts of cooled air entering each air-mixing box from the first said plenum and the amounts of air entering each air-mixing box from the room.

7. An atmosphere control system for a building having a plurality of rooms which comprises: a. a powered cooler for supplying quantities of cool air, b. means which define and delimit an air-distributing passage that extends from a point adjacent said powered cooler to the immediate proximity of said rooms, c. the outlet of said powered cooler being connected to said air-distributing passage for feeding cool air into said air-distributing passage from said powered cooler, and said air-distributing passage conducting said cool air to the immediate proximity of said rooms, d. a plurality of air-mixing boxes, e. said air-mixing boxes being disposed adjacent to said rooms and each of said air-mixing boxes having structure forming two inlet ports, a fan mounted between said inlet ports and a discharge port leading to a room, f. said fan in said air-mixing box acting to move air from said inlet ports to and through said discharge port and thence into said room, g. a cool air flow path between said air-distributing passage and one of said inlet ports of each said air-mixing box to conduct cool air from said air-distributing passage to said one inlet port, h. a warm air flow path from each said room to a second of said inlet ports of said air-mixing box feeding said room to conduct air from said room to said second inlet port, i. structure forming a return flow path from said rooms to the inlet of said powered cooler to enable said powered cooler to receive and cool return air from said rooms and to incorporate the cooled return air in the air which said powered cooler supplies to said air-distributing passage, j. temperature responsive means in said rooms, k. a proportioning damper in each said air-mixing box between the inlet ports thereof and the fan therein to vary the relative amounts of air entering each air-mixing box from said air-distributing passage and the amounts of air entering each air-mixing box from the room, and l. means providing a continuously-open path which extends from the outlet of said powered blower to the inlet of said powered blower, m. said continuously-open path means conducting substantially all of the air, supplied by said powered blower, from said outlet of said powered blower to said inlet of said powered blower whenever all of said proportioning dampers in all of said air-mixing boxes are closed and act to prevent air in said air-distributing passage from entering said air-mixing boxes, n. thereby preventing any build-up of pressure within said air-distributing passage, o. said continuously-open path means conducting progressively less of the air, supplied by said powered blower, from said outlet of said powered blower to said inlet of said powered blower as said proportioning dampers in said air-mixing boxes respond, to said temperature responsive means in said rooms, to progressively permit air from said air-distributing passage to enter said air-mixing boxes.

8. An atmosphere control system for a building having a plurality of rooms which comprises: a. a powered cooler for supplying quantities of cool air, b. means which define and delimit an air-distributing passage that extends from a point adjacent said powered cooler to the immediate proximity of said rooms, c. the outlet of said powered cooler being connected to said air-distributing passage for feeding cool air into said air-distributing passage from said powered cooler, and said air-distributing passage conducting said cool air to the immediate proximity of said rooms, d. a plurality of powered air-mixing boxes, e. said air-mixing boxes being disposed adjacent to said rooms and each of said air-mixing boxes having structure forming two inlet ports, a fan mounted between said inlet ports and a discharge port leading to a room, f. said fan in said air-mixing box acting to move air from said inlet ports to and through said discharge port and thence into said room, g. a cool air flow path between said air-distributing passage and one of said inlet ports of each said air-mixing box to conduct cool air from said air-distributing passage to said one inlet port, h. a warm air flow path from each said room to a second of said inlet ports of said air-mixing box feeding said room to conduct air from said room to said second inlet port, i. structure forming a return flow path from said rooms to said powered cooler to enable said powered cooler to cool return air from said rooms and to include the cooled return air in the air which said powered cooler supplies to said air-distributing passage, j. temperature responsive means in said rooms, k. a proportioning damper in each said air-mixing box between the inlet ports thereof and the fan therein to vary the relative amounts of air entering each air-mixing box from said air-distributing passage and the amounts of air entering each air-mixing box from the room, l. continuously-open passages interconnecting said rooms with said return air structure, m. means providing a continuously-open path between said air-distributing passage and said return air structure, n. said continuously-open passages between said rooms and said return air structure and said continuously-open path means coacting to connect said rooms with said air-distributing passage via said return air structure, o. whereby said rooms are connected to said air-distributing passage both by said air-mixing boxes and by said continuously-open path means and the continuously-open passages which interconnect said air return structure with said rooms.

9. An atmosphere control system for a building having a plurality of rooms which comprises: a. a cooling unit that includes a blower which can supply quantities of cooled air, b. structural elements of said building which define and delimit parts of rooms of said building and which also define and delimit part of a large cross section plenum that extends from a point adjacent said cooling unit to the immediate proximity of said rooms, c. the outlet of said blower of said cooling unit being connected to said plenum for feeding cool air into said plenum from said cooling unit, and said plenum conducting said cool air to the immediate proximity of said rooms, d. a plurality of air-mixing boxes, e. said air-mixing boxes being disposed adjacent said rooms, and each of said air-mixing boxes having structure forming two inlet ports, a fan mounted between said inlet ports and a discharge port leading to a room, f. said fan in said air-mixing box acting to move air from said inlet ports to and through said discharge port and thence into said room, g. a cool air flow path between said plenum and One of said inlet ports of each said air-mixing box to conduct cool air from said plenum to said one inlet port, h. further structural elements of said building which define and delimit parts of rooms of said building and which also define and delimit part of a second large cross section plenum that extends from the immediate proximity of said rooms to a point adjacent said cooling unit, i. the inlet of said blower of said cooling unit being connected to said second plenum, j. a warm air flow path from each said room to a second of said inlet ports of said air-mixing box feeding said room to conduct air from said room to said second inlet port, k. structure forming flow paths from said rooms to said second plenum to include return air from said rooms in the air flowing through said second plenum, l. said second plenum conducting return air from said rooms to said cooling unit and thereby enabling said cooling unit to cool return air from said rooms and to include the cooled return air in the air which said cooling unit supplies to the first said plenum, m. temperature responsive means in said rooms, n. proportioning damper means in each said air-mixing box between the inlet ports thereof and the fan thereinto vary the relative amounts of cooled air entering each air-mixing box from the first said plenum and the amounts of air entering each air-mixing box from the room, o. the first said plenum and said second plenum being horizontally-directed, p. one of said plenums being located immediately above the other of said plenums, q. the lower limit of said one plenum and the upper limit of said other plenum being defined and delimited by a horizontally-directed partition means, r. the return air flow through said second plenum being in one direction relative to said rooms, and s. the cold air flow through said one plenum being in the opposite direction relative to said rooms.

10. An atmosphere control system for a building having a plurality of rooms which comprises: a. a cooling unit that includes a blower which can supply quantities of cooled air, b. structural elements of said building which define and delimit parts of rooms of said building and which also define and delimit part of a large cross section plenum that extends from a point adjacent said cooling unit to the immediate proximity of said rooms, c. the outlet of said blower of said cooling unit being connected to said plenum for feeding cool air into said plenum from said cooling unit, and said plenum conducting said cool air to the immediate proximity of said rooms, d. a plurality of air-mixing boxes, e. said air-mixing boxes being disposed adjacent said rooms, and each of said air-mixing boxes having structure forming two inlet ports, a fan mounted between said inlet ports and a discharge port leading to a room, f. said fan in said air-mixing box acting to move air from said inlet ports to and through said discharge port and thence into said room, g. a cool air flow path between said plenum and one of said inlet ports of each said air-mixing box to conduct cool air from said plenum to said one inlet port, h. further structural elements of said building which define and delimit parts of rooms of said building and which also define and delimit part of a second large cross section plenum that extends from the immediate proximity of said rooms to a point adjacent said cooling unit, i. the inlet of said blower of said cooling unit being connected to said second plenum, j. a warm air flow path from each said room to a second of said inlet ports of said air-mixing box feeding said room to conduct air from said room to said second inlet port, k. structure forming flow paths from said rooms to said second plenum to include return air from said rooms in the air flowing through said second plenum, l. said second plenum conducting return air from said rooms to said cooling unit and thereby enabling said cooL-ing unit to cool return air from said rooms and to include the cooled return air in the air which said cooling unit supplies to the first said plenum, m. temperature responsive means in said rooms, n. proportioning damper means in each said air-mixing box between the inlet ports thereof and the fan therein to vary the relative amounts of cooled air entering each air-mixing box from the first said plenum and the amounts of air entering each air-mixing box from the room, o. the first said plenum being located between said rooms, p. the first said structural elements being the upper portions of confronting walls of said rooms plus a horizontally-directed ceiling extending between said upper portions of said confronting walls, and q. a lower ceiling defining the bottom of the first said plenum.