US3275068A - Air distribution system - Google Patents

Description

P 27, 1955 w. L. M GRATH I 3,275,068

' AIR DISTRIBUTION SYSTEM Original Filed Jan. 18, 1962 5 Sheets-Sheet l [,5] I FIG. I

: I I I 3: 0 D w Ii O. O 5 INVENTOR. E WILLIAM L. MC GRATH. I5 BY c. F. m.

ATTORNEY.

Sept. 27, 1966 w, NICGRATH 3,275,068

AIR DISTRIBUTION SYSTEM Original Filed Jan. 18, 1962 5 Sheets-Sheet 2 55 j F|G.2

V --v-]I mi 1 I 5o 22 I f I INVENTOR.

"" WlLLlAM L. MCGRATH;

ATTORNEY.

Sept. 27, 1966 w. L. M GRATH AIR DISTRIBUTION SYSTEM 5 Sheets-Sheet 5 Original Filed Jan. 18, 1962 MC GRATH.

INVENTOR.

WILLIAM L ATTORNEY.

United States Patent 3,275,068 AIR DISTRIBUTION SYSTEM William L. McGrath, Syracuse, N.Y., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Original application Jan. 18, 1962, Ser. No. 167,106, now Patent No. 3,163,100, dated Dec. 29, 1964. Divided and this application Nov. 9, 1964, Ser. No. 409,904 2 Claims. (Cl. 16531) This application is a division of my copending application Serial No. 167,106,, filed January 18, 1962, now Patent No. 3,163,100 issued December 29, 1964, and relates to air conditioning, more. particularly to means for selectively adjusting thedistribution of conditioned air to conditioned areas, without-interfering with the operation of the'air conditioning system.

A variety of equipment has been evolved serving to maintain the air in any given area. under desired temperature, humidity, and-purity conditions. This is generally accomplished by suitably treating the air in the conditioned area by means of heaters, refrigeration equipment, humidifiers and/ or air purifiers of a variety of types functioning' alone or in combination. After suitable treatment, the conditioned air is distributedto the conditioned area viasuitable supply ducts through registers which function to control air distribution paths and velocity inthe conditioned area. It is also desirable to recirculate some of the previously conditioned room air admixing it with newlyconditioned air to obtain desiredair change and air movement.

Where a central air conditioning system is employed to provide air of desired characteristics to a variety of different remotely located areas, conditions in these remotely located areas may vary sufiiciently so that different occupants of different areas will requiredifferent rates of air conditioning. Thus where a centrally located refrigeration system is employed to control air for distribution to different rooms of a building, the occupants of a room exposed to the sun or some other heat load would require a greater rate of cooling than those in rooms in shaded portions of the building. As is apparent, a happy medium of refrigeration system operation or heating system operation such as will please the occupants of different parts of the building Will not often be attainable.

Individual control of the air conditions in a given area to which air is fed from the air conditioning equipment is often controlled by controlling the flow of, air to these areas. Thus a heating or cooling coil is positioned in a duct through which air is directed to the various areas to be conditioned. Dampered outlets at these areas permit the occupants to control the flow of air to. the conditioned area by adjustment of the damper; at the outlet. found, however, that conditions often arise where enough of the outlets from the air supply ducts are closed sothat there is a rise in static pressure within the duct and a resultant decreasein flow'of air over the-heating or cooling surfaces. The resultant decreaseinair [flow over the heat-.

ingor cooling surfaces resultsin an imbalance within the refrigeration-or heating system due to a lack of required heat exchange betwen the heat-transfer medium and the air.

It is with the above problems and. desiderata in mind that the present means have been evolved,- means apparatus serving to permit the individual control of air distribution from air conditioning equipment to a conditioned area in which the occupant of the conditioned area may selectively determine the quantities of conditioned air provided withoutinterfering with the functioning of. central air conditioning equipment utilized to condition air for other areas.

-It is accordingly an object of this invention to provide improved means for controlling air distribution from air conditioning equipment. It will be understood by those skilled in theartthat the term air conditioning includes heating, cooling, humidifying, dehumidifying and air purifying, whether for industrial. or comfort purposes.

A further object of ,the invention is to provide improved means for controlling air distribution from a central conditioning point at a variety of different distribution points with the control action provided at any one distribution point not adversely affecting the operation of the conditioning equipment. I

It is an additional object of the invention to provide a novel air discharge register serving to implement the distribution of conditioned air, and the admixture of return air from the conditioned area with the conditioned air stream.

A further object of the invention is to provide improved means for maintaining desired air pressures in the air conditioning ducts adjacent the heat exchangers of the cooling or heating equipment employed for conditioning the air flowing through said ducts so asto insure desired air flow over the heat exchangers, and thereby to maintain desired heat exchange through the heat exchanger surface.

Another object of the invention is to provide improved means for manual selective control of conditioned air distribution in any conditioned area by the occupants thereof.

These and other objects of the invention which will become hereafter. apparent are attained by provision of a novelregister construction and mode of operation for use at the outlet points of the distribution ducts of an air conditioning system. Thus a duct extends from the heating or cooling coils of the air conditioning equipment to the conditioned areas. The novel register is positioned in these areas to provide desired design conditions. This register comprises a yieldably mounted damper plate selectively movable within the duct to adjustably constrict the flow of air through the duct. A return air inlet is formed in theregister to permit air from the conditioned. area to be induced for flow through the register with the conditioned air. The yieldable damper mounting is such that as the static pressure in the duct builds up above a desired design level as determined by the conditions necessary to obtain efficient functioning of the heating or cooling coil, the 'baflie plate or damper will be displaced to permit air flow through the duct to obtain the desired design pressures. A control knob suitably positioned in the conditioned area is coupled via a control assemblyincluding a rack and a pinion for movinga control rod which acts on the crank of a shaft coupled by a spring clutch to a shaft on which the damper-is supported.

An important feature of the invention resides in the novel yieldable mounting for the damper plate which permits selective. opening or closing of the register by the occupants of a conditioned area but is responsive to abnormally high pressure conditions in the duct thereby opening the register to provide desired air flow past the heat exchangers in theduct.

Another feature of the invention resides in the arrangement of the bafile plate or damper whereby the quantity of air recirculated from the conditioned. area is inversely proportional to the quantity of conditioned air supplied. Thus, the damper is so arranged that as it is moved to constrict the duct, the air velocity emerging from the register increases, thereby inducing a greater quantity; of air flow throughthe recirculating intake of the duct.

The specific details of a preferred embodiment of the invention, and their mode of functioning will be particularly pointed out in clear, concise and exact terms in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a schematicview of a portion of an air conditioning system in which a heat exchanger coil is arrangedto change the temperature of an air stream flowing along a duct to two distribution points;

FIGURE 2 is a schematic elevational view of'a register maintaining-a predetermined mini-mum quantity .of air' a portion of an air FIGURE 3.

flow over the. heat'exchanger of the air conditioning sys-.

tern; and

FIGURE -'7 is a detail viewion an enlarged scale, of a.

further modification of means for maintaining a predetermined minimum quantity of air ,flow over the heat exchanger of the air conditioning, system.

Referring now more particularly to the drawings, like numerals in the various figures will be employed to designate like parts. As best seen in FIGURE 1, an" embodiment of the instant invention is illustrated in connection with an air conditioning system which may be employed for heating or cooling a plurality of conditioned areas.

The system 10 comprises an air conditioning source in the form of a heat exchanger 11 arranged within supply duct 12 in heat exchange relationship with the air flowing through the duct. A fan13 may be utilized in conventional fashion to induce air fiowthrough-filter 14 and through duct 12 which confines an air stream along. a flow path over heat exchanger 11 to the areas-to be conditioned. The heat exchanger '11 is coupled to appropriate heating or cooling apparatus 15 which may be either a;

furnace, or refrigeration system, as will be understood by those skilled in the art, depending on whether the air conditioning system is to be employed for heating or cooling purposes. It will be further apparent that the heat exchanger 11 may also be of a type which functions alternatively as the. evaporator coil of a refrigeration system or the condenser coil of the refrigerationsystem in which case apparatus 15 will comprise a compressor and alternatively functioning heat exchanger coil along with the appropriate expansion mechanism, reverse valving and controls.

The supply duct 12 is shown to'extend to two conditioned areas A and B, it being understood that this is shown by way of example, and that the number of areas to which conditioned air is supplied may be varied as desired and depending on the air handlingcapacities of satisfy aesthetic requirements, and to permit desired air. flow patterns to be obtained in the conditioned area. A- bafiie plate or damper 25 is supported on damper shaft 26, shaft 26 and damper 25 being suitably mounted for pivotal movement as seen in FIGURE 4. Damper 25 may be moved from a'lirniting position abutting stop member 28 and providing full flow of air through outlet grill 21 when the damper 25 is to the right as viewed'in 'FIG- URE 4, to a non-flow position when the damper is to the 7 living room E.

let so asto permit continued induction of roomair when damper 25 is in the full open position. a

The register 20 is formed with a return air inlet 27 to the right of damper 25 as viewed in FIGURE 4.

Adjustment of the positionv of damper 25 ,is accomplished by the novel damper mounting which includes. a novel yieldable spring clutch 30 shown schematically in Clutch 30 comprises a clutch plate 31 arranged over shaft 26 and rotatable freely with respect thereto. A clutch plate 32 is'mounted for rotation with a control shaft 33 suitably supported for rotation in-bearings 35. A thumb screw 36 connects clutch plate 31 to clutch plate 32 for rotation therewith. Extending fro-m clutch plate 32 is a detent 40 which is movable withthe clutch plate 32 into engagement with a lug 41: formed on damper'shaft 26. 1A spring member 45, here ,illustrated in the shape of'a conical coil, spring; is arranged between clutch plate 31'and damper shaft-26. .Spring 45 is wound around shaft 26 and one end of the spring is anchored to move with clutch'plate 31 While the other end of spring 45.is secured to a damper" shaft 26 for in FIGURE 6. Air conditioning system.60 comprisesa,

heat exchanger 61 arranged within main supply duct 62 in heat exchange relationship with the air flowing through Fan 63 maybe utilized to induce .air' through the duct, filter 64 and through main duct 62 to auxiliary ducts 65 and 66.- Heat exchanger 61 is coupled to appropriate heating or cooling apparatus 67, similar to apparatus 15 shown in FIGURE 1. 7

Supply duct 62 connects withauxiliary ducts 65 and 66 which communicate with the areas E, F, G, H to be' conditioned. By way of illustration and not limitation,

these areas may comprise the'living room, dining room, and bedrooms, respectively, in a dwelling.

Ordinarily, a thermostat .68 for controlling the operation of the apparatus 67 and fan 63 is provided in one ofthe first story rooms of the Within the areas F, G and H there are provided outlets 70 having adjustable dampers 71 therein for modulating the air flow into each area as desired. The dampers may be controlled manually or automatically as desired.

In area E, outlet 73 is provided with a novel, register.

Openings 80, 81 and 82 may be defined within the outlet;

The register may be provided with a first manually adjustable damper 74, controlling flow-through opening '80, a second damper 76 responsive to a predetermined PICS? sure within supply duct 65 sensed by controller 76 for V A modification of the means for controlling the air 7 flow through outlet 73is illustrated inFIGURE .7. this case, the outlet 73' may have openings 83 and .84.

An adjustable damper '85 controls the how of air through openings 83. Damper 185 may be either manually or automatically adjustable.

Damper 86 pivotally mounted on shaft is designed to perform the functions of both'dampers -76 rand;,7-7.

Secured to shaft 87 is a lever, 88 comprised of arms 95 and 96. Adjustably mounted on arm 95 is balance weight a 89. The balance weight89 is connected to arm 95 by left as viewed in FIGURE 4. Baffle or deflector 24' is 7 suitable fastening means, for example, set screw 90. Arm

96 is movable within elongated opening 91 in Weight: Thus, it is apparent that after a predetermined rotational movement of damper. 86, arm v96 of lever 88 will engage dwelling, as for example',,in the the top of opening 91. Furthermovement of the damper is resisted until the pressure in the duct system is greater than the resistance provided by the force of weight 92. Then weight 92 is raised from support 93 and damper 86 is moved further toward the full open position to vent air into the area served by outlet 73'.

Operation The aforedescribed novel register 20 finds particular utility in connection with an air conditioning system having a plurality of distribution points for the conditioned air, remote from the conditioning source. Thus, in an air: conditioning system as illustrated in FIGURE 1 novel registers 20 are positioned at the conditioned areas A and B remote from the conditioning source or heat exchanger 11.

The air flow from the conditioning source to the conditioned areas is generally obtained by means of fan 13. As is apparent to those skilled in the art, the quantities of air flowing in heat exchange relationship with heat exchanger 11 determine the heat [flow between the heat exchanger and the air stream. The heat exchange equipment is generally designed to operate within given temperature ranges so that in order to obtain given air conditioning temperatures the heat exchanger is designed of a given capacity to accommodate the heating and/ or cooling loads of the conditioned areas. Since the capacity of the heat exchange equipment is such that maximum operating efficiency is obtained within given temperature ranges, it is desirable to insure the presence of air flow over the heat exchanger 11 so as to obtain these desired temperature ranges. Similarly, the air handling capacities of the duct 12 and fan 13 are selected to provide desired design conditions.

Where an air conditioning system is installed in which the occupants of individual conditioned areas may selectively determine whether conditioned air will be provided from the supply duct, it is necessary to make certain that the adjustment of air supply in any one conditioned area will not effect the operation of the air conditioning system to the detriment of other areas. This is accomplished by the adjustable register '20 of the present invention.

In use, the occupant of any given conditioned area, A or B as illustrated in FIGURE 1, may selectively determine the flow of air into the conditioned area by adjusting control knob 55. Rotation of knob '55 rotates pinion 54 which in turn acts on rack 53 to move same thereby pulling on rod 51 which in turn pulls crank arm 50. The pull on crank arm '50 effects rotation of shaft 33 which moves detent 40 against lug 41 causing shaft 26 to rotate with resulting movement of baffle 25.

When bafiie 25 is moved via the aforedescribed adjusting mechanism to a position closing off the flow of air through register 20, as effected by moving baffle 25 to the left as viewed in FIGURE 4, there will be a reduction in the quantity of air flowing through the system. When this flow of air drops beneath a desired design level, the spring 45 which has been preselected to yield under a stress indicating a pressure above desired design pressure in the supply duct 12. As a result of this yielding, bafile 25 will move against the biasing action of spring 45 towards the right as viewed in FIGURE 4, thereby increasing the flow of air through register 20, notwithstanding the manual adjustment made by the room occupant.

When it is desired to vary the preselected yield value of spring 45, thumb screw 36 may be loosened and clutch plates 31 and 32 may be suitably rotated With respect to one another. The thumb screw or other suitable fastening means, as for example, a set screw, may then be moved to secure the plates 31 and 32 together.

It Will be observed that when the baffle plate is moved towards a closed position, the increase in air velocity resulting from the construction of flow through register 20 will-increase the quantity of .air induced via return air opening 27.

In FIGURE 5, the graph illustrates the static" pressure within the duct required to give desired air flow for design conditions-to obtain. Thus, as indicated on the graph, as the cubic. feet per minute of air flow through supply duct I12 increases, there is a proportionate drop in the static pressure in the duct. Points C and D on the curve illustrate a desired. design range within which the air flow through the duct work should operate to obtain eflicient heat exchanger operation. Point C indicates the optimum desired fan loading condition, and point D indicates minimum conditions acceptable. Spring 45 is accordingly selectedto yield under a pressure greaterthan that at point D so that the bafiie will open, or move to the right as indicated in FIGURE 4, thereby increasing duct air flow and bring the system within its desired design range.

The novel mechanism for controlling the air flow through outlet 73 in area E functions to assure that the adjustment of the air supply in each of a plurality of areas will not adversely efiect the operation of the air conditioning system.

Assume that each of the dampers 71 are adjusted so that the desired quantity of air is passing over heating or cooling apparatus 67. Thermostat 68 controls the normal operation of apparatus 67 and fan 63. If one or more of the dampers -71 are closed, there is a reduced load requirement and the air supply over heat exchanger 16 may be adversely affected. The static pressure rise within the supply duct will be sensed by controller 76 which will actuate damper 76 toward the open position. If the duct pressure rises to a second predetermined level, controller 78 will actuate damper 77 toward open position. The increased discharge of air into area E will function to insure desired air flow over heat exchanger 61 and will also relatively quickly influence thermostat 68 to terminate fan and/ or heating or cooling apparatus operation.

The control mechanism shown in FIGURE 7 functions in a like manner to that shown in FIGURE 6. Damper may be adjusted to permit a desired flow of air into area B. If one or more of the dampers in the other areas are closed and the pressure rises undesirably in the supply duct, the damper 86 will be pivoted toward open position. Rotational movement of the damper will be stopped when lever arm 88 reaches the limit of the lost motion connection provided by the opening'91 in weight 92 through which the lever arm 88 extends.

If .there is adequate air flow over heat exchanger 61, system operation will again be controlled by thermostat 68. On the other hand, upon a further rise in the static pressure above a predetermined value such as will overcome the force exerted by weight 92, damper 86 will be pivoted toward the full open position.

It is then seen that operation of an air conditioning system provided with the present invention is enhanced. Improved means have been provided for controlling air distribution from a central conditioning point a variety of different distribution points with the control action provided at any one distribution point not adversely affecting the operation of the conditioning equipment. Furthen there has 'been provided novel adjustable register means for use in an air distribution system in which manual adjustment of air discharge may be provided,

but individual adjustment may not function to cause the system to operate in an improper manner.

While I have shown preferred embodiments of my invention, it is obvious that other modifications will be apparent to persons skilled in the art, and I desired that my invention be limited only within the scope of the appended claims.

I claim:

1. In an air distribution system for supplying conditioned air to a plurality of zones to be conditioned, the

.7 V combination of a central station for conditioning air com-- prising a heat exchanger, temperature responsive control means for controlling operation of said central station, duct means communicating said central station with each zone to be conditioned, adjustable damper means for controlling the discharge of air from the duct means into the zones to :be treated, mechanism responsive to the attainment of preselected pressure conditions within the duct means to vent the duct means to one of said zones thereby maintaining a predetermined minimum.quan-tity of air flow in heat exchange relationship with the heat exchanger in the central station, said rnechanism including rn'eans responsive to a first predetermined pressure condition in the duct means and a second predetermined pressure condition in the ductmeans to adjust said damper means,

said adjustable damper means including a first damper,

and a second damper, and said means including a first control to actuate the first damper'in response to a first determined pressure in the duct means and a second controlto actuate the second damper in response to a second predetermined pressure in the duct means.

2. In an air distribution system for supplying conditioned air to a plurality of zones to be conditioned, the combination of a central station for conditioning air comprising a heat exchanger, temperature responsive control means for controlling operation of said central station, duct means communicating said central station With each zone to be conditioned, adjustable damper means for controlling the discharge of air from the duct means into 8 the zones to be treated, first mechanism yieldable in response to a first determined pressure in the duct meansto adjust said damper means and second mechanism yieldable in response to a second determined pressure in the. duct means to further adjust said damper means, the damper means comprising a damper pivotally mounted on a shaft, the first mechanism including a lever secured to the shaft comprising a first arm and a second arm, a balance weigh-t mounted on said first arm, and said second mechanism including a second balance weight'having a slot therein receiving the second arm, the end of, the," slot serving as a stop for movement of the second arm in the slot whereby the first predetermined duct pressure applied to said damper rotates said lever until the second 1 15 arm engages the stop while application of the, second pre- 1 determined duct pressure to said damper furtherrotatesg said lever. carrying the second balanceweight th'erewithQ References Cited by the Examiner UNITED STATES PATENTS 5/1961 Waterfill 165-31 X 4/ 1965 I Ostrander l6516 X FOREIGN PATENTS 1/1946 Great Britain. 4/1960 Great Britain.

ROBERT A. OLEARY, Primary Examiner.

. M. ANTONAKAS, Assistant Examiner.

Claims (1)

1. IN AN AIR DISTRIBUTION SYSTEM FOR SUPPLYING CONDITIONED AIR TO A PLURALITY OF ZONES TO BE CONDITIONED, THE COMBINATION OF A CENTRAL STATION FOR CONDITIONING AIR COMPRISING A HEAT EXCHANGER, TEMPERATURE RESPONSIVE CONTROL MEANS FOR CONTROLLING OPERATING OF SAID CENTRAL STATION, DUCT MEANS COMMUNCATING SAID CENTRAL STATION WITH EACH ZONE TO BE CONDITIONED, ADJUSTABLE DAMPER MEANS FOR CONTROLLING THE DISCHARGE OF AIR FROM THE DUCT MEANS INTO THE ZONES TO BE TREATED, MECHANISM RESPONSIVE TO THE ATTAINMENT OF PRESELECTED PRESSURE CONDITIONS WITHIN THE DUCT MEANS TO VENT THE THE DUCT MEANS TO ONE OF SAID ZONES THEREBY MAINTAINING A PREDETERMINED MINIMUM QUANTITY OF AIR FLOW IN HEAT EXCHANGE RELATIONSHIP WITH THE HEAT EXCHANGER IN THE CENTRAL STATION, SAID MECHANISM INCLUDING MEANS RESPONSIVE TO A FIRST PREDETERMINED PRESSURE CONDITION IN THE DUCT MEANS AND A SECOND PREDETERMINED PRESSURE CONDITION IN THE DUCT MEANS TO ADJUST SAID DAMPER MEANS, SAID ADJUSTABLE DAMPER MEANS INCLUDING A FIRST DAMPER, AND A SECOND DAMPER, AND SAID MEANS INCLUDING A FIRST CONTROL TO ACTUATE THE FIRST DAMPER IN RESPONSE TO A FIRST DETERMINED PRESSURE IN THE DUCT MEANS AND A SECOND CONTROL TO ACTUATE THE SECOND DAMPER IN RESPONSE TO A SECOND PREDETERMINED PRESSURE IN THE DUCT MEANS.

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