US2136336A - Zone air conditioning system - Google Patents

Description

Nov. s, 1938. A. c. GRANT -2,' 3' ,336)

ZONE AIR CONDITIONING SYSTEM Filed Dec. 31, 19:54

Arthur 0. iant auto (Mu;

gwoentoo v Patented Nov; 8, 1938 ZONE AIR CONDITIONING SYSTEM Arthur C. Grant, St. PauL'Minn assignor to Minneapolis-Honeywell Regulator Company, 1 Minneapolis, Minn., a corporation of Delaware Application December 31, 1934, Serial No. 759,918

11 Claims.

' This invention relates to zone air conditioning systems for use in-buildings where it is desirable to differently condition various rooms or groups of rooms.

In conditioning buildings and especially in houses it is desirable to have certain rooms such as the living room, dining room and library maintained at a certain. temperature and relative humidity while it is desirable to have other rooms such as bedroomsand servants quarters maintained at another temperature. This is also true for summer cooling. as well as for winter heating. I

It is therefore an object of this invention to provide a novel zone air conditioning system whereby certain rooms of a building are maintained at one condition and the other rooms at another condition.

Another object of this invention is to provide 20 a novel zone air conditioning system wherein certain rooms of a building are conditioned by means of an air conditioning unit and other rooms are conditioned by direct radiation.

A further object is to provide an automatic zone air conditioning system for winter heating and for summer cooling whereby various rooms I of a building are maintained at difierent conditions and wherein the conditioning system may be readily changed from winter heating to sum- 30 mercooling operation.

' Another object is to provide a zone air conditioning system having an air conditioning unit for certain rooms of a building and direct radiation means for other'rooms wherein the air,

conditioning unit and the direct radiation means are independently controlled and wherein a common circulating means is used to circulate conditioning fluid through the air conditioning unit and the direct radiation means.

Other objects and advantages will become apparent to those skilled in the art by reference to the accompanying specification, claims and drawing in which drawing there is diagrammatically shown the zone air conditioning system of this invention.

The invention is shown and described as a conditioning system for four rooms A, B, C and D. Rooms C and D which are the rooms mostly used, such as a living room, dining room and study in a domestic building are heated or cooled and humidified by means of an air conditioning unit. The rooms A and B which are remote and not used as often as the rooms C and D such as bedrooms and servants quarters are heated or.

55 cooled by direct radiation. The term fidirect radiation is used to distinguish conditioning by radiators from conditioning by an air conditioning unit. Various types of radiators, such as exposed, enclosed or shielded, may be used for conditioning and the manner of conditioning caused thereby is termed for purposes of illustration as direct radiation.

- Although heatmay be obtained from any source, for purposes of illustration, the heat is generated in a hot water boiler III which may be gas-fired, the gas entering the boiler ill from some source not shown through a pipe l2. Located in the pipe I! is a gas control valve Ii for controlling the supply of gas to the boiler ill. The gas valve is moved to open position by energizing a solenoid or motor mechanism i3 and upon deenergization thereof the valve H is closed. Located on the boiler iii in such a manner as to respond to changes in temperature in the boiler is a conventional boiler thermostat i4 which is secured in place by means of a. binding post ii. The thermostat Hi carries a contact i5 which is moved into engagement with a stationary contact I 6 when the boiler temperature drops below a predetermined value and which is moved out of engagement with the contact l6 when the boiler temperature rises above the predetermined value. Wires I8 and I9 lead from some source of power, not shown, the wire l8 being connected to a manually controlled switch arm 20 and the wire l9 being connected to the solenoid or motor mechanism l3. The manually operated switch arm 20 is adapted to engage a contact 2i which is connected by means of a wire 22 to the binding post I! of the thermostat M. The stationary contact i6 is connected by means of a wire 23 to the solenoid or motor mecha-' nism i3.

When the control means for the boiler I is to be placed in operation for winter heating, the switch arm 20 is moved into engagement with the contact 2i. When the temperature 'of the boiler i0 is below a predetermined value, contact l engages contact Hi to complete a circuit from wire l8, switch arm 20, contact 2i, wire 22, binding post ii, thermostat i4, contact i5, contact [6, wire 23 and solenoid l3 to wire iii to energize the solenoid i3 to open the valve II to admit gas to the boiler III to raise the tempera-- ture of theboiler' l0. When the temperature of the boiler l0 reaches the predetermined value, the thermostat i4 moves the contact i5 out of engagement with the contact is to break the above circuit to deenergize the solenoid l3 to olose the valve Ii to stop firing of the boiler. In

this manner, the heating fluid in the boiler I is maintained at a constant temperature.

Connected to the top of boiler I0 is a hot water supply pipe 25, having a manually operated shutofi valve 26 located therein. The supply pipe 25 is connected to a four-way connection 21. Also, connected to the four-way connection 21 is a pipe 28 having a control valve 29 located therein, said control valve 29 being moved to open or closed positions by means of a reversible electric motor 24 having the usual limitswitches containedtherein. The pipe 28 connects to a pipe 30 and risers 3| extend upwardly therefrom and are con nected to radiators 32 located in rooms A and B. Return risers 33 extend downwardly from the radiators 32 located in rooms A and B and connect into a pipe 34 which contains a four-way connection 35. A circulating pump designated at 31 is operated by an electric motor 44 and .a pipe 36 connects the four-way connection 35 to the circulating pump 31. A pipe 38 connects the circulating pump 31 with the boiler H] toreturn water from the radiators 32 to the boiler II] to be reheated therein. Located in the pipe 38 is a manually controlled shut-off valve 39. When the manually controlled shut-off valves 26 and 39 and the control valve 29 are opened and the circulating pump 31 is placed in operation, hot water will be circulated from the boiler |U through the radiators 32 to cause heating of the rooms A and B by direct radiation.

Connected to the four-way connection 21 is a pipe 46 leading from some source of cooling medium and a manually controlled shutofi valve 4| is located in this pipe 46. Connected to the pipe 38 between the circulating pump 31 and the shut-off valve 39 is a pipe 42 leading to the source of cooling medium and having located therein a manually controlled shut-01f valve 43. The cooling medium supplied to the pipe 48 may emanate from any known source such as a mechanical refrigeration system, an ice cooling system or a city water supply system. By closing the manual shut-off valves 26 and 39 and by opening the manually operated shut-off valves 4| and 43, cooling fluid is supplied to the system for summer cooling instead of heating fluid from the boiler l8. With the shut-off valves in the positions just described, and if the valve 29 is opened and the circulating pump 31 is put in operation,

cooling fluid will be circulated through the radiators 32 in the rooms A and B to cool the same by means of direct radiation. From the above, it is seen that the radiators 32 may either heat or cools the rooms A and B by direct radiation, depending upon whether the rooms should be heated or cooled by manually manipulating the manually controlled shut-off valves 26, 39, 4| and 42.

An air conditioning unit of any known type, having a heat exchanger 46 located therein is designated at 45. The heat exchanger 46 is connected by means of a pipe 41 to the four-way connection 21 and by means of a pipe 48 to the fourway connection 35. When the circulating pump 31 is put in operation, heatingfluid or cooling fluid is circulated through the heat exchanger 46 depending upon the positions of the shut-off valves 26, 39, 4| and 43. Air is passed over the heat exchanger 46 by means of a, fan 49 driven by an electric motor by means of a belt 56. The air is drawn through filters 52 and passed over the heat exchanger 46 and is conducted by means of ducts 53 through registers 54 into the rooms C and D. Located above the heat exchanger 46 in the air conditioning unit 45 is a humidifyins device of any known type illustrated as a spray device 55, which is supplied with Water through a pipe 58 from some source not shown. The

supply of water to the humidifying spray device 55 is controlled by means of a valve 56 which is opened by energizing a solenoid or motor device 51 connected thereto and which is closed by deenergizing the solenoid 51.

From the above, it is seen that heated or cooled air is supplied to the rooms C and D, depending upon whether the rooms C or D should be heated or cooled and also that the humidity of the air so supplied is controlled by means of the humidifying spray device 55. 4

Located in the room A is a room thermostat 60 which is mounted for operation on a binding post 6|. The thermostat 60 carries a contact 62 which is selectively moved into and out of engagement with contacts 63 and 64. Contacts 63 and 64 are connected by means of wires 69 and respectively to switch arms 65 and 66 respectively of a double throw, double-poled reversing switch. The switch arms 65 and 66 when moved to the right are adapted to engage respectively the contacts 61 and 68 and when moved to the left are adapted to engage respectively the contacts 68 and 61'. 1| and 12 are line wires that lead from some source of power not shown and which are connected to opposite ends of a, primary 13 of a step-down transformer 14. One end of the secondary of the step-down transformer 14 is connected by means of a wire 16 to the binding post 6| of the thermostat 60. The other end of the secondary 15 is connected by means of a wire 11 to the electric motor 24. The contacts 61 and 68 of the reversing switch are also connected by means of wires 18 and 19 respectively to the electric motor 24. I

Assume that the valve 29 is held in a closed position by means of the electric motor 24, that the switch arms 65 and 66 of the reversing switch are in engagement with the contacts 61 and 68 'and that the system is conditioned for winter heating operation. When the room thermostat 60 calls for heat, the contact 62 thereof is moved into engagement with the contact 63 thereby completing a valve opening circuit from the secondary 15 of the step-down transformer 14 through wire 16, binding post 6|, thermostat 66, contacts 62 and 63, wire 69, switch arm 65, contact 61, wire 19, electric motor 24 and wire 11 back to the secondary 15 of the step down transformer 14. Upon completion of this circuit, the electric motor 24 is operated in one direction to open the control valve 29 to permit circulation of the heating fluid through the radiators 82 of rooms A and B to heat these rooms A and B by means of direct radiation. When room A has become sufficiently heated, the thermostat 66 moves the contact 62 thereof into engagement with the contact 64, thereby completing a valve closing circuit from the secondary 15 of stepdown transformer 14 through wire 16, binding post 6|, thermostat 60, contacts 62 and 64, wire 10, switch arm 66, contact 68, wire 18, electric motor 24, and wire 11 back to the secondary 15 of the step down transformer 14. Upon completion of this circuit, the electric motor 24 is operated in the reverse direction to move the valve 29 to a closed position to stop circulation of the heating fluid through the radiators 32.

Assume now that the shut-oil valves 26, 39, 4| and 43 are positioned for summer cooling operation, that the reversing switch has also been positioned for summer operation by causing engagement of switch arms 85 and 66 with contacts 68' and 61' respectively, that control valve 28 is in a closed position and that the temperature of the room A rises above "a predetermined value. Upon such rise in temperature, thermostat 88 moves the contact 82 into engagement with contact 84 to complete a circuit from secondary 15 of the step-down transformer 14 through wire 18, binding post 6], thermostat 88, contacts 62 and 64, wire 18, switch arm'88, contact 81', wire 18, electric motor 24 and wire 11 back to the secondary 15 of thestep-down transthe secondary 15 of step-down transformer 14 through wire 16, binding post 8|, thermostat 88,

contacts 62 and 63, wire 68, switch arm 65, contact 68', wire 18, electric motor 24, and wire 11 back .to the secondary 15. The completion of this circuit causes reverse energization of motor 24 to move the valve 28 into closed position to. stop circulation of the cooling fluid to the radiators 32. 1

Electric motor 24 also operates a lever 8| which carries a mercury switch 82 of the usual type having a pair of electrodes located therein which are contacted by means of the usual mercury upon thetilting of the mercury switch 82 to a given position. When the valve 28 is closed, the arm 8| is in the down position as shown in the drawing and the mercury in the mercury switch 82 is out of engagement with the electrodes of mercury switch 82. In other words, when the valve 28 is closed, the mercury switch 82 is in open circuit position. When the valve 28 is moved to open position by the electric motor 24, the lever 8I is moved upwardly to tilt the mercury switch 82 into circuit closing position.

Leading from some source of power not shown are line wires 83 and 84. One of the electrodes of the mercury switch 82 is connected by means of a wire 85 to the line wire 83. The other electrode of mercury switch 82 is connected by means of wires 86 and 81 to the electric motor 44 which drives the circulating pump-3L The electric motor 44 is in turn connected by means of wires 88 and 88 to the line wire 84.

When the valve 28 is moved to an open position, the mercury tube 82 is tilted to cause the mercury contained therein to engage the electrodes'thereof to complete acircuit from the line wire 83 through wire 85, mercury switch 82, wire 88, wire 81, electric motor 44, wire 88 and wire 88 back to the line wire 84. Upon completion of this circuit, the electric motor 44 is energized to cause operation of the circulating pump 31. When the control valve 28 is moved to a closed position by the electric motor 24, the mercury switch 82 is tilted to the open circuit position thereby breaking the above mentioned circuit to stop operation of the electric motor 44 to stop operation of the circulating pump 81.

From the above, it is seen that when the system is set for winter operation in the manner described and when the room thermostat 88 calls for heat, the control valve 28 is opened and the motor 44 is energized to operate the circulatingipump 31 to cause circulation of the heating fluid from the boiler I8 through the radiators a: to cause heating of the rooms A and B by direct radiation and that when the temperature of the room rises above a predetermined value, the control valve 28 is closed and the circulating pump 81 is stopped to prevent circulation of the heating fluid through the radiators 32. It is also seen that when the structure as set out above is set for summer operation, that is for cooling, and when the temperature of the room rises above a predetermined value, the control valve 28 is opened and the circulating pump 31 is operated to cause circulation of the cooling fluid to the radiators 32 to cool the roomsA and B by direct radiation and that when "the temperature in'the room lowers below'a predetermined value, the control valve 28 is closed and the circulating pump 31 is stopped to prevent circulation of the cooling fluid through the radiators 32.

Located in the room C is a room thermostat 8I supported for operation on a binding post 82. The room thermostat 8| selectively moves a contact 88 into engagement with either contact 84 or contact 85. Contact 84 is connected by means of a wire 88 to a switch arm 88 of a reversing switch and contact 85 is connected by means of a wire 81 to a switch arm 88 of the reversing switch. The switch arms 88 and 88 of the reversing switch are moved selectively.

into engagement withcontacts I88 and.I8I or contacts MI and I88 respectively.

A double coil relay comprises an energizing coil I02 and a bucking or neutralizing coil I83. The relay is operatively connected to switch arms I84, I85 and I88 to rnove these switch arms into engagement with contacts I81, I88 and I88 respectively upon energization of the energizingv coil mally held out of engagement with the contacts I81, I88 and I88 by a biasing means such as gravity, springs or other means not shown. Upon energization of the energizing coil I82, the switch arms are moved into engagement with their respective contacts against the bias of the opening means and upon energization of the neutralizing or bucking coil I83 which neutralizes the pulling efl'ect of the energizing coil I82, the switch arms are moved out of engagement with their respective contacts by the biasing means which tends to maintain the switches in open position.

- Line wires leading from some source of power not shown are designated.at H8 and III and these wires are connected to opposite ends of a primary I I2 of a step-down transformer II 3. The step down transformer I I3 is provided with a secondary II4 one end of which is connected by means of a wire v I I5 to one end of the energizing ,coil I82. A wire I I8 also connects the same end of the energizing coil I 82 with one end of the bucking or neutralizing coil I83. Theother end of the neutralizing coil I83 is connected by I82. The switch arms I84, I85 and I86 are nor- I means of a wire II1 to the contact I M of the reversing switch. The contact I88 of the reversing switch is connected by means of a wire II 8 and a wire II8 to the other end of the secondary I I4 of the step-down transformer I I3. The other end of the energizing coil I82 is connected by means of a wire I28 to the binding post 82 of the room thermostat 8|." The switch arm I84 is conter heating and ,that switch arms 98 and 99 are moved into engagement with contacts I and IOI. Upon a call for heat by the thermostat 9i, the contact 93 is moved into engagement with the contact 94 thereby completing a circuit from the secondary I I4 of step-down transformer II3 through wire II9, wire II9, contact I00, switch arm 99, wire 96, contacts 94 and 93, thermostat 9I, binding post 92, wire I20, energizing coil I02 and wire II back to the secondary I I4. Upon completion of this circuit, the energizing coil I02 is energized to move switch arms I04, I05 and I06 into engagement with contacts I01, I08 and I09 respectively. Upon the engagementof switch arm I 04 with contact I01, a holding circuit is completed from the secondary II4 of step-down transformer II3 through wire II9, wire I2I, switch arm I04, contact I 01, energizing coil I02 and wire II5 back to the secondary II4. This holding circuit maintains the energizing coil I02 energized to maintain the switches in engagement with their respective contacts even though the contact 93 of the room thermostat 9I is moved out of engagement with the contact 94.

Upon a rise in temperature above a predetermined value, thermostat 9I moves the contact 93 into engagement with the contact 95 thereby completing a neutralizing or bucking circuit from the secondary II4 of step-down transformer II3 through wire II9, wire I2I, switch arm I04, contact I01, wire I20, binding post 92, thermostat 9|, contacts 93 and 95, wire 91, switch arm 99,

contact IOI, wire II1, bucking coil I03, wire II6 and wire II 5 back to the secondary I I4. Upon completion of thisbucking or neutralizing circuit, the bucking coil I 03 of the relay is energized to neutralize the pulling effect of energizing coil I02 whereby the biasing means moves the switch arms I04, I05 and I06 out of engagement with the contacts I01, I 08 and I09.

When the switch arms 96 and 99 are moved into engagement respectively with the contacts IOI' and I00 for summer cooling operation, the exact reverse action is accomplished. Upon a rise in temperature of the room above a predetermined value, the thermostat 9| moves the .contact 93 into engagement with contact 95 to complete a circuit through the contact I00 oi! the reversing switch to cause energization of the energizing coil I02 01' the relay to cause closing of switches I04, I05 and I06 with respect to the contacts I01, I08 and I09. By movement of switch arm I04 into engagement with the contact I01, a holding circuit is completed for the coil I02 of the relay as above. Upon a decrease in temperature below a predetermined value, the contact 93 is moved into engagement with contact 94 by the thermostat 9I to complete a circuit through the contact I0'I' of the reversing switch to cause energization of the bucking or neutralizing coil I03 which neutralizes the pulling effect of the energizing coil I02 which allows opening of the switches I04, I05 and I06 with respect to their contacts. I01, I09 and I09 by means of the biasing means.

Connected to the line wire III is a wire I23 which is in turn connected to two wires I24 and I25. The wire I24 is connected to the contact I08 and the wire I25 is connected to the contact I09. The switch arm I05 which cooperates with the contact I08 is connected by means of a wire I26 and the wire 81 to the motor 44 which controls the operation of the circulating pump 31. The motor 44 of the circulating pump 31 is connected by means of the wire 88, a wire I21, a wire I28 and a wire I29 to the line wire H0. The switch arm I06 which cooperates with the contact I09 is connected by means of a wire I30 to the motor 5I which operates the fan 49 of the air conditioning unit 45 and the motor 5I is in turn connected by a wire I3I, the wire I29 and the wire I29 to the line wire IIO.

When the switch arms I05 and I06 are moved into engagement with the contacts I09 and I09, an electric circuit is completed from the line wire III through wire I23, wire I24, contact I09, switch arm I05, wire I26, wire 91, electric motor 44, wire 98, wire I21, wire I29 and wire I29 to the line wire IIO to cause energization of the electric motor 44 to cause operation of the circulating pump 31. Another circuit is also completed from the line wire III, through wire I23, wire I25, contact I09, switch arm I06, wire I30, electric motor 5I, wire I3I, wire I28 and wire I29 to the line wire I I0 to cause energization of the electric motor 5| to cause operation of the fan 49 of the air conditioning unit 45.

From the above it is seen that for winter operation when the thermostat calls for heat to move the contact 93 into engagement with the contact 94, the circulating pump 31 is operated to cause circulation of the heating fluid through the heat exchanger 46 and the electric motor 5I will be energized to cause operation of the fan 49 to force air over the heat exchanger 46 and deliver this heated air to the rooms C and D to cause heating thereof. When the temperature rises above a predetermined value so as to move contact 93 into engagement with contact 95, the motor 44 is deenergized to cause stopping of the circulating pump 31 and the motor 5I is deenergized to cause stopping of operation of the fan 49 whereby heating fluid is not supplied to the heat exchanger 46 and whereby air is not passed overthe heat exchanger 46 or delivered to the rooms 0 and D. For summer operation, when the temperature of the room C is above a predetermined value, contact 93 of the thermostat 9| is moved into engagement with the contact 95 to move switch arms I04, I05 and I06 into engagement with the contacts I01, I09 and I09 to cause operation oi. the circulating pump 31 and the fan 49 of the air conditioning unit 45 to deliver cooled air to the rooms C and D to lower the temperature thereof. When the temperature in the room C falls below a predetermined value, the contact 93 of the thermostat 9I is moved into engagement with the contact 94 to move the switch arms I04, I05 and I06 out of engagement with the contacts I01, I09 and I09 respectively to stop operation of the circulating pump 31 and the fan 49 to stop delivery of the cooled air to the rooms C and D.

Located in the room C is a humidity responsive device I33 of usual design, containing a switch which is moved to closed position when the relative humidity of the room decreases below a predetermined value and which is moved to open position when the relative humidity of the room increases above a predetermined value. The humidity responsive device I33 is connected to the switch arm I06 by means of a wire I34 and the humidity responsive device I33 is also connected by means of a wire I35 to the motor device or solenoid 51. The solenoid 51 is also connected by means of a wire I36 to a contact I31. Cooperating with the contact I31 is a manually operated switch arm I38 which is connected by means 01 a wire I39 to the connection of wires I29 and I29.

When. the parts are adjusted for winter operation, the switch arm I38 is moved into engagement with contact I31 and when the room thermostat calls for heat so as to move switch arm I96 into engagement with contact I99 and when the relative humidity of the room C is below a predetermined value, a circuit is completed from the line wire III through wire I23, wire I25, contact I99, switch arm I96, wire I34, humidity responsive device I33, wire I35, solenoid 51, wire I36, contact I31, switch arm I38, wire I39 and wire I29 to the line wire H0. Completion of the above-circuit causes energization of the solenoid 51 which causes opening of the valve 56 to admit water to the humidifying spray device 55 to add water vapor to the heated air delivered to the rooms C and D. If the relative humidity of the room rises above a predetermined. value, the

humidity responsive device I33 opens the above circuit to cause deenergization of the solenoid 51 to close the valve 56 to stop operation of the humidifying spray device 55. Also, if the temperature in the room C rises above a predetermined amount so as to move switch arm I96 out of engagement with contact I09, the above circuit is broken to causedeenergization of solenoid 51 to close the valve56 to stop humidifying spray 55.

Since it is not advisable to add water vapor to operation of the the air delivered to the rooms C and D for sum- 7 cause circulation of the heating fluid through the radiators 32 in rooms A and B to cause heating thereof by direct radiation regardless of temperature or humidity conditions existing in rooms C and D. Upon a rise in temperature in room A above a predetermined amount, the control valve- 29 is closed and the circulating-pump 3.1 is stopped to prevent circulation of the heating fluid through the radiators 32 of rooms A and B. When the temperature in the room C lowers below a predetermined value, circulating pump.3'| is placed in operation to cause circulation of heating fluid through heat exchanger 46 and the fan 49 is placed in operation to pass air over the heat exchanger 46 into the rooms C and D regardless of temperature conditions existing in rooms Aand B. If the relative humidity in the room C is less than a predetermined value, the humidifying spray device 55 is placed in dperation to add water vapor to the heated air delivered to the rooms and D to increase the relative humidity thereof.

When the temperature in the room C rises above a predetermined value, the circulating pump 31 is stopped to prevent circulation of the heating fluid through the heat exchanger 46, the fan 49 is stopped to prevent delivery of air to the rooms C and D and the adding of water vapor to the air by means of the humidifying spray device 55 is prevented. Further, if the relative humidity in the room C rises above a predetermined value, he humidifying spray device 55 is placed out of operation even though heated air may be supplied to the rooms C and D by the fan 49.

From the above, it is seen that the control valve 29 is controlled solely by the room thermostat 69 of room A and that the fan 49 is controlled only by the room thermostat 9| of the room C and that circulating pump 31 is controlled either by the room thermostat 69 of room A or the room theralso possible to maintain the relative humidity in the rooms C and D at a certain value regardless of the relative humidity existing in the rooms A and B. i

A brief description of the summer operation of I the air conditioning system is as follows: when the temperature in room A rises above a predetermined value, the control valve 29 is opened and the circulating pump 31 is placed in operation to cause circulation of cooling fluid through the radiators 32 of rooms A and B to cause cooling of these rooms'by direct radiation regardless 01 the condition existing in the rooms C and D and when the temperature of the room A falls below a predetermined value, the control valve 29 is closed to prevent circulation of the cooling fluid through the radiators 32. When the temperature in room C rises above a predetermined value, the circulating pump 31 is placed in operation to cause circulation of the cooling fluid through the heat exchanger 46 and the fan 49 is placed in operation to pass air over the heat exchanger 46 to deliver cooled air to the rooms C and D. Upon a decrease in temperature, in-room C below a predetermined value the fan 49 is deenergizedto stop the flow of cool air to' the rooms C and D. Since the switch I38 is moved out of engagement with the contact l3'l during summer or cooling opera tion, the humidifying spray 55 is rendered inoperative by the manually operated switch arm I 36.

From the above, it is seen that I have invented an automatic zone air conditioning system wherein a room or group of rooms may be conditioned to a different degree than another room or another group of rooms and that provision is made for winter operation and for summer operation and all that is necessary to convert the system from winter operation to summer operation is the throwing of two reversing switches and the manual resetting of the four shut-off valves.

Various modifications may be made in the sys-v tem embodying my invention without departing from the spirit and-scope thereof and I desire therefore that only such limitations shall be placed thereon as are imposed by the prior art or set forth in the appended claims.

I claim as my invention:

1. In a system of the class described for conditioning a plurality 'of rooms, a source of conditioning fluid, heat exchanger means for certain of said rooms, other heat exchanger means for otherof said rooms, conducting means between said source and, said first heat exchanger means and between said source and said other heat exchanger means, a condition responsive device in certain of said rooms, another condition responsive device in other of said rooms, and means under the command of one of said condition responsive devices for causing circulation of condiditioning fluid, heat exchanger means in certain of said rooms for directly conditioning said rooms,

of said rooms comprising a heat exchanger mechanism and air circulating means, means connecting said source of conditioning fluid and the heat exchanger mechanism of said air conditioning unit, a condition responsive device in said certain of said rooms, and means under the command of said condition responsive device for causing circulation of conditioning fluid through tioning fluid and said heat exchanger means,

an air conditioning unit for indirectly conditioning other of said rooms comprising a heat ex-\ changer mechanism and air circulating means,

means connecting said source of conditioning fluid and the heat exchanger mechanism of said air conditioning unit, a condition responsive device in said certain of said rooms, another condition responsive device in said other of said rooms, and means under the command of one of said condition responsive devices for causing circulation of conditioning fluid through said heat exchanger means and the heat exchanger mechanism of said air conditioning unit and under the command of the other condition responsive device for causing circulation of conditioning fluid through the heat exchanger mechanism oi. said air conditioning unit and operation of the air circulating means.

4. In a system of the class described for conditioning a plurality of rooms; a source of conditioning fluid, heat exchanger means for certain of said rooms, conducting means between said source and said heat exchanger means, a control device in said conducting means, other heat exchanger means for other of said rooms, conducting means between said source-and said other heat exchanger means, a condition responsive device in said certain of said rooms, a condition responsive device in said other of said rooms, circulating means for circulating conditioning fluid through said conducting means, means responsive to one of said condition responsive devices and associated with said control device and said circulating means for circulating conditioning fluid through said heat exchangers for all of said rooms, and means responsive to the other of said condition responsive devices and associated with said circulating means for circulating fluid through said heat exchangers for said other of said rooms.

5. In a system of the class described for conditioning a plurality of rooms, a source of conditioning fluid, heat exchanger means in certain of said rooms for directly conditioning said ,rooms, conditioning fluid conducting means between said source and said heat exchanger means, a control device in laid conditioning fluid conducting means, an air conditioning unit for indirectly conditioning other of said rooms comprising a heat exchanger mechanism and air circulating means, conditioning fluid conducting means between said source and the heat exchanger mechanism of said air conditioning unit, a condition responsive device in said certain of said rooms, a condition responsive device in said other of said rooms, circulating means for circulating conditioning fluid through said conditioning fluid conducting means, means associated with one of said condition responsive devices, 5

said control device and said circulating means for circulating conditioning fluid through said heat exchangers and the heat exchanger mechanism of said air conditioning unit, and means associated with the other condition responsive l0 device and said circulating means for causing circulation of heating fluid through the heat exchanger mechanism of said air conditioning unit.

6. In a system of the class described for con- 15 ditioning a plurality of rooms, a source of conditioning fluid, heat exchanger means in certain of said rooms, conditioning fluid conducting -means between said source and said heat exchanger means, a control device in said condi- 20 tioning fluid conducting means, an air conditioning unit for other of said rooms comprising a heat exchanger and an air circulating means for delivering conditioned air to said other rooms,

conditioning fluid conducting means between said 25 source and said heat exchanger of said air con.- ditioning unit, a condition responsive device in said certain of said rooms, another condition responsive device in said other of said rooms,

circulating means for circulating conditioning 30 fluid through said conditioning fluid conducting means, means operatively connected to one oi said condition-responsive devices, said control device and said circulating means for circulating conditioning fluid through said heat ex- 35 changer means for conditioning said certain of said rooms, and means operatively connected to said other condition responsive device, said circulating means and said air circulating means for causing circulation of conditioning fluid,

through said heat exchanger of said air conditioner and to cause delivery of conditioned air to said other of said rooms.

'7. In a system of the class described for conditioning a plurality of rooms, heat exchanger 45 means for certain of said rooms, a control device for said heat exchanger means, an air conditioning unit for other of said rooms comprising a heat exchanger and a fan, circulating means for circulating heating fluid through said 50 'heat exchanger means and through said heat perature to cause circulation of heating fluid so through said heat exchanger and to pass air over said heat exchanger whereby said other rooms are heated, means for stopping the supply of heating fluid and for supplying cooling fluid to said heat exchanger means and said heat ex- 65 changer of said air conditioning unit, and means for reversing the action 01' said thermostats when cooling fluid is supplied to said heat exchanger means and said heat-exchanger of said air conditioning unit. I

' 70 8. In a system of the class described for conditioning a plurality of rooms, radiators for certain of said rooms, a control device for said radiators, an air conditioning unit ior other of said rooms comprising a heat exchanger, a fan and humidifying means, a humidity responsive device in the other of said rooms ior'controlling theoperation of said humidifying means, circulating means for circulating heating fluid through said radiators and said heat exchanger, a thermostat in certain of said rooms responsive to a decrease in temperature to operate said control device and said circulating means to, circulate heating fluid through said radiators to.

heat the certain of said rooms, a thermostat in the other of said rooms responsive i v a decrease in temperature to condition said humidity responsive device for operation and to operate said circulating means and said fan to circulate heating fluid through said heat exchanger and to pass air over said heat exchanger to the other of said rooms, means for stopping the supply of heating fluid and for supplying cooling fluid to said radiators and said heat exchanger, and means for reversingthe action of said thermostats when cooling fluid is supplied to said radiators and said heat exchanger of said air conditioning unit.

9. In a system of the class described for conditioning a plurality of rooms, radiators for certain of said rooms, a control device for said radiators, an air conditioning unit for other of said rooms comprising a heat exchanger, a fan and humidifying means, a humidity responsive device in the other of said rooms for controlling the operation of said humidifying means, circulating means for circulating heating fluid through said radiators and said heat exchanger, a thermostat in certain of said rooms responsive to a decrease in temperature to operate said control device and said circulating means to circulate heating fluid through said radiators to heat the certain of said rooms, a thermostat in the other of said rooms responsive to a decrease in temperature to condition said humidity responsive device for operation and to operate said circulating means and said fan to circulate heating fluid through said heat exchanger and to pass air over said heat exchanger to the other of said rooms, means for stopping the supply of heating fluid and for supp y cooling fluid to said radiators and said heat exchanger, means for reversing the action of said thermostats when cooling fluid is supplied to said radiators and said heat exchanger of said air conditioning unit and means for rendering said humidity responsive device inoperative when cooling fluid is supplied to said heat exchanger.

10. In a system of the class described for conditioning -a plurality of rooms. heat exchanger means for certain of said rooms, an air conditioning unit for other of said rooms comprising a'heat exchanger and a fan, means for controlling the circulation of heating fluid through said heat exchanger means and through said heat exchanger oi said air conditioning unit,

a thermostat in certain of said rooms associatedwith said circulation controlling means responsive to a decrease in temperature to cause circulation of heating fluid through said heat exchanger means, a thermostat in other of said rooms associated with said circulation controlling means and said fan and responsive to a decrease in temperature to cause circulation of heating fluid through said heat exchanger and to pass air over said heat exchanger whereby said other rooms are heated, means ifor stopping the supply of heating fluid and for supplying cooling fluid to said heat exchanger means and said heat exchanger of said air conditioning unit, and means for reversing the action'of said thermostats when cooling fluid is supplied to said heat exchanger means and said'heat exchanger of said air conditioning unit. r

11. In a system of the class described for conditioning a plurality of rooms, flrst heat exchanger means for certain of said rooms, a second heat exchanger means for other of said rooms, circulation controlling means for controlling the circulation of heating fluid through said heatexchanger means, a thermostat responsive to a decrease in temperature in said certain rooms for controlling said circulation controlling means to increase the circulation of heating fluid through said flrst heat exchanger means, a thermostat responsive to a decrease in temperature in the other rooms for controlling said circulation controlling means to increase the circulation or heating fluid through said second heat exchanger means, means for stopping the supp y of heating fluid and for supplying cooling fluid to said heat exchanger means, and means for reversing the action of said thermo'stats when cooling fluid is supplied.

ARTHUR 6. GRANT.

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