US2206009A - Air conditioning system - Google Patents

Description

June 25, 1940. c. A. CUMMINGS AIR CONDITIONING SYSTEM Filed Feb. 27, 1937 a 1 M m a O y p 2 1/ A UN & mw 6 Z 3 MI/ 0/ 334 0 ///3 7 r2 8 3 M 4 9 2 4 4 5 Z a j 8 0 I 5 4 MWL w 2 x M n fi w "atented June 25, 1940 UNITED STATES PATENT OFFICE 2,206,009 AIR CONDITIONING SYSTEM Application February 27, 1937,

9 Claims.

This invention relates in general to air conditioning systems and is more particularly concerned with the maintaining of comfortable conditions within a space or enclosure located near a large body of water such as, for instance, the interior of a ship or a beach resort building.

Cooling systems for maintaining comfortable conditions within buildings or other enclosures are well known in the art. Such systems, however, involve a considerable quantity of bulky and expensive apparatus and involve heavy operating expenses. Due to the large space required, the

heavy first cost, and the heavy operating expense of such cooling systems, they have been applied only to relatively expensive permanent buildings and to the more luxurious ocean liners. A large part of the trade, such as beach resort buildings and the smaller vessels, have heretofore been without the advantages of summer cooling.

The primary object of my invention is to provide a simple and effective system for cooling the interior of a ship or other enclosure located near a large body of water, such system being inexpensive in first cost and very cheap in operating cost, and also requiring but little space.

Further objects of my invention will appear from the following detailed description and the appended claims.

For a detailed description of my invention reference is made to the accompanying drawing, the single figure of which indicates diagrammatically one form which my invention may take.

Referring to the drawing, reference character I indicates generally the hull of a ship and the reference character 2 indicates a space within the ship suc for instance, as the dining-room thereof. Leading from a point adjacent the surface of the water outside of the vessel is an air duct 8, this duct connecting at its other end to the inlet of a fan 4. A duct 5 connects the discharge of the fan 4 with the interior of the space 2. The fan 4 is provided with a motor 8 which may take the form of a variable speed electric motor. It will be seen, therefore, that the fan 4 causes air to be withdrawn from outside the vessel adjacent the water level and discharged into the space 2. The withdrawal of the air from adjacent the water level causes the air passing to the inlet duct 3 to be drawn across the surface of the water. Due to this drawing of the air across the surface of the water, the air is cooled by contact with the water and by evaporation of water into the air.

Located within the space 2 is a humidity controller generally indicated as I. The humidity Serial No. 128,252

controller I includes a bell crank lever 8 having a control arm 9 and an actuating arm ill, Control arm 9 is arranged to engage a control resistance Ii. Connected to the free end of the actuating arm I8 is a humidity responsive device which consists of a plurality of strands of'hair or other humidity responsive material l2, these strands being connected at their upper ends to a clamp l3 and at their lower ends to a clamp ll. Also connected to the free end of actuating arm I8 is a tension spring i5, this spring being connected at its other end to a suitable fixed support IS. The lower clamp i4 is suitably connected to an adjusting screw i1 which is suitably threaded in a fixed support l8. From the foregoing it should be apparent that spring I! will act to rotate the bell crank lever 8 in a clockwise direction and take up any slack in the humidity responsive strands l2. Upon an increase in humidity the strands i2 will increase in length, this permitting the bell crank lever 8 to be moved in a clockwise direction under the action of spring I, thus moving the control arm 9 across the resistance II from left to right. Conversely, upon a decrease in humidity, the moisture responsive strands l2 will decrease in length, this causing the bell crank lever 8 to be rotated in a counterclockwise direction against the action of the spring ll, thus moving the control arm 9 across the control resistance from right to left. The position of the control arm 9 on the control resistance II will therefore depend upon the humidity prevailing in the space 2. By turning the adjusting screw II, the desired position of the control arm 9 on resistance II for a given value of humidity may be obtained.

Reference character 20 indicates generally a proportioning motor. This motor may preferably take the form shown and described in Patent No. 1,989,972, issued to Lewis L. Cunningham on February 5, 1935. This proportioning motor is adapted to rotate a shaft 2| upon which. is mounted a series of cams 22, 28 and 24. This motor is provided with the usual line wire connections 28 and 28 and is operatively connected 45 to the control arm 9 of the humidity controller I and to the left and right ends of control resistance II by wires 21, 28 and 29 respectively. As will'be seen from reference to the above noted patent, the angular position of the proportioning motor shaft 2| will be dependent upon the position of the control arm 8 upon the control resistance' I l. The arrangement in this particular case is such that as the control arm 9 moves across control resistance il in a clockwise direc- 35 tion (indicating an increase in humidity) the shaft 2| will be rotated in a clockwise direction in an amount proportionate to the movement of control arm 9. Conversely, as the control arm 9 is moved in a counter-clockwise direction the proportioning motor 20 will rotate its shaft 2| in a counter-clockwise direction an amount proportionate to the movement of control arm 9. It will be seen, therefore, that the angular position of the proportioning motor shaft 2| will be dependent upon the position of the control arm 3 on the control resistance II, and that for each position of control arm 9 on resistance H there will be a corresponding angular position for shaft 2|. In general, the motor 20 is controlled in a graduating mannerby the humidity responsive means or in other words, the position of the motor is gradually varied in accordance with changes in the value of the humidity.

The cams 22, 23 and 24 raised portions 30, 3| and 32 operating with these cams are switch blades 33, 34 and 35, which are formed as cam followers and which may take any desired form. There are shown herein as comprising pivoted strips crimped at their mid portions to provide cam following surfaces. Cooperating with the movable switch blades 33, 34 and 35 to form switches are stationary blades 36, 31 and 38 respectively. The cams 22, 23 and 24 are mounted on shaft 2| with their raised portions 30, 3| and 32 angularly displaced from one another. The arrangement is such that upon clockwise movement of shaft 2| the raised portion 38 of cam 22 first engages the switch blade 33, causing upward movement thereof for engagement with stationary blade 36. Upon further rotation of shaft 2| in the same direction the raised portion 3| of cam 23 will engage the switch blade 34 thus moving it upwardly into engagement with the blade 31. At the same time that the raised portion of cam 3| causes engagement of switch blade 34 with blade 31 the switch blade 33 will ride off the raised portion 30 of cam 22, causing it to disengage the blade 36. Upon further rotation of shaft 2| in a clockwise direction the raised portion 32 of the cam 24 will engage the switch blade 35 thus forcing it upwardly into engagement with blade 38. At the same time that the raised portion 32 causes engagement of blades 35 and 38 the switch blade 34 will ride off the end of the raised portion 3| of the cam 23 thus causing disengagement of switch blades 34 and 31. It should be apparent, therefore, that upon clockwise rotation of the proportioning motor shaft 2| the switch 33-36 will be first closed and upon continued rotation of shaft 2| the switch 34-31 will be closed while the switch 33-36 will be simultaneously reopened. Also upon continued rotation of shaft 2| the switch 35-38 will be closed and simultaneously the switch 34-31 will be reopened. It should thus be apparent that when the humidity is relatively low, the control arm 9 will engage the left hand end of control resistance II and the proportioning motor will assume an extreme counter-clockwise limit of rotation, in which position all three switches are in open position. Upon increase in humidity the proportioning motor will rotate shaft 2| in a clockwise direction thus causing closure of switch 33-36. Upon a further increase in humidity, control arm 9 will move further along control resistance thus causing further rotation of shaft 2|, this causing closing of switch 34-31 and opening of switch 33-38, Upon are provided with respectively. Co-

- wire 46 to a binding post to which is portion of the further increase in humidity the control arm 9 will move further across control resistance I thus causing the proportioning motor to further rotate shaft 2|, this causing closing of switch 35-38 and opening of switch 34-31. It should also be apparent that upon falling humidity the shaft 2| will be rotated in the opposite direction, this causing the switches to be operated sequentially in reverse order.

Reference character 40 indicates generally a three-speed control box for the fan motor 6. Located within this control box is an auto transformer coil 4| which is connected to the line wires 42 and 43 by wires 42 and 43 respectively. One end of the auto transformer coil 4| is connected to the fan motor 6 by wire 44. The other terminal of the fan motor 6 is connected by a wire 45 to a suitable binding post on the control box 40, this binding post being connected by a connected a wire 41 which leads to the switch blade 36. The wire 41 is also connected to the switch blades 31 and 38 by wires 48, 49 and 58. The switch blade 33 is connected by wires 5| and 5| to a tap of transformer coil 4|. The switch blade 34 is connected by wires 52 and 52' to a second tap of transformer coil 4|, and the end of transformer coil 4| is connected to switch blade 35 by wires 53 and 53'.

When the switch 33-33 is closed, aian circuit is established as follows: transformer coil 4|, tap wire 5|, wire 5|, switch blades 33 and 36, wire 41, wire 46, wire 45, fan motor 6, wire 44 and wire 44 to transformer coil 4| It will be apparent, therefore, that when switch 33-36 is closed, the fan motor 6 will be energized by the transformer coil 4| between the line'wire 42 and the tap wire 5|. Due to this small portion of the transformer coil in use. the fan will operate at low speed. This is the condition occurring for a low value of humidity. As the humidity increases, the switch 34-31 will be closed and simultaneously switch 33-36 will be opened. This will establish a new fan circuit as follows: transformer coil 4|, wire 44'. wire 44, fan motor 6, wires 45. 46, 41, 48 and 49, switch blades 34 and 31, wire 52, and tap wire 52 to transformer coil 4|. Therefore, when switch 34-31 is closed,'the portion of the transformer coil between the line wire 42 and the tap wire 52' will energize the fan motor. The fan will thus operate at a higher speed than when switch 33-36 is closed. This is the operating speed for intermediate value of humidity.

As the humidity in the space continues to increase the motor shaft 2| will be rotated in the manner hereinbefore described to cause closing of switch 35-38-and to simultaneously cause opening of switch 34-31. When the switch 35-38 is closed, the fan motor circuit will be as follows: line wire 42. wire 42, wire 44'. wire 44. motor 6, wires 45, 46, 41, 48 and 58, switch blades 35 and 38, and wires 53, 53' and 43' to line wire 43. It should therefore be seen that when switch 35-38 is closed, the entire thrown across the fan motor, thus causing it to operate at its maximum speed. the humidity within the space is relatively high. The control system which I have disclosed will therefore cause the speed of the fan to be increased as the humidity within the space increases, and will cause the fan speed to decrease upon decrease in humidity within space 2.

From the foregoing it should be apparent that I have provided a system which acts to draw air across the surface of sea or other water and to discharge it into the space to be conditioned, the rate of discharge of air into the. conditioned space depending upon the humidity of the air within said space. Due to thedrawing of the air across the surface of the water itis cooled both by exchange of heat between the relatively cool water and the air, and by evaporation of water into the air. This dual cooling action reduces the temperature of the air considerably below the temperature within the space 2 and the discharge of such air into said space therefore acts to reduce the temperature within said space to a value which is more comfortable to the occupants. With this type of cooling action it will be apparent that the amount of cooling obtained is dependent upon outside conditions, such as the temperature of. the outside air. and its wet bulb depression. While the cooling action will be limited by these conditions this arrangement will nevertheless be eflective to make conditions within the conditioned space considerably more comfortable than would exist otherwise.

While the temperature of the air directed to the conditioned space will vary with outside air conditions, such as the temperature of the air, and the wet bulb depression of the air.-the humidity of the delivered air will remain much more constant. This constant humidity tendency will occur due to the fact that the temperature of the water over which the air is drawn will remain relatively constant. In passing the air over the surface of the water, the dew-point temperature of the air will tend to approach the water temperature. Thus if the dew-point temperature of the air is higher than that of the water, the humidity of such air will be relatively high. Un-

- dcr this condition, there will be a condensation of contact with the water will occur.

part of the water vapor in the air with the surface of the water, and dehumidiflcation will result. Conversely, should the dewpoint temperature of the air be below the water temperature, the humidity of such air will be relatively low, and humidiflcation of the air due to Thus in this manner, the humidity of the air discharged into chamber 2 will reason, while the cooling system may not always be capable of maintaining a fixed temperature within the space, it will, however, be practically always capable of maintaining the humidity at a desired value.

It is very desirable to vary the fan speed as the occupant load varies so as to more nearly approach the comfort zone, and so as to conserve on operating costs. With a system of the type which I have disclosed. control of the fan in accordance with temperature within the space would be unsatisfactory due to the limited or varying cooling effect obtained. In other words, should the cooling effect obtained be insufllcient to reduce the delivered air temperature below the value of temperature desired in the space, the fan would be run at full speed even though the space were unoccupied.

By controlling the fan speed in accordance with the humidity within the space control in accordance with occupant load and consequent conservation of operating expenses is obtained without the disadvantage of having the fan operate unnecessarily and without result, as would sometimes occur with other types of fan controllers. It will be apparent that the humidity within the enclosure will tend to increase as the number of occupants within such enclosure increases. In other words, due to the fact that the occupants tend to remain constant. For this give ofl moisture by evaporation, the humidity of the air within the space will increase in substantially direct proportion with the number of 00- cupants. Therefore, as the number of occupants within the enclosure 2 increases the humidity within such enclosure will increase correspondingly. This increase in humidity will affect the humidity controller I which will in turn cause increase in fan speed. Similarly, should the number of occupants decrease, the moisture content of the air will tend to decrease and this will cause the humidity controller 1 to reduce the fan speed. In this manner the rate of discharge of cool air into the space 2 is controlled in accordance with the number of occupants within such space, the fan being operated at low speed when the space is relatively unoccupied and being run at higher speeds as the number of occupants increases. As the cool ng load within the space will vary with the number of occupants. the fan speed is therefore controlled in accordance with the cooling load. Due to the fact that the humidity of the air delivered to the space 2 willremain relatively constant, the system will be capable of maintaining the humidity below a desired value and hence futile operation of the fan, as would occur with a temperature controller, is obviated.

It will be apparent that by adjusting the adjusting screw ll of the humidity controller 1 the desired fan speed for a given value of humidity within the space may be obtained. If desired the humidity controller I may be adjusted in this mannerto insure a minimum fan speed at all times. this causing a supply of air to the chamber for ventilation purposes regardless of the number of occupants within such space.

while I have illustrated my invention as applied to cooling the interior of a ship. it will be obvious that it may be applied to analogous enclosures such as beach resort buildings or other structures. Also, while I have shown and described a preferred embodiment of my invention, it will be apparent that many changes will be obvious to those skilled in the art which are within the scope of my invention. I therefore ,desire to be limited only by the scope of the appended claims and the prior art.

I claim as my invention:

1. In an air conditioning system for ships or other enclosed spaces located near a body of water, duct means having an inlet adjacent the surface of the water and leading to a space to be conditloned,'means for causing a controlled flow of air through said duct means into said conditioned space, said last recited means including a controller for varying the air flow, means responsive to the humidity in said space, motor means controlled by said humidity responsive means for actuating said controller, said motor means being controlled as to position by said humidity responsive means in a graduating manner, and said controller being actuated by said motor means in such manner as to increase the rate of air flow as the humidity in said space increases.

2. In an air conditioning system for ships or other enclosed spaces located near a body of water, duct means having an inlet adjacent the surface of the water and leading to a space to be conditioned, variable speed fan means for causing a flow of air through said duct means into said conditioned space, means responsive to the humidity in said space. motor means controlled as to position in a graduating manner by said'humidity responsive means, and a plurality of controlling devices sequentially actuated by said mo- '5 tor means, each of said controlling devices being arranged to effect a change in fan speed as it is moved from one position to another.

3. In an air conditioning system for ships or other enclosed spaces located near a body of water, duct means having an inlet adjacent the surface of the water and leading to a space to be conditioned, means for causing a controlled flow of air through said duct means into said conditioned space, said last recited means including a controller for varying the air flow, means responsive to the humidity in said space, motor means controlled as to position in a graduating manner by said humidity responsive means, and means for controlling said controller, said last mentioned controlling means comprising a plurality of devices sequentially actuated by said motor means.

4. In an air conditioning system for ships or other enclosed spaces located near an external large body of water, duct means having an inlet adjacent the surface of the water and leading to a space to be conditioned, means for causing a flow of air through said duct means into said conditioned space, means for varying the rate of air flow through said duct means, and means responsive to the humidity in said space in control of said air flow varying means.

5. In an air conditioning system for ships or other enclosed spaces located near a body of water, duct means having an inlet adjacent the surface of the water and leading to a space to be conditioned, means for causing a flow of air through ,said duct means into said conditioned space, means for varying the rate of air flow through said duct means, and means responsive to the humidity in said space in control of said air flow varying means, said humidity responsive means acting to increase the air flow as the humidity in said space increases.

6. In an air conditioning system for an enclosed space comprising in combination, means including duct means for passing air into contact with waterfor cooling such air by evaporation and.for discharging this cool moist air into a space to be conditioned, means for causing a controlled flow' of air through said duct .means into said conditioned space, said last recited means including a controller for varying. theair flow, means responsive to the humidity in said space, motor means controlled by said humidity responsive means for actuating said controller, said motor means being controlled as to position by said humidity responsive means in a graduating manner, and said controller being actuated by said motor means in such manner as to increase the rate of air flow as the humidity in said space increases.

7. In an air conditioning system for an enclosed space comprising in combination, means including duct means for passing air into contact with water for cooling such air by evaporation and for discharging this cool moist air into a space to be conditioned, means for causing a controlled flow of air through said duct means into said conditioned space, said last recited means including a controller for varying the air flow, means responsive to the humidity in said space, motor means controlled as to position in a graduating manner by said humidity responsive means, and means for controlling said controller, said last mentioned controlling means comprising a plurality of devices sequentially actuated by said motor means and so arranged as to increase the rate of air flow as the humidity increases.

8. In an air conditioning system for an enclosed space comprising in combination, means including duct means for passing air into contact with water for cooling such air by evaporation and for discharging this cool moist air into a space to be conditioned, means for causing a flow of air through said duct means into said conditioned space, means for varying the air flow through said duct means, and means responsive to the humidity in said space for controlling said air flow varying means, said controlling means. causing air flow increase when the humidity in said space exceeds a predetermined value.

9. In an air conditioning system for ships or other enclosed spaces located near an external large body of water, duct means having an inlet adjacent the surface of the water and leading to a space to be conditioned, means for causing a controlled flow of air through said duct means into said conditioned space, said last recited means including a controller for varying the air flow, means responsive to the humidity in said space, motor means controlled by said humidity responsive means as toposition in a graduating manner, said air flow. controller being actuated by said motor means.

CHARLES A. CUMMINGS.

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