US2170101A - Air conditioning system for railway cars - Google Patents

Description

g- 1939- E. w. TEST ET AL 2,170,101

' AIR CONDITIONING SYSTEM FOR RAILWAY CARS Original Filed July 15, 1931 6 Sheets-Sheet 1 Ell/2721307 5: R Zflb WZe 5i Mae/ MP Win/thew fkienson Aug. 22, 19-39. E. w. TEST ET AL 2,170,101

7 AIR CONDITIONING SYSTEM FOR RAILWAY .CARS

Original Filed July is, 1951 6 Sheets-Sheet 2 v 12714;; WTQSZ qr e 7 50 Aug. 22, 1939 E. w. TEST ET AL 7 AIR CQNDITIONINQ SYSTEM FOR RAILWAY CARS Original Filed July 15, 1951 6 Sheets-Sheet 3 Aug. 22, 1939. E. w. TEST ET AL 2,170,101

AIR CONDITIONING SYSTEM FOR RAILWAY CARS 7 Original Filed July 15, 1931 6 Sheets-Sheet 4 2771076 Ida's 7%]Zzsi Zia/i471, J? Walker 17mm]? Pezzrs 07L E. w. TEST ET- AL 2,170,101

6 Sheets-Sheet 5 Aug. 22, 1939.

AIR CONDITIONING'SYSTEM FOR RAILWAY CARS ori inal Filed July 15, 1931 Zia/emanam5 7% 176st fl [czPfi/z P 7%7225/7127 Hamid/Z ZTPeiens on 6 Sheets-Sheet 6 E; W. TEST ET AL nuu Original Filed July 15, 1931 QwN m xho AIR CONDITIONING SYSTEM FOR RAILWAY CARS Aug. 22, 1939.

lllllllllll llkummvl\ Patented Aug. 22, 1939 UNITED "STATES PATENTOFFICE I 2,170,101 AIR CONDITIONINGCSYSTEM FOR RAILWAY Y ARS poration of Delaware Application July -15, 1931, SerialNo. 550,904 Renewed May 2, 1938 8 Claims.

This invention relates to an air conditioning system for railway cars and is especially designed for application to astandard Pullman car.

Contrary to common belief, there is no set tem- Dcrature at which a room should be maintained for those inside to be comfortable. It has been found by experiment that in cold weather a room may remain comfortable when kept at a constant minimum temperature, but that in hot weather, the comfortable temperature will vary in relation to the temperature of the outside air.

For example, in the winter time, a room may be held at a temperature of 70 and will be thought comfortable by all those who enter it regardless of the severity of the outside cold. In the summer time, however, if the outside air registers 95, a person entering a room in which the temperature is 70 would feel chilled andcomfortable temperature would be said not to exist. When the temperature of .the outside air, there-' fore, is higher than that of the room which is being ventilated, the mean interior temperature must vary so as to lessen the difierential between the two temperatures.

This invention, therefore, has for its primary objects to automatically maintain appropriate temperature and humidity in the interior of a railway car at all times functionally related to the outside temperature; to thoroughly cleanse, humidify, heat, cool and otherwise treat the air passing into the passenger space; to vary the mean temperature within the car to correspond with the comfort temperature as influenced andafifected by the temperature of the outside air; to combine an overhead ventilating system with an auxiliary independently operated heating coil so as to produce and maintainuniform temperature in all portions of the car interior, and-to so arrange and locate the various elements that they may be economically applied to existing cars.

Further and other objects and advantages will become apparent as the description is read in conjunction with the accompanying drawings, in which I Fig. l is a schematic drawingpf the complete system including the control units;

Fig. 2 is a diagrammatic, perspective view of a car equipped withthis invention, showing particularly the arrangement of the various elements on the car underframe;

Fig. 3 is a perspective view of one end of the car with parts broken away to expose the air conditioning chamber Fig. 4 is a, horizontal sectional view looking down on the air conditioning chamber;

Fig. 5 is a vertical, sectional view taken on the line 55 of Fig. 4;

Fig. 6 is a transverse, sectional view. taken on the line 6-6 ofFig. 4;

Fig. 7 is a plan view of the car, the fan condi- 5 tioning chamber and duct system being shown in full lines;

Fig. 8 is a longitudinal, sectional view of the car showing the location of the conditioning chamber over the ladies lavatory; and

Fig. 9 is a transverse, sectional view through the ceiling ducts, taken on the line 9-9 of Fig. 7.

v The invention may be applied to all types of railway cars, and it is for the purpose of disclosure only that a standard Pullman sleeping car has been chosen to illustrate one embodiment'of the invention. The invention is, therefore, not tobe limited by the specific disclosure except as required by the prior art. 2

The car shown in the drawings is of the closed vestibule monitor top type, and comprises a body generally designated 20 mounted on car trucks 2| in the usual manner. The car is divided into a passenger space 22, drawing room 23, ladies lavatory and salon 2d, and a passageway leading 25 from the passenger space to the vestibule 26 adjacent the ladies end of the car. The other end of the car, which is not shown in the drawings, contains the men's lavatory and smoking room and has a closed vestibule similar to the vestibule 30 26.

The air conditioning chamber of the present invention is located above the ladies lavatory and salon where there is adequate space for the necessary apparatus. At this end of the car is a locker 21 which can be conveniently used to house the various pipe connections extending between the air conditioning chamber and the apparatus mounted on the car underframe. The corresponding locker at the other end of the 0 car is customarily used for an electrical control box, making it less convenientior using that end of the car for the air conditioning apparatus.

The conditioning apparatus is designed to filter, humidify, heat and cool all air which is delivered to-the passenger space and may be divided into the following units:

A. The conditioning chamber including the fan and fan casing, but exclusive'of the dual ceiling ducts;

B. The filters;

C. The heating system;

- D. The humidifier;

E. The cooling system.

F. The ceiling ducts.

up the air conditioning system will be described as classified above.- 1

- A. The conditioning chamber including the fan and fan casing, but exclusive of the dual ceiling ducts Referring to Fig. 3, which shows a perspective View of the air conditioning chamber and the apparatus which it houses, it will be seen that the chamber, generally designated 28, is defined by side walls 29 and 30, spaced away from the side decks 3| and 32 of the car and opening at one end, for convenience called the forward end, into the bifurcated ceiling duct 33 and at the other, or rearward, end communicating with the fan casing generally designated 34.

Between the lower deck 35 and the false cell-- ing 36 over the passageway 25 is an open 'space 31 communicating through grilles 38 with the passageway. This air space opens into a channel 39 between the side deck 3| and a side wall 29 of the conditioning chamber through a plurality of openings 40 in the lower side deck. The forward end of the channel 39 is closed by a partition 4| so that air admitted to the channel- 89 through the openings .40 must -find its outlet through an opening 42 (Fig. 4) at the rear end of thechannel.

A fan intake casing 431s situated between the sloping roof or upper deck 44 of the car and the ceiling 45 of the vestibule, and comprises a downwardly extending branch 48 -opening into the vestibule through an adjustable grille 41, a forwardly extending branch 48 communicating with the opening 42 at the rear end of the channel 39, and a. horizontal tubular portion 48 connecting the branches and 48 with the fan casing 34. Air is drawn into the casing 34 by a fan 50 which then forces the air into the conditioning chamber 28. A suitable motor 5| drives the fan.

It is of particular advantage to take the fresh air, which is to be conditioned and then delivered to the passenger space, from the car vestibule since the air therein is comparatively still allowing the larger particlesof dirt and cinders to settle to the floorof the vestibule and not be drawn through the fan. The cracks and crevices around thevestibule diaphragms and the vestibule doors admit suihcient fresh air to the vestibule to satisfy the needs of the conditioning system. 1

The grille 41 in the vestibule ceiling may be regulated to control the amount of fresh air admitted to the circulation. Ordinarily, it is allowed to remain fullyopen, in'which state approximately 30% of the air drawn into the conditioning chamber is fresh air; This ratio. may be changed as desired by adjustment of the vestibule ceiling grille.

B. The filters air as it passes through the filters 53 which preferably constitute separate units that can be quickly removed for cleaning or replacement. The type employing a fibrousmaterial interposed between the metal screens is well suited for this purpose.

In order to facilitate the removal of the filters when desired, the upper deck is provided with a hatch 55 directly above the filters.

C. The heating system The heating system is designed to maintain a temperature of 70 during cold weather which may be increased to 75 to satisfy theindivldual preferenceof certain passengers. At night, the mean temperature is lowered to about 60 to provide comfortable sleeping temperature.

The varying mean temperatures of which this apparatus is capable are controlled by a threeway thermostat which will later be described and is an added feature of the present invention. The normal heating of the car to a particular desired temperature is accomplished automatically in the manner now to be described.

A vapor heating coil, or any other suitable heating means, generally designated 56, comprising a plurality of sections 51, 58, 59 and lifl'is placed transversely in the conditioning chamber 28 insthe path of the circulating air. The four sections are connected by a. header 8i, having a connection 52 with the train steam line 83 (Fig. 1).

Referring to Fig. 1 wherein the entire system is diagrammatically shown, it will be seen that there are two valves which control the admission of steam to the heating coil. One of these valves, designated 64, is electrically controlled by a three-way thermostat 55 having thermometers 86, 61 and 68.

4 The thermometers are mercury filled and have their bases connected to a positive wire 68. Wires 10, 1|, and 12 protrude into the thermometer bulbs 66, 81 and 58, respectively, at heights corresponding to desired temperatures, and lead to a remote control box 13 which "selectively engages the appropriate wire.

suitable source not shown through positive wire 68, mercury thermometer 88, conductor 12, remote control 13, cohductor 14, valve 84, and return conductor 15.

When the temperature in the passenger space falls sufficiently to break the circuit in the thermometer 68, the valve 54 is opened and vapor is admitted to the steam coil 58 to heat the incoming air. The steam vapor passes through the coil after which it is-led to the atmosphere through a pipe 16. At the atmospheric opening of this pipe is a thermally controlled Sylphon valve 11 adapted to close the intake pipe 62 whenver the temperature at the exhaust is above a. predetermined value. The purpose of this valve is to conserve steam.

Sections 58, 59 and Gil of the heating coil are provided with Sylphon bellows valves 18, 19 and 80, respectively, exposed to the outside air. These valves are adapted to vary the heating surface of the coil by automatically cutting out sections of the heater when they are not required. For example, the valve 18 may be set to open at 40, the valve 18 at 20 and the valve at 10. Above 40, only the section 51 carries the steam vapor.

Referring to Fig. 6, wherein the valve 88 is shown in cross section, it will be seen that contraction of the Sylphon 8| of the valve withdraws the valve stem 82 from its seat in the vapor pipe 93 thereby allowing the steam vapor to pass from the header 8| into the heating section 60. Valves I8 and I9 are similar to valve 80, differing only in the temperature at which they are set to function.

The purpose of these three valves is to make the heating surface bear some relationship with the temperature of the outside air. It is quite obvious that when extremely cold air is being admitted into the conditioning chamber from the vestibule that more heating surface is needed to effectuate a proper heating of the air than when airof more moderate temperature is being circulated. Consequently the three valves act' to automatically provide the necessary heating surface. v

The heating arrangement which is used in this apparatus inherently serves to increase the rate of steam flow through the radiator sections in proportion to the temperature of the circulated air. If the air passing through the coils is relatively cold, part of the steam will condense and thereby reduce the pressure within the radiator coils. The pressure differential between the steam coil and the steam line will result in a faster inflow of steam into the coil, and proper heating of the air is thereby assured. The valve I1 serves as an automatic regulator to close the heater intake when the temperature at the exhaust reaches a predetermined amount, and is of standard construction.

The remote control unit 65 enables the car attendant to fix the mean temperature at which the car is to be kept. With the switch in the position shown in Fig. 1, the car-will be maintained at approximately 60; when moved to the right to establish connection between conductor II and conductor I4, the mean temperature will be approximately 70; and when moved further to the right to include the thermometer 66 in the circuit, the mean temperature will be approximately 75. These mean temperatures may, of course, be varied by suitably positioning the protruding wires in the thermometer stems;

An auxiliary heating coil 84 runs along each side of the car beneath the car seats 85 and is connected directly to the main steam line. The auxiliary coil is controlled by a thermostat 86 which-operates entirely independently of the control for the heating coil in the air conditioning chamber. Although the floor thermostat operates independently of the control for the overhead heating coil, there is a relationship in the cycle of operation of the two controls; since the floor thermostat responds to the effect of the heat issuing from the overhead duct, and the thermostat controlling the overhead coil responds to the heat issuing from the floor coil. It has been found that the combination of an overhead drawn into the conditioning chamber when the main heating coil in the conditioning chamber is thermostatically out out, making the elimination of the main heating coil unnoticeable to the passengers.

. D. The humidifier Since the capacity of air for moisture varies in proportion to its temperature, there is no necessity for humidifying air drawn into the conditioning chamberexcept during cold weather. Accordingly, the humidifier of this invention is attached directly to the heating coil and functions only when it is in operation.

Referring to Fig. 1, the humidifier, generally designated 81, is shown connected with the outlet I6 of the heating coil by a pipe 88 running upwardly .to the top of the car and then projecting into the conditioning chamber at 89. The protruding portion 89 terminates in a coiled delivery tube 90' which sprays the vapor into the path of the circulating air, and by its shape silences the humidifier.

In the same way that the delivery of steam to the heating coil is automatically increased in proportion to the temperature of the circulating air, so also is the rate of humidifying affected by the temperature of the incoming air This is an especially desirable feature of the humidifier, as it serves to automatically increase the input of moisture to the air in proportion to the normal need for greater moisture content.

In order to safeguard against too high relative humidity prevailing within the car interior, a hygrostat 9| may be placed in the passenger space to shut off the humidifier when the relative humidity has reached a predetermined maximum. The hygrostat is of the bleeder type wherein a compressed air line 92 is opento atmosphere at 93 until closed-by the Sylphon 94 at which time the compressed air builds up a pressure in the tube 93 to actuate a Sylphon bellows valve 95 in the main pipe 88 of the humidifier. It has been found by experiment, however,

that a hygrostat is normally not required because of the inherent automatic regulation of the humidifier.

E. The cooling system The cooling of the air in the summer time is accomplished by a. cooling coil, generally designated 96, containing a secondary refrigerant such as brine, and arranged to be cut 01f from the brine circulating system when the cooling coil is not in operation.

For the purpose of this disclosure, an ammonia compressionrefrigeration system has been shown for cooling the secondary refrigerant system, but this invention is not limited to a particular type of refrigerating system as an absorption or other system could be used to accomplish the same purpose. Many of the advantages of this invention could also be attained with a direct expansion system, eliminating the secondary refrigerating system entirely.

The general layout of the refrigerating system is shown in Fig. 1 in which the ammonia compressors are indicated at 91 driven by an electric motor 98 through a suitable drive 99. The ammonia gas after being compressed in the com.- pressors 91 is delivered to a condenser I00 through pipe IOI wheie the gaseous ammonia is condensed. From the bottomof the condenser, the liquid ammonia is drawn through pipe I02 to an expansion valve I03 communicating with a shell and tube evaporator I04. The liquid ammonia expands in the evaporator, cooling all surfaces with which it comes in con-tact, and the evaporated ammonia is drawn from the top of the evaporator through an accumulator I05 and connection I06 back to the compressors.

The cooling water for the compressors and the condenser is drawn from a cooling tower I01 through connection I08 leading to the water jackets of the two compressors. After passing through the water jackets, the water is taken through pipe I09 to the condenser I where it serves to condense the gaseous ammonia. The, water then passes through pipe IIO back to the cooling tower I01 where it is sprayed into the interior and cooled by a fan III located at one end of the tower. Circulation of the cooling and condensing water isefiected by a pump I I2 interposed in the water circuit and the water in the cooling tower is maintained at a constant level by a float valve II3 serving to draw water from a water reservoir II4 when necessary. A branch feed II5 connected to the sprays in the cooling tower enables the spraying tube II6 to be flushed in case of stoppage.

The indirect system of refrigeration is used in preference to the direct system to avoid all possibility of ammonia fumes entering the car interior. The secondary refrigerant system comprises a closed brine circuitpassing through the evaporator I04.- Upon being cooled by the expanding ammonia, the brine is conducted through a pipe II1 to a brine reservoir II8 preferably located in the locker 21 at the head of the passageway 25. A pipe IIO connects the auxiliary 'tank II8with the cooling coil 96 through a passage I20. After passing through the cooling coil, the brine returns to the evaporator thru pipes HI and I22. Circulation of the brine in the system is maintained by a pump I23 interposed in the circuit.

A by-pass I24 is provided between theinlet and outlet of the cooling coil for the purpose of shunting the brine circuit around the cooling coil when the latter is not needed-for cooling purposes. The by-pass is provided with a Sylphon bellowsvalve I25, the stem I26 of which is adapted to move the valve head I21 to and from the bottom end of the pipe I2I. When the valve is in the position shown in Fig. 1, the brine passing upwardly in the pipe H9 is directed through the pipe I20 into the cooling coil, the return of the brine being made through pipes I2I and I22. When the valve.is in its shunt position, that is in the position closing the pipe I2I, the brine is.-by-passed around the cooling coil from pipe II9 to pipe I22 through pipe I28.

The by-pass valve is controlled by a thermostat I29 of the bleeder type. The thermostat corresponds to the hygrostat associated with the humidifier and comprises a compressed air line I30 having an opening I3I adapted to be closed by a thermally responsive Sylphon bellows I32. The compressed air 1inea92 an d -I30 both receive their compressed air from an air reservoir I59.

The by-passing of the brine around the cooling coil when cooling of the air is not required enables the brine system to be maintained at a low temperature in instant readiness for use. This is especially important when cars are left standing in the yards or at a station for a consider-t able period of time as the brine system with its relatively large capacity by reason of the auxiliary tank II8 stores up sufficient cold while the car is running (the motor 98 receiving its energy directly from the rotation of the car axles) to supply the cooling needs of the car when not in motion, or when ascending steep grades. In this way, use of heavy and expensive batteries is diselectrical circuit involving the thermostat I33 is shown in Fig, 1, the switch I34 being provided operation, its temperature is approximately 200 and the temperature differential between the incoming air and the heating coil causes a rapid transfer of heat to the air. The cool brine in the cooling coil 96 absorbs part of the heat given up by the heating coil to the airso that the air delivered to the car interior will gradually raise the temperature within the car to its desired value. The total effect of the warm air passing over the coolingcoil (which, of course, is shunted from the circulating brine system when the heating coil is in operation) as feltin the car interior is a gradual heating of the incomingair and passengers do not sense any change in the temperature. If the order of the heating coil and cooling coil were reversed, as soon as the heating coil was placed in operation, the passengers would be aware of a warm blast of air being delivered to the car interior,

The placing of the cooling coil after the heating coil furnishes a third way for tempering the warm air introduced into the car interior. The other two means of effecting the gradual increase of temperature in the passenger space comprise the three Sylphon valves 18; 19, and 80 and the automatic regulation of steam flow in the radiator coil by the condensation of steam in the coil.

In order to increase the cooling surface of the coil 96, the pipes may be connected by fins in a manner well known to the refrigeration art.

It is possible that the warm air drawn into the conditioning chamber in the summer time contains too much moisture and the cooling coil in such cases will dehumidify the air by the condensation on the pipe and fin surfaces.

The ammonia compression refrigerating system requires the placing of the compressors and I motor, the condenser, the evaporator and cooling tower beneath the car body and the arrangement of these various elements with respect to the present equipment carried by standard cars presents a formidable problem. It has been found that existing train equipment can be left in its customary position beneath the car body if the compressors and motor be mounted in a box I35 (Fig. 2) adjacent the air brake cylinder I36, and the cooling tower I01 be suspended from the car underframe adjacent thereto. The condenser I00 is placed on the other side of the car adjacent the water storage tank II4 which has its customary location near the center of the car across from the air brake cylinder. The two battery boxes I31 and I38 on opposite sides of the car need not be disturbed if the evaporator I04 is located between the battery box I31'and the end of the car on the same side as the condenser I00 and the water tank II4. This arrangement of the elements of the car underframe does not interfere with the foundation brake gear and requires very little rearrangement of the train equipment now carried on standard Pullman cars.

F. The ceiling ducts After the air has been properly conditioned in passing through the conditioning chamber 28, it is delivered to the car interior through dual ceiling ducts I39 and I40 provided with a plurality of grilles I4I opening into the car interior. The two ducts run the length of the car between the false ceiling I42 and the upper deck I43. Ventilators I44 are provided at intervals in the side decks 3i and 32 .to provide a cross circulation over the ducts I39 and I40, there being sufficient J space between the ducts and the upper deck to permit the passage of air. In this way the dead air space between the upper deck and the false ceiling is done away with, the result being that the temperature of the air in the ducts can be kept more uniform and less cooling is required in the summer time.

The triple thermostat 65 that controls the heating coil and the thermostat I29 which controls the cooling coil are preferably placed on the bulkhead I45 in'the direct path-of the circulating air so as to in eifect control the temperature of the circulating air rather than the temperature in the car itself. By so arranging the thermostats, a more uniform mean temperature can be obtained due to the virtual elimination of lag which is inescapable when the thermostats are placed in their customary positions at eye level.

As shown in Fig. 8, suitable grilles I 45 in the ceiling ducts provide ventilation in the drawing room 23 and like grilles are provided in' the ladies ,lavatory 24 and in the'mens smoking room (not shown).

Summary of the system and its operation It will be seen from the above description that a constant circulation of air is maintained in the passenger space in which approximately 70% of the air in the car interior is recirculated and 30% is takenfrom the car vestibule. All the air delivered to the car interior, whether it be air taken from the passenger space or fresh air, is thoroughly conditioned in the chamber 28 so as to provide maximum comfort to the passengers.

The constant drawing in of fresh air into the conditioning chamber without expellinglany of the vitiated air builds up a slight pressure in the car interior which causes a constant seepage of air to the outside-through the cracks and crevices in the car body such as at the window sashes. This prevents outside air with its dirt and cinders from finding ingress into the car interior.

The heating coil in the conditioning chamber is of suflicient capacity to at all times maintain the temperature of the car interior at as high a temperature as may be required. The capacity of thecooling coil, however, is limited so that the mean interior temperature of the car bears a functional relationship with the mean exterior temperature in warm weather. For example, if the temperature of theoutside air is 85, it is impossible for the cooling coil to sufficiently lower the temperature of the car interior to cause the thermostat I29 to operate the by-pass valve I25. As a result, the temperature within the car is somewhat higher than it would be in more moderate weather.

It may be said that the appa atus is so de-- signed to maintain a uniform temperature up to a certain maximum outside temperature. after which the limited capacity of the cooling coil automatically raises the mean interior temperatures so as to lessen the temperature differential between the inside and the outside air. This feature of the apparatus gives greater comfort to the occupants of the car than if the car. temperature was maintained constant throughout all ranges of outside temperature. v

It is desirable that the speed of ,the fan 50 be greater when the cooling coil is functioning than when the heating coil is in operation. Means are, therefore, provided associated with the cooling coil by-pass valve I25 for accomplishing this function. The valve-stem I25 carries an arm I41 adapted toclose a circuit between wires I48 and I49.

The closing of the circuit operates a relay I5Il which takes the resistance I5I from the field of the fan motor 5I and thereby decreases its speed.

' The field circuit can then be traced from a suitable source of current not shown through conductor I52, resistance I53, conductors I54, I55 and I56 back to the source of current. When the by-pass valve is' in the position shown in Fig. 1 and the circuit between conductors I48 and I49 is open, since there is a break in the conductor I54, the field current can betraced through conductor I52, resistance I53, resistance I5,I, conductors I55 and I56, back to the source of current.

Access to the conditioning apparatus may be had through suitable hatches provided in the roof'of the car. The hatch I51 permits inspection of the cooling coil; the hatch 55 enables the filters 53 to be removed for cleaning and also exposes the humidifier and a part of the heating coil, and the hatch I58 gives access to the fan and fan motor.

The cooling and heating elements in the conditioning chamber may be manually cut out so that with the blower operating alone, the apparatus serves as a forced ventilating system continually-filtering the air drawn into the conditioning chamber. i

The air conditioning system of this invention is inherently capable of maintaining a uniform desired temperature, the desired temperature being determined by the temperature of the outside air. It also cleanses all air admitted to the car interior and supplies it with moisture if necessary.

The system is entirely automatic in its operation, but the desire-d mean temperature may be varied manually by a remote control adapted to be operated by the car attendant.

What we claim is: p

1. A system for conditioning the air of a railway car and the like comprising an air conditioning chamber, a fan at one end of the chamber delivering a predetermined ratio of circulated air and fresh air to the chamber, an air filter adjacent the fan in the path of the mixed air, a thermostatically controlled steam heating coil in the chamber, a humidifier intermediate the filter and the heating coil normally operable whenever the heating coil 7, is inoperation but hygrostatically controlled to prevent excessive humidity and a thermostatically controlled cooling coil adjacent the heatingcoil, said cooling coil serving to temper the air upon receiving heat from the heating coil.

2. A system for conditioning the air of a railway car and the like comprising an air conditioning chamber, a fanat one end of the chamber delivering a predetermined ratio of circulated air and fresh air to the chamber, an air filter adlivering a predetermined ratio of circulated air and fresh air to the chamber, a heater in the chamber having a plurality of heating sections, means for controlling the operation of the heater, means responsive to car temperature for controlling said first named means, auxiliary means adapted to control the operation of the individual sections, said auxiliary means being responsive to the temperature conditions exterior of the car.

4. A system for conditioning the air in railway cars and the like comprising an air conditioning chamber, a fan at one end of the chamber delivering a predetermined ratio of circulated air and fresh 'air to the chamber, a heater in the chamber having a plurality of heating sections, means for controlling the operation of the heater, auxiliary means adapted to control the operation of the individual sections, a thermostat within the car for controlling said first named means, and thermostats on the exterior of the car associated with the auxiliary means for determin ing the number of heating sections to be in effective operation when the first named means is cal'ing for heat from the heater.

5. In a railway car of the type including a car body, passenger space in the car body, and

a closed space at one end of the car, the combination of means for conditioning the air of the passenger space including an air chamber over the closed spaced having inlet and outlet openings, a heater in the chamber, means for circulating air through the chamber over said heater and thence to the passenger space through overhead ducts, a thermostatic control for the heater, an auxiliary heater adjacent the car floor in the passenger space controlled by separate thermostatic. means, and a tempering heater adjacent the air chamber inlet opening in series with the said auxiliary heater.

6. In an air conditioning system, the combination of a heating coil, a cooling coil, a fan for delivering air to said coils, and automatic means for increasing the speed of the fan when the cooling coil is in operation.

7. A system for conditioning the air in railway cars and the like comprising an air conditioning chamber, a fan for delivering a predetermined ratio of circulated air and fresh air to the chamber, a heater in the chamber having a plurality of heating sections, means for controlling the operation of the heater, means responsive to car temperatures controlling said first named means, auxiliary means adapted to control the operation of the individual sections, said auxiliary means being responsive to the temperature conditions exterior of the car.

8. In a ventilating system including air conditioning apparatus, the combination of an air chamber, means. for delivering air to the chamber for treatment, a vapor humidifier in the chamber and a coiled delivery nozzle for the humidifier.

' ELLIS W. TEST.

MARTIN P. WINTHER. HARTIN F. PETERSON.

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