US2144169A

US2144169A - Method and apparatus for conditioning air

Info

Publication number: US2144169A
Application number: US732240A
Authority: US
Inventors: Edward T Turner
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-06-25
Filing date: 1934-06-25
Publication date: 1939-01-17
Anticipated expiration: 1956-01-17

Description

Jan. 17,1939.

' E. T. TURNER 2,144,169

METHQIJ AND APPARATUS FOR CONDITIONING AIR Filed June 25, L934 3 Sheets-Sheet 1 \w llll k/ISATTORNEY E. T. TURNER 2,144,169 I METHOD AND APPARATUS FOR CONDITIONING AIR Filed June 25, 1934 5 Sheets-Sheet 2 f E. 77 TURNER;

1- llVVENTOR M5 ATTORNEY Jan. 17, 1939. E. T. TURNER 2,

METHOD AND APPARATUS FOR CONDITIONING AIR Filed June 25, 1934 s Shets-Shet 3 INVNTOR b E. 7? TURNER.

hLsATTO/YNEY Patented Jan. 17, 1939 UNITED STATE METHOD AND' APPARATUS FOR CQNDITIONING Alllit Edward T. Turner, Dayton, Ohio Application June 25, 19.34, Serial No. 732,240

41 Claims.

This invention relates to a method and apparatus for conditioning air andis designed more particularly for residential air conditioning although it is not limitedto such use.

One object of the invention is to' provide a simple and eificient' method of conditioning air which can be carried out at a low cost, thereby making residential air conditioning available to persons of moderate means. 1d A further object. of the invention is to provide a method of air conditioning in which waste air will be utilized in modifying the temperature of the air which is to be conditioned.

A further object of the invention is to provide a method of'heat exchange whereby the heat of one fluid may be efficiently transferred to a second fluid. A further object of the invention is to provide a simple and efficient method of modifying the dew point temperature of fresh air which is to be supplied to a room. H

A further objectof the invention is to provide a method ofair conditioning in Whichthe dew point temperature of fresh air to be supplied to a room will be progressively varied in a plurality of successive operations, x

A further object of the invention is to provide a method of conditioning air wherein the fluid used to modify the dew point temperature of fresh air may be utilized to modify. the dry bulb temperature of air which is to be delivered to a room.

A further object of the invention is to provide a method of air conditioning in which the fluid employed will be progressively cooled by a plurality of successive operations, thereby lowering the cost of refrigeration. a

A- further object of A further object of the invention is to provide apparatus for performing the method which will be of a simple inexpensive construction and which may be operated at.a low cost. l

Other objects of" the inventionwill appear as the method'and apparatus are describedin detail.

In the accompanying drawings Fig. -1- is a sectional view, partly in elevation, of one form of l {10 apparatus for carrying out my invention; Fig. 2

is a sectional detail view of a controlling valve;

Fig. 3' is a sectional view, partly in elevation, of another form of apparatus for carrying 701115 the method; Fig. '4 is a sectional detail view of a poras tion of a baiile and Fig. 5, is a sectional view,

partly in elevation, of a third form of apparatus for carrying out my invention. L 1

I In these drawings I have shown certain form of apparatus as illustrative of thevarious ways in which theseveral steps of the method may be performed. In an air conditioning apparatus it is preferable to withdraw from the room to-which conditioned air is being supplied a quantity of old air and after this room air has been reconditioned to return it to the room, and in each of the several forms of apparatus here shown I have provided a main air conduit for this purpose; In Fig. l the main air conduit is shown at 5 and communicates at one end with an outlet 6 in the floor of the room and communicates at its otherend'with one or more inlets E leading to the room. It will be understood that the term room as herein used is intended to include any enclosure to which conditioned air is to be supplied and that it may comprise one compartment or a plurality of compartments. Inthe form here shown this conduit is of a U-shape and is provided with a motor driven fan 8 for circulating the room air through the same, this fan being in the present instance arranged near the outlet end of the conduit. It is also important that a sufficient quantity of fresh air should be supplied to the room and, preferably, a fresh air conduit 9 is connected with the main or room'air conduit 5 at some suitable point. this fresh air conduit is connected with the main conduitin advance of the fan 8 so that that fan will serve to draw the fresh air through conduit 9. There must, of course, be discharged from the room, to waste, a quantity of old or room air corresponding to the quantity of fresh air introduced into the room. This waste air may be disthe invention is to provide a method of heating air whereby the desired 40 temperature may be secured at a low fuel cost.

charged through any suitable outlet but, inthe present construction, I'have shown a waste air conduit l0 connected with 'the main conduit as this facilitates the utilization of the'waste air in a manner which will be hereinafter described. If desired, the waste air conduit may be arranged just beyond the fan 8 so that a portion of the air will be forced from the main conduit through the waste air conduit by the-fan.

As here shown,

The-fresh air is treated, by subjecting it to i the action of a liquid, to impart theretoa pre; determined" dew point temperature prior to its being mixed withthe room air in the main conduit 5. The'liquid used" for this purpose may be of any suitable character but preferably water is used. A continuous supply of fresh cool water may be utilized for modifying the dew point .temperature of the air or the same water may be recirculated through the system and cooled after each passage through the air. Where an ample supply of cool water is available at low cost the first mentioned or fresh water system is usually preferable and in that form of the apparatus shown in Fig. 1 I have employed a fresh water system and have shown a pump H for lifting the water from a well l2 and delivering the same to the humidifying device, which is indicated as a whole by the reference numeral I 00. It will be obvious, however, that the water may be taken from any suitable source and when taken from a water system it will usually be under suflicient pressure to avoid the necessity of using a pump II. The device I flflfor imparting the desired dew point temperature to the fresh air, which is commonly called a humidifier, is of such a construction that the outgoing fresh air will have a dew point temperature closely approaching the temperature of the incoming water and the outgoing water will have a temperature closely aproaching the wet bulb temperature of the incoming fresh air. This device preferably comprises a casing l3 having near one end, in the present instance its lower end, an inlet M for fresh air which, as here shown, is connected with a fresh air supply pipe I5, and having near its other end an outlet l6 for the air, which is connected with the fresh airv supply pipe 9 leading to the-main conduit 5. The casing may be of any suitable character and, in the present instance, it comprises merely an enlargement of the fresh air conduit. Water from the pump II, or other source of supply, is delivered through a supply pipe I! into the upper portion of the casing and is there discharged through a distributor or spray headv IS. The water discharged from the distributor I8 flows downwardly, in a direction opposite the direction of flow of the air through the casing, and inasmuch as the casing isof larger diameter than the conduits 9 and IS the air will flow relatively slowly through the same. In order to maintain this air in such contact with the water, or other liquid, as to effect the desired heat exchange, the casing may be provided with a baffle over which the water flows. This baflle may be of any suitable character which will retard the flow of the water and spread the same into thin sheets of water so that relatively large surface areas of the water will contact with the air. In the present construction, I have shown the baffle as comprising a body of coarse material, such, for example, as coke, as shown at l9. This coke rests upon a screen 20 carried by a spider 2| arranged in the casing Just above the air inlet IS. A second screen 22 is arranged between the baffle and the distributor l8 and serves to distribute the water throughout the entire cross sectional area of the casing. In order that the proper heat transfer may be maintained between the air and the water, either with or ,without a batfle, it is important that the rate of flow of the water should be determined in accordance'wlth the heat content of the air entering the casing.

This may be accomplished by providing the supply pipe I! with a restricted orifice, but when the heat control of the incoming fresh air is subject to wide change it is desirable that the controlling device shall be of a character which can be adjusted as occasion demands, such as the valve 23. It is also desirable. that this valve shall be automatically adjusted'to maintain the proper flow of water through the casing under all conditions and I have here shown a valve adjusting device which is controlled in accordance with the temperature of the Water discharged from .the casing. As has been heretofore stated, the water passing through the easing countercurrent to the air will absorb heat from the air, when the air is of a higher temperature than the water, so that the dew point temperature of the air at the outlet l6 will approximate the temperature of the water delivered to the casing. In a proper installation the dew point temperature of the outgoing air may be only one or two degrees higher than the temperature of the water delivered to the casing. Likewise the water which is discharged from the casing will have a temperature only slightly lower than the wet bulb temperature of the incoming fresh air. In practice the water will have a temperature approximating the wet bulb temperature of the incoming air just before the initial contact of the fresh air with the water and the temperature of the water will be slightly lowered by the fresh air before it is discharged, due to the partial evaporation of the water, unless the fresh air is saturated. The water is discharged from the casing into a suitable receptacle, such as a catch basin 24, here shown as formed integral with the casing and arranged just below the air inlet. The controlling valve 23 is actuated by a thermostatic device comprising a bellows 25 and a bulb 26, for a volatile fluid, which is arranged in the catch basin 24. The bellows 25 is connected with the valve through a lever 21 in such a manner that when the temperature of the Water in the catch basin rises, thus indicating a rise in the heat content ofthe fresh air, the bellows 25 will expand and thus open the valve to provide an increased flow of water. It is desirable that the valve shall be of such a character that the flow of water will not at any time be completely interrupted and that the area of the valve port will increase in direct ratio to" the movement of the valve member. In the valve shown in Fig. 2 the-valve member is in the form of a slidable pin 28 adapted to extend into a valve port 29 but of such a diameter that the port will not be completely closed when the pin is fully inserted therein. The end of the pin is tapered in such a manner that the area of the opening will increase in direct proportion to the outward movement thereof. The catch basin is connected with a discharge pipe 30 through which the water escapes therefrom and the outlet leading to this discharge pipe is controlled by a float operated valve 3| to maintain the water in the catch basin at all times at a depth sufficient to cover the bulb 26. When the Water at the source of supply has a temperature lower than the desired dew point temperature for the fresh air it is delivered to the casing l3 without modification but should cold water not be available it may be necessary, in order to secure the desired dew point temperature in the air, to cool the water before it is delivered to the casing and for this purpose it may be passed through a cooling, element 32, which may be of any suitable character.

In heatexchangers of the character described herein, it is important, first, that the quantity of the water circulated-through the system shall be the smallest quantity which will effect the desired results and, second, that the temperature differential between the infiuent water'and the efliuent air shall be reduced to a minimum, that is, that the temperature of the air leaving the ture of the incoming water.

.contacts the effluent water and in a properly conthe'wet bulb temperature change of the air.

- V conditioner shall-closely approach the tempera- To enable the desired results to be, attained with a minimum quantity of water, the temperature change of the water must be the maximum attainable and this in turn requires that the temperature of the eiiluent water shall closely approach the wet bulb temperature ofthe influent' air. Thus in an eflicient apparatus the temperature differential-will be small and substantially the same at both ends of the apparatus.

The influent air becomes saturated when it apparatus in which the temperature change of the water will be from ...three to five times the temperature differentials.

To efiect the relatively large temperature changes with respect to the temperature diflerentials it is important that the'delivery of war ter to the apparatusbe properly regulated, that the water shall flow counter-current to the air and shall be spread into thin sheets to provide large surface areas for contact. with theair, and that the how of water shall be re-. tarded so that itdoes not appreciably oppose the free flow of the air.

The water, which is discharged from the, casing i3 into the catch basin 24 at a temperature approximating the wet bulb temperature of the incoming fresh air, will have a temperaconduit 5.

ture substantially lower than the dry bulb tem-' perature of the room air and may therefore be utilized to cool the air which is to be delivered tothe room, that is, in the present instance, the air which. is circulating through the main For this purpose I have arranged within the conduit 5 a heat exchange element 33, here shown, as a coil of pipe provided with fins 34. The water from the catch basin 24 is delivered to the upper end of the element,33

' and thus caused to flow through that element in a direction opposite to the direction of flow of the air through the ,conduit 5. Any suitable means may be provided for/circulating the water through the element 33 but preferably the.

discharge pipe 30 is connected with a pump 35.

the outlet of which is connected by a pipe 36 with the'upper end of the element 33. I The lower or dischargeend of the element? is connected with a waste pipe-31 which may be .pro-

wided with a valve 38 :for a purpose which will. hereinafter appear.' 'The quantity of the cool water flowing through the heat exchange eleme nt33 may-be controlledin accordancewith the temperature of the room (air-ahdfor this purpose I have provided thedischarge pipe 39 with a branch pipe 39 which may lead to waste. This branch pipe is controlled by afvalve 40' which is actuated by a thermostatic device which,

3 in the present instance, comprisesa bellows 4|,

opcratively connected with the valve,and a bulb exchange device Hit.

ment being such that when the temperature of the air in theconduit 5 falls the bellows 4! 'will openthe valve 40,. and thus permit 'a portion of the water to" escape to waste, so that a smaller quantity of water may be circulated through the 'cooling element 33. If desired, the discharge line 30 may be provided with ,a valve so that the supply of water to the pump and cooling element'may be cut off at will. The rate of flow .of the water through the cooling element is so controlled as to bring about the desired exchange I of heat, this being in the present instance acl-complished by regulating the operation of the pump 35.

It may at times, particularly in hot weather, be desirable to pre-cool the fresh air before it is delivered to the heat exchange, device or humidifier I00, in order to secure in the heat ex- This pro-cooling 'of the fresh air may be effected at a very' small operating cost by utilizing the waste air, which is discharged from the room,

. through the medium of a suitable heatexchange apparatus. In the construction here illustrated the heat exchange apparatus comprises two casings 44 and 45, which may, if desired,,be arranged one above the other. One of these casings, in the present instance the lower casing Mi, is provided with an inlet 46 for fresh air and an outlet 41 for fresh air, this outlet being connected with the fresh air supply pipe l5 which leads to the casing l3of the humidifier or heat In the form here shown the casing fi l is separate from and arranged above a catch basin 48, so that the fresh air may enter at the bottom of the casing. With this arrangement a supply pipe for fresh air is unnecessary and the air may be admitted to the basement, or other compartment in which the apparatus is installed, through a window 49. The second casing, 45, is provided near its lower end with an inlet 50 fOr room air which is here shown as connected with the waste air pipe l0. At its upper end this casing is provided withan outlet 5! for air. Both casings may, if desired,

be provided with baiiles, 52"" and 53, similar to the baifle' in the casing It.

The water is withdrawn from the catch basin 48 by a pump 54 and is delivered through a pipe 55 to adistributor 5B in the upper portion of the upper casing 45 so thatthis water passes down- "Wardly over the baffle 53 countercurrent to the room air, which is passing upwardly through the casing; In warm weather this room air will be at a temperature substantially lower than the outside temperature and the water passingthrough thesame will be discharged into a catch change device the desired dew point temperature without the use of an excessive amount of water.

basin 5'! ,at a temperature approximating the Wet bulb temperature of the incoming room air,

this-air being then discharged through a conduit 58 to the exteriorof the building. The water is discharged from the catch basin 5! by ravity through a pipe 59 to a distributor'GB in the upper portion of" the lower casing 44 and flows downwardly over the baffle 52 countercurrent to the fresh air,which is passing upwardly through the. casing, thus causing the dew point'temperature of the fresh'air to beinaterially lowered, so that when delivered to the first mentioned heat exchange casing I3 itwill have a relatively low dew point-temperature. The water is discharged from thecasing 44 into the catch basin, 48 and it will thus be apparent that thetwater is cirl 42 arranged in the main conduit 5, the arrange-' culated through an. endless circuit ,a part bf which-comprises the casing 45 through which the room air passes and another part of which comprises a casing 44 through which the fresh air passes. The rate, of flow of the water may be regulated to secure the desired heat exchange in any suitable manner. As here shown, this control is effected by a valve 8| which is controlled by a thermostatic device comprising a bellows B2 and a bulb 83 immersed in the water in the catch basin 48. This pro-cooling of the fresh air before it is delivered to the heat exchange casing l3 will not only reduce the amount of water necessary to impart the final'dew point temperature to this fresh air but will also cause the water to be discharged from the casing l3 at a relatively low temperature and thus increase its cooling action on the air in the main conduit 5. In order to prevent the water which circulates through the casings 44 and 45 from becoming stale I provide for a constant but slow change of that water. As here shown, a waste pipe 84 leads from the catch basin 48 and is provided with a restricted outlet 85 through which a small quan tity of water will constantly fiow. A constant supply of fresh water is provided through a float controlled inlet .valve 66.

Under some temperature conditions the passage of the fresh air through the heat exchange casing 44 may impart thereto the desired dew point temperature, suitable for mixing with the room air in the main conduit 5, and under these circumstances the operation of the heat exchange device or humidifier I08 will be interrupted so that the casing 13 will merely constitute a portion of the conduit leading from the casing 44 to the main conduit 5. This interruption may be effected by merely stopping the operation of the pump l I or otherwise interrupting the supply of water to the casing. It will be obvious that in cold weather the room air will have a temperature higher than the outside air and therefore action of the heat exchange apparatus 4445 will serve to raise the temperature of the fresh air rather than to lower the same and the heat exchange device or humidifier I00 need not be used. The apparatus thus automatically accommodates itself to exterior air conditions and the only action necessary on the part of an operator is to interrupt the operation of the heat exchange device or humidifier I00 when this becomes desirable.

In cold weather the heat exchange element 33 in the main conduit 5 may be used for heating the air which is to be delivered to the room and when this is to be done the valve 43 is closed to cut off the supply of cool water to the pump 35, and the valve 38 is closed to cut ofi the connection between the heat exchange element 33 and the waste line 31. The element 33 is then connected in circuit with a similar element 61 arranged in a heater so that water, or other suitable liquid,

' will be heated in the heat exchange element 61 and cause to circulate through the element 33 in the conduit 5. In the arrangement here shown the heater element 61 is connected at its lower or discharge end with a pipe 68 which leads to the pump 35 and is provided with a valve 69 by means of which the connection may be interrupted when a the heat exchange element 83 is to be used for cooling purposes. The upper or receiving end of the heating element 61 is connected by a pipe 10 with the lower or discharge end of the heat exchange element 33, this connection also being controlled by a valve, I I. The heater or furnace may be of any suitable construction but. I have here bustion in the heater casing 72 and will flow through the heat exchange element 33 in a direction opposite the direction of flow of air through the main conduit, thus causing in each instance a relatively large exchange of heat. The operation of the gas burner 13 may be automatically I controlled according to the temperature of the room air and, as here shown, a gas supply pipe "i i which leads to the burner i3 is provided with a valve 15 which is actuated by a bellows l6 connected by a pipe ll with the bulb 82 in the main conduit 5, the arrangement being such that an increase in temperature of the air in the main conduit 5 will cause the bellows 76 to expand and close or partially close the valve '15. If desired, the gas supply pipe 'h'i may also be provided with a valve 18 which is automatically operated to cut off the gas in the event of the excessive heating of the liquid in the circuit. As here shown, this valve is actuated by a bellows 19 connected with a bulb 80 arranged in an enlargement or chamber 8| formed in the pipe 88 between the heating element 8'! and the pump. Obviously if the heater used solid fuel these thermostatically controlled devices would be connected with dampers instead of with valves. Means are also provided for reducing or interrupting the flow of liquid through the circuit when the liquid has been excessively heated. To this end a valve 82 in the pipe 68 is actuated by a bellows 83 connected with a bulb 84 also located in the chamber 8|.

The heater is constantly supplied with air which passes through the casing 12 and is discharged at a high temperature, usualy passing to waste, and I have provided means for utilizing the heat of the air and other products of combustion discharged from the casing 12 to preheat the air delivered to the casing and thus reduce the amount of fuel required to heat the liquid inthe element 61. As here shown, the air is delivered to the lower portion of the casing through a supply conduit 85 and is discharged from. the upper end of the casing through a conduit 86.- In order to utilize the heat in the conduit 86 to raise the temperature of the air in the conduit 85 I have arranged in the conduit 85 a heat exchange element or coil 81 and in the conduit 86 a heat exchange element or coil 88, these coils being connected in a circuit including a pipe 85 and a pump 90, which circulates a liquid through the circuit. In the present arrangement the pump discharges through a pipe 9] into a receptacle 92 which is connected with the coil 88 and the flow of liquid from the receptacle to the coil is controlled by a valve 93. It will be apparent that the liquid passes through both conduits, 85 and 85, in a direction opposite to the directions of flow of air or other fluid in those conduits, and the rate of flow of the liquid through the circuit is so controlled, by the pump 90 and the valve 93, that the liquid inthe element 88 will pass from the conduit 86 at a relatively high temperature, which may approach the tcmperature .of the air or other productsof combustion entering that conduit, and the air passing through the conduit 85 will be heated by the hot liquid circulating through the element 81 to a relatively high temperature and will be dis- 85 is connected with the outlet conduit 58 leading/ venience to-avoid two'outlet openings in the wall vided for controlling from the casing 45. While the air is discharged from this casing 45 at a temperature somewhat lower than room temperature it will nevertheless, in cold weather, be substantially higher than. outside temperature and the heat available in the heat exchange element 81 will raise this air to a higher temperature than it: would raise the coldoutside air. The discharge conduit 86 for the heater casing is also shown as connected with the outlet 58 but this is largely a matter of con-' of the building. Dampers 94 and 95 are prothe flow of air through the conduits.

In that form of the apparatus shown in Fig. 3,

' the air is withdrawn from the room and returned thereto by means of a main conduit IM and a portion of this conduit, as shown at, I02, constitutes the casing of a heat exchange device or humidifier for modifying the dew point temper- I ature of the room-air before it is returned to the room. Mounted in the casing I02 is a distributor I03 arranged to discharge finely divided liquid through the casing in a direction opposite to the direction of the flow of air thereto; Preferably a ballie is arranged in the'casing below the distributor and the liquid is caused to flow over this 'baflie to expose relatively large surface areas thereof to the action of the air. This bafile may be of any suitable character but the type of bafile shown in detail in Fig. 4 is very eflicient. As there shown the distributor comprises a series of downwardly directed nozzles I04 which receive liquid from the pipe I05 and have at their lower ends small outlets I06 through which the liquid will be. slowly discharged. Arranged beneath the distributor are a plurality of series of plates I01, which are preferably of. material ,having high heat conductivity; such as copper. The plates of the upper series are slightly inclined and are arranged beneath the corresponding nozzles I04 so that the liquid will drip from said nozzles onto the inclined surfaces ofthe plates and. spread over the same in a thin film. The plates of each lower series are inclined ina direction opposite the direction of inclination of the plates of the next higher series and are arranged beneath the corresponding plates of the next higher series to re'ceivethe water therefrom. The plates of each series are spaced relatively short distances apart and, due to their inclination, provide a series of relatively narrow tortuous passageways through the baflle. The air passing through each of these passageways will contact with a wet surface on one side of the pasageway and with a dry surface on the other side of the passageway, but as the plates have a. large heat conductivity the dry sides thereof will be maintained at a temperature approaching thatof the liquid a'ndwhen the liquid is cooler thanthe air the dry sides of the plates will ab sorb considerable quantity of heatfrom the air. Due to this arrangement a relatively small quantity of liquid will sufiice to cause the air to be to a main reservoir 0.

discharged at a dewpoint temperature approximating that of the incoming liquid.

. The liquid may be'supplied to the distributor from any suitable source of supply and, in the arrangement shown water is taken from a well 1 by a pump IOB'and delivered through a pipe I09 The delivery of the water from the well, or other source of supply, is so controlled as to maintain the water in'the reservoir H0, at or above a predetermined level.

In the present construction the pump is operated by an electric motor III and a snap switch H2 is interposed in the circuit of the pump motor and is controlled by a float. H3 in the reservoir to cause the pump to operate intermittently at such intervals as may be necessary to maintain the desired supply of waterin'the reservoir. The level of the water in the reservoir fluctuates through rather a wide range and if the water was delivered directly from the reservoir to the distributor I03 the head or pressure on the dis tributor would vary with changes of level in the reservoir, In order to maintain a constant head on the distributor I have provided asecond or '1 supplemental reservoir I I4 to which the water isdelivered by gravity from the main reservoir I I0: The outlet for the mainreservoir is controlled by a valve H5 which is actuated by a float H5 in the supplemental reservoir, the arrangement of the valve and float being such as to maintain the water in the reservoir 4 at a substantially constant level. The water is discharged from the supplemental reservoir H4 through a pipe III which is connected by a pipe IIB with the distributor I03, the pipe II8 being provided with a cut-off valve H9.

It is not always desirable to continuously operate the heat exchange device or humidifier in the portion I02 of the main conduit-and I have here shown means for controlling the operation of that device in accordance with the temperature of the room air. For this purpose a valve I20 is inserted in the pipe H8 leading to the distributor I03 and is connected through a lever system, comprising a pivoted arm I2'I, with an expansible device or bellows I22 which is connect'ed with a fluid bulb I23 arranged in the main conduit IOI, so that whenthe temperature of the room air'is lowered the bellows will contract to close the valve and whenthev temperature rises .to a predetermined degree the bellows will expand to open the valve. Preferably a spring I24 is connected with the pivoted arm HI and so arranged that when that arm has been moved past an intermediate position the spring will quicklycomplete the movement of the arm to either ,open or close the valve.

The water which is passed through the air in the portion I02 of the conduit IOI may be utilized to modify the temperature of the room air before it enters vsaid portion of the conduit. In the construction shown the water from the distributor I03 after passing through, the air isdelivered to a receptaclev or catch basin I25 from which it is discharged through, a pipe I26 to a tubular 'element I21 arranged in the conduit l0l in advance of the portion I02 thereof and from which the liquid is discharged through a pipe I28 tov waste. The arrangement is such that the liquid,

flows through the tubular element I21 in a direction opposite the flow of the air through the conduit; thus modifying the temperature of the air and enabling the desired dew point, temperature to be imparted thereto in the portion I02 of the conduit by a smaller quantity of water than would otherwise be necessary. A valve I29 in the pipe I28 is controlled by a fioat I in the catch basin I25 to maintain the tubular element full of water at all times.

A supply of fresh air at desired dew point temperature is constantly delivered to the room, and, in the present construction, a fresh air conduit 230 is connected with the main conduit IOI above the distributor I03 and has an enlarged portion 23I forming a casing, the lower end of which is open to provide an inlet for fresh air, which may be received from a window 232 in the basement or other compartment in which the apparatus is installed. A distributor 233 is arranged in the casing 23l to discharge liquid therethroughin a direction opposite to the flow of the air and is connected by a pipe 234 with the supplemental reservoir I I4. If desired, baiiles 235 may be arranged in the casing 23I beneaththe distributor and, as here shown, the distributor and baiile are of the types illustrated in Fig. 4. The water is discharged from the casing 23I to a receptacle or catch basin 236 from which it is discharged through a pipe 231. A valve 238 in the pipe 231- is controlled by a float 239 in the catch basin to maintain a substantial quantity of water in the catch basin at all times. The

rate of flow of the water through the casing is automatically controlled according to the, wet bulb temperature of the incoming fresh air and for that purpose a regulating valve 240 is interposed in the pipe 234 and is controlled by an expansible element or bellows 24I connected with a fluid bulb 242 in the catch basin 236. The air passing through the casing in contact with the,

water will be discharged therefrom at a dew point temperature approaching the temperature of the incoming water, and the water will be discharged from the casing at a temperature approaching the wet bulb temperature of the incoming fresh air. Consequently the. thermostatically controlled valve 240 will be operated in accordance with the wet bulb temperature of the incoming air. A cut-ofl valve 243 is also mountedin the I pipe 234 to completely interrupt the how of liquid therethrough when desired.

Water from the catch basin 236 may be discharged to waste but I prefer to modify the temperature thereof in accordance with the wet bulb temperature of the room air and again utilize the same. I have therefore, connected the discharge pipe 231 with a pump 244 by which the water is delivered through a pipe 245 to a distributor 246 inthe casing 241 of a heat exchange device which is supplied with room air. As here shown, the lower end of this casing opens into a receptacle 248, the upper portion of which is in open communication with a conduit 249 connected with the main conduit IOI at a point in advance of the heat exchange device therein. If desired, a motor operated fan 250 may be arranged in the conduit 249 to insure a proper flow of room air through the same. This room air enters the open lower end of the casing and is discharged from the top of the casing through a,

waste conduit 25I. If'desired, a battle 252 may be arranged in the casing beneath the distributor and, in the present instance, the distributor and baflie are of the types shown in- Fig. 4. The lower portion of the receptacle 248 constitutes a catch basin for the water discharged from the casingand the outlet for this catch basin is connected with a pipe 253 leading to the catch basin I25 in the main conduit IN. The water is delivered to the catch basin 248 at a temperature approaching the wet bulb temperature of the room air and passes therefrom to the catch basin I25 and then through the tubular heat exchange element I21 in the main conduit. If

the heat exchange and humidifying device in the portion I02 of the main conduit is in operation the water from the catch basin 248 will be mixed with the water from the distributor I03 before it is delivered to the tubular element I21. The outlet for the catch basin 248 is connected by apipe 254 with the distributor 233 in the fresh air casing 23 I, this pipe beingprovided with a valve 255. When water is being delivered from the supplemental reservoir II4 to the distributors I03 and 233 the valve 255 will be closed and the apparatus will operate in the manner above described, but by closing the valve 243 in the pipe 234, which connects the supplemental reservoir with the distributor 233, closing the valve 256 in the pipe 253 and opening the valve 255 in the pipe .254 the apparatus may be operated on a closed circuit, the water circulating repeatedly through the fresh air casing 23I and the room air casing 241. In warm weather the valve 255 will be closed andcool fresh water will be supplied to the distributor I03 and 233 and inasmuch as the room air will then be at a temperature lower than the exterior air the water passing through the room air casing 241 will be cooled and delivered to the heat exchange element I21 to cool the room air in the conduit IOI usually desirable to interrupt the supply of cool water, either by stopping the pump or by closing the valves H9 and 243, and to then open the ture of which has been accordingly raised. However, if desired, the apparatus as a whole may be utilized in cold weather and the fresh water may be heated as by means of a coil 251 in the main reservoir I I0. 7 v

Also if desired the apparatus as a whole may be operated on a closed circuit by connecting the liquid discharged pipe I28 for the tubular element I21, with the pump II I, by means of a pipe 258, and closing a waste valve 259 in the pipe I28 and also closing a valve 260 in the pipe connecting the pump with the well or other source of supply. A valve 26I serves to prevent the flow of liquid through the pipe 258 when the pump is connected with the well. When the pump is connected with the waste pipe I28 and the apparatus as a whole is operated on a closed circuit the coil 251 in the main reservoir llfl'may be utilized for either heating or cooling the water as may be necessary.

In that form of apparatus shown in Fig. 5 the device for imparting the desired dew point temperature to the fresh air which is to be delivered to the room is of the recirculating type and is provided with means for cooling the liquid as it circulates through the device. In this form of apparatus a main conduit I receives the air from and returns the same to the room in, the manner above described and is provided with a fan I36 for circulating air. through the same. A waste air conduit I31 leads from the conduit I35, in the present instance at a point adjacent to the inlet end of the conduit I35. This waste air con- In cool weather it is duit is connected with the air inlet I38 of a. heat I I a pipe I62 with an injector I63. A steam generthe evaporator.

aun ies;

is delivered a the casing I 39 through a distributor basin I44. The water is withdrawn from the catch basin I 44 by a pump I45 which delivers the same through a pipe I46, a cooling element I41 and pipe I48 to a distributor I49 in the upper end of the casing I50 .of a second heat exchange device. The casing I50 has. .at its lower end an inlet II for fresh air-and at its upper-end an outlet I52 for air, which is connected by a conduit I53 with the main conduit I35. The water passes, preferably over a bailie I54, through the casing I50 in a direction opposite ,to the direction of flow of 'fresh air through that casing and is discharged into a catch basin I55. A pump- I56 withdraws the water from the catch basin I55 and delivers the same through a pipe I51 to the distributor I42 in the casing I39 of the heat exchange device I40. The rate of flow of the 'water through the 6 two casings is controlled by the operation of the pumps and may also be further controlled according to the dewpoint temperature of the fresh air entering the casing; I50'by means of a valve I58 which is here shown as actuated byan ex'pansible element or bellows I59 which is connected with a bulb I60 immersed in the water inthe catch basin I55, in the manner above described. The water thus circulates through an endless circuit and itsternperaturewill be raised by the absorption of heat from the fresh air passing through the easing I50. The room air which is delivered to the casing I39 being at a lower temperature than'the' fresh air will absorb heat from the. water as it passes, through the casing, I39 but ordinarily the temperature of the room gair willnot be low enough to impart the desired temperatureto the water and I have therefore interposed in the water line between the casings I39 and I50 the coolingelement I41. prises a refrigerating apparatus which utilizes water vaporas a cooling medium. As here shown, the cooling element I41'comprises a housing connected at its lower end with the discharge pipe I46 of the pump I45 and connected at its upper end with the pipe I48. Arranged within this housing is an evaporator IBPWhich may be of any suitable kind and is here shown as of a conventional type. This evaporator isconnected by ator I64 is connected, by a pipe I65 with the injector I63"and the steam discharged through the injector I63 willdraw vapor from the evaporator I6I and thus lower the temperature within the housing I41 in a well known manner. a The steam and vapors are discharged from the injector to a condenser I66 and the condensate. is delivered from the condenser to a receiver I61 which is connected by a pipe I 68 with the evaporator; to provide a continuous 'supply 0 water to Only aportion of the water in the receiver I61 is delivered to the evaporator and into the generator, against the pressure therein, an injector I69 is connected with the steam discharge pipe I 65 by a pipe I and has its discharge This cooling element com- 'the remainder of this water is returned to the generator I64. ,In order to introduce this water.

the respective conduits.

water entering the injector is not always cool enough to. completely condense the steam I have provided the pipe I13 with a cooling element I14 which is connected by a pipe I with the pipe I48 leading from the cooling element I41. Cool water is thus circulated through the cooling element I14 and is discharged therefrom through a pipe I16 which, in the present instance, leadsto the catch basin I55. The cooling element I14 'water into the'g enerator' thev steam .should be will thus so'reduce the temperature of the water entering the injector I69 as to cause the condensation of the steam in that injector and the proper introduction of the water into the gener I ator. By the use of this injector system I am able to circulate the water through a closed system and return the same tothegenerator without danger of air leaks whichwould destroy the vacuum which is necessary to the effective oper- -ation of the evaporator and to maintain "suflicient pressure in the generator for eflicient operation.

The steam generator may be of any suitable character which will provide steam frili the desired amount and at the desiijedpressure' and,

as here shown, it comprises a'boi ler whichisheated by a gas burner I11. The economical tion of steam pressure. according to variations in the heat content of the fresh air and l. have plished by means of a valve I10 in the fuel supply line, which valve is actuated by an expansi ble element or bellows I19 connected with a bulb I80 in the fresh air conduit I53. If desired, the

. operation of the apparatus may require a variaamount of water passing through the cooling element I41 may be automatically regulated by means of a valve I8-I which is actuated by a float I82 in the catch basin I55., By thus utilizing the waste room air to partially cool the circulating medium or water the amount of refrigerant necessary to maintain this water at the desired tem-- perature is substantially reduced and the cost of operating the apparatus is correspondingly reduced.

If desired, the fresh air which is being delivered to the room at a relatively low temperature, through the conduit I53, may be utilized to precool room air which is delivered tothe-heat exchange device I40, thereby enabling the water passing through the heat exchange device to be reduced to a lower temperature than would otherwise be possible. For this-purpose I have mounted in the conduit I53 a tubular heat exchange element 2| 0 which is connected at one end with the discharge sideof a pump 2H and is connected at its otherend by a pipe 2I2 .with

a, similar tubular element 2I3 in the room air waste pipe I31, this latter element being connected at'its discharge end with the intake of the pump 2H,. A liquid is circulated by the pump through the closed circuit thus formed and flows through the tubular elements in. directions opposite the (direction of flow of the air through Thus the liquid is cooled in the tubular element 2I0 and this cool liquid flowing through the tubular element H3 1 absorbs heat. from theroom air. The temperature" of the fresh air will, of course, be raised somewhat but this is not seriously objectionable because this air is passed about a cooling element I83 in the main room air conduit I35 be- 30 pr0vided means for controlling the supply of tfuel to the burner I 11 in accordance with the- ,temperature of the fresh air discharged from the casing I50 to the main conduit. This is accom= pression.

fore it is delivered to the room, and the cooling in conduit I35 is effected at a relatively high temperature and therefore the cost is relatively low. Further, by so pre-cooling the room air before it is delivered to the heat exchange device I40 the Water may be delivered to the refrigerating device I4'I at a relatively low temperature and less refrigeration will be necessary to secure the desired temperature in the water delivered to the heat exchange device I50 for fresh air.

In this form of apparatus a separate system is provided for cooling the air which has been withdrawn from the room and is to be again delivered thereto. Refrigeration may be effected much more economically at high temperatures than at low temperatures and I have provided means for effecting the major portion of-the air cooling operation at a relatively high temperature and then further cooling the air to the desired low temperature by a second operation. In this manner a higher efiiciency and lower cost is attained than could be attained if the air was cooled to the desired temperature at one operation. For this purpose, a cooling element or coil I83 is-arranged within the main conduit I35 and supplied with a cooling medium to further coo-l the recirculated room air after it has been partially cooled by mixing the humidified fresh air therewith. As here shown, the cooling element I83 has its lower or discharge end connected by a pipe I84 with the intake of a pump I85, the discharge side of which is connected with the housing I06 of a cooling element and the upper end of this housing is connected by a pipe I8! with the lower end of the housing I88 of a second cooling element, and the upper end of this second housing is connected by a pipe I89 with the upper or inlet end of the cooling element I83 in the conduit I35. The pump I85 thus serves to circulate a suitable liquid through the endless circuit which includes the two cooling or refrigerating units I86 and I88 and the liquid is thus progressively cooled and the amount of refrigerant and the cost of refrigeration is correspondingly reduced. As is well understood the cost of effecting refrigeration is proportional-to the logarithm of the ratio of compression, and the higher the temperature at which refrigeration is effected the higher must be the ratio of com- By effecting refrigeration progressively a large portion of it may be effected at a lower temperature than would be possible if complete refrigeration was effected at one time or by a single operation. Arranged within the housings I86 and I88 are evaporators I99 and I9I in which water may be used as the refrigerating medium. A steam generator I92 has-a discharge pipe I93 which is separately connected with two injectors I94 and I95, the injector I95 being preferably of a somewhat larger size than the injector I94. The injector I94 is connected by a pipe I96 with the evaporator I and the passage of steam through that injector serves to draw vapor from the evaporator and to reduce the temperature of the liquid therein. The injector I is connected by a pipe I91 with the evaporator I9I and the passage of steam through the injector I95 serves to draw vapors from the evaporator I9I. Both injectors have their discharge ends connected with a condenser I98 which discharges into a receiver I99. This receiver is connected by a pipe 200 and suitable branches with the evaporators I 90 and I9I so that a portion of the liquid of condensation is returned to the evaporators. The remainder of the water in the receiver I99 is returned through a pipe 20I to the steam generator I92, the water being introduced into the generator by an injector 202 and a cooler 203 being interposed in the pipe 20I and connected with the pipes I89 and I84 to so cool the liquid as to condense the steam in the injector 202, in the manner hereinbefore described in connection with the injector I69. It will be apparent that the liquid which is discharged from the cooling element I83 is first partially cooled in the housing I86 and is then further cooled in the housing I88, the larger size of the injector I95 serving to draw a greater amount of vapor from the evaporator I9I and thus maintain the temperature in the housing I88 substantially lower than the temperature in the housing I86. The steam generator here emplcyed may also be of any suitable character and is shown as a boiler heated by a gas burner 204 and the steam pressure is automatically controlled in accordance with the room temperature by means of a valve 205 in the as supply pipe which is controlled by a thermostatic device comprising a bulb 206 in the main conduit I35. While the apparatus of Fig. 5 is shown as a cooling apparatus, it will be obvious that it may be combined with asuitable heater, as in the manner shown in Fig. 1, and when so combined the apparatus would operate the year round to maintain the room air in the proper condition, the' refrigerating device being employed in warm weather and the heating device being employed in cool weather.

It will be obvious that the various elements and sub-combinations of the several forms of the apparatus here illustrated are, in part at least, interchangeable and that these elements 'and sub-combinations may be grouped in various arrangements or combinations other than those here illustrated.

While I have shown and described certain forms of apparatus for carrying out my method of air conditioning I wish it to be understood that I do not desire to be limited to the details of either the method or the apparatus as various modifications may occur to a person skilled in the art.

Having now fully described my invention, what I claim as new-and desire to secure by Letters Patent is:

1. A method of supplying conditioned air to a room which comprises withdrawing air from said room, causing a supply of fresh air to-fiow through a chamber, causing liquid to flow through said chamber in a direction opposite the direction of flow of fresh air and in contact therewith, thereby modifying the temperature of both said fresh air and said liquid, utilizing said liquid after it has passed through said fresh air to modify the temperature of air withdrawn from said room, and delivering said fresh air and said modified room air to said room.

2. The method of supplying conditioned air to a room which comprises withdrawing air from said room, passing a portion of the withdrawn room air in heat exchanging relation to a liquid to modify the temperature of the latter, passing fresh air in heat exchanging relation to the modified liquid to modify the temperature of the fresh air, circulating a liquid through a closed circuit, modifying the temperature of the liquid in a portion of said circuit, passing withdrawn room air about another portion of said circuit to modify the temperature of said room air and delivering said modified fresh air and said modified room air to the room. I

3. The method of supplying conditioned air to a room which compriseswithdrawing air from said room, passing a portion of the withdrawn room air in'heat exchanging relation to a liquid to modify the temperature of the latter, passing fresh air in heat exchanging relation to the modified liquid to modify the temperature of the fresh air, circulating a liquid through a closed circuit, modifying the temperature of the liquid in a portion of said circuit, automatically controlling the modification of the temperature of the liquid in said circuit in accordance with the temperathe liquid therein, withdrawing air from said room and subjecting the air so withdrawn to the action of another portion of said circuit to cause the air to be heated thereby, subjecting a supply of fresh air to the action of a liquid to modify the dew point temperature of said air and delivering said fresh air and the heated room air to said room.

5. The methodpf supplying conditioned air to a room which comprises withdrawing air from said room, passing fresh air through a'chamber, delivering water from a source of water supply to said chamber at a low temperature, causing said water to flowthrough said chamber in a direction opposite the direction of flow of said fresh -air and causing relatively large surface areas thereof to contact with said fresh air in said chamber, automatically controlling the delivery of water to said chamber in accordance with the wet bulb temperature of :the air entering said chamber to supply said water insuch quantities as to cause said fresh air to be discharged from said chamber at a dew point temperature approaching the temperature of the water delivered to said chamber, mixing said fresh air with air withdrawn from said room, and delivering the mixture to said room.

. 6. A method of supplying conditioned air to said chamber at a low temperature, causing said water to flow through said chamber in a direction opposite to the direction of flow of said fresh air,

' controlling the flow of said water to cause relatively'large surface areas thereof to contact with the fresh air in said chamber, controlling the rate of flowof said water through said chamber to cause said fresh air to be discharged from said chamber at a dew point temperature approacning the temperature of the water delivered to 'said chamben and to cause said water to be discharged from said chamber at a temperature approaching the wet bulb temperature of the fresh air entering said chamber, causing the water discharged from said chamber to pass in room which comprises withdrawing air from saidroom, causing a supply of fresh airto fiow through a chamber, causing liquid to flow through said chamber in adirection opposite to the direction of flow of said fresh air and in contact therewith,

controlling the rate of flow of said liquid to cause said fresh air to bedisoharged from said chamber at a dew point temperature approaching the temperature of the liquid entering the chamber," and to cause the liquid to be discharged from said chamber at a temperature approaching the wet bulb temperature of the air entering said chamber, controlling the discharge of liquid from said chamber according to the temperature of the room air to cause said liquid to be discharged to waste or to be circulated through withdrawn room air to modify the temperature of the latter, and delivering said fresh air and said modified room air to said room.

8. A method of supplying conditioned air to a room which comprises withdrawing air from said room, passing a portion of said withdrawn air through a chamber, passing a liquid through said chamber in a direction opposite the direction of flow of said air and in heat exchange -relation to said air to cool said liquid, subjecting said liquid to the action of a cooling medium tofurther-cool the same, passing said cooled liquid through a second chamber, passing fresh air through said second chamber in a direction opposite to the direction of flow of said liquid to lower the dew I point tem'peratureof said fresh air, and delivering said fresh air to said room.

9. A method of supplyingconditioned air to a room which comprises withdrawing air from said room, passing a portion of said withdrawn air through a chamberypassing a liquid through said chamber in a direction opposite the direction of flow of said air and in,heat exchange relation.

to said air to modify the temperature .of said liquid, then passing said liquid through a second chamber, passing fresh air through said second chamber in a direction opposite to the direction tion opposite to the direction of flow of said fresh air and in heat exchange relation to said fresh air to further modify the dew point temperature of said fresh air, and delivering. said fresh air to said room.

10. A method of supplying conditioned air to a room which comprises withdrawing air from said room, circulating aliquid in an endless circuit, passing a portion of the air withdrawn from said room through the liquid in a part of said circuit and in a direction opposite the direction of flow of .said liquid to lower the temperature of said liquid, subjecting said liquid to the action of a cooling medium to further lower its tem-' perature, passing fresh air through the cooled liquid-in another part of said circuit and in a. direction opposite the flow of said liquid to lower the dew point temperatures of said fresh air, controlling the action of said cooling medium in accordance with the temperature of the fresh air discharged from the last mentioned part of said circuit, and delivering said fresh air to said room.

11. A method of supplying conditioned air to a room, circulating a liquid in an endless circuit, passing a portion of the air withdrawn from said room through the liquid in a part of said circuit and in a direction opposite the direction of drawn from said room to pass through theliquid in,a portion of said second circuit in a direction flow of said liquid to lower the temperature of said liquid, subjecting said liquid to the action of a cooling medium to further lower its temperature, passing fresh air through the cooled liquid in another part of said circuit and in a direction opposite the flow of said liquid to lower the dew point temperature of said fresh air, circulating a liquid through a second endless circuit, passing a portion of the air withdrawn from said room about a part of said second circuit, subjecting the liquid in another part of said second circuit to successive actions of a cooling medium to pro- 'gressively reduce the temperature thereof, and delivering said fresh air and the last mentioned portion of the withdrawn room air to said room.

' 12. A method of supplying conditioned air to' a room which comprises circulating a liquid through an endless circuit, withdrawing air from said room, passing said air about a portion of said circuit in a direction opposite the direction of fiow of the liquid therein and returning said air to said room, causing the productsof combustion from a heater to pass about another portion of said circuit in a direction opposite the direction of flow of the liquid therein, circulating a liquid through a second endless circuit, causing'air withopposite to the direction of flow of the liquid therein, causing fresh air to pass through the liquid in another portion of said second circuit in a directionopposite the direction of flow of the liquid therein, and delivering said fresh air and the first mentioned room air to said room.

13. A method of heating air or the like which comprises circulating a liquid through an endless circuit, passing the air to be heated about a portion of said circuit, passing products of combustion from a heater about another portion of said circuit,circulating a liquid in a second endless circuit, passing the products of combustionwhich have passed the first mentioned circuit about a portion of said second circuit, and passing air about another portion of said second circuit and delivering the last mentioned air to said heater.

14. An apparatus for supplying conditioned air to a room comprising a main conduit for withdrawing air from said room and for delivering modified air to said room, means for circulating a liquid in a closed circuit through said main conduit, means external to said main conduit to modify the temperature of the liquid in said circuit, a casing, means for passing airfrom said main conduit through said casing, means for passing a liquid through said casing in heat exchanging relation to said air tomodify the temperature of said liquid, a second casing, means for passing the liquid from the first mentioned casing through said second casing, and means for passing fresh air through said second casing in, heat exchanging relation to the liquid therein to modify the temperature of said fresh air and for delivering the fresh air from said second casing to said main conduit.

15. An apparatus for supplying conditioned air to a room comprising a main conduit for with-'" drawing air from said room and for delivering modified air to said room, means for circulating a liquid in a closed circuit through said main conduit, means external to said main conduit to modify the temperature of the liquid in said circuit, a casing, means for passing air from said main conduit through said casing, means for pass- .ing a liquid through said casing in heat exchanging relation to said air to modify the temperature of said liquid, a second casing, means for passing the liquid from the first mentioned casing through said second casing, means for passing fresh air through said second casing in heat exchanging relation to the liquid therein to modify the temperature of saidfresh air and for delivering the fresh air from said second casing to said main conduit, and means controlled in accordance with the wet bulb temperature of the fresh air entering said second casing to regulate the flow of the last mentioned liquid.

16. An apparatus for supplying conditioned air to a room comprising a main :conduit for withdrawing air from said room and for delivering modified'air to said room, a temperature modifying device, an endless circuit for a liquid having a part in said main conduit and a part in heat exchange relation to said temperature modifying device, a casing, means for withdrawing air from said main conduit and passing said air through said casing, means for passing a liquid through said casing in contact with the air therein, a

second casing, means for passing a liquid from the first mentioned casing through said second casing, means for passing fresh air through said second casing in contact with the liquid therein and, for delivering said fresh air to said main conduit, and a single device for circulating air through said main conduit and said casings.

17. An apparatus for supplying conditioned air to a room comprising a main conduit for withdrawing air from said room and for delivering modified air to said room, a heater, heat exchange elements mounted respectively in said heater and said main conduit and connected in an endless 19. In an apparatus for supplying conditioned air to a room comprising a main conduit for withdrawing air from said room and for delivering modified air to said room, a heater, heat exchange elements mounted respectively in said heater and saidmain conduit and connected in an endless circuit for liquid, means controlled in accordance with the temperature of the room air to automatically control the operation/of said heater, a"

casing, means for passing air from said main conduit through said casing, means for passing a liquid through said casing in heat transferring relation to said air to modify the temperature of said liquid, asecond casing, means for passing the liquid from the first mentionedca'sing through said second casing, and means for passing fresh air through said second casing in heat exchange relation to the liquid therein to modify the temperature of said fresh air and for delivering thefresh air from said second conduit,

20. In an apparatus for supplying conditioned air to a room, a casing having near one end thereof an inlet forfresh air and having near the other casing to said main end thereof an outlet for fresh air, means for delivering a liquid to said casing adjacent to said outlet and causing said liquid to flow toward said an inlet for fresh air and having near its upper end an outlet for fresh air, means for passing a liquid through said casing in a direction opposite the direction of flow of said air and causing relatively large surface areas of said liquid to contact said air, a receptacle below said fresh air inlet to receive the liquid from said casing, means controlled by the temperature of the liquid in said air to a room, a casing having near one end'therereceptacle to so control the rateof flow of said liquid through said casing that said fresh air will be discharged through said outlet at a dew point temperature approaching the temperature of the liquid entering said casing, and means for intr'oducing said fresh air into the room.

22. In an apparatus for supplying conditioned of an inlet for freshair and having near the other end thereof an outlet for fresh air, means for passing a liquid through said casing in a direction opposite the direction of flow of said air and causing relatively large surface areas ofsaid liquid to contact said air, a valve to control the rate of flow of said liquid, said valve having a perma nently'open restricted passageway; means controlled in accordance with the wet bulb temperatureof the fresh air entering said casing to vary the capacity of the passageway insaid valve, whereby said fresh air wilLbedischarged -from said casingat a dew point temperature approxi mating the temperature of the incoming liquid, and means for delivering said fresh air to a room.

23. In an apparatus fon supplying conditioned air to a room,'a casing having near one end thereof an inlet for fresh air and having near the other end thereof an outlet for fresh air; means for passing a liquid through said casing in a direction opposite the direction of flow of said air and causing relatively large surface areas of said liquid to contact said air, means for so controlling the rate of flow of said liquid through said casing that the fresh air will be discharged through said outlet at a dew point temperature approaching the temperature of the liquid entering said casing, and the liquid will be dischargedfrom said casing at a temperature approaching the wet bulb temperature of the fresh air entering said casing,

means for delivering fresh air from said casing todrawing air from said room and returning the same to said room, a cooling element in said con.- duit, and means for circulating the liquid discharged from saidcasingthrough said cooling element.

means for withdrawing air from said room and passing the same through one of said casings in direct contact with said liquid and in a direction in direct contact with saidliquid and in a direction Opposite the direction of flow of said liquid to modify the dew point temperature of said air,

a third casing, means for passing said modified fresh air through said third casing, means for passing water from an exterior source of supply throughsaid third casing in direct contact with said fresh air and in a direction opposite the direction of flow of said fresh air to modify the dew point temperature of said fresh air, means controlled in accordance with the wet bulb temperature of the fresh air entering said third cas-.

ing to control the quantity of water delivered to said third casing, and means for delivering fresh air from said third casing to said room.

In an apparatus for supplying conditioned air to a room, two casings, means for causing liquid to pass through'said casings successively,

means for withdrawing airfrom said room and I passing the same through oneof said casings in a direction opposite the direction of flow of said liquid to modifythe temperature of said liquid, means for passing fresh air through the other of said casings in direct contact with said liquid and in a direction opposite the direction of flow of said liquid to modify the dew point temperature ofsaid air, a third casing, means for passing said modified fresh air through said third casing,

' from said third casing through said conduit.

26. In an apparatus for supplying conditioned.

air to a room, two casings, means for causing liquid to pass through said casings successively, means for withdrawing air from said room and passing the same through one of said casings in a direction 'opposite. the direction of flow of said liquid to modify the temperature of said liquid means for passing fresh air through the other of said casings in direct contact with said liquid and in a direction opposite thedirection of flow of said liquid to modify the dew point temperature of said air, a third casing, means for passing said modified fresh air through said third casing. means for passing a l quid through said third casing in direct contact with said fresh air and in a direction opposite the direction of flow of said fresh air to further modify the dew point temperature of said fresh a r, means for delivering said fresh air from said th rd casing to said room; means comprising a conduit for withdrawing air from said room and returning the same thereto, means for circulating a liquid through a closed circuit having a part arranged in said conduit, and means for heating the liquid in another a liquid to modify the dew point temperature of 24. In an apparatus for supplying conditioned air to a room, two casings, means for causing liquid to. pass through said casings successively,

said,air, means for delivering the modified fresh air to said room, a conduit for withdrawingair from said room and returning the same to said room, a tubular element to modify the. temperature of the air in said conduit, and means for circulating said liquid through said tubular element.

28. In an apparatus for supplying conditioned from said room and returning the same to said room, a tubular element to modify the temperature of the air in said conduit, a means for circulating said liquid through-said tubular element, and means controlled by the temperature of the air 'in said room to control the amount of liquid circulated through said tubular element.

29. In an apparatus for supplying conditioned air to a room, means for passing fresh air through a liquid to modify the dew point temperature of said air, means for delivering the modified fresh air to said room, a conduit for withdrawing air from said room and returning the same to said room, a tubular element to modify the temperature of the air in said conduit, a liquid heating apparatus, and means for circulating through said tubular element either liquid from said heating apparatus or liquid which has been passed through said fresh air.

30. In an apparatus for delivering conditioned air to a room, a casing, means for passing fresh air and a liquid through said casing in opposite directions'to modify the dew point temperature of said fresh air, means for delivering the modified fresh air to said room, a receptacle to receive liquid from said casing, a discharge pipe leading from said receptacle, a conduit for withdrawing air from said room and returning the same to said room, a tubular element in said conduit, a liquid heater comprising a second tubular element, means for interchangeably connecting said discharge pipe and said second tubular element with said first mentioned tubular element and for causing liquid to circulate through the first mentioned tubular element, an air inlet and an air outlet for said heater, and means for circulating a liquid through said inlet and said outlet successively to cause heat from the outgoing products of combustion tobe transferred to the incoming air.

31. In an apparatus for supplying conditioned air to a room, a casing having an inletand an .outlet for air, a discharge conduit to conduct air from said casing to said room, means for passing a liquid through said casing in contact with said air to lower the dew point temperature of said air, a second casing having an inlet and an outlet for air, a conduit to conduct air from said room to the inlet of said second casing, means for passing liquid which is discharged from the first mentioned casing through said second casing. tubular elements arranged in the respective conduits, and 'means for circulating a liquid through said tubular elements successively in a direction opposite the directions of flow of the air in said conduits to cause, the temperature of the air in the last mentioned conduit to be modified before it is delivered to said second casing.

32. In an apparatus for supplying conditioned air to a room, a conduit to deliver air to said room, a distributor to discharge liquid through the air in a portion of said conduit, a tubular element arranged in the path of air which is being delivered to said room to modify the temperature thereof. and means for causing said liquid to circulate through said tubular element after it has passed through the air in said portion of said con- 'duit.

33. In an apparatus for supplying conditioned air to a room, a conduit for withdrawing air from said room and returning the same thereto, a tubu lar element arranged in said conduit, a casing having an inlet for fresh air and an outlet connected with said room, means for passing liquid through said casing in contact with the air therein, a second casing, means for passing air which has been withdrawn from said room through said second casing, means for passing liquid discharged from the first mentioned casing through said second casing, and means for delivering liquid discharged from said second casing to said tubular element.

34. In an apparatus for supplying conditioned air to a room, a conduit for withdrawing air from said room and returning the same thereto, a tubular element arranged in said conduit, a casing having an 'inlet for fresh air and an outlet connected with said room, means for passing liquid through said casing in contact with the air therein, a second casing, means for passing air which has been withdrawn from said room through said second casing, means for passing liquid discharged from the first mentioned casing through said second casing, and operable means for causing the liquid discharged from said second casing to be delivered either to said tubular element or to the first mentioned casing.

35. In an apparatus for supplying conditioned air to a room, an air conduit, a distributor to discharge liquid through a portion of said conduit in a direction opposite the direction of flow of air therethrough, a series of plates arranged below said distributor, each plate having an inclined surface to receive liquidfrom said distributor, and a second series of plates below the first mentioned series, each plate of said second series being inclined in a direction opposite the direction of inclination of the plates of the first mentioned series and arranged to receive liquid from the adjacent plate of said first mentioned series.

36. In an apparatus for supplying conditioned air to a room, an air conduit, a distributor to discharge liquid through a portion of said conduit in a direction opposite the direction of flow of air therethrough, and .a plurality of series of heat conducting plates arranged one above the other beneath the distributor, the plates of each series being spaced one from the other and the plates of adjacent series being inclined in opposite directions to form relatively narrow tortuous air channels, the plates of the uppermost series being arranged to receive liquid from said'distributor and the plates of each lower series being arranged to receive liquid from the corresponding plates of the next higher series.

37.In an apparatus for supplying conditioned air to a room, a casing having an inlet and an outlet for air, means for passing air from said room through said casing, means for passing water through said casing in a direction opposite the direction of flow of said air, an evaporator, a

steam generator, an injector connected with said I generator and said evaporator to draw vapor from the latter, a condenser connected with said injector, means for delivering a portion of the water from said condenser to said evaporator, means for delivering another portion of the water from said condenser into said steam generator, a housing enclosing said evaporator, means for passing water delivered from said casing through said housing, a second casing having an inlet for fresh air and an outlet for air, means for passing water from said evaporator housing through said second casing in a direction opposite the direction of fiow of air through said second casing, means far delivering air from the outlet of said second casing to said room, and means for delivering the water discharged from said second casing to the first mentioned casing.

38. In an apparatusfor supplying conditioned arately connected with said steam pipe and reair to a room, an air conduit leading to said room,

'a cooling element arranged within said conduit,

two refrigerating units each comprising an evap orator and a housing enclosing said evaporator, means for connecting said housings one to the other, means for connecting one of said housings with the inlet end of said cooling element, means for connecting the other' of said housings with the discharge end of said cooling element and for circulating water through said housings and said cooling element, a'steam generator, a steam pipe leading from said generator, two injectors sepspectively connected with the two evaporators, a condenser connected with 'said injectors, means for delivering a portion of the water from said condenser to said ,evaporators, and means for delivering another portion of the'water from said condenser to said steam generator.

39. In an apparatus for delivering conditioned air to a room, an air conduit leading to said room, a cooling element arranged in said conduit, an

evaporator, a housing enclosing said evaporator jector connected with said steam pipe and with the first mentioned evaporator, a second injector of greater capacity than the first mentioned injector connected with said steam pipe and with the second evaporator, a condenser connected with both injectors, a receiverconnected with said condenser, and means for connecting said receiver A with both evaporators, a third injector connected with said steam pi and withsaid steam generator, means for delivering water from said receptacle to said third injector, and means for cooling the water before it is delivered to said third-injector.

'40. In an apparatus for supplying conditioned air to a room, means comprising a conduit for withdrawing 'air from said room and returning the same thereto, means for progressively modifying the temperature of the air passing through said conduit including a distributor to discharge finelyvdivided liquid through the air in aportlon of said conduit, a tubular element arranged in said conduit in advance of that portion thereof through which said liquid is discharged, means for causing the liquid which has passed through said portion of said conduit to circulate through said tubular element.

- 41. In an apparatus for supplying conditioned air to a room, a vertical casing, means for causing water to flow downwardly through said casing, means within said casing to spread said water into thin sheets and to retard the flow thereof, means for causing air withdrawn from said room to flow upwardly through said casing, a second vertical casing, means to deliver said water from the first mentioned casing to said second casing and to cause the same to flow downwardly therethrough, means within said second casing to spread said water into thin sheets and to retard the flow thereof, means to cause fresh air to flow upwardly through said second casing, means controlled in accordance with the wet bulb temperature of the fresh air entering said secondcasing 1 fresh air from said second casing to said room.

EDWARD T. TURNER.