US2035653A - Ventilating and air-conditioning apparatus - Google Patents

Description

March 31, 1936. F HASKELL I 2,035,653

VENTILATING AND AIR CONDITIONING APPARATUS Filed March 10, 1934 3 Sheets-Sheet 1.

INVENTO R..

Hedericl FHaJ'K e ll March 31, 1936.

F. F, HASKELL 2,035,653 VENTILATING AND AIR CONDITIONING APPNRATUS Fil ed March 10, 1934 s Sheets-Sheet 2' F. F. HASKELL 2,035,653

March 31, 1936.

VENTILATING AND AIR CONDITIONING APPARATUS 3 Sheets-Sheet 3 Filed March 10, 1954 luvEm-on,

.Fi'e deri elf IL'HuJ/fvll Cal Patented Mar. 31, 1936 "vEN'rmA'rlNG AND AIR-CONDITIONING APPARATUS Frederick r. Haskell, Portland, Maine, asslgnor of twothirds to on R. Maddocks, Boothbay- Harbor, Maine Application March 10, 1934, Serial No. 7l4,959

11 Claims.

' through a filtering medium, subsequently subjectinstance, hu-

ing it to various treatments, as for midifying, heating or cooling it, then projecting the treated'air into the space in the room in which the apparatus is installed.

Briefly stated, my invention contemplates structure calculated to accomplish the foregoing objects in the most effective manner and embodying a simple, eficient and moderate cost equipment adapted for use in the home, ofiice or other enclosed spaces, all for the purpose of maintaining a clean and proper condition of the air therein.

The arrangement of the respective units is such that coordination therebetween exists in all cases, and the whole equipment is characterized by the absence of complex and non-essential paraphernalia which, if employed, might cause those unskilled in mechanical and electrical matters more or less apprehension and concern as to their ability to maintain service when the responsibility of caring for it was placed in their hands.

In devices of the class under consideration the requirement of providing clean air, which means filtered air, is of course elemental. I have sought and attained this object in my present conception; but there are other results to be acquired if the modern and exacting demand for the most desirable atmospherical conditions in the house hold or the office is to be satisfactorily met.

For instance, medical science teaches us that a room the air in which has been brought to the proper per cent of humidity provides much more healthful surroundings than one in which the air lacks the correct proportion of moisture.

Furthermore, the temperature in a room in which the air is insufficiently humidified must be raised considerably, to procure the same degree of comfort, from that in which proper humidification prevails. Hot, dry air tends to aggravate throat and lung troubles, and a certain degree of moisture in the air tends to allay them.

Engineers base their humidification calculations on the assumption that the air in a room of the average built house changes twice in every hour. If this be correct it is obvious that to supply sufficient and effective humidification of the air in a. room a quite considerable quantity of water must be constantly evaporating or vaporizing. For this reason I equip my appaartus with a water tank of ample capacity, thus requiring less frequent filling.

And to obviate the necessity of maintaining this large body of water at the boiling point in temperature-I have adopted a flash system of steam 5 generation which I not only find more economical but enables 'me to get instantaneous action for vaporizing thewater for humidification purposes.

Artificial humidification is seldom required during the warmer months of; the year, but in these 10 months other treatment of the filtered air is reatly to be desired. I refer, particularly, to air cooling. f

In my air-conditioner I provide means whereby the humidifying unit may be replaced, in part, It by one supplying refrigeration, using for. the latter either electria'natural or dry ice methods of cooling.

r The air filter, mixing chambers and air-circulating elements are used in common, whether the go apparatus is employed in humidifying, air-heating or air-cooling operations. And when using the electrical method of refrigeration the elec-= tric heating unit mainly vused for vaporizing the water may be utilized for the purpose of de- 25 frosting the cooling coils, when this becomes necessary.

A feature of particular importance in my apparatus'resides in the structural design of the parts. whereby they but slightly obstruct the outlook so or view through the window. The sash is raised but a very short distance and the top of the apparatus rises only to a position abreast the lower rail of the sash.

The window may be lowered without disturbing a single part of the apparatus and this is of paramount advantage when the device is not in service during extremely cold weather as it eliminates the possibility of the water in the supply tank freezing. 40

Other objects and advantages of the invention will be apparent and the import thereof understood by reference to the description found-in the following specification when taken in connection with the accompanying drawings disclosing an embodiment which, at the present time, I consider preferable to other possible forms in which the invention might be carried out.

In the drawings,-

Fig. 1 is a front elevation of my air-conditioner;

Fig. 2 is a. sectional elevation thereof, the section being taken on line 22, Fig. 1;

Fig. 3 is a perspective view showing the motor box and window box in separated relation;

Fig. is a fragmentary sectional elevation of the motor box drawn to an enlarged scale; 7

Fig. 10a shows a graduated plate, used in conjunction with a hand wheel to indicate position of feed valve;

Fig. 11 is a sectional elevation of the window box and a portion of the motor boisl'iowing the air deflector;

Fig. 12 is a perspective view of the window box and the end fillers used in connection therewith;

Figs. 13, 14 and 15 illustrate details of construction of the window-connecting parts;

Fig. l6 is an enlarged view of a detail shown in Fig. 13;

Fig. 1'7 is a fragmentary sectional view of the motor box, showing the air'deflector and one of the knobs by which it is actuated;

Fig. 18 illustrates a water tank equipped to maintain a constant level of water in the water tank;

Fig. 19 is a plan view of a water tank hinged to swing outwardly from the motor-box;

Figs. 20 and 21 show, respectivel two methods of cooling the filtered air, each being applicable for use in the air-conditioner;

Fig. 22 is a sectional elevation of the parts shown in Fig. 21, the section being taken on line 22-22, Fig. 21;

Fig. 23 is a front elevation of the apparatus shown as it would be used when taking the outside air through an air ductin the wall of the building;

Fig. 24 is a fragmentary sectional elevation of the device shown in Fig. 23, the section being taken on line 24-24, Fig. 23, and

Fig. 25 discloses an alternate method of operating the apparatus.

Similar reference characters are employed to, identify like parts in all the different views of the drawings.

Referring to the drawings, W represents a window sash, X the window stool, and S the window opening or space beneath the raised sash.

The holding elements of the air-conditioner comprise the window-box'l and the motor-box 2. Telescoping collars la and provide, respectively, the means for interconnecting the members I and 2, the screws 3 being employed to secure them together.

The outer side of the window-box (see Fig. 16) has fixed thereto a'flanged strip 4, the downwardly extending flange 4a thereof abutting on the inner side of the sash W. Secured to and extending for the full width of the sash is a Z strip 5, the upper leg 5a of which interlocks with'the flange 4a, forming to allintents and purposes a weather strip, excluding the'air from the room but permitting the window being lowered without removal or disturbing of any part of the apparatus. Fig. 13 shows the window opened and Fig. 14 shows it closed. When the lower sash is raised, means (not shown) are provided for closing the opening between the lower andgipper sashes, W and We, respectively.

It will be understood that while the foregoing is preferred construction, other means for accomplishing the .same object may be adopted, provided, however, that in all cases the window can be lowered and fully closed without interference or' without manipulation of any part of the apparatus. The present embodiment has been described and illustrated in connection withso-called double-hung windows,,but the apparatus is applicable for use with casement windows as well.

In the outer, open side of the window-box I preferably mount a wire mesh screen 6. While this screen is not absolutely essential or indispensable, it is, nevertheless desirable, as'it exeludes from the interior of the apparatus major objects in the air, as flies, mosquitoes and the larger floating particles of foreign matter in the outside atmosphere and leaves the filtering element, later to be described, free to take care of the finer impurities which seek admittance to the motor-box. I I

As the widths of windows vary greatly, I make fillers have an inturned flange 1b by means of which the filler is secured to the window stool X.

- The fillers are made overlengths and cut of! the length of the window-box a minimum dito accommodate any particular width of window space.

In the top of the collar 2a, see Fig. 3, is a slot 8 in whichis slidably mounted an. air-filtering frame element 9. Two finger lugs ll rising from the frame permit the framev being raised from out of its position in the slide-way II for cleaning purposes.

The filtering element 9a may be made of various materials, preferably some animal substance, as chamois skin, hair or silk fabric. These materials clean easily and are not fragile. Chamois skin, unless wet, is pervious to air and will exclude the finest physical matter. It is exceptionally easy to clean ,and provides a more uniform filtering surface than most materials, particularly those in which the interstices are not regular.

within the space C of the motor-box is suspendedan electric motor It on the shaft of which 'is mounted a fan wheel- II. In the front wall of the motor-box, in axial alignment with the fan wheel, is a shutter frame l4 having-a plurality of vanes'orslats l5.

I preferably construct this shutter unit so that the vanes thereof may be placed in various positions'in order that the impaction of the air thereon may be so directed that it is caused to pass out into the room in any predetermined direction. The deflection of the air may be upwardly or downwardly as shown in Figs. '7 and 6, respectively, or to either side, as shown in Figs.

-4 and 5.

Below the shutter is a door l6 providing entrance to the lower portion of the motor-box 2. On the lower head ll of the motor-box is mountedan electric heating unit l8 supplied with current from any available source.

On opposite sides, respectively, of the motorbox are secured rails IS on which the vapor tank 20 is slidably mounted, and suspended from a cross bar 2|, within the vapor tank is a water tank 22 equipped with a needle valve 23, the latter being actuated by the hand wheel 24.

Water in the tank 22, released in drops by opening the needle valve, falls on the bottom head 20a of the vapor tank which, being highly heated by the electric unit i8, rapidly vaporizes and passes upwardly through the space G between the two tanks, into the mixing chamber D.

Instead of dropping the water directly on to the head 26a, which I designate as the humidifier hot-plate, an absorbent, fire-proof material, as asbestos, may be placed on the hot-plate, the water falling thereonto. This element, 20b, is shown in Fig. 10.

Heat deflected from the under side of the head 20a rises through another space H, surrounds the ascending vapor and commingles with the cold air entering the chamber D after being filtered, the air then passing out of the motorbox, cleaned, humidified and heated.

In some instances the use of a warm, dry air is desirable, as for instance, drying the hair after shampooing, drying clothing and other possible uses for dry air. The air-conditioner supplies this by simply closing the needle valve 23 and operating the heating unit i8.

Figs. 9 and 10 disclose how the water tank may be refilled by partially withdrawing it from the motor-box, sliding it outwardly on the slides I3.

I may elect to mount the'vapor tank as illustrated in plan view in Fig. 19 in which it is shown as swinging from a hinged connection at 25. Dot and dash lines in this figure depict the tank swung outwardly through the door of the motor-box for water-filling purposes. I

In instances where convenient access to a service water main may be had an arrangement shown in Fig. 18 may be adopted. The pipe 26 extends from the main water service pipe line (not shown) upwardly into the motor-box, and by means of the union 21 and interconnecting fittings joins the automatically operating valve 28 which, through the agency of the ball float 29 maintains a constant water level in the tank 22. An overflow pipe 30 joined to the water tank pipe by the union 3i, takes care of overfioWage of the water should the valve 28 fail to act. The unions 2! and 3i and nipples 26a and 3012 form a part of the regular equipment for the air-conditioner and are used in conjunction with any one of the units which require their service.

While clean air is as essent al in the home or ofiice in the summer time as in the colder months in the year, humidity by artificial means is seldom required except in the winter time. A simple", low cost method of cooling the interior spaces, however, has long been sought.

In my apparatus I have provided facilities whereby I am enabled to utilize any one of various agencies for accomplish ng air cooling, and in Fig. 20 I illustrate one of them embodying an electric refrigerating unit of conventional design. This unit coord nates and cooperates with other agencies used in common in the air-conditioner for other purposes, and in conjunction therewith provides the householder or office worker with a cont nuously replenished supply of clean, filtered and cooled air.

The refrigerating unit shown in Fig. 20 may be equipped with conventional water connections through which a running stream of water acts to dissipate the condenser heat.

The refrigerating or brine coil Ea extends upwardly and lies in the path of the incoming air which, at this point is filtered air; and due to the downwardly deflecting action of the deflector plate 33 which directs the filtered air on to the coil, the heat is more quickly absorbed by the cooling element than if the ar was driven straight through the upper portion of the airconditioner. The air is thusdrawn through the motor-box in a diverted course.

Electric refrigerators are now a common household utilit and taking cognizance of this fact I have arranged the working elements of my air-conditioner whereby, should the unit E be put out of commission for any reason, connection with the household refrigerating plant, or with any other auxiliary refrigerating unit for that matter, could be quickly made by simply opening certain valves and closing others.

By reference to Fig. 20 it will be observed that on the unit E are two valves, 34 and 35, and making connection wth the pipes on which are located these two valves are the branches 26a and 30a. which join, respectively, the pipes 26 and 30. On the branch pipes 26a and 36a are valves 36 and 31, respectively.

Now, by opening valves 36 and 35 and 0105-- ing valves 36 and 31, the electrical refrigerating unt E may be put into operation. Conversely, by closing valves 34 and 35 and opening valves 36 and 31 any auxiliary refrigerating unit may be put into service by passing the cooling agent through pipes 26 and 30.

It will thus be ev'dent by examination of Figs. 18 and 20, that by means of the unions 21 and 3| either the automatic water-level-maintaining equipment for the tank 22, or the auxiliary refrigerating arrangement just set forth may utilize the pipes 26 and 30 when either service is required.

Furthermore, in localities where the water service mains carry very cold water, the utilization of these pipes 26 and 30, together with the brine coil Ea will effect more or less of a. reduction of the temperature of the air as it passes through the motor-box. Pipe 26 admits, and pipe 36 discharges the cold water.

When defrosting of the brine coil in the electrical refrigerating unit E becomes necessary, a very expeditious method of eifecting a rapid and complete release of the abnormal accumulation of ice on the coil is to turn on the current to the electric heating unit l8. As the ice melts,

the waterfalls into a pan Eb from which it is conducted to the pan 32 through the pipe Ec.

A method which doubtless would appeal to many and which in its application is perhaps the simplest form of refrigeration suitable for my apparatus is illustrated in Figs. 21 and 22. The water tank 22, shown in Fig. 2, is removed from the vapor tank 23 and the latter filled with chopped ice I, either natural or dry. Then by inserting a partition 38 in the motor-box and securing it to the lugs 39 by the screws 40 the current of filtered a'r is drafted downwardly on one s de of the partition, nearly to the bottom of the tank 26, then around the partition and upwardly on its opposite side, finally discharging it through the open shutter i4 into the room. It will be noted that the ar in its onward course contacts with substantially the whole outer surface of the tank, thereby beconzing qu'ckly and thoroughly cooled.

It is quite frequently required to clear a room of smoke or obnoxious odors. To accomplish this the direction of rotation of the motor is changed if positioned as wardly therethrough. But with the motordirection of rotation reversed the fan wheel would'draft the air into the motor-box through the shutter and cause it to impact on thecurved deflector plate 33 which, shown in full lines in Figs. 2, 11 and 20, would prevent a free egress of the vitiated air from the motor-box outwardly into the outside atmosphere.

To .obviate this difiiculty I provide means to lower the deflector plate into a position in which it is shown in dot and dash lines, Fig, 2, thereby enabling the fan wheel to force the air in a straight course through the motor-box into the out-of-doors. Obviously, to permit-the air to pass out freely, the filtering element frame 9 is first removed preparatory to putting the air-' clearing operation intoeflect.

Provision for'raising and lowering the deflector plate is made by cutting slots ll in opposite sidesof the motor-box and extending a short lateral portion of the plate on each side into andthrough these slots sufliciently far to secure On each a knob 42 through the actuation of which re-positioning of the plate is made possible.

I support the air-conditioner, preferably, on standards 43 and for extra security tie the body of the motor-box to the wall of the room by a bracket 44'. I

While a window space seems a very appropriate place in which to install my air-conditioner, I am not so particularly concerned as to its location so long as its interior is in communication with the outside air.

In Fig. 24 I illustrate an installation in which there is no connection whatsoever with a window or window space.

An air duct 45 is made in the wall of the room and a box comparable tothe window-box hereinbefore described, secured therein. In this instance, however, I install a slide 46, outwardly of the filtering element, the slide having the functional characteristics of the window with respect to its ability to close communication between the interior of the motor-box and the outside atmosphere.

While I prefer to keep the vapor space G segregated from the dry air space H until the currents passing upwardly from each reach and commingle in the mixing chamber D, it is, ob-

viously, possible to operate an apparatus, otherwise in accord with my invention, which eliminates the vapor tank 20. Such a structure is fragmentarily illustrated in Fig. 25 in which the hot plate 20a is supported on legs 200, the vapor tank being dispensed with.

And while considering the subject of humidification as it applies to the present embodiment,

I wish to stress the fact that, in my method, I am enabled to perfectly control the per cent of moisture with which the air in the room is to be charged, by a definite amount of water released from the tank and regulated by the needle valve 23, this method of control being vastly more accurate than any attempt to provide a regulatory system having to do with the control of the heat unit where it operates on a large body of water.

The handle 24, which actuates the valve 23, has a pointer 24a operating over a graduated disc has shown in Fig. 10a. The valveadiustment is best performed by slightly withdrawing the tank from the motor-box through the front doorway. I

In summation, I will point out among other predominant characteristics of my air-conditioner, its unobstrusiveness when installed in a window space; its ability to provide clean, filtered air eifectively humidified, heated or. cooled, or medicated if desired, by placing a volatile medicament in the water tank; its capacity for utilizing various elements in common in accomplishing either of the numerous objects sought in the invention; its novel system for control of the vaporizing of the water forany desired per cent of humidification; and finally its simplified structure, low cost in operation and efliciency in service. 1

What I claimis:

1. Apparatus of the class described comprising cally disengaged when the sash is lowered to a fully closed position, a relatively long, narrow motor-box disposed inwardly of and having interior communication with said window-box, an air-filtering element, means to deflect the air downwardly after passing through said filtering element, and a fan wheel to draft the filtered air through said motor-box.

2. An air-conditioning apparatus comprising a motor-box, a door in the front side thereof, an air-filtering element, a vapor tank, a bottom head for said tank, constituting a hot-plate for humidiflcation purposes, a water tank suspended within and in spaced relation, laterally, to said vapor tank, a slide-way on which said vapor tank is supported and along which it may be drawn outwardly through the door-way for said door, for purposes of filling said water tank, a valve to regulate the discharge of water from said water tank on to said hot-plate, a fan wheel, and means to deflect the air downwardly into contiguous relation with'the said tanks, after passing inwardly from said air-filtering element.

3. A ventilating and air-conditioning apparatus adapted to be installed in a room adjacent an motor-box, a fan wheel mounted'to revolve in two directions of rotation, means to change the direction of rotation of said fan wheel, a removable air-flltering element positioned, normally, between the screen and the fan wheel, a shutter on the front side of said motor-box aligning with said air-filtering element, a deflector plate normally positioned to receive the impact of the air and divert it downwardly after it has been drawn through said air-filtering element. and means for lowering said deflector plate out of the direct and straight path of the air current when said fan wheel, with' its direction of rotation ch ged, drafts air from the room through said shutter and projects it through said motor-box and screen into the outside atmosand having a'transverse slot in the top thereof, an air-filtering element disposed in said motorbox and removable therefrom through said slot, a screen in the outer side of said window-box, a fan wheel revoluble in said motor-box, a vapor tank having a bottom head constituting a hotplate, a water tank removably disposed in said vapor tank, a valve in the bottom of. said water tank, a heater beneath said hot-plate adapted to heat the same, whereby water deposited in small volume on said hot-plate may beinstantaneously vaporized, and a deflector plate adapted to change the course-of the filtered air as it leaves said filtering element and divert it downwardly to meet the vapor rising from said hotplate, the fan wheel acting to thoroughly mix the filtered air and vapor before projecting it from the apparatus.

5. An air-conditioning apparatus comprising a two-part holding member, one part adapted to be disposed in a window space, wholly inside of the window, and the other part secured to and extending inwardly and downwardly from the first part, an air-filtering element in said member, an

' air deflector adapted to change the direction of flow of the filtered air from the horizontal to a downward direction immediately after passing through said filtering .element, a fan wheel to draft the air through said member and outward at its upper, front end, a water tank, a hot-plate, a heating unit, and means to control the output of vapor from said member by the amount of water discharged on to said hot-plate, said control embodying a valve through the manual opening or closing of which a greater or lesser amount of water is discharged from said water tank, the amount of opening of the valve being predetermined by humidity requirements at the time.

6. An air-conditioning apparatus comprising a window-box mounted in a window frame and extending only to the inside face of the sash therefor, whereby the outside entrance of air to the window-box may be closed by simply lowering the window, a motor-box connected to said windowbox and extending inwardly and downwardly therefrom and having interior connection therewith, an air-filtering element through which outside air passes on its course from the windowbox to the motor-box, said element embodying an animal substance, a motor secured in the upper end of said motor-box, a fan wheel actuated by said motor, a shutter operable in the upper, front side of said motor-box adapted to deflect the air in any predetermined direction as it is projected by said fan wheel from said motorbox, and a deflector plate disposed between said fan wheel and said air-filtering element whereby it causes the air to deviate, after passing through the air-filtering element, from a horizontal course to a downward one.

7. An air-conditioning apparatus comprising a motor-box adapted to be positioned in a room and having its interior in communication with the outside atmosphere, an air-filtering element through which outside air passes in its course toward said motor-box, a deflector plate, a fan wheel adapted to draw air downwardly and around said deflector plate, a slide-way in said motor-box, a vapor tank supported by said slideway, a water tank disposed in said vapor tank in mutually spaced relation, two nipples secured in the side of said motor-box, a union on each of said nipples, an automatically operating waterlevel mechanism in said water tank, two pipe connections on said water tank, one for water feed and the other for overflow service, said pipe connections joining, respectively, the two said unions, two pipes making connections with the outer ends of said nipples and supplying, respectively, water conducting means to replenish the supply in said tank, and overflow facilities therefor, a heater in the bottom of said motor-box, and a valve mounted in the bottom head of said water tank adapted to prcdeterminately regulate the discharge from said water tank in various volumes, either in drops or in a stream.

8. An air-conditioning apparatus adapted to be positioned in a room abreast of'an opening therefrom in communication with the outside atmosphere, comprising a relatively long, narrow motor-box having its interior in communication with the said opening to the outside atmosphere, a fan wheel revolubly mounted in said motorbox, a filtering element through which air passes from the outside to the interior of the motor-box; a frame on the front side of the motor-box,

'having an opening therein, a shutter in said frame opening adapted to deflect the air, as it passes from the motor-box into the room, in any desired and predetermined direction, a water tank in the lower portion of said motor-box, a hot-plate element, a heater for heating said hotplate element, and means to release the water in said tank and direct it on to said hot-plate in various and predetermined quantities and volume, whereby humidiflcation may correspondingly be increased or decreased by the vaporization of the water discharged on to said hot-plate.

9. An air-conditioning apparatus adapted to be positioned in a room abreast of an opening thereinto from the outside, comprising a motorbox, an air-filtering element in said motor-box, a fan wheel adapted to draft air from the outside atmosphere into said motor-box through said air-filtering element, a deflector plate adapted to divert the air downwardly after passing through said air-filtering element, a slide-way in said motor-box, a tank, adapted to be filled with ice, supported on and slidable along said slide-way, and a partition partially dividing into two compartments the lower space in said motor-box, abreast of said tank, the air drafted by said fan wheel and deflected by said deflector plate continuing downwardly on one side of said partition, around its lower end, and upwardly on the opposite side thereof, and in its circuitous course contacting with substantially. the entire outer surface of said tank before finally being projected by said fan wheel through the upper, front end of the motor-box into the room.

10. An air-conditioning apparatus comprising a motor-box, the interior of which is in communication with the outside atmosphere, an airfiltering element, a shutter in the front side of the motor-box, a fan wheel revolubly mounted adjacent said shutter and in alignment therewith, a deflector plate forming one side of a passage-way for filtered air drafted downwardly by said fan wheel from the filtering element, a slide-way in said motor-box, an electric refrigerating unit supported on said slide-way, the cooling coil for said unit extending upwardly into said passageway, two nipples secured in the side of said motor-box, outside pipes connected, respectively, to said nipples, a union on each of said nipples, intermediary pipes joining, respectively, said unions and the refrigerating unit pipes running to and returning from the cooling coil, a valve on each of said intermediary and said refrigerating upon closing the valves on the refrigerating unit pipes and opening the valves on the intermediary pipes, the electric refrigerating unit mechanism is cut out and the cooling medium for said cooling coil supplied through said outside pipes. and a heating unit in the bottom of said motor-box for the purpose of defrosting the cooling coil.

11. An air-conditioning apparatus adapted to t be installed in a room adjacent an opening there- 7 unit pipes, said valves providing means whereby vertically central-mixing chamber, a water tank positioned below said mixing chamber, means to partially withdraw said water tank from said holding member for purposes of filling, either with water or ice, a hot-plate on to which water is directed irom said water tank, a heating unit at the bottom, interior portion of the holding member adapted to provide heat both for heating said hot-plate and for raising the temperature of the air in said mixing chamber. and a waterdischarge device for said water tank for regulating the outflow of water irom said water tank in any predetermined amount, whereby the per cent of humidity in the room is proportionate to the amount of water released from the water tank and directed on to said hot-plate.

FREDERICK 1". I-IliSKliiLI.-.

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