US1949379A - Ventilating and air treating apparatus - Google Patents

Description

A. SARGENT Feb. 27, 1934.

VENTILATING AND AIR TREATING APPARATUS Filed May 10, 1932 4 Sheets-Sheet l I INVENTOR KQATT RNEY A. SARGENT Feb. 27, 1934.

VENTILATING AND AIR TREATING APPARATUS Filed May 10, 1932 4 Sheets-Sheet 2 INVENTOR fQ/L 1 (4 ATTORNEY Feb. 27, 1934. SARGENT 1,949,379

VENTILATING AND AIR TREATING APPARATUS Filed May 10, 1932 4 Sheets-Sheet 3 u a a q a u xwj" sxxzian Q ISINVENTOR mm 5 M LAT RNEY Feb. 27, 1934. A. SARGENT 1,949,379

VENTILATING AND AIR TREATING APPARATUS Filed May 10, 1952 4 Sheets-Sheet 4 LINE IN OR F V .96 VENT Patented Feb. 27, 1934 UNITED STATES PATENT OFFICE VENTILATING AND AIR TREATING APPARATUS Allston Sargent, Bronxville, N.

Campbell Metal Window Corporation,

Y., assignor to New 8 Claims.

My invention relates to new and useful improvements in ventilating and air treating apparatus of the character or type adapted for installation in a room or chamber in order to 5 ventilate the same and produce therein desired atmospheric conditions, for example, to maintain the air supplied to, or existing in the room or chamber at a desired temperature, or desired relative humidity.

The invention in its preferred embodiment particularly contemplates an efficient unit structure which may be installed in a room or other chamber, and provided with means for supplying the latter with fresh air from an outside source, and also with means for imparting to the air within the space desired characteristics of temperature, for example, to heat the air, or to reduce its temperature to a degree desired.

n The invention in a more specific embodiment also contemplates the provision of means which will deaden or eliminate noise which might enter the room or chamber through that portion of the unit which operates to supply fresh air from an outside source. The primary object of the invention is to provide a unit which may be installed in a room or other chamber, and which will efficiently supply the same with fresh air, and treat the air within the space to maintain the desired atmospheric conditions for the occupants.

The invention consists in the improved construction and combination of parts, to be more fully described hereinafter, and the novelty of which will be particularly pointed out and distinctly claimed.

- In the accompanying drawings, to be taken as a part of this specification, I have shown a preferred embodiment of my invention, and in which drawings- Figure 1 is a view in front elevation of the complete unit installed in connection with a window of a room in order to obtain a supply of fresh air from a space below the raised sash 45 of the window;

Fig. 2 is a top plan view of the construction shown in Fig. 1, certain features of an adjacent wall and window being in horizontal section;

Fig. 3 is an enlarged view in front elevation, showing a front panel of the enclosure or cabinet removed, and showing the internal elements in front elevation, certain parts being shown broken away for clearness, and other parts being shown in section, and in dotted lines;

Fig. 4 is a vertical section on the line 4-4 95 of Fig. 3, and showing a portion of the means (Cl. 257138l for supplying fresh outside air to the interior of a room;

Fig. 5 is a section on the line 5--5 of Fig. 3, showing one embodiment of an air treating means for treating air withdrawn from the room and 00 returning the same thereto after treatment;

Fig. 6 is a detail section on the line 6--6 of Fig. 1;

Fig. '7 is a detail section on the line 'I-'l of Fig. 4; Fig. 8 is a detail in elevation of the damper operating device;

Fig. 9 is a top plan view of a heat exchange element and humidifying receptacle associated therewith;

Fig. 10 is a diagram of an electrical circuit for supplying current to a motor employed in the invention, and

Fig. 11 is a section on the line 11--11 of Fig.

3 through an air filter member.

In the accompanying drawings, 1 designates, generally, an enclosure or cabinet adapted to be installed in the space to be ventilated, preferably adjacent an outer building wall A beneath a sill B of a window frame C and window sash D. This cabinet may be made of sheet metal, including a rear, vertical wall 2, vertical end walls 3 and a horizontal top wall 4, said end and rear walls rising from a base plate or board 5 which is adapted to rest on the floor E of a room. The end walls are each provided with an inwardly directed edge flange 6 extending along the vertical and top edge portions thereof, which flanges are provided with inset edge portions 7 to which the top wall 4 is secured by screws 8. The front edge of the horizontal wall 4 terminates about midway between the front and rear of the end panels 3, as clearly shown in Fig. 2, and this front edge of the top wall 4 is provided with a down-set flange or lip 9 lying in the same plane as the top flanges 7 on the end walls. At the lower, front portion of the cabinet the flanges 7 are connected by a horizontal cross piece or flange 10, lying in the same vertical plane as said flanges '7.

The front of the cabinet is closed by a detachable vertical wall or panel 11, the lower edge of which rests on the base piece 5 and the upper edge of which is provided with an inwardly directed wall member 12 at an angle to the front wall, and preferably in a horizontal plane, the vertical side edges of the panel 11 and the member 12 resting respectively on the vertical and horizontal portions of the flanges 7 on the end walls 3, and the inner transverse edge of the-110 member 12 resting on the flange 9, when the front panel is assembled in place. The front panel is detachably held in position to close the front of the cabinet by means of inwardly directed clips 13 at the lower portion thereof, which set over the flange (Figs. 4 and 5), and by means of a clamping screw 14 passed through an opening in the inner edge of the member 12 and threaded into the flange 9. The front panel may be readily removed by disengaging the screw 14, and then lifting the panel vertically to disengage the clip members 13 from the flange 10, when it is desired to have access to the interior of the cabinet. The interior of the cabinet is divided by a substantially vertical wall 15 and a laterally offset wall 16 into two compartments 17 and 18, for a purpose to be presently described, said walls 15 and 16 extending from the horizontal wall 4 to the base wall 5. The walls 15 and 16 extend from the rear wall 2 to the front edge portion of the cabinet, so that when the front panel member 11 is in place, the vertical and horizontal portions thereof contact the vertical front edges of the walls 15 and 16, and the top, horizontal edge of the wall 15, respectively, to close the compartments 17 and 18 from each other.

At its rear portion the horizontal wall 4 is provided with an air inlet duct, preferably in the form of a box or trunk 19, provided with a rearwardly extending inlet duct or neck projecting beyond the rear face of the inlet box 19 and adapted to overlie the window sill B adjacent to which the apparatus is installed. The duct or neck 20 is telescopically engaged, as at 21, by a neck 22 of an inlet box extension member 23 having a forward open wall 24 provided with inlet louvres 25, the wall 24 having above its inlet opening a horizontal flange 26. The construction is such that when the apparatus is located in place, the inlet box 23 may, by virtue of the telescoping connection 21, be adjusted so that the flange 26 may be projected into a window opening and located beneath a window sash D, the latter being lowered onto said flange 26 to seal the opening at this point. In order to adapt the inlet to windows of varying widths, the transverse width of the inlet duct is preferably made of less width than the usual width of windows, so that the air-receiving end of the duct can readily be located between the vertical side members of a window frame, and beneath a raised window sash.

In order to seal the space between the sides of the member 23 and the vertical portion of a window frame, I provide the ends of the box 23 with laterally extending, vertical channel-irons constituting flanges 27, each of which carries a filler piece or plate 28 having a flange 29 to abut the adjacent vertical face of the window frame. The flller pieces 28 are horizontally adjustable with reference to the plates 27 in order to be adjusted to the width of the window, and for this purpose have horizontal slots 30 to receive the shanks of clamping screws 31 carried by the plates 27 and adapted to receive clamping nuts 32 adapted to clamp the filler pieces rigidly in adjusted position against the plates 27. The flller pieces are provided with horizontal flanges 33, which form a substantial continuation of the upper horizontal flange of the channel-iron, and together therewith may receive a suitable packing upon which the sash rests when lowered into engagement with the flange 26.

The inner end of the air inlet box 20 communicates through an opening 34 in the top wall 4, with the interior of the compartment 17, but the interior of the air inlet box is closed off by a forwardly curved baffle wall 35 from the interior of the compartment 18, so that air entering the air inlet duct passes only to the compartment 17. The air inlet box 20 may be shut off entirely from the compartment 17, or the amount of air entering the compartment 17 may be regulated, by means of a damper plate 36 mounted on a shaft 37 mounted to rock in bearing apertures in the end walls of the box 20 at the top thereof, the damper plate being movable by said shaft to take a position across the interior of the duct 20, as indicated in dotted lines in Fig. 5, to thereby shut off the supply of "air to compartment 17, or to the position shown in full lines in Figs. 4 and 5 to permit the air to enter compartment 17. The damper is operated by an extension of its pivot shaft which carries a crank arm 38 having a spring locking pin 39 to cooperate with spaced sockets in a quadrant 40 mounted on the end of the box 20.

The top wall 12 of the front panel member is provided with a rectangular opening 41 overlying the compartment 17, and also with an opening 42 overlying compartment 18, these openings constituting the air outlets from said c0mpartments, as will be presently described. In each opening is seated a removable grill 43 having a surrounding flange 44 resting on the wall 12 around its opening.

Within the compartment 17 is an air impelling means, preferably comprising a centrifugal blower fan 45 mounted in a double-eyed casing 46, the outlet 47 of which connects with an upwardly flaring discharge duct 48, the upper end of which rises to a point closely adjacent to the casing wall 12 and is substantially coextensive with the outlet opening 41 therethrough. This centrifugal blower operates to draw fresh air through the duct 20 into the compartment 17 and discharge the air up through the duct 48 and out through the opening 41 into the space containing the unit. The discharge duct 48 is rectangular in cross-section and made preferably of sheet metal, and the walls thereof are covered externally, as is also the circumferential wall of the blower casing. with a layer 49 of sound deadening and absorbing material such as acoustical felt, suitably attached thereto by cement. The inner surfaces of the duct 48 are likewise covered with sound deadening and absorbing material 50 cemented thereto and covered by a layer 51 of perforated leather, or other material, such as kribble cloth, to prevent the air blast from dislodging fiber from the sound deadening material, and cemented in place, as at 51 In duct 48 is an inclined deflector plate 48 extending transversely thereof from front to rear, and acting to deflect or distribute the air so that the discharge thereof will be equally distributed over the area of the outlet 41. The sound deadening and absorbing material described serves to absorb the sound waves propagated through the inlet 34 to the compartment. and prevent external noises entering the room through the outlet 41.

Between the inlet 34 and the compartment 17. is an air filtering screen 52, comprising a rectangular metallic frame 53 supporting a wire mesh screen 54 over which is laid and held a sheet of suitable air filtering material such as 55, held in place by an overlying wire backing 56 see Figs. 7 and 11), hinged at 56 to the frame, and at its free end having a locking pin 56 to project through a slot 59 in the strip 59 and be engaged by a slotted holding latch 59 pivoted on said strip to thereby detachably hold the backing down over the material 55. The screen is slidably held in inclined channel-guides 5'7, mounted, respectively, on the wall 15 and the end wall 3 of the chamber 17, the screen being inserted in said channel-guides through a slot 58 in the wall 4, the upper edge member of the screen frame 53 being provided with a closure finishing strip 59 to close the slot 58 and overlie the adjacent portion of the wall 4 to limit the downward movement of the screen when inserted. The finishing strip 59 is provided with finger pieces 60 by which the screen may be inserted and removed from the unit. It will be seen that by the arrangement just described, fresh air may be drawn from a source outside the room, filtered by the screen 52 so as to remove dust particles therefrom, and then delivered into the room to revivify the air therein, this being accomplished without the propagation of sound from external sources into the room, due to the fact that the sound waves are deadened or absorbed in the chamber 17 and by the construction of the outlet duct 48. It will be noted that the screen 52 is of large area relative to the area of the inlet 34, so as to present an extended filtering surface to the incoming air, and thereby reduce resistance to the air in being drawn by the impeller into the compartment 17, and assure that the impeller will deliver efficiently an ample supply of fresh air through the outlet 41.

In the compartment 18 is located apparatus for receiving air from the interior of the room, treating such air, and returning it to the room, with a desired characteristic, for example, temperature, humidity, etc. In order to supply the compartment 18 with air from the interior of the room, the front panel 11 is provided at its lower portion with horizontally disposed inlet louvres 61, which for symmetry extend entirely across the panel, but are closed by a plate 61 (shown in section in Fig. 4 and indicated by dotted lines in Fig. 1), adjacent the compartment 17, so that air from the room cannot enter the latter compartment. In the compartment 18 is a centrifugal fan blower 62, mounted in a double-eyed blower casing 63 having an upwardly directed outlet duct 64. This casing and duct are covered externally with sound deadening material 65, such as acoustic felt, so as to deaden sound which might emanate from any vibration of the fan and duct. The upper end of the duct 64 terminates preferably at a point below the horizontal center of the compartment 18 and is so arranged as to deliver the air upward toward the outlet 42 from the compartment. In the embodiment shown, above the upper end of the outlet duct 64 is arranged a heat exchange unit, including vertically disposed headers 66, 66 connected by transverse horizontal flow pipes 67, upon which are mounted vertically disposed fin members 68 constituting a plurality of vertical air fiues. The arrangement is such that the air delivered by the blower flows upwardly through the fiues 69 between the fins 68 and has its temperature modified according to the temperatureof the heat emitted by the fins. The heat exchange element may be either a heat emitting element to raise the temperature of the air, or may be a cooling element in the low temperature side of a refrigerating system in order to lower the temperature of the air, but in the present embodiment I have shown it as being a heat radiator. For this purpose the header 66 is provided with an inlet connection coupled to an angle fitting 70, the inlet 70 of which is coupled by a short pipe section '70 to the outlet of the body '71 of a thermostatically operated valve. This valve 71 is thermostatically operated by a fiuid thermostat bulb or element '72 mounted on the valve body and located external of the enclosure, so as to be subject to room temperature. It is unnecessary to enter into a detailed description of this thermostatic valve, which preferably is a type now on the market made by the American Radiator Company and known as the Arco Radiatherm. Other types of thermostatic valves may be used if desired. The inlet of the thermostatic valve is connected to a supply p'pe 73 leading to a suitable source of steam supply and controlled by a hand valve 74. It will be understood that this thermostatic valve responds to a rise in room temperature to cut off or reduce the flow of steam to the heat exchange element, and upon a drop in room temperature to open the valve to permit steam to fiow to said element, and thus maintain the latter at a proper temperature to heat the air passing therethrough so that the heated air flowing out of the outlet 42 will maintain the room at a desired temperature. The heating fluid from the thermostatic valve enters the inlet header 66 flows transversely through the tubes 67 into the outlet header 66, and thence into a fitting '75 which is connected by an angle coupling 76 to a pipe 7'? extending through the partition 15 and discharging into a thermostatic return trap 78, the outlet of which empties into the return line 79 of the circulatory heating system.

It will be understood that if the heat exchange element is to be employed to reduce the temperature of the air in the room, and which is driven through the compartment 18 by the impeller 62, the heat exchange element instead of being supplied with a heating fluid by the pipe 73, would be supplied with a refrigerant through said pipe leading from a suitable source, and the refrigerant after cooling the heat exchange element would be returned to the refrigerant source by means of the return pipe '77. In this case, the heat exchange element would abstract heat from the air passing through the compartment 18, thereby cooling such air and delivering it through the outlet 43 at a lower temperature into the room, and thereby producing acooling effect therein. When the heat exchange element acts by refrigeration to cool the air, it will also act to abstract moisture therefrom and thereby have a dehumidifying effect. The heat exchange element is supported rigidly in the casing by means of horizontal stringers 80 rigidly connected in any suitable manner to the wall 15 and the right-hand end wall 3, the headers of the element being bolted, as at 81. to said stringers.

When the heat exchange element is to'be employed for heating the air, my invention also includes means for adding moisture to the heated air to humidify the same. This humidifying means comprises a relatively narrow receptacle or tank 82 arranged in the space between the sets of fins 68 of the heat radiator, the receptacle 82 having its bottom portion 83 extending beneath the lower ends of the fins and being V- shaped in cross-section, as shown in Fig. 5, and the upper end 84 of the tank extending vertically above the upper ends of the fins and being open, as at 85. The tank 82 is formed at one end with a lateral extension or overhanging part 82, the

bottom of which is seated on the top of header 66, and on the opposite end wall of the tank is a. flange or lip 82 resting on the upper end of the inlet connection or fitting 69, whereby the tank rests on and is supported removably by said header and connection. This arrangement will permit insertion and removal of the tank from operative position. This tank is adapted to contain water to be vaporized by the heat radiated from the heat exchange element, the vapors from the water passing out of the open end of the tank and being taken up by the air previous to its passage outward into the room through the outlet 43. The front and rear vertical walls of the tank are arranged closely adjacent and preferably in contact with the inner edges of the fins 68 (see Fig. 5), so that heat from the fins will heat the side walls of the tank to accelerate the vaporization of the water. The tank is supplied with water from a feed pipe 86 having an outlet valve 87 discharging into the tank and automatically controlled by a float 88 and float operated lever 89 to maintain the water at a desired level by opening the valve whenever the water level falls to a determined point, and to close when the level is at the desired point. The water feed line contains a hand valve 90 which can be set to fix the maximum amount of water which can flow from the float valve when the latter is opened by fall of the float, and this valve can also be used to shut off the water supply when humidification is not desired.

Both the float valve 87 and the hand valve 90 may be of any well known type which will serve the purposes described. In order to accelerate the evaporation of the water in the tank, a serpentine heating coil 91 is arranged in the tank so as to be submerged in the water therein, the inlet end of this coil being connected communicatively, as at 92, to the fitting to receive fluid heating medium from the supply 73, and the outlet end 93 of the coil is brought through the bottom wall of the tank, as at 94 (Fig. 5), to which the pipe is suitably sealed to prevent leakage of the water from the tank at the point of emergence of the pipe, said outlet end being connected to the outlet fitting 76, so that the heating medium or the condensate thereof flowing from the coil passes into the return line of the heating system. The lower end of the humidifying tank is located over the outlet 64 from the impeller casing 63, and by its V-shaped construction serves to divide the air stream from the blower into two streams, which respectively pass through the front and rear sections or sets of fins of the radiator, so that the air delivered by the blower is efficiently heated and passes in two currents from the upper ends of the fins, both currents taking up moisture emitted from the top of the humidifier tank. The outer or under face of the V-shaped bottom of the tank is covered by heat insulating material 95, such as asbestos, to prevent the air stream from cooling the tank. The curved wall 35 at the rear of casing 18 serves to deflect the rear stream of air forward over the top of the tank, and thereby facilitates entraining of the vapor by this air current.

Within the compartment 18 and housed within the recess formed by the wall 16, is an electric motor 96 set on the base board 5, the motor being arranged with its rotor parallel with the front of the cabinet or enclosure, and carrying oppositely disposed drive shafts 97, 98, respectively, extending laterally through the compartments 17 and 18, and carrying the impeller rotors 45, 62, respectively, so that the latter are driven simultaneously when the motor is energized. The motor is supplied with current by any suitable circuit, which preferably includes a variable rheostat or switch 99 to control speed of the motor, and a cut-out switch 100 by which the circuit may be established and broken. It will be noted that the offset portion of the wall 16 forms a recess 96*, offset from the chamber 18 and in which the motor 96 is arranged, thus permitting the motor to be located not only in the path of the relatively cool air entering the louvre openings 61, but also to be sufficiently far away from the heat exchange element in the chamber 18 as not to be deleteriously affected by the heat emitted therefrom.

When the unit as above described is installed in a room or chamber to be ventilated, and the atmosphere of which is to be treated or modified, the apparatus is arranged with the air inlet duct 22 projected through a window opening, and the sash D of the window is lowered to make sealing contact with the flange 26, the filler pieces 28 being adjusted outwardly to close the spaces between the sash, the vertical side members of the window frame, and the sides of the duct, so that air can only enter the room through the inlet louvres 25. If it be desired to supply the room with fresh, outside air, and also to treat the air content of the room, the damper 36 is opened to the full line position shown in Figs. 4 and 5, or is adjusted to an intermediate position by the hand crank 38. The motor 96 is energized to drive the impellers 45, 62 at a speed to give the desired air impelling effect, so that air will be drawn from the outside through the box 23, extension duct 22 and boxes 29, 19 into compartment 17 and driven by the impeller 45 through the air duct 48 and through the outlet 41 into the room. This air will be filtered by the filter member 52, and any noise caused by sound waves entering the chamber 17 will be deadened or muffled so that no sound is propagated from the system into the room into which the fresh air is delivered. At the same time that the fresh air is supplied, as above described, the air in the room, including that supplied from chamber 17, will be drawn by the impeller 62 through the louvre openings 61 into the compartment 18. The air drawn into compartment 18 will be drawn into the impeller casing and delivered upward through the outlet duct 64 and divided by the tank bottom into two currents or streams which will be blown through the fiues between the fins of the heat exchange element into the space in the cabinet above the same, whereby this air is heated, and flowing into the space above the heating element, will take up moisture vapors given off by the water in the tank 79 and thence be projected into the room to mix with the air therein. It will be understood that if the heat exchange element is a heat radiator, the temperature of the air will be in creased as it passes through chamber 18, but if the heat exchange element be a refrigerating coil, this air will have its temperature reduced to produce a cooling effect in the room.

If it be desired to dispense with a supply of fresh, outside air and merely to treat the air which is in the room, the damper 36 is closed, under which conditions the apparatus in compartment 18 alone will function to have any effect on the air in the room. On the other hand, if it be desired to dispense with the air-treating effect, the damper 36 may be opened so that fresh air will pass into the room and the supply of heat-change-effecting medium to the heat exchange element may be cut off by means of the control valve'74. When the damper 36 is closed so as to cut off supply of air to compartment 1'7, no air will be driven from outlet 41, due' to the fact that the type of impeller shown will revolve in its own air without creating back pressure. Certain features of easing construction and arrangement disclosed, but not claimed herein, are claimed in my application, Serial No. 706,498, filed January 13, 1934, as a division of this application.

It will be understood that while I have shown a preferred embodiment in which provision is made for receiving supply of fresh air through a space beneath a sash of a window, my invention is not limited to such provision, as the duct 20 alone, or this duct having the extension piece 22 applied thereto, may be made to register with any desired opening in a room wall and leading to a source of fresh air.

What I claim and desire to secure by Letters Patent of the United States is- 1. An apparatus of the character described comprising an enclosing casing to be located in a chamber to be ventilated, said casing containingside the chamber and having a fresh air outlet into the chamber, air-impelling means in said fresh air compartment to draw air in said inlet and including a delivery duct through which the fresh air is expelled through said outlet, said airtreating compartment having an air inlet and an air outlet to communicate with the chamber, air treating means and air-impelling means in said last-named compartment, said impelling means operating to draw air from the chamber into the air-treating compartment to be treated therein, and return the treated air through said outlet to the chamber.

2. An apparatus of the character described comprising an enclosing casing to be located in a chamber to be ventilated, said casing containing a fresh air compartment, and an air-treating compartment, said fresh air compartment having air inlet means to receive fresh air from outside the chamber and having a fresh air outlet into the chamber, air-impelling means in said fresh air compartment to draw air in said inlet and including a delivery duct through which the fresh air is expelled through said outlet, means for'filtering the air entering said fresh air compartment, sound absorbing surfaces in said compartment, said air-treating compartment having an air inlet and an air outlet to communicate with the chamber, air-treating means and airimpelling means in said lastnamed compartment, said impelling means operating to draw air from the chamber into the air-treating compartment to be treated therein, and return the. treated air through said outlet to the chamber.

3. An apparatus of the character described comprising an enclosing casing to be located in a chamber to be ventilated, said casing containing a fresh air compartment, and an air-treating compartment, said fresh air compartment having air inlet means to receive fresh air from outside the chamber and having a fresh air outlet into the chamber, air-impelling means in said fresh air compartment to draw air in said inlet and including a delivery duct through which the fresh air is expelled through said outlet. means associated with said duct for absorbing sound waves entering said fresh air compartment, said air-treating compartment having an air inlet and an air outlet to communicate with the chamber, air-treating means and air-impelling means in said last-named compartment, said impelling means operating to draw air from the chamber into the air-treating compartment to be treated therein, and return the treated air through said outlet to the/chamber.

4. An apparatus of the character described comprising an enclosing casing to be located in a chamber to be ventilated, a partition dividing said casing into a fresh air compartment and an air-treating compartment, said freshair compartment having air inlet means to receive fresh air from outside the chamber and having a fresh air outlet into the chamber, air-impelling means in said fresh air compartment to draw air in said inlet and including a delivery duct through which the fresh air is expelled through said outlet, a filter supporting frame between said inlet and said impelling means, guides on the casing wall and said partition to slidably receive said frame, the casing wall having a slot through which said frame may be slidably engaged with and removed from said guides, said air-treating compartment having an air inlet and an air outlet to communicate with the chamber, air-treating means and air-impelling means in said last-named compartment, said impelling means operating to draw air from the chamber into the air-treating compartment to be treated therein, and return the treated air through said outlet to the chamber.

5. An apparatus of the character described comprisinga casing having an air inlet at the bottom portion thereof and an air-outlet at the upper portion thereof, heat emitting means in said casing between said inlet and outlet and including horizontally spaced elements, an opentopped receptacle arranged in the space between said elements and heated thereby, and adapted to contain vaporizable liquid, and air-impelling means beneath said heat emitting means and delivering air past said elements and receptacle, whereby the air is heated and humidified and then discharged through said outlet.

6, An apparatus of the character described comprising a casing having an air inlet at the bottom portion thereof and an air outlet at the upper portion thereof, heat emitting means in said casing between said inlet and outlet and including horizontally spaced elements, an opentopped receptacle arranged in the space between said elements and heated thereby, and adapted to contain vaporizable liquid, the bottom portion of said receptacle being located beneath said elements, and air-impelling means beneath said heating means and delivering air to said elements, the bottom of the receptacle dividing the air current into streams to flow in contact with the respective elements, whereby the air is heated and humidified and then discharged through said outlet. I

7i An apparatus of the character described comprising a casing having an air inlet at the bottom portion thereof and an air outlet at the upper portion thereof, heat emitting means'in said casing between said inlet and outlet and including horizontally spaced elements, an. open.- topped receptacle arranged in the space between said elements and heated thereby, and adapted means in said casing between said inlet and outlet and including horizontally spaced elements, an

open top receptacle arranged between said elements and heated thereby and adapted to contain vaporizable liquid, supply and outlet connections for said elements, a tubular heating element in said receptacle and connected to said supply and outlet connections respectively, and air-impelling means beneath said heat-emitting means and delivering air past said elements and receptacle whereby the air is heated and humidified and then discharged through said outlet from the casing. ALLSTON SARGENT.

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