US2310222A

US2310222A - Unit air conditioner

Info

Publication number: US2310222A
Application number: US349618A
Authority: US
Inventors: Charles N Deverall
Original assignee: Niagara Blower Co
Current assignee: Niagara Blower Co
Priority date: 1940-08-02
Filing date: 1940-08-02
Publication date: 1943-02-09
Anticipated expiration: 1960-02-09

Description

Feb. 9, 1943. I c. N. DEVERALL UNIT AIR COND IIIONER Filed Aug. 2, 1940' 3 Sheets-Sheet 1 BY)? wNTOR TTORN EY 3 Feb. 9, 1943. N. DEvERA-LL 2,310,222

UNIT AIR CONDITIONER Filed Aug. :2, 1940 s Sheets-Sheet 2 ATTORN EYS W Patented Feb. 9, i943 UNIT Am CONDITIONER Charles N. Deverall, Buffalo, N. Y., assignor to Niagara Blower Company, New. York, N.

corporation of New York Application August 2, 1940, Serial No. 349,618 15 Claims. (01. 99-259) This invention relates to a unit air conditioner and more particularly to such a unit for maintaining the proper temperature, humidity, pressure, air movement of both primary and secondary air, and smoke density of the smoke laden air in a smokehouse in which food products are being cured and smoked although the unit air conditioner forming the subject of the invention can also be employed in the processing of other mate- I rials, such asin drying leather.

One of the principal objects of the invention is to provide a compact and simple air conditioning unit containing the necessary mechanisms for supplying air to a smokehouse or similar enclosure ,in which materials are processed; varying the amount and velocity of the air so supplied to obtain the desiredmovement of both th primary and secondary air within the enclosure; introducing smoke to the air so supplied when required; heating the air so introduced when required; withdrawing air from the enclosure to maintain the desired static pressure in the smokehouse; returning a part of the airso withdrawn, together with outside air, to the smokehouse to maintain the desired humidity therein; and humidifying the air supplied to the enclosure, when required By the provision of these various instrumentalities in a single compact unit, installation of the equipment is greatly simplified and the greater part of the fabrication can be efiected at the factory instead of in the field; heat losses are reduced, resistance to air flow is minimized; the danger of leakage. can be completely eliminated; the amount ,of floor and overhead space required for the equipment can be greatly reduced; the

amount of materials necessary for the equipment can be reduced thereby lowering the cost of the: equipment and permitting of the use of more cost;

ly materials and finer finishing inspection and repair of the equipment is facilitated especially where a battery of identical units are in'use in a packing plant; and anextremely sensitive control of the condition and movement of the air within the smokehouse can be readily obtained.

Another object of the invention is to provide such a unit which is substantially the same height as the smokehouse and can be placed flush against the rear wall of the smokehouse thereby to simplify and reduce the amount of ductwork necessary to connect the unit with the overhead ducts of the smokehouse.

, Another object is to provide such a unit which can also be mounted horizontally thereby to permit of mounting the unit on top of or underneath the smokehouse where the conditions encountered render such mounting of the unit desirable.

Another purpose is to provide such a unit which is'composed of two readily separable major sections thereby to facilitate shipping of the unit to the location and to facilitate the transportation of the unit through doors, corridors and elevators in getting the unit into location within the packing plant.

, Another object is to provide such a unit in which all danger of outside air, return air, and smoke laden air short circuiting in'the unit is avoided thereby accurate control of the conditions within the smokehouse.

Another aim is to introduce the smoke laden air into the unit in such manner as to reduce to a minimum the fouling of the equipment by creosote deposits thereby to eliminate the necessity of frequent cleanin particularly of the finned heating surface from which a creosote deposit is diflicult to remove.

Another object is to provide such a unit in which all of the interior parts of theunit are readily accessible through conveniently removable access panels thereby facilitating inspection, adjustment, repair and cleaning of the unit when required.

Another object of the invention is to provide such a unit which is mounted on removable feet to facilitate the transportation of the unit to its charge of the fan from either of two diametrically opposite sides of the casing thereby rendering the unit readily-adaptable to installation when peculiar conditions are encountered. I

Another object is to provide such a unit from which any water of condensation is readily drained and in which water for humidification is readily introduced.

Another object is to arrange the motor controlled dampers in the ductwork between the unit and the smokehouse to provide flexibility in supplying any make or form of control desired by the packer. I v 3 other objects and advantages of the unit form. ing the subject of this invention will appear from drawings wherein:v

Fig. 1 is a side elevation of a smokehouse the subject of the present invention and showing a part of the smokehouse broken away to disclose the interior tracks and overhead ductwork thereof.

Fig. 2 is a vertical transverse section through the smokehouse, this section being taken on line 2-2, Fig. 1.

Fig. 3 is a vertical section through the air conditioning unit illustratedin Figs. 1 and 2, this section being taken on line 3 -3, Fig. 4. v

Fig. 4 is a vertical section taken on line 4-4, Fig. 3.

Fig. 5 is a side elevation of the air conditionin: unit.

Fig. 6 is a diagrammatic representation of the control instruments used in connection with the air conditioning unit to regulate thetemperature, humidity and static pressure of the air within the smokehouse.

While the air conditioning unit embodying the present invention can be used in connection with any type of smokehouse, the smokehouse illustrated is of the insulated panel type of construction having side walls "I, II, a roof l2, a rear wall l3 and a front wall l4 having an access door l5 which can be mounted in any suitable manner. The smokehouse is shown as provided with an overhead track 20 which is suspended in any suitable manner from rods 2|, these rods being preferably suspended from the ceiling (not shown) of the packing plant so that the smokehouse can be made of light construction. With such a smokehouse the food products to be cured and smoked can be hung from trees (not shown) suspended from the overhead track 20 or can be hung upon trucks (not shown).

The air is introduced into the smokehouse through a central overhead duct 24 which extends through the rear wall l3 of the smoke: house. This duct is provided within the smokehouse with a plurality of downwardly directed nozzles 25 which direct the air downwardly. After passing around the produce the air so discharged is withdrawn through openings 28 in the undersides of overhead ducts 21. Each of these ducts 21 is shown as arranged alongside oneof the side walls III, II of thesmokehouse and extends through. the rear wall l3 thereof.

The air conditioning unit forming the subject of the present invention includes a casing comprising an upper casing section A and a lower casing section B,- the casing and its component sections being of box-like rectangular form. The smokehouse and the unit are arranged back to back and hence the upper casing section A includes arear wall 38, side walls 3|, 32, a front wall 33 and a top wall 34, these walls being suitably reinforced with angle bars. Similarly the lower casing section Bincludes a rear wall- 40,

. side-walls 4|, 42, a front wall 43 and a bottom wall 44, these walls being likewise suitably reinforced with angle bars. The lower casing section B is supported by removable feet 45 and its lower end is formed to provide a drain pan provided with a drain 46. The two sections A and B are provided around the opposing edges oftheir side and=front walls with horizontal angle bars, indicated generally at 41, these angle bars of the two sections being arranged back to back and providing a convenient means for bolting or otherwise securing the two sections A and B together.

The upper section A houses the scroll 50 of 'a supply fan, indicated generally at 5l,this scroll 7 equipped with the air conditioning unit forming having inlets 52 at its opposite sides and an outlet 53 extending through an opening 54 at the upper end of the rear wall 30 of the upper casing section A. The fan wheel 55 arranged within the scroll 50 is mounted on a horizontal fan shaft 55, the ends of which are supported by bearings 51 suitably mounted on the side walls 3| and 32 of the upper section A of the casing. The supply fan is shown as being driven by an electric motor 68, mounted on the top wall 34 of the casing and as having a pulley 6| on its motor shaft, this pulley being connected to a pulley 62 on the fan shaft 56 by a drive belt 63. The outlet 53 of the supply fan is adapted to be directly connected with the rear end of the central overhead supply duct 24 of the smokehouse so that the air and smoke delivered by the supply fan is introduced into the smokehouse throughthe downwardly directed nozzles 25. The scroll 50 is also preferably provided with an access door 58 for cleaning the fan wheel 55.

Opposite the opening 54 through which the outlet 53 of the fan projects, the front wall 33 of the upper casing section A is formed to provide an opening 64 surrounded by a flanged neck 65, this opening having a removable cover 86 which permits of ready access to the chamber in which the fan is located.

Immediately below the flanged neck 65 a smoke inlet opening 61 is provided, this opening being surrounded by a flanged neck 68 which permits of attachment to a' smoke pipe 69, this smoke pipe leading from the usual smoke ,pot (not shown) which supplies smoke for the operation of the smokehouse. The volume of smoke drawn into the unit through'the smoke pipe 89 is controlled by dampers Ill in this pipe, these dampers being under the manual control of a hand lever 1|. section A a horizontal perforated pipe 12 is provided, this pipe being perforated as indicated at 13 and being adapted to be connected with a water or steam supply pipe 14 for humidifying the air drawn into the fan 5| when this becomes necessary.

At the extreme open upper end of the lower casing section B a plurality of volume control dampers are provided. Each of these dampers is journaled along its central horizontal axis to the side walls 4| and 42 of the lower casing section B, as best shown in Fig. 4 and are interconnected to work in unison by a horizontal bar 16. The dampers are adjusted by means of a hand lever 11 arranged exteriorly of the casing and connected to the shafts of one of the dampers. This hand lever 11 traverses a segment 18 on the side wall 42 of the lower casing section B, this segment being so designed that the hand lever 11 can be set in any adjusted position and hence hold the volume control dampers 15 in such adjusted position.

A suitable number of heating coil sections, indicated generally at 88. are arranged in the lower casing section B. These heating coil sections can be provided in any number having any desired amount of heating surface and are shown as being three in number, each of the coils comprising a tubular inlet header 8| having a pipe 82 for supplying steam, a tubular outlet header 83 having a condensate outletpipe 84 and the I On the oppositeside of the upper casingviding access to the coil sections 88.

Each of the three coil sections 88 is shown asbeingindependently removable from the lower casing section B "and for this purpose the

steam connections

82 and 84 for these coils pass through a removable access plate 88 which is secured to the side wall 4| ofthe lower casing section B around an opening 89 which is of such size as to permit the coil sections 88to be slid out of the casing: after the plate 88 has been removed.

To facilitate this removal the individual coil sections' are supported within the casing in the '85 adjacent their return bends, this plate being shown as flanged at its lower end to slidably rest upon the same pair of angle bars 89.

To. permit of ready access to the coil sections I 88 for'the purpose of inspecting or cleaning them while in place; the front wall 43 is provided with a large rectangular opening 9| which is flanged around the margin, as indicated at 92, and to this flange is secured a removable panel 93 profBeloW-the coil sections 88 the lower casing section Bis formed to provide a supply chamber 95 for outside and return air," the lower wall of this/supply chamber being formed by a horizontal'baflle plate 98 which is secured at its opposite ends to the rear and front walls 48, 43 of the lower casing section B, as? best shown in Fig. 3, butis spaced from the side walls H, 42 thereof so as to provide openings91. Outside air is admitted to thissupplychamber 95 through an inlet I88 which is arranged in'the front wall 43 of e'lower casing section B and discharges the outside 'airon top of the .baiile plate 98. To prevent the bypassing of outside air this inlet I88 is narrower in a horizontal direction than the bailie plate 98, as best illustrated in Fig. 4. This outside air inlet I88 is connected to an outsideair duct I8I.

Below the baille plate 9.8 the lower casing secl85; In thisgexhaust chamber is arranged the scroll I86 of a static pressure fan, indicated generally at I81, this scroll having inlets I88 at its opposite sides and an outlet I89 extending through an opening H8 in the lower part of the rear wall 43. of the lower casing section B. The

fan wheel III arranged within the scroll,I88 is mounted on ahorizontal fan shaft II2, the ends oi which are supported by bearin s II3 suitably mounted on the'side walls 4! and 42 of the lower casing section B of the casing. The static pressure fan is shown as being driven by an electric motor 5 mounted on a removable bracket II8 projecting outwardly from the lower end of the side wall H of the'casing. This motor is shown as having a drive pulley 1 on its drive shaft.

this pulley-being connectedto a pulley II8 on.

the fan shaft I I2 by a drive belt I I9. The outlet lator I32 and through this regulator controls the .tion B is formed toprovide an exhaust chamber the other motor 0 close the corresponding set of.

'42 of-the'lower casing section B is provided with a return air inlet I25, each of these inlets leading into the corresponding space 91 at each side of the baflle plate 98 so that the two inlets I25 are intersected by the plane of this baille plate 98, as best shown in Fig. 4. Each of these inlets I25 is connected by a duct I28 with the end of the corresponding overhead side return duct 21 of the-smokehouse, as best shown in Figs. 1 and 2. Referring to the diagrammatic representation of the control instruments used in connection with the air conditioning unit as above described toregulate the temperature, humidity and static pressure of the air within the smokehouse, the

numeral I38 represents -"an air pressure supply line through which air is supplied at, say 15 pounds pressure, to a static pressure regulator I3 I which can be arranged within the smokehouse and to a double pen recording regulator I32. The numeral I33 represents an automatic water pan 'of a wet bulb thermostat I34 the sensitive part of which is encased with acovering of absorbent material I35, the lower part of which is immersed in the water contained in the automatic water pan I33. The automatic water pan is also arranged to support a dry bulb thermostat -I38 and the automatic water pan can be arranged in one of the return air ducts I28 so that the sensitive parts of the wet and dry bulb thermostats are responsive to the wet and dry bulb temperature of the air within the smokehouse.

The control line I48 from the dry bulb thermostat I38 leads to the double pen recording regu- -tor controls the air pressure in a line I48 leading to a diaphragm valve I41 which controls the supply of water or steam to the perforated humidifying pipe 12 arranged in the upper casing section A of the air conditioning unit. This air pressure line I48.also leads to a motor I48 controlling a set of dampers I49 in one or both of the return,

air ducts I28 and also leads to amotor I58 controlling a set of dampers I5I in the outside air ducts IN. The motors I48 and I58 work in bpposition to each other,the change in pressure in the line I48, under control of the wet bulb thermostat I34, actuating one of these motors to open the correspondin set of dampers and actuating dampers.

The outlet line I55 from thestatic pressure regulator I3I controls the damper motor I58 controlling a set ofjda'mpers I51'in the exhaust duct Installation and operation of the air I unit v conditioning motor 88 -for the supply fan can be readi1y-re--.-

' ulated by the handle 11.

moved; the bracket IIB carrying the static pressure fan motor II5 can also be removed; and the removable feet 45 can also be removed. By this ,means not only is it possible to ship the unit in a knockdown condition but the assembly of the unit is facilitated inasmuch as the two major sections are of such weight that they can readily be set in position. Further the removability of the feet 45 permits of adjusting the overall height of the unit and its duct openings as may be desired to suit the particular conditions encountered, feet of the desired height being supplied for this purpose.

In installing the, unit air conditioner, the unit can be placed directly up against therear wall of the smokehouse and the outlet 53 of the supply fan placed directly in the central overhead'inlet duct 25 of the smokehouse as illustrated, thereby effecting a substantial saving in duct work and avoiding the danger of leakage, loss of heat, and

power loss through resistance to air flow. It the conditions surrounding the installation render it desirable to arrange the unit horizontally as on the roof of the smokehouse or in an existing smoke pit below the smokehouse, this can readily be done with the unit. If further peculiar conditions render it desirable to have the supply fan 5| discharge in the opposite direction from that shown, it will be seen that the entire upper sec tion A of the casing can be turned completely around and such reversal readily efiected, this requiring but a slight alteration in the attaching flanges 41.

The various motor control dampers I49, I,5I and I51 are not, however, built into the unit. These motor operated dampers are-purposely mounted in the corresponding ducts leading to or from the unit in order to provide flexibility in s pplying any make or form of control desired by the packer. I

When once installed the air conditioning unit occupies very little floor and overhead space and is connected with a minimum amount of ductwork.

In the operation of the air conditioning unit smoke is supplied from a suitable smoke pot (not shown) through the smoke pipe 69 into the upper, section A of the unit, the admission of the smoke being under manual control of the dampers 10 regulated by the hand lever N. This smoke is drawn into the inlet 52 of the supply fan 5I together with air drawn from the lower section B of the air conditioning unit under control of the vol-1 ume control dampers 15 which are manually reg- The smoke laden air so drawn into the fan 5| is discharged through the outlet 53 of the fan directly into the overhead central duct 24 arranged within the smokehouse and in this air, this density being determined by the proportional adjustment of these volume control dampers and the smoke 'dampers 10.

The smoke laden air so discharged downwardly through the nozzles 25 travels around the prod- .ucts contained within the smokehouse to cure and smoke the same. A distinct secondary movement of the air within the smokehouse is also obtained "so as to insure adequate air-movement house is regulated through, a suitable adjustto' contact with all surfaces of the produce contained within the smokehouse. The air is withdrawn through the outlet openings 26 in the bottom of the overhead side outlet ducts 21 arranged within this smokehouse and is drawn downwardly through the ducts I26. past the control dampers I49 into the return air openings I25 in the lower part of the lower casing section B of the air conditioning unit. These openings are arranged to discharge into the spaces 91 at the sides of the battle plate 96 and hence a part of this return air enters the supply chamber 95 above this baflle and the other part enters the exhaust chamber I05'below this plate 96. The exhaust chamber I05 is exhausted by the static Pressurefan I01, the inlets I09 of which are arranged in this chamber I05 and the outlet I09 of which discharges into the exhaust duct I20, this discharge being under control of the dampers I51.

Outside air is also drawn into the supply chamber 95. This outside air is under control 01' the motor operated dampers I 5I in the fresh air duct IOI leading to the-outside air inlet opening .I00 to this supply chamber 95. In order to prevent short circuiting of this outside air to the exhaust chamber I05, this air is introduced immediately above the baffle 96 at its center and parallel with its major axis so that there is no'danger of this outside air flowing down through the openings 91 at the sides of the baflle plate 96 along with the return air being ex-.

hausted from the unit, as previously described.

The outside air and the return air drawn into the supply chamber 95 mixes and passes up through the several coil sections 80 contained in the upper part of the lower section B of the unit and is heated thereby when heat is required in the air admitted to the smokehouse. This heated mixture of return and outside air is then drawn past the volume control damper 15 by the supply fan 5|, as described at the start of the description of the operation, this heated mixture being also mixed with the smoke supplied 1 through the smoke inlet 61.

, outlet duct I20 from the static pressure fan I01 7 the smoke is discharged downwardly through the chokes oil the quantity of air relieved from the smokehouse and hence increases the pressure of the air within the smokehouse. Conversely; the opening ofpthese dampers I51 permits a less restricted discharge of the air and hence decreases the pressure of the air within the smokehouse.

Thetemperature maintained within the smokement provided in the double pen recording regulator I32. When the temperature within the smokehouse drops below this setting, the'dry bulb thermostat I36 in one of the outlet ducts I25 actuates the double pen recording regulator I32 to adjust the air pressure in its outlet line I to open the diaphragm valve I42 and admit an increased amount of steam to the bank or heating coil sections in the lower section B or the heating 'coil perature of the coils restoring the temperature of the air within the smokehouse to the settin of the double pen recording regulator. Conversely, a rise in temperature in the smokehouse above the setting of the double pen recording regulator eiiects a shutting off of the diaphragm valve I42 and hence a decrease in the amount of steam admitted to the heating coil sections 80.

The humidity, preferably the absolute humidity, maintained within thesmokehouse is regulated through a suitable adjustment provided in the double pen recording regulator I32. When the humidity in the smokehouse rises above the setting of the double pen recording regulator I32, the wet bulb thermostat I34 in one of "the outlet ducts I26 actuates the double pen recording regulator I32 to adjust the air pressure in its outlet line I46 to open the damper II in the outside air duct IIlI, through the medium of the damper motor I50, and at the same time to close the dampers I49 in the return air duct or ducts. I26 through the medium of the damper motor I48. This proportionate openingof the outside air dampers and closing of the return air dampers serves to admit a greater proportion of outside air and since the humidity of the outside air is always lower than the humidity maintained within the smokehouse, this opening of the outside air dampers and closing of the return air dampers serves to lower the humidity of the air within the smokehouse. Conversely, when the humidity in the smokehouse drops slightly below the setting of the double pen recording regulator I32, the wet bulb thermostat I34 actuates the double pen recording regulator I32 to adjust the pressure in its outlet line I45 to open the outside air dampers I5I and close the return air dampers I49. Thus, the propor-' tion of humid return air in the mixture delivered to the smokehouse is increased and hence the low humidity therein restored to the setting of the double pen recording regulator I32.

If the humidity in the smokehouse drops below the capacity of the outside and return air dampers I5I and I49 to control, the wet bulb thermostat I34 actuates the double pen-recording regutions 80 can be slid out or the side of the unit in the manner of a drawer.

Where the smokehouse is operated under conditions demanding a high humidity, a certain amount of condensation necessarily occurs in the bottom of the air conditioning unit through the contact of the humid return air with the relatively cool walls ofthe unit. This water of condensation flows down these walls into the pan formed at'the bottom of the lower section B of the casing and out through the drain 46.

From the foregoing it will be seen that the present invention provides a very simple and compact air conditioning unit containing the necessary mechanisms for supplying air into the smokehouse or similar enclosure; varying the amount and velocity of the air so supplied to obtain the desired movement of both the primary and secondary air therein; introducing smoke to the air so supplied when required; heating the air so introduced when required; withdrawing air from the enclosure to maintain the desired static pressure therein; returning a part of the air so withdrawn together with outside air to maintain the desired humidity in the enclosure; and hu- 'midifying the air supplied to the enclosure by the addition of water or steam when required. By

the provision of these instrumentalities in a single compact unit the problem of installation is reatl simplified, the cost of the equipment greatly reduced and losses also eliminated. The-air conditioning unit as a whole is also renderedadaptable to meet various installation conditions. At

the same time a control of. increasedaccuracy can be obtained, particularly in the elimination of the leakage of heat or air and in the elimination of any danger of by-passing of air in the unit.

I claim as my inventiqn:

1. An air conditioning unit for conditioning the air in enclosures in which materials are proc essed, comprising a casing, a supply fan secured Y to said casing and having'its inlet co eating with the interior thereof and i s outlet adapted to deliver air to said enclosure, means for admitting return air from said enclosure into said casing at the end thereof opposite said suplator I32 to adjust the air pressure in its outlet vided in the casing. Thus, by removing the panel as in the mint wall of the unit the sup ly mi 1| is rendered entirely accessible tor cleaning the same or making any'minor repairs. Similarly, the removal of the large panel 93 in this same front wall or the casing renders the entire bank of heating coil sections'accessible for cleanminor' repairs and renders the volume control dampers "I5 accessible for similar purpom It more extensive repairs or cleaning of and outlet pipes 32 and for these sections can be disconnected and theplate ll removed so that any one or-all or the heating coilsec-' sections ll is required, the inletmeans for, admitting outside air into said casing,

ply fan, means adjacent said return air admitting means for admitting outside air into said casing, heating coils arranged in said casing between said supply fan inlet and said return, and outside air admitting means for heating the retumand outside air drawn'into said supply fan, a volume control damper housed in said casing and controlling the total volume of said return and outside air drawn through said casing and into said supply fan, and means for regulating said volume controldamper.

' 2. An air conditioning unit for conditioning the air in enclosures in which materials are processed, comprising a casing, a supply fan secured to said casing" and having its. inlet communicating with the interior thereof and its outlet adapted to deliver air to said enclosure, means for admitting return air from said enclosure into said casing at the end thereof opposite said supply tan, means adjacent said return airadmitting heating coils arranged in said casing betweensaid supply fan inlet and said return and outside air admitting means for heating the return and outside air drawn into said supply fan, a volume control 'damper housed-in said casing intermediate said heatingeoils and said supply fan inlet and controlling the total volume of said'retum and outside air drawn through said casing and into said supply fan, and means for regulating said volume control damper.

3. An air conditioning unit for conditioning the air in enclosures in which materials are processed, comprising a casing, a supply fan arranged at one end of said casing and having its inlet communicating with the interior thereof and its outlet arranged to deliver air to said enclosure, means arranged in said casing at the end thereof opposite from said supply fan and forming a supply chamber and an exhaust chamber therein, said supply chamber being in communication with said inlet of said-supply fan Q air in enclosures in which materials are processed, comprising an elongated casing, a supply fan arranged at one end of said casing and having its inlet communicating with the interior thereof and its outlet arranged to deliver air to said enclosure, a baflle plate extending transversely across the interior of said casing at the opposite end of said casing from said supply fan and forming an exhaust chamber at the extreme and or said casing and a supply chamber intermediate said exhaust chamber and said inlet of said supply fan, said supply chamber being in communication with said inlet of said supply fan and said chambers being in communication with each other, means for admitting outside air to said supply chamber, means for admitting return air jointly to said supply and exhaust chambers, an exhaust fan discharging said return air from said exhaust chamber and heating coils arranged in said casing between said inlet of said supply fan and said supply chamber for heating the outside and return air drawn into said supply fan. 5. An air conditioning unit for conditioning the air in enclosures in which materials are processed, comprising an elongated casing, a supply fan arranged at one end of said casing and having its inlet communicating .with the interior thereof and its outlet arranged to deliver air to said enclosure, a baflie plate extending transversely across the interior of said casing at the opposite end of said casing from said supply fan and forming an exhaust chamber at the extreme end of said casing and a supply chamber intermediate said exhaust chamber and said inlet of said supply fan, said supply chamber being in communicationwith said inlet of said supply fan and said baiile plate being spaced from one wall of said casing to provide an opening establishing communication between said chambers,.means for admitting outside air to said supply chamber parallel with said baflle plate, means for admitting return air to said opening between said baflie plate and said one wall of said casing, an exhaust fan for'discharging said return air from said exhaust chamber and heating coils arranged in said casing between said inlet of said supply fan and said-supply chamber for heatingthe outside and'return air drawn into said supply fan. 6. An air conditioning-unit for conditioningthe air in enclosures in which materials are proccommunicating with the interior thereof and its outlet arranged to deliver air to said enclosure;

I means arranged in said casing at the end thereof opposite from said supply fan and forming a supply chamber and an exhaust chamber therein,

said supply chamber being in communication with said inlet of said supply fan and said chambers being in communication with each other, means for admitting outside air to said supply chamber, means for admitting return air from said enclosure jointly to said supply and exhaust chambers, an exhaust fan secured to said casing and discharging said return air from said exhaust chamber, heating coils arranged in said casing between said inlet of said supply fan and said supply chamber for heating the outside and return air drawn into said supply fan, a volume control damper housed in said casing intermediate said heating coils and said supply fan inlet and controlling the total volume of said return and outside air drawn through said casing and into said fan, and means for regulating said volume control damper.

7. An airconditioning unit for conditioning the air in enclosures in which materials are processed, comprising an elongated casing, a supply fan arranged in one end of said casing and having its outlet arranged to deliver air to said enclosure, means arranged in said casing at the end thereof opposite from said supply fan and forming a supply chamber and an exhaust chamber, said exhaust chamber being in communication with said supply chamber and said supply chamber being in communication with the inlet of said fan, means for admitting outside air to said supply chamber, means for admitting return air from said enclosure jointly to said supply and exhaust chambers, an exhaust fan discharging said return air from said exhaust chamber and heating coils arranged in said casing between said supply chamber and said supply fan for heating the outside and return air drawn:

into said supply'fan, said casing being composed of two major separable. sections, the first comprising the end of said casing containing said supply fan and the second comprising the end of said casing containing said heating coils and supply and exhaust chambers.

8. An air conditioning unit for conditioning the air in enclosures in which materials are processed, comprising an elongated casing, a supply fan arranged in one end of said casing and having its outlet arranged to deliver air to said enclosure, means arranged in said casing at the end thereof opposite from said simply fan and forming a supply chamber and an exhaust chamber, said exhaust chamber being in communication with said supply chamber and said supply chamber being in communication with the inlet of said fan, means for admitting outside air to said supply chamber, means for admitting return air from said enclosure jointly to said supply and exhaust chambers, an exhaust fan discharging said return air from said exhaust chamber, heating coils. arranged in said casing between said supply chamber and said supply fan for heating the outside and return air drawn into said supply fan, a volume control damper arranged in said casing intermediate said heating coils and said acrea e sections, the first comprising. the end of said casing containing said supply fan and the second comprising the end of said casing containing 'the air in enclosures. in which ,materials are processed, comprising a casing, a supply fan secured to said casing and having its inlet communicating withv the interior thereof and its means for admitting return air from said enclosure into said casing at the end thereof opoutlet adapted to deliver air to said enclosure,

of said supply fan and said supply chamber for posite said supply fan, means adjacent said rev.

turn air admitting means for admitting outside air into, said casing, heating coils in said casing between said supply fan inlet .and said return and outside air admitting means for heating the return and outside air drawn into said supply fan, a volume control damper housed in said casing and controlling the total volume of said return and outside air drawn through said casing and into said supply fan, means for regulating said volume control damper and means arrangedbetweensaid volume control damper and said supply fan for humidifying the air drawn into said supply fan. i

10. An air conditioning unit for conditioning and supplying smoke laden air to smokehouses,

comprising a casing, a supply fan secured to said casing and having its-inlet communicating with the interior thereof and its outlet adapted to deliver air to said smokehouse,-means for admitting return-air from said smokehouse into said casing at the end thereof opposite said supply fan, means adjacent said return air admitting means for admitting casing, heating coils arranged in said casing between said. supply fan inlet and said return and outside air admitting means for heating the return and outside air drawn into saidsupply fan, and means arranged between said coils and said supply fan for admitting smoke to said return and outside air drawn into the inlet of said supply fan. I 11. An air conditioning unit for conditioning and supplying smoke laden airto smokehouses,

comprising a casing, a supply fan secured to said casing and having its inlet communicating with the interior thereof and its-outlet adapted to deliver air to said Smokehouse, means for adoutside air into said opposite from said supply fan and forming a supply chamber and an exhaust chamber therein, said supply chamber being in communication with said inlet of said supply fan and said chambers being in communication with each other; means for admitting outside air tosaid supply chamber, means for admitting return air jointly to said supply and exhaust chambers, an exhaust .fan secured to said casing and discharging said return air from said exhaust chamber, heating coils arranged in said casing between said inlet heating the outside and return air drawn into said coils and supply fan for admitting smoke to said return and outside air drawn into said supply fan.

13. In apparatus for conditioning the air in an enclosure in which materials are processed, and having a casing, a supply fan arranged at one end of said casing and having its inlet communieating with the interior thereof and' having its outlet arranged to deliver air to said enclosure, means arranged in said casing at the end thereof opposite from said supply fan and forming a supply chamber and an exhaust chamber therein, said supply chamber being in communication with said inlet of said supply fan and said chambers being in communication with each other,

- admission of said outside air to said supply chamber, means for admitting return air from said enclosure jointly to said supply and exhaust chambers, a return air damper controlling the admission of said return air to said chambers, an exhaust fan secured to said casing and discharging said return air from said exhaust chamber, an exhaust damper controlling the discharge of return air by said exhaust fan, and heating coils arranged in said casing between said inlet of said supply fan and said supply chamber for heating the outside and return air drawn into said supply fan; the combination of means responsive to the dry bulb temperature of the air in the enclosure and controlling the admission of heating medium to said heating coils, means responsive to the humidity of the air in said enclosure and controlling the relative mitting retum' air from said -smokehouse into said casing I supply fan, means adjacent said return air admitting means for admitting outside air into saidcasing, heating coils arranged in said casing at the end thereof opposite said supply fan for admitting smoke to said return and outside air drawn into the inlet of said suppm fan, a volume control damper arranged in said casing intermediate said heating coils andsaid smoke admitting means and controlling the volume of said outside and return air drawn into said supply fan and means for regulating said volume control damper:

12. Anair conditioningunit for conditioning and supplyingsmoke laden air to smokehouses, comprising a casing, a supply fan arranged at one end of said' casing and having its inlet cominunicating with the interior thereof and its outlet arranged to deliver air to said smokehouse,

positions of said return air and outside air damp.-

ers to control the humidity of the air within the enclosure and means responsive to the pressure of the air within said enclosure 'and controlling said exhaustvdamper to maintain apredetermined air pressure in said enclosure.

14. In apparatus for conditioning and supplying smoke laden air to smokehouses, and having a casing, a supply fan arranged at one end of said casing and having'its inlet communicating with the interior thereof and having its outlet arranged to deliver air to said smokehouse,-

meansv arranged in said casing at the endthereof opposite from said supply fan and forming a supply chamber and'an exhaust chamber therein, said supply chamber being in communication with said inlet of said supply fan and said chambers being in communication with each other, 'means for admitting outside air to said supply chamber, an outside air damper-controlling the admission of said outside air to said supply chamber, means for admitting return air-from said 'smokehouse Jointly to said supply and exhaust chambers, a return air damper controlling,

- the admission of said return air to said chambers,

means arranged in said casing at the end thereof an exhaust fan secured to said casing and discharging said return air from said exhaust chamher, an exhaust damper controlling the discharge of return air by said exhaust fan, heating coils arranged in said casing between said inlet of said supply fan and said supply chamber for heating the outside and return air drawn into said supply fan, a volume control damper arranged in said casing intermediate said heating coils and said supply fan inlet and controlling the volume of said return and outside air drawn into said supply fan, means for regulating said volume control damper, means arranged between said heating coils andsupply fan for admitting smoke to said return and outside air drawn into said supply fan, a smoke damper controlling the admission of said smoke to said smoke admitting means, means forregulating said smoke damper, and means responsive to the dry bulb temperature of the air in the smokehouse and controlling the admission of heating medium to said heating coils; the combination of means responsive to the humidity of the air in said smokehouse and controlling the relative positions of said return air and outside air dampers to control the, humidity of the air in said smokehouse and means responsive to the pressure of the air in said smokehouse and controlling the position of said exhaust damper to maintain a predetermined air pressure in .said smokehouse.

15. In apparatus for conditioning and supplyingsmoke laden air to smokehouses, and having a casing, a supply fan arranged at one end of said casing and having its inlet communicating with the interior thereof and having its outlet arranged to deliver air to said smokehouse, means arranged in said casing at the end thereof opposite from said supply fan and forming a supply chamber and an exhaust chamber therein, said supply chamber being in communication with said inlet of said supply fan and said chambersan outside air damper controlling the admission of said outside air to said supply chamber, means for admitting return air from said smokehouse jointly to saidsupply and exhaust chambers, a return air damper controlling the admission of said return air to said chambers, an exhaust fan secured to said casing and discharging said return air from said exhaust chamber, an exhaust damper controlling the discharge of return air by said exhaust fan, heating coils arranged in said casing between said inlet of said supply fan and said supply chamber forheating the outside and return air drawn into said supply fan, a volume control damper arranged in said casing intermediate said heating coils and said supply fan inlet and controlling the volume of said return and outside air drawn into said supply fan, means for regulating said volume control damper, means arranged between said heating coils and supply fan for admitting smoke to said return and outside air drawn into said supply fan, a. smoke damper controlling the admission of said smoke to said smoke admitting means, means for regulating said smoke damper, means responsive to the dry bulb temperature of .the air in the smokehouse and controlling the admission of heating medium to said heating coils, and humidifying means arranged between said supply fan and said volume control dampers to humidify the air supplied by said supply fan to said smokehouse: the combination of means responsive to the humidity of the air in the smokehouse and controlling the relative positions of said return air and outside air dampers, means operatively connecting said last means with said humidifying means to control the humidity 01' the air in said smokehouse and means responsive to, the pressure of the air in the Smokehouse and controlling the position of said exhaust damper to maintain a predetermined air pressure in said smokehouse. 7

CHARLES N. DEVERALL