US2247987A - Apparatus for heating and ventilating - Google Patents

Description

APPARATUS FOR HEATING AND VENTILATING Original Filed May 21, 1931 2 Sheets-Sheet l C C. Carson July 1, 1941. v c. c. CARSON I APPARATUS FOR HEATING AND VENTILATING 2 Sheets-Sheet 2 Original Filed May 21, 1931 f Q Qu WM NLT at. 6am

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Patented July 1, 1941 APPARATUS FOR HEATING AND 1 VENTILATINGQ 4 Clifford C. CarsomtS ttLouis, Mo.

' Original application May. 21,1931, SerialLNoQ Divided and this. application March 12,1937,.SerialNo.130,575

Claims (01.257-137) This invention relates to combined heating and ventilating systems for rooms or enclosures such as factory buildings and'aims to provide an improved, efficient and economical apparatus for heating and ventilating the working area so as to insure a practically uniform, comfortable distribution of heated air and ventilating air, while the, upper portion of the room or enclosure is maintained at a lower temperature than usual, so as to reduce the heat loss. This application is a division of my application Ser. No. 539,062, filed May 21, 1931, now Patent 2,076,399.

Other aims and advantages of the invention will appear in the specification, when considered in connection with the accompanying drawings, wherein:

Fig. 1 is a diagrammatic sectional view of a monitor type building showing two unit heaters embodying the invention;

Fig. 2 is avertical sectional view on an enlarged scale of one of the unit heaters in Fig. 1;

Fig. 3 is a vertical sectional view of the other heater; and i .Fig. 4.is a sectional view takenon the line 4-4 of Fig. 3.

Heretofore, considerable difficulty has been experienced in obtaining the proper distribution of heating and Ventilating air in large rooms or buildings. Ordinary unit heaters and ventilators, now in general use, do not distribute the air properly. One of the reasons is due-.to'the fact that. heated air projected into a room tends torise because its density'is less than that of the" relatively cold room air through which it passes. Further, when-the warm air in a room or building comes in contact with the relatively cold walls or surfaces, it is'cooled and its volume is decreased due to the lower density. As a result,.,the;constantly.cooled or chilled air which comes in contact with the building surfaces exposed to the outside elements produces a tendency to maintain a zone of low pressure-compared with the mean room pressure in the regions adjacent to such exposed surfaces.

In most industrial or factory buildings, it is frequently necessary to use materials which permit the concentration of loss of heat tothe outside air-near those portions of the room or building composing the upper glass sash, walls, the roof, monitor sash, etc. Large areas of glass in the roof monitors of such buildings, and the great height of this roof from the floor, concentrate a great proportion of the totalheat losses in the building to these surfaces The natural tendency of'warm air is to rise and this tendency is often increased, very materially by the low pressure zones against such upper surfaces of a room due to the chilling of the room air lying against the upper surfaces. The chilling oi the-air, in effect, produces a pull of room air toward the exposed surfaces.

In practice, the air in a room being heated and/or ventilated by unit heaters or unit ventilators, tends to stratify the warm air concentrating under the upper surfaces of the room. Hence, great dirficulty is experienced in producing a condition of comfort both as to temperature and as to fresh air in that portion ofthe room near the floor, which, in most cases, is the only space in the room which is inhabited. It is apparent that the building up of high temperatures under the exposed upper surfaces of the room or building, increases the loss of heat through such surfaces and increases the tendency to decreasing room pressure adjacent to such surfaces. It is the main purpose of this invention to heat and ventilate a room by the use of unit heater ventilators .of improved design, which, in their operation, preventan accumulation or stratificationof high temperature air in'the upper portions of ,a room, as is obtained by the presentmethods. The invention also proposes to utilize improved means for projecting a larger proportion of fresh air into the space near the floor level than is obtained by the apparatus now used. It is also a further aim to obtain a more even distribution of the heated and ventilating air and more comfortable working conditions in all inhabited parts of a room.

In accordance with this invention,'I propose to utilize a portion of fresh, outside air which is introduced for the, purpose of ventilation in producing a stream or streams of moving air at a temperature below the mean room temperature above a projected stream of warm air from a heating unit. The idea is to partially isolate the upper space of the room from those spaces near. the floor and decrease the tendency of the warm stream to rise and stratify in the upper spaces of the room. .The idea is to partially offset the tendency of the heated air to produce reduced. pressures adjacent to the exposed building surfaces which causean increase in the lwkage or infiltration of outside air through. cracks and openings in that portion of the building. .,;Ref;erring particularly :to .the accompanying drawings, there isshown anyinstallation applied to an ordinarymonitor. type building [0 outlined in Fig.,1.- In thisinstance, twoiheater-ventilator units are shown as being arranged at opposite sides of the building. One of them is of the floor type which is somewhat similar to that shown in my copending application, Ser. No. 398,443, filed October 9, 1929, while the other is of the suspension type somewhat similar to that shown in my copending application, Ser. No. 409,657 filed November 25, 1929., now Patent No. 1,820,719. The unit shown at the right hand side of" Fig. 1 and in Figs. 3 and 4 comprises a casing II in which is arranged heat transfer elements I2 and a series of centrifugal fans l3 of conventional design enclosed: by scrolls: [L

to be heated. The fans are conveniently arranged on a common shaft and are drivenby amotorla suitably supported on the casing Between: the

fans and the heater elements there is shown a plurality of dampers or valves I6 for regulating the flow of air through or around the heating elements-,-so-as to control the volume or heated air according to the room requirements.

this i-nstance,-there is shown a by-pass l1 behind the heater elements and separated there'- frombymeans- 0f a partition Ht. The airis admitted to the housing throughan intake opening 1-8 'near the base and an intake conduit 2|] leading through the wallet the-building to the outside, the mouth of the'intake conduit having a series-of weather louvres 2-! to prevent rainfrom beating in; In the intake conduit 28 there is preferablyarranged a pre-heater in the formof heating elements 22' near the top of the conduit a-nd a by-pass 23 through which: a portion of the air maybe admitted without passing through the preheaten The by-pass 23 is preferably controlled-by-a damper 24 which may be either manually-or--automatica-lly controlled in accordance with the temperature. The air is first mixed in the chamber around the fan scrolls and, then; ad-

mitte'd -to the fans to be dischargedthroug-h the passagesi-n the casinginto a mi-Xingchamber 25 above" the-heater elements l2. From themixing chamber, the air is adapted to be discharged througnlarg'e hcrizontalnozzles 26 into the room or space to be heated. I 7

-; r A confining curtain' oirelatively cold, freshair is -discharged abcveeachhot ai-rstream through ductsil'and nozzles 281 These aircurt-ains are preferably created by each of the centrifugal .fan's- I 3, being discharged tangentially intothe ductsuz'l firom the scrolls I4. The'arrangement is. such. that the relatively cold curtains or ourtains counteract the tendency of the hotair to rise. beforeit hasg-iven up a substantial portion of .itssheat.v The. velocities of the two streams or strata. are so. regulated that the mean direction of.- .traveiofthe currents is represented bythe dotted. line,.F-'ig. 1. Thus, theheated air may be confined. to travel across. the building before it circulates above the breathing line.

To control or. regulate the admission of air to the unit. and alsoto enable it to be used either as a. Ventilator .or; a heater to recirculate room air, there is shown. a damper 29 in the opening or duct; land: a. damper 30in the intakeconduit 2o. he: proportion of. fresh, outdoor air and recirculatingeroomz air can be varied at will. Moreover; either inlet can beclosed entirely while the other isopen: to convert the unit into a re- LGircula-ting: heater, or a fresh. air heater and vena. r. .Furthen bycclosing the damper 29: and .8 1 cig hedamners 16,..the unitican be used to ietsq uce ventilating air in eomthrou filial: Hz-w thout heating ny pa -crit- The suspended heater l l shown in Figs. 1 and 2 is similar in most respects to the floor type of heater just described. In this instance, the casing is horizontal and the cold air intake duct 20 is connected to its rear end, extending through the wall of the building above the windows. The intake duct IQ for they room. air extends downwardly to a point near thefloor level. Furthermore, the outlet nozzles are curved to direct the air downwardly at an angle of thirty degrees or more to the horizontal into the space to be heated. The partition l8 within the heater casing extends forwardly to provide a separate conduit II for the by-passed air within the heater casing.

Thus, three separate superposed streams or strata are discharged; and the intermediate, relatively cold air. stream travels at a lower velocity than the upper curtain or confining stream. The hot .up. at. thermouth. The middle stratum o1'r 1-.e1a-

.tively cold. all: not; only acts: as. a confining curhairr tendingto. overcome the buoyanc of the h t: a r; butalsm separates the. hot air from the upper cold: air curtain. until the air is. dissipated andbegins to liiix,v

example; the velocities and. temperaturcs; of the difilcrent: strata. of air areso controlled; prgrcglllated that the mean direction of travel; bsllbfita niially along the dotted line in Fi 1. In. both dia rams the dotted lines. represent hc deal direction of intermingled air and .thiscircul tieninsmes a maidmum. heat distribu.- ion; the. lower. portion of the. space tobe heated and ventilated thereby greatly reducing the temperature and heat. losses. in the upper part of he space...

While both types of unitheaters are, shown in ab iljdi ait Willbe understood that a single. unit y h used very efiectivelyin relativelysmall buildings or spaces. When two or morev units are used it is sometimes desirable to. arrange them. in staggered or offset: relation on opposite sides of the room or space.

Qbviousl the. invention is. not restricted: to the particular; embodiments. thereof herein shown and; describ cl...

- is claimcdsis:

l- .Aicombined; unit heater and ventilator-compri ng. combination, a casing; a fan within thccasine; a heat exchange element. in. the case ings. an air. intake :duct. leading Outside. of: the enclosure to. be; heated and ventilated; a heat transfer-element in. saidduct; a second air intake chant ng: adantedito admit room air to the casing; a. dischargeduct for the heatedtair; a wide nozzle above said, discharge. duct; a conduit. leading fimmthe, f to the nozzle so. arrangedas to dischar e cold air: at a high velocity above the heated aim: and a. damper-controlled bypass in saidcasing; around said heat transfer element connected. to. direct a; wide.- stream of by-passed air between the relatively heated air stream and hc. air stream 'issuingfrom said nozzle.

w -2;-, Ann-it heatenventilator comprising, incommd liqnwa casing; afan within the casing; a 9 19111 clt'aldmittingair into the casing; a heat transfer element: in; a portion of the casing; a discharge. outlet leading from the heat transfer element; a. bypass channel aroundsaid heat transfer element arranged to discharge air above theheated'air stream: to regulate the to the fan and having a discharge nozzle above said by-passed air stream arranged to project a confining stream of relatively cold air above the discharging lower streams.

3. A unit heater-ventilator comprising, in combination, a casing; a fan within the casing; a conduit for introducing fresh air into the casing; an air preheater in said conduit; a conduit for admitting room air into the casing; an air mixing chamber adjacent to the fan; a heat transfer element in a portion of the casing; a discharge outlet leading from the heat transfer element; a by-pass channel around said heat transfer element having a discharge outlet above the heated air outlet; means to regulate the how of air through the passages; and a separate channel connected to the fan and having a discharge nozzle above both of said outlets arranged to project a confining stream of cold air above the discharging lower streams.

4. A unit heater of the class described comprising, in combination, a casing; a heat exchanger in a portion of the casing; an outlet leading from the casing to discharge heated air into the space to be heated; a. by-pass within the casing around the heat exchanger connected to deliver a separated stream of relatively cold air above the hot air stream; means to deliver air through the casing; means to vary the relative volumes of air passing through the heat exchanger and said by-pass to control the temperature of the heated air; and a separate air conduit connected to said air delivering means having an outlet above and adjacent to the discharging stream of by-passed air and arranged to deliver a confining stream of cold air substantially parallel with the air streams discharging from the casing.

5. A unit heater of the class described comprising, in combination, a casing; a heat exchanger in a portion of the casing; a by-pass within the casing to deliver air around the exchanger; means for directing the resulting streams in separate strata into the space to be heated above the breathing line; dampers connected to control the volume of air passing through the heat exchanger and by-pass; and a separate conduit connected to said air delivering means to discharge a cold air curtain parallel with the air discharged from. said casing.

CLIFFORD C. CARSON.

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