US2076399A - Method of heating and ventilating - Google Patents

Description

April 6, 1937. c, c. CARSON 2,076,399

METHOD OF HEATING AND VENTILATING Original Filed May 21; 1951 2 Sheets-Sheet l INVENTOR C C Carson/ ATTORNEYS April 6, 1937. c. c. CARSON METHOD OF HEATING AND VENTILATING Original Filed May 21, 1931 2 Sheets-Sheet 2 INVENTOR $3 CCarJon/ 964w, ATTORNEYS Patented Apr. 6, 1937 UNITED STATES METHOD or REATING AND vnnma'rmo Clifford C. Carson, Cleveland, Ohio Application May 21, 1931,' Serial No. 539,062

Renewed August 19, 1936 2 Claims.

This invention relates to combined heating and ventilating systems for rooms or enclosures such as factory buildings and aims to provide an improved, efiicient and economical method of heating and ventilating the workingarea 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.

Other aims and advantages of the invention will appear in the specification, when considered in connection with the accompanying drawings, wherein: 1

Fig. 1 is a diagrammatic sectional view of a monitor type building showing two unit heaters arranged to carry out the method;

Fig. 2 is a vertical 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

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 3.

Heretofore, considerable difiiculty has been ex- 25 perienced in obtaining the, proper distribution of heatingand ventilatingair 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 30 that heated air projected into a room tends to rise 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 35 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 40 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 per- 45 mit the concentration of loss of heat to the '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 50 great height of the roof from the floor, concentrate a great proportion of the total heat 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 of the air, in eflect, produces a pull of room air toward theexposedsurfaces.

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 difficulty is experienced in producing a condition of comfort both. as to temperature and as to fresh air in that portion of the 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, prevent an accumulation or stratification of high temperature air in the upper portions of a room, as is obtained by the present methods. The invention also proposes to utilize an improvedmethod and means of projecting 'a larger proportion of fresh air into the space near the floor level than is obtained by the methods now used. It is also a further aim to obtain a more even distribution of the heated and ventilating airand more comfortable working conditions in all inhabited parts of a room.

, Inaccordance 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 air stream to rise and stratify in the upper spaces of the room. The idea is to partially ofiset the tendency of the heated air to produce reduced faces which cause an increase in the leakage or infiltration of outside air through cracks and openings in that portion of the building.

drawings, there is shown an installation applied to an ordinary monitortype building It outlined in Fig. 1. In this instance, two heater-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 co-pending application, Serial No. 398,443, filed October 9, 1929, while the other 'is of the suspension type somewhat similar to that shown in my co-pending application, Serial No. 409,657, flledNovember 25, 1929. The unit shown at the righthand side of Fig.1 and in Figs. 3 and 4 ,comprises a casing H in which is arranged heat transfer elements I! and a series of centrifugal fans ll of conventional design enclosed by scrolls Referring particularly to the accompanying I4. The construction is such that the fans deliver air through the heater elements into the space to be heated. The fans are conveniently arranged on a common shaft and are driven by a motor l5 suitably supported on the casing. Between the fans and the heater elements there is ,shown a plurality of dampers or valves I 6 for regulating the flow of air through or around the heating elements, so as to control the volume of 10 heated air according to the room requirements.

is preferably arranged a preheater in the form of heating elements 22 near the top of the con duit and a by-pass 23 through which a portion of the air may be admitted without passing through the preheater. The by-pa'ss 23 is preferably controlled by a damper 24 which may be either manually or automatically controlled in accordance with the temperature. The air is first mixed in the chamber around the fan scrolls and, then, admitted to the fans to be discharged through the passages in the casing into a mixing chamber 25 above the heater elements I2. From the mixing chamber, the air is adapted to be discharged through large horizontal nozzles 26 into the room or space to be heated.

A confining curtain of relatively cold, fresh air is discharged above each hot air stream through ducts 21 and nozzles 28. These air curtains are preferably created by each of the centrifugal fans l3, being discharged tangentially into the ducts 21 from the scrolls M. The arrangement is such that the relatively cold curtain or curtains counteract the tendency of the hot air to rise before it has given up a substantial portion of its heat. The velocities of the two streams or strata are so regulated that the mean direction of travel of the currents is represented by the dotted line, Fig. 1. Thus, the heated 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 also to enable it to be used either heater just described.

as a ventilator or a heater to recirculate room air,- there is shown a damper 29 in the opening or duct l9 and a damper 3i! in the intake conduit 20. and recirculating room air can be varied at will.

Moreover, either inlet can be closed entirelywhile the other is open to convert the unit into a recirculating heater, or a fresh air heater and ventilator. Further, by closing the damper '29 and all of the dampers I 6, the unit can be used to introduce ventilating air into the room through duct 27 without heating any part of it.

The suspended heater H' shown in Figs; 1 and 2 is similar in most respects to the floor type of 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 I 9' for the room air extends downwardly to a po' t near the floor level. Furthermore, the outlet Thus, the proportion of fresh, outdoor air.

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 I8 within the heater casing extends forwardly to provide a separate conduit H 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 air nozzle or discharge duct 26' is shown as being directed downwardly at an angle to the upper nozzles to prevent eddy currents from being set up at the mouth. The middle stratum of relatively cold air not only acts as a confining curtain tending to overcome the buoyancy of the hot hot air from. the upper cold air curtain until the air is dissipated and begins to mix.

In this example, the velocities and temperatures of the different strata of air are so controlled or regulated that the mean direction of travel is substantially along the dotted line in air, but also, separates the- Fig. 1. In both diagrams the dotted lines represent the ideal direction of intermingled air and this circulation insures a maximum heating distribution in the lower portion of the space to be heated and ventilated thereby. greatly reducing the temperature and heat losses in the upper part of the space.

While both types of unit heaters are shown in a building, it will be understood that a single unit may be used very effectively in relatively small buildings or spaces. Whentwo or more units are used it is sometimes desirable to arrange them in staggered or offset relation on opposite sides of the room or space.

Obviously, the invention is not restricted to the particular embodiments thereof herein shown and described.

-What I claim is:-

1. That method of heating and ventilating a at high velocity and at a lower temperature than;-

the by-passed air above both of said streams whereby to cause the resultant air currents to.

travel for a substantial distance through the lower portion of the room or enclosure.

2. That method .of heating and ventilating a room or enclosure which comprises introducing air from a source outside the room or enclosure; mixing this air with a portion of air from the room or enclosure; heating a: portion of such mixed air and discharging it into the space to be heated; by-passing a portion 01' the mixed air above the heating means and discharging it above the stream of heated air at a slightly greater velocity; controlling the quantity of bypassed air to vary the temperature and volume of the heated air delivered to the enclosure; and producing an upper wide stream of relatively cold air discharging immediately above and substantially parallel with the by-passed stream.

CLIFFORD 'C. CARSON.

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