H ILLINO I S UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN PRODUCTION NOTE University of Illinois at Urbana-Champaign Library Large-scale Digitization Project, 2007. UNIVERSITY OF ILLINOIS ENGINEERING EXPERIMENT STATION BULLETIN No. 192 INVESTIGATION OF HEATING ROOMS WITH DIRECT STEAM RADIATORS EQUIPPED WITH ENCLOSURES AND SHIELDS CONDUCTED BY THE ENGINEERING EXPERIMENT STATION UNIVERSITY OF ILLINOIS IN COOPERATION WITH THE NATIONAL BOILER AND RADIATOR MANUFAC- TURERS' ASSOCIATION AND THE ILLINOIS MASTER PLUMBERS' ASSOCIATION BY ARTHUR C. WILLARD PROFESSOR OF HEATING AND VENTILATION AND HEAD OF DEPARTMENT OF MECHANICAL ENGINEERING ALONZO P. KRATZ RESEARCH PROFESSOR IN MECHANICAL ENGINEERING MAURICE K. FAHNESTOCK SPECIAL RESEARCH ASSOCIATE IN MECHANICAL ENGINEERING SEICHI KONZO RESEARCH GRADUATE ASSISTANT IN MECHANICAL ENGINEERING ENGINEERING EXPERIMENT STATION PUBLISHED BY THE UNIVERSITY OF ILLINOIS, URBANA JUNE, 1929 5000 3 o 59S3 UIVERSITY OF ILLINOIS (t PRESS Il CONTENTS PAGE I. INTRODUCTION . . . . . . . . . . . . . 7 1. Preliminary Statement . . . . . . . . 7 2. Object of Investigation . . . . . . . . 8 3. Scope of Investigation . . . . . . . . 8 4. Acknowledgments . . . . . . . . . 9 II. DESCRIPTION OF APPARATUS . . . . . . . . 9 5. Low Temperature Testing Plant . . . . . 9 6. Test Rooms ....... . . .. 9 7. Cold Room ...... . ....14 8. Refrigerating Apparatus . . . . . . . 16 9. Recording Instruments and Thermocouples . .16 10. Weighing System . . . . . . . . . 19 11. Unenclosed Radiators . . . . . . . . 19 12. Enclosures. . . . . . . . . . . . 20 III. DiscussioN OF TEST METHODS AND RESULTS. . . . 28 13. Limiting Conditions for Tests .. . . . . 28 14. Temperature Measurements. . . . . . .29 15. Operation of Plant . . . . . . . . . 29 IV. TESTS OF UNENCLOSED RADIATORS . . . . . . . 30 16. Results of Performance Tests . . . . . . 30 17. Radiator Rating . . . . . . .. . . 44 V. TESTS WITH ENCLOSURES. . . . . . . . . . 45 18. Introduction . . . . . . . . . . . 45 19. Results of Tests . . . . . . . . . . 45 VI. TESTS WITH METAL AND CLOTH SHIELDS . . . . . 47 20. Metal Shield . . . . . . . . . . . 47 21. Special Radiator with Integral Shield . . . . 47 22. Cloth Covers . . . . . . . .. . . 48 CONTENTS (Continued) PAGE VII. COMPARISON OF THE PERFORMANCE OF THE VARIOUS TYPES OF ENCLOSURES.. . . . . . . . 49 23. Performance of Enclosures . . . . . . .49 24. Heat Losses from the Room. . . . . . . 50 25. Relative Steam Condensing Capacity . . . . 51 VIII. SURFACE TEMPERATURE AND GRADIENTS OF WALLS, FLOORS, AND CEILINGS.. . . . . . . . 52 26. Temperature Gradients through Floor and Ceiling 52 27. Temperature Gradients through Walls. . . .52 28. Temperature Gradient in the Air in the Cold Room . . . . . . . . . . . . 58 IX. WARMING AND COOLING TESTS OF ROOMS . . . . . 59 29. Preliminary Statement . . . . . . . . 59 30. Cooling Test . . . . . . . . . . . 59 31. Heating Room with Unenclosed Radiator. . . 60 32. Heating Room with Enclosed Radiator . . . 63 X. AIR CIRCULATION WITHIN ROOMS HEATED BY DIRECT RADIATORS ... . . . . . . . . .64 33. Air Circulation with Unenclosed Radiator . . 64 34. Air Circulation with Enclosed Radiator . . . 66 XI. CONCLUSIONS . .. . . . . . . . . . . 68 35. Conclusions . . . . . . . . . . . 68 LIST OF FIGURES P 1. Plan Section of Low Temperature Testing Plant . . . . . . . . 2. Elevation Section of Low Temperature Testing Plant . . . . . . 3. Inside View of Test Rooms . . . . . . . . . . . . . . 4. Outside of Cold Room, Showing Rheostats, Recording Instruments, and Automatic Expansion Valve . . . . . . . . . . . .. 5. Refrigerator Doors Opening into Basements under Test Rooms .. 6. Refrigerating Apparatus, Including Ammonia Compressor, Condenser, and Receiver . . . . . . . . . . . . . . . . . . 7. Inside of East Test Room Showing Fume Generator and Standard Support- AGE 10 11 12 ing Thermocouples and Recordii 8. Thermocouple Switchboard 9. Unenclosed Radiator . . . 10. Enclosure No. 1 . . . . . 11. Enclosure No. 2 . . . . . 12. Enclosure No. 3 . . . . .. 13. Enclosure No. 4 ... . . . 14. Enclosure No. 5 . . . . . 15. Enclosure No. 6 . . . . . 16. Enclosure No. 7 . . . . . 17. Enclosure No. 8 ...... 18. Enclosure No. 8a ..... 19. Enclosure No. 9 ...... 20. Enclosure No. 10 . . . . . 21. Enclosure No. 12 ..... 22. Dimensions of Enclosures Tested. ng Instrument Bulbs . . . . . . 17 . . . . . . . . . . . . 18 . . . . . . . . . . . . 20 . . . . . . . . . . . . 21 . . . . . . . . . . . . 21 . . . . . . . . . . . . 22 . . . . . . . . . . . . 22 . . . . . . . . . . . . 23 . . . . . . . . . . . . 23 . . . . . . . . . . . . 24 . . . . . . . . . . . . 24 . . . . . . . . . . . . 24 . . . . . . . . . . . . 25 . . . . . . . . . . . . 25 . . . . . . . . . . . . 26 . . . . . . . . . . . . 26 . . . . . . . . . . . . 27 23. Room Temperature Gradient and Steam Condensing Rate for Radiator with Enclosure No. 2 in West Test Room . . . . .. . . . . 40 24. Room Temperature Gradient and Steam Condensing Rate for Radiator with Enclosure No. 3 in West Test Room . . . . . . . . . . 40 25. Room Temperature Gradient and Steam Condensing Rate for Radiator with Enclosure No. 9 in West Test Room . .. . . . . . . . 41 26. Room Temperature Gradients and Steam Condensing Rates for Radiator with Enclosures Nos. 8 and 8a in East Test Room . . . . . . 41 27. Room Temperature Gradients and Steam Condensing Rates for Radiator with Enclosures Nos. 10 and 11 in West Test Room . . . . . . 42 28. Room Temperature Gradients and Steam Condensing Rates for Radiator with Enclosures Nos. 5 and 5a in East Test Room .. . . . . 42 NO. LIST OF FIGURES (Continued) NO. PAGE 29. Room Temperature Gradient and Steam Condensing Rate for Radiator with Enclosure No. 1 in West Test Room . . . . . . . . . . 43 30. Room Temperature Gradients and Steam Condensing Rates for Radiator with Enclosures Nos. 12 and 12a in West Test Room . . . . . 43 31. Room Temperature Gradients and Steam Condensing Rates for Radiator with Enclosures Nos. 4, 6, and 7 in West Test Room . . . . . 44 32. Typical Temperature Gradients through Walls of West Test Room, Test No. R-9 . . . . . . . . . . . . . . ... . 53 33. Vertical Temperature Gradient in Air in Cold Room . . . . . . . 58 34. Cooling Curves for West Test Room . . . . . . . . .... .59 35. Warming Curves for Unenclosed Radiator in West Test Room . . . .61 36. Warming Curves and Condensate Rate for Radiator Equipped with En- closure No. 5 in West Test Room . . . . . . . . . . 62 37. Fume Generator . . . . . . . . . . . . . 65 38. Air Circulation in West Test Room (Section A-A, Fig. 1) with Unenclosed Radiator ..... .......... . .........66 39. Air Circulation in West Test Room (Section A-A, Fig. 1) with Enclosure N o. 3 . . . . . . . . . . . . . . . . . . ... . 67 LIST OF TABLES 1. General Results, West Test Room. ..... . . . . . . . 31 2. General Results, East Test Room ..... . . . . . .... .37 3. Comparison of Performance Factors for Enclosures . . . . . . . . 49 4. Comparison of Steam Condensing Capacities of Similar Enclosures on Two Different Sized Radiators ...... . . . . . . . . 51 5. Multipliers for Determining K. ..... . . . . . .... .55 INVESTIGATION OF HEATING ROOMS WITH DIRECT STEAM RADIATORS EQUIPPED WITH EN- CLOSURES AND SHIELDS I. INTRODUCTION 1. Preliminary Statement.-This bulletin is a report of the re- sults of the work of the last year and a half under the terms of a co- operative agreement between the National Boiler and Radiator Manufacturers' Association, the Illinois Master Plumbers' Associa- tion, and the University of Illinois, providing for an investigation of steam and hot-water heating systems. The agreement was formally approved March 9, 1926, and became operative on April 10, 1926. The results presented in this bulletin are based upon the work done since the publication of Bulletin No. 169 entitled "Effect of Enclo- sures on Direct Steam Radiator Performance," in which were re- ported the results of the first year's work under this agreemeLt. The two cooperating associations have been represented since the publication of the first bulletin by an advisory committee, the membership of which is as follows: C. D. Brownell, Chairman, representing the Illinois Master Plumbers' Association, Champaign, Illinois C. A. Bolton, representing the Illinois Master Plumbers' Association, Chicago Heights, Illinois C. K. Foster, representing the National Boiler and Radiator Manufacturers' Association, Chicago, Illinois H. R. Linn, representing the National Boiler and Radiator Manufacturers' Association, Chicago, Illinois R. F. Prox, representing the National Boiler and Radiator Manufacturers' Association, Terre Haute, Indiana F. W. Herendeen, representing the National Boiler and Ra- diator Manufacturers' Association, Geneva, New York O. J. Prentice, representing the Steam Specialties Manufac- turers, Chicago, Illinois H. S. Ashenhurst, representing the Insulation Manufac- turers, Chicago, Illinois W. H. O'Brien, representing the Southern Pine Association, Chicago, Illinois Seward Best, representing the Heating Contractors, Quincy, Illinois J. M. Robb, representing the Heating Contractors, Moline, Illinois ILLINOIS ENGINEERING EXPERIMENT STATION H. F. Burch, representing the Heating Contractors, Rock Island, Illinois J. F. Powers, representing the Heating Contractors, Spring- field, Illinois It is the function of this committee to propose such problems for investigation as are of the greatest interest to the installer of small direct steam and hot-water heating systems, operating on gravity circulation. Of these problems, the Engineering Experiment Station Staff selects for study those which can best be investigated with the facilities and equipment available at the University. The cooperat- ing associations provide funds for defraying a major part of the ex- pense of this research work. 2. Object of Investigation.-The immediate object of the tests reported in this bulletin was to determine the effect of various types of present-day commercial radiator enclosures, shields, and covers on the heating effect produced and the steam condensed by a direct cast-iron radiator placed in an actual room subjected to zero weather conditions. 3. Scope of Investigation.-The effect of an enclosure, shield, or cover upon the heating effect produced in a room and the steam con- densing capacity of a radiator depends upon many factors. The tests made in connection with the present investigation were planned to determine the influence of all of the factors which enter into this problem in the case of various commercial radiator enclosures and shields. In conjunction with the work on enclosures and shields, tests were run on an unenclosed radiator, a variety of cloth covers, and a special shielded radiator. In order to provide for all the factors affecting the performance of bare, enclosed, and shielded radiators, actual rooms with typical outside walls, windows, and doors, and located in a specially con- structed low temperature testing plant for maintaining constant out- side temperatures of zero or less, were used. In such a plant it was possible to place the radiator in the actual environment existing in practice, and investigate not only the heat emission of the radiator itself, but also the heating effect produced in the room as well. The intelligent design and selection of radiators and enclosures depends fully as much on the effect produced in the room as on the conven- tional heat emission factor so generally taken as the sole criterion of excellence in the past. The investigation which is reported in this bulletin is an elaborate extension of a previous investigation in this field, the results of which HEATING ROOMS WITH DIRECT STEAM RADIATORS were published in Bulletin No. 169. The latter investigation was confined strictly to the heat emission or steam condensing capacity of bare and enclosed radiators under the usual laboratory conditions. The correlation of the results of that investigation with those of this investigation is entirely satisfactory. 4. Acknowledgments.-The investigation has been carried on as a part of the work of the Engineering Experiment Station of the Uni- versity of Illinois, of which DEAN M. S. KETCHUM is the director, and of the Department of Mechanical Engineering, of which PROFESSOR A. C. WILLARD is the head. Acknowledgment is also made to the manufacturers who furnished the radiators, enclosures, and shields used in this investigation. II. DESCRIPTION OF APPARATUS 5. Low Temperature Testing Plant.-The plant is designed spe- cifically for the purpose of accurately studying direct steam and hot water heating problems, including those phases of building construc- tion and insulation which are of special interest to the heating con- tractor and engineer, as well as the building owner and manufacturer of heating equipment, under conditions approaching as nearly as pos- sible those found in actual practice. The general arrangement of the plant is shown in Figs. 1 and 2. The main portion of the plant, consisting of the cold room, the two test rooms with their respective attics and basements, and the re- frigerating coils, is located on the upper floor of the Mechanical Engineering Laboratory. The auxiliary equipment including the re- frigerating apparatus, with the exception of the coils, the thermo- couple switchboard, and the steam control and weighing apparatus, is located on the lower floor of the laboratory. 6. Test Rooms.-Figures 1 and 2 show the arrangement of the two test rooms which are identical in construction, each one having two walls exposed to the air in the cold space in which the refrigerating coils are located. The cross-hatched walls in Figs. 1 and 2 are com- posed of corkboard. The two exposed walls of both test rooms, indi- cated by light lines, can be removed and replaced with any desired wall construction without disturbing the floors or ceilings. As shown in these figures, the insulated walls of the cold room form the two remaining walls of each of the test rooms. Both test rooms are iden- tical in every detail, being 9 ft. by 11 ft. with 9-ft. ceiling heights. 10 ILLINOIS ENGINEERING EXPERIMENT STATION HEATING ROOMS WITH DIRECT STEAM RADIATORS FIG. 2. ELEVATION SECTION OF Low TEMPERATURE TESTINa PLANT ILLINOIS ENGINEERING EXPERIMENT STATION FIG. 3. INSIDE VIEW OF TEST ROOMs The exposed walls at the present time are standard frame construc- tion, consisting of /%-in. redwood siding, building paper, 3%-in. tongue and groove yellow pine sheathing, 2-in. by 4-in. yellow pine studding, and 3%-in. wood lath with 12-in. gypsum plaster. The ceilings are made of %-in. wood lath and 3%-in. gypsum plaster, with no flooring in the attics. The floors are of standard 21%-in. by 136-in. standard yellow pine flooring over building paper placed on 3%-in. thick tongue and groove yellow pine sub-floors. Figure 3 shows the inside of both test rooms, with radiators in front of the windows, which are placed in exposed walls as shown in Figs. 1 and 2. Each test room has one double window 4 ft. 6 in. by 5 ft. overall. The window stools are 34 in. high, making it possible to test radiators with a height up to 32 in. The windows are fitted with shades and curtains as shown in Figs. 3 and 7. Figures 1 and 3 show the locations of standard 134-in. thick yellow pine doors, 3 ft. by 7 ft., with glass upper panels. These doors lead directly from the test rooms into the cold space. Figure 2 shows the attics and basements located above and below each of the test rooms. These attics and basements are for the pur- HEATING ROOMS WITH DIRECT STEAM RADIATORS FIG. 4. OUTSIDE OF COLD ROOM, SHOWING RHEOSTATS, RECORDING INSTRU- MENTS, AND AUTOMATIC EXPANSION VALVE pose of exposing the ceilings and floors of the test rooms to air of any desired temperature. The attics were formed by building the ceilings of the test rooms about 3 ft. 10 in. below the ceiling of the cold room, and the basements were made by building the floors of the test rooms about 2 ft. 8 in. above the floor of the cold room. The exposed walls of the attics and basements are composed of 2 layers of 2-in. cork- ILLINOIS ENGINEERING EXPERIMENT STATION FIG. 5. REFRIGERATOR DOORS OPENING INTO BASEMENTS UNDER TEST ROOMS board, and are equipped with refrigerator doors as shown in Fig. 5. Each wall contains one door, located as shown in Fig. 1, which opens directly into the cold area, and which may be adjusted to obtain any desired amount of opening. Each attic and basement is equipped with electric heaters, as shown in Fig. 2, consisting of shaded electric light bulbs, so placed that the heat is evenly distributed over the total floor and ceiling surfaces and shielded in order to prevent the floors and ceilings from receiving heat by direct radiation. The volt- age to each group of heaters in each attic and basement is separately controlled by rheostats conveniently located outside of the cold room, as shown in Figs. 1 and 4. These heaters, so arranged and controlled, when used in conjunction with the refrigerator doors give a very flexible and sensitive method of controlling the temperatures in the attics and basements. 7. Cold Room.-In order that two walls of the test rooms might be exposed to conditions corresponding to those prevailing during the heating season, it was necessary to enclose the test rooms in a cold space in which the temperature and wind movement could be controlled. This makes it possible to run tests at any time of the year under exactly similar conditions. Figure 4 shows the outside of HEATING ROOMS WITH DIRECT STEAM RADIATORS FIG. 6. REFRIGERATING APPARATUS, INCLUDING AMMONIA COMPRESSOR, CONDENSER, AND RECEIVER the cold room, which is 16 ft. by 27 ft. 4 in. by 16 ft. 11 in. in height. Figures 1 and 2 show details of construction. The walls consist of 2 layers of 3-in. corkboard, with /1 in. of cement mortar between them, and /·1 in. of cement plaster on the inner and outer surfaces. The ceiling is made of 2 layers of 3-in. corkboard laid in hot asphalt on a 3-in. wood deck which is supported independently from the walls of the room. The floor consists of 4 in. of concrete laid on 6 in. of cork- board, which in turn is laid on the 10-in. concrete floor of the labo- ratory. Entrance to the cold room is through either test room, as shown in Fig. 1. The doors leading from the laboratory into the test rooms are of the heavy refrigerator type, as shown in Fig. 4. Two refrigerator windows, having four separate sheets of glass and three air spaces in each, are located in the north wall as shown in Figs. 1 and 4. Wind movement in the refrigerated space is obtained by means of three 16-in., specially built, oscillating fans located as shown in Figs. 1 and 2. ILLINOIS ENGINEERING EXPERIMENT STATION 8. Refrigerating Apparatus.-The plant is designed for an oper- ating temperature of zero deg. F. in the cold room when the tempera- ture at the breathing level in the test rooms is 70 deg. F. The tem- perature in the cold space is maintained by means of a 5-ton direct expansion ammonia refrigerating unit of the compressor type, located on the lower floor of the laboratory, as shown in Fig. 2. The compres- sor, which is motor driven and automatically controlled by a thermo- stat placed in the cold room, is shown in Fig. 6 together with the ammonia condenser and receiver. The ammonia is expanded through an automatic expansion valve directly into the coils shown in Figs. 1 and 2. These coils are special, cast-iron refrigerating sections having a total area of 1440 sq. ft. A baffle, shown in Figs. 1 and 2,' was erected between the coils and the test rooms for the purpose of in- creasing the air circulation over the coils and of shielding the walls and windows of the test rooms from direct radiation. 9. Recording Instruments and Thermocouples.-The type of tests conducted in this plant necessitates the accurate duplication and maintenance of conditions over comparatively long periods of time. The selection and installation of apparatus, therefore, had to be based on considerations relative to the adaptability for controlling conditions as well as to accuracy of observations. Figures 1, 2, and 4 show the location of the recording instruments which were installed for the purpose of control. Each test room, and the cold room, has separate instruments and instrument panels. Figure 7 shows the inside of one of the test rooms with the standard in the center of the room supporting the recording instrument bulbs and thermocouples. Three of these bulbs are located in each of the test rooms; one 3 in. above the floor, one at the breathing level, and one 3 in. below the ceiling. In the corner of the test room, Fig. 7, may be seen leads going to the recording instrument bulbs in the attic and basement. One bulb is located in the center of each attic and basement, 3 in. above the ceiling and 3 in. below the floor. Fig- ure 1 shows the location of the three recording instrument bulbs in the cold room, each of which is placed at a height corresponding to the breathing level of the test rooms. Figures 7 and 37 also show the apparatus used for generating fumes and making studies of the air circulation in the test rooms. It consists of a portable standard, supporting three pairs of concentric glass dishes which contain ammonium hydroxide and hydrochloric acid. The vapors from these two chemicals, when allowed to mix, form dense white fumes of ammonium chloride. The clamps and HEATING ROOMS WITH DIRECT STEAM RADIATORS FIG. 7. INSIDE OF EAST TEST ROOM SHOWING FUME GENERATOR AND STANDARD SUPPORTING THERMOCOUPLES AND RECORDING INSTRUMENT BULBS platforms holding the glass dishes may be adjusted on the standard in order to place the dishes at any desired level. The plant is equipped with a complete thermocouple system for the purpose of observing both air and surface temperatures. The use of thermocouples makes it possible to obtain the necessary tem- ILLINOIS ENGINEERING EXPERIMENT STATION FIG. 8. THERMOCOUPLE SWITCHBOARD perature data without entering the rooms or otherwise disturbing the test conditions. It also makes it possible to observe surface temper- atures and certain air temperatures which could not be obtained accurately by means of thermometers. The thermocouples are made of No. 22 B. & S. gage, double cotton-covered copper and constantan wire. The leads from all the couples are formed into cables and con- nected to the switchboard, shown in Fig. 8, which is located on the low- er floor of the laboratory directly beneath the cold room. Figure 7 shows one of the standards supporting six thermocouples used in determining air temperatures at six different elevations in the center of the test rooms. The height at which each one of these thermo- couples is located is shown in Fig. 2. Figures 1 and 2 show the location of thermocouples by means of which the temperature gradients through the walls, floor, and ceiling HEATING ROOMS WITH DIRECT STEAM RADIATORS of the west test room were determined. These figures also show the thermocouples used in determining the temperature of the inside and outside surfaces of the wall back of the radiator, and the thermo- couples located at each recording instrument bulb for the purpose of checking and adjusting these instruments. All thermocouples for ob- serving surface temperatures had the junctions, and approximately 4 in. of the leads on both sides of the junctions, embedded in the surfaces. The wires were placed in a deep scratch in the surface, and were sealed into the surface itself by means of plaster of paris in the case of plaster surfaces, and shellac in the case of wood surfaces. The wires were then filed flush with the surface and thus became an integral part of it. 10. Weighing System.-The condensate weighing system, and the method of regulating the pressure of the steam in the radiators or heating units in the test rooms, is similar to that used in the tests described in Bulletin 169. As shown in Fig. 2, the piping, separator, receiver, weighing tank, and scales are placed on the lower floor of the laboratory, directly beneath the test rooms. Each test room is piped separately and is fully equipped to be operated independently of the other one. Separators are used to remove all entrained moisture from the steam, and mercury manometers are used to indicate the steam pressure. The temperature of the steam just before it enters the radiators is observed by means of thermocouples. Glass sections, 1%6-in. in inside diameter, are installed in the 1/l-in. vertical risers to the lower tappings of the radiators. The condensate leaves the radiators through these same connections, and is collected in receivers having gage columns. The weighing tanks are connected through water seals to the receivers, and the minimum subdivision of the scales used for weighing the condensate is 0.01 pound. The separators, receivers, and piping are all heavily lagged, and the glass sections in the vertical risers are enclosed in triangular glass observation boxes for protection and prevention of heat loss. Each radiator is equipped with a %-in. pipe leading from the tapping for the lower air vent on the last section to the lower floor of the laboratory, where the amount of venting is controlled by means of hand-operated gate valves. 11. Unenclosed Radiators.-The unenclosed radiators used for the tests included in this bulletin were 6-section, 26-inch, 5-tube, cast- iron radiators having rated areas of 21 sq. ft. The surfaces were brushed and painted (not dipped) with two coats of flat black paint. Figure 9 shows one of these radiators located under the curtained ILLINOIS ENGINEERING EXPERIMENT STATION FIG. 9. UNENCLOSED RADIATOR window with a space of 2/1 in. between the back of the radiator and the plaster surface of the exposed wall. 12. Enclosures.-Figures 10 to 21 show the enclosures, covers, and shields tested. In all tables, and in the text, each piece of apparatus tested, whether it is an ordinary enclosure or a cloth shield, is desig- nated as an enclosure. In order to differentiate between them and to simplify the presentation and discussion of results, each enclosure is numbered as shown in these figures. Figure 22 gives the important dimensions of each of the enclosures, including the clearances be- tween them and the radiator. Enclosure No. 1, shown in Fig. 10, is a common commercial type of metal shield. Enclosures Nos. 2, 3, 5, 8, 8a, 9, and 10, shown in Figs. 11, 12, 14, 17, 18, 19, and 20, respectively, are commercial metal enclo- sures of different types. It should be noted in Fig. 22, column F, that the clearance between the top of the radiator and the bottom of the humidifying pan is practically the same in each case. The inside widths and lengths of these various enclosures, given in Fig. 22, col- HEATING ROOMS WITH DIRECT STEAM RADIATORS FIG. 10. ENCLOSURE No. 1 FIG. 11. ENCLOSURE No. 2 ILLINOIS ENGINEERING EXPERIMENT STATION FIG. 12. ENCLOSURE No. 3 FIG. 13. ENCLOSURE No. 4 HEATING ROOMS WITH DIRECT STEAM RADIATORS FIG. 14. 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Co C- Coý 'C " Co ti Co Co9 = Coý Co Co Co C- Co Co Coý Co Co Co ý Co Co Co Co Co Co - Co C ! m ý -I- --ý wco4CoqloNoc C^N^^MMN"" l^NNNCOM^MMNN'^N" *^C'l -CO^'-f OOe'N^OCOM~-OOO ^~Oh-O~Oi - -C Co Co 0Co Co Co0 Co C .-*NO ^tt Wt'OO~O'-l CO Ftc lh-Wai '-'N'^i' ' h. -- .N:88==r. C "too ~ LOC CO Co~o .t-C-C o C(O0'.C-C-- C-l- o~ CoO >C CO1 M 0 01,: CD 0! t0: CO 0 < CO CO C0 tO tC 00 Cl CO C0 1O zo T i Co -0 Co oo - - to CO Co C Co. o Co C ao 000 Co Co 0- . .+++.++ ....+++++++.+++++.+ SC 10 , t o . CO3 0 0 Co P4 0t p E ; tO HZ ~ ~ HEATING ROOMS WITH DIRECT STEAM RADIATORS *Co~om~o~o thoo~otrte~a~o-Co Nt-NOt-'h NO tteq,;t-a corEEcW * cccm Co o C e o oCOe * 4 o Co Co CoCd - o C * t-eq e ot-N t - oeq- - Co~t t~oCoC$ OOOO 0 0 Fý EH oH C-c P; || 3^ ILLINOIS ENGINEERING EXPERIMENT STATION 0Z C, 00 C 4)4 000 000 04 a00 00 004 -40 V5 t 00 0 - 0 1, N 0000 m0,)0 n Ijo <^ co cj ^ ^c ^ cci I pi i fp aHH lxlHHHHHHHS IaB 4))0 00000) 0) 00 0 00 000-000)0 000d)0000 - - - -= ~~3 0))0))0)00)0 .0- * . . . 000)O0000 * . . . . . . . . . . . . . . . . . . .f- *0 - .- .- - - -Oc- -o · - **** to m m* m o oc o o 53 o t- lo lo a wc oo *o -o oo t- to * a *ý : * to t- o a * oo" ooaco .*t o L.o .a . m .o L. o co m* o .I * *3 * *0)0* 0** 0-0**OOO ) 00 .00 . .0 . 0 0 00 000 *0) 0 o 00 -0 I %'00 0) « !a u 07 HEATING ROOMS WITH DIRECT STEAM RADIATORS N qN NNnN MN NN ciCNNN cqNNNNNN NN NNNC 3iii aiiaii . ii i...ii ..ii i. .. 0301~0)000000N -m0c00^00^ * >0t0c00 0N000.NOC4 -q * '3JJ * **'*^-<-NNCrd~0e100(t(5t-hmOiqlO~~-l-OOO lOO'-lM^ I 0, ...... -- -- * 0000000000000O<00000C00000000NN00O00OOOOOOOOOO000OO 9 A z NcdiA c44ds2 I^qx 21 b"X- ^ 4 'q.1 "1 C4" 4" i^, 4q "4 0000000- 00000000.-thttA -0,.0N0000 000h-.000 0000 'i»-00».00,00 I L -L tt -- t- - *-> >f~ftt^ 0 *^ 00 00 .0<0.-iM t00 00000000N00000 ^ 0 ®t. a)0-0..00 cq000c00p EW gg ..00OhQ C 0O~kd0m0N ~0000 m0 Q 000N000000 00 - - - - - - -~0.00000000000000 ~000 0 E 0 0,. Ot aab ~ §1 ENGINEERING EXPERIMENT STATION N- VC Co -400 Co CoO C-C-Co C- I:O 'C) Co 0)000) Co 0000)1 C-C '190 C- Co Coo) CoC g'doi^OOOSOOd~d ~~didl^iO^'OiNOO~^QOO~aOt^; o6 6 qc;ii tý c C- 0)4m()Cc Ccot 000c0 C- 00000w 0) m 0O = m o -4-4imo~ 19 00 ll1 C- 0-4 C- -4-400-4 C- 1C 04 Cý 11o -40 C-ý 0-0 ý Co ý Co ') Co C- 1 X0C oC))oC o o 00O 000 Ci O1ý1 C- 0): C Ci 0ý -ý -4 C! 0! 1o C- t7 1- 1ý Co Co: C- Co Co 09-4 "o ll4 - ý Co * OC-oo0C~CCCCOOObOa>0-C'ltOS~oC~ t-00Cto03 OtO|o>lfOot-lQO^.«0oCO- ýX-1*0=OOSOýNOt-OWMOiM-^OOlt-^OiWht-tDO'-ih-OsOO-^l ColOtoo Co o^o)0OoCOCOIC~tOoio~totNoto CoDo^oO~O0Q0C~Oto00C m- W C-lo C- C- C-o Co Co " Co C- t-)0 C- Co m - C-o C o n t- Co C- C- Do o CCoCCoCCoo Co Co CoD CoD Co Coo Co Co CoCot Co Co Co Co Co Co Co CoCoCo Co CoCoo w0o0 Zo=o)= 0Co - -Coo oo)Cq- otCot C t- tC- o Q Cooo m 4 c- i0)0>o0 Co Co C~itflo Co io Co Co >0 Co o'oio' Coi D Co Co ' m M o)) 0 o 0 CO CCCCCoN Co t Co Co Co 0 Cq o r- CoCoCo C- 0)'1) oSS- Co lCioLCo Ct~t~traxso0)C-0C-Co oC-C ioioioC-, -oC ~oio o'o' ~~os -4-4 mmm÷÷OORAMwwmmQ~÷÷÷÷mmAMWH÷÷÷÷÷÷ l io-ColNCOColCoCo0 00Coo - 0l0 Co o I I ..i.I I. I . I I I . III. III l.III ILLINOIS 4 0 C0 s.l I's ·-.aol CO 0 z c3 0 'C) CO Co ,-40,4CO iCoO m o bOC-0'C omoC-CO 333ilt-l^ liNllintNNMNMiliiNNMM| 0) ¶ NC)TTNNOC. .4,4CNoNo-- CoNoNNoNoN ------------ ------ HEATING ROOMS WITH DIRECT STEAM RADIATORS C 0 0'00 1 -0 000 00 C0C000 0 00 0000i CS00 c R - 10 000 0000 OS » c 00 C< CO Oi.,0 00 00000000000000-0000000000dd 0000 --00000000000000000 m00N Nme09-O0mo N " 0 I " Om- Ommm 000000000000000000000000 0000000 00000000000000000000000000000000000000000000000000000000 0 000 0C MN 0 O M ON 000 00 0 0000 .O 0! 00 (NN $Nir-MMNCO^dO-'w2MiddCO-^-'WOOi 0oDt- 0000000000000N OO 0 O000000000 0000N00000 00 00000000000000N000000000000000000IR i ! I cl c cl cl o N" 000000 Nm 0m00000000000r N3nm -030N0N-000N0N0N --0m otccc===cOm 0=o ==-COO O-moC -r- tf^^eMEESia ESBScoScEOSUSSEioSBOGESUBZEE$i'co^^' 0 N o00 o000004-00c!-!00 N q0000000000 0 N: 0 0000000000 "0lO=-) 0 0 L- 00000000000o000 0 0O 0 00 o-l c ocmo==m=ýmQco0o= o Cve wo8cow cc (O^ OMMCMMMMc MMtWe WWtWWO WW t M 0"'"" wwCOM -Ci II Im S* * *NNN -0000000 N000-0000000 N g m0000000000000N 000. 0 ----- ---000000000000000000000 0 re 8,~ ~ 00000 Q z *si s'sa ls3.S ~g .d g 00 S'"' 0 *0)0. ffl~0 I ) I I I 1 ) I I ) ILLINOIS ENGINEERING EXPERIMENT STATION o I I I I II Crd/d' a m Te7vw 1,40 1a I / / -/4 -/./ / /// 3 4 5 6 7 8 9 He/h A1 ,bove F/oor //7e FIG. 23. RooM TEMPERATURE GRADIENT AND STEAM CONDENSING RATE FOR RADIATOR WITH ENCLOSURE NO. 2 IN WEST TEST ROOM Col/ Room Tem/p. ?' .deg. F l 4. 7/ /b., Enc/sure Vo. 3, Tes E -6 I54 I .4, ?enc/osed R'ad'/or, TesR-s et lbt' of' Ste;a& Co-,na~ed e . l l I .. ' c/ se.'r No.3 -- --- -- -.. - ----"--- ---I I- ST _ __mpera __ gm.,,3~ Helghf Above F/oor n Feet FIG. 24. RoOM TEMPERATURE GRADIENT AND STEAM CONDENSING RATE FOR RADIATOR WITH ENCLOSURE NO. 3 IN WEST TEST ROOM I- z2 m D M~ M l of Sfe'm' Cotid~ - C/t~e~c/osed 9ardLz I' -0.7 -I.I tO -60 d^ 4.9 /b., Enc/osure No 2, Test E-3 I ITT S5.44, L/&onc'se'c/o'r & Tesf -8 - - - S/er '' Te1_ e a' I ½ =^^=^ --- -- -/ I ^ - . ~ r d rl In II -r rl I /r C, I n -I rrl rr / fc HEATING ROOMS WITH DIRECT STEAM RADIATORS 4bo At~ve ~F/oar A /i7 e$ FIG. 25. ROOM TEMPERATURE GRADIENT AND STEAM CONDENSING RATE FOR RADIATOR WITH ENCLOSURE NO. 9 IN WEST TEST ROOM He/ghf Abokve IFoor ,// FEe~ FIG. 26. RooM TEMPERATURE GRADIENTS AND STEAM CONDENSING RATES FOR RADIATOR WITH ENCLOSURES NOS. 8 AND 8a IN EAST TEST ROOM ILLINOIS ENGINEERING EXPERIMENT STATION FIG. 27. ROOM TEMPERATURE GRADIENTS AND STEAM CONDENSING RATES FOR RADIATOR WITH ENCLOSURES NOS. 10 AND 11 IN WEST TEST ROOM ; I l i i I Ii i I I -5 -/S U 23 4 79/4, E7ncosure //o. So, Te~s EZ'-3 468/ , Enc/osure Noa 5, T7es E- 7 s. U/wc/ose? /a4d/R7/ot, T/s,- '/I Thlil /0 6 7 8 9 F/oor /7 Feef // /2 FIG. 28. ROOM TEMPERATURE GRADIENTS AND STEAM CONDENSING RATES FOR RADIATOR WITH ENCLOSURES NOS. 5 AND 5a IN EAST TEST ROOM y K K6 ,! C 70 JT^ I I II I 0/5h Zes;- I- I __ H83rem/mea1 "-/ O I K 01 / 2 I _ z I olf I/7 s /^iplS'^'i ^ A i 1 Z ^ 32 I .nc/osure ANo. 5" (Low Ze(s)II I I He/gh7 Above- F/oor /;h Feet "JfJ I I I I I .5 1 I I ZJ& ; .... I I * I I I I --- He/lgý7t Above ! I HEATING ROOMS WITH DIRECT STEAM RADIATORS FIG. 29. ROOM TEMPERATURE GRADIENT AND STEAM CONDENSING RATE FOR RADIATOR WITH ENCLOSURE NO. 1 IN WEST TEST ROOM -/ 0( -Co/d ,oo0 Tem ./,' deq. Ale/ /b of St'ea~'w Coa^zw ^ V7e/7£'/