Document B8x1v3gayog5RrZ1apEe1DmGJ

282 CHAPTER 12 1957 Guide Electric Motors and Machinery Motors and the machinery which they drive, if both are located in the room, convert all of the electrical energy supplied into heat. This heat is retained in the room if the product manufactured'is not removed until its temperature is the. same as the room temperature. If power is transmitted to the machinery from the outside, then only -the heat equivalent of the brake horsepower supplied is used. In some mills this is the chief source of heating, and it is frequently sufficient to overheat the building even in zero weather, thus requiring cooling by ventilation the year round. Table 7 shows the heat output equivalent Table 7. Heat Equivalents'of Various Sources* Machinery (Motor in room) = Motor Hp/efficiency x 2544 Btu/hr. Machinery (Motor outside room) = Motor Hp x 2544 Btu/hr. Electric Lights = Kilowatts x 3413 Btu/hr. Gas (Producer = 150) (Manufactured = 535) (Natural = 1000) Btu/cu ft. * Additional values are given in Chapter 13, Table 26. of various sources of heat in a factory. For information concerning the heat supplied by persons, refer to data given in Chapter 6, and also Table 25, Chapter 13. For appliances see Table 26, Chapter 13. INTERMITTENTLY HEATED BUILDINGS In the case of intermittently heated buildings additional heat is required for raising the temperature of the air, the building materials and the ma terial contents of the building to the specified inside temperature. The rate at which this additional heat must be supplied depends upon the heat capacity of the structure and its material contents, and upon the time in which these are to be heated.15 This additional heat may be computed and allowed for as conditions re quire, but inasmuch as the heating system proportioned for taking care of the heat losses will usually have a capacity about 100 percent greater than that required for average winter weather, and inasmuch as most buildings may either be continuously heated or have more time allowed for heating up during the few minimum temperature days, no allowance usually is made, except in the size of boilers or furnaces. For churches, auditoriums and other intermittently heated buildings, additional capacity should be provided. RESIDENCE HEAT LOSS PROBLEMS The following Examples 6 and 7 will illustrate the procedure for calcu lating the heat loss of a residence, uninsulated and insulated, in accordance with the recommendations given in this chapter. Example 6: Calculate the heat loss of the residence shown in Fig. 2 located in the vicinity of Chicago. From Table 1, design outdoor conditions are --10 F and 12 n>P" wind velocity. Inside temperature from Table 2 is assumed to be 70 F. The attic unheated. Assume ground temperature to be 50 F (see Fig. 3, Chapter 34) unde basement and garage floors and 32 F adjoining basement walls. Estimate infiltratifh losses by the air change method. No wall, ceiling or roof insulation is to be cob; sidered in this problem, but all first and second floor windows, except in the garage, Heating Load 283 Table 8. LossHeat Calculation Sheet for Uninsulated Residence (Fig. 2) A Room ob Space Bedroom A and Closet Bedroom B and Closet Bedroom C and Closet Bedroom D and Closet Bathroom 1 Bathroom 2 Living Room Dining Room Kitchen and Entrance to Garage Layette and Vestibule Entrance Hall Garage Room? |B C DE Part of Structure or Infiltration Air Changes Net Area or Air Volume CoSPFI ClENT Temp. Diff. Walls Glass Ceiling Infiltration (H)* 238 sq ft 40 sq ft 252 sq ft 1510 cfh* 0.29 0.45 0.74 0.018 so 80 ^ 39.8** 80 Walls Glass Ceiling Infiltration ($$)* 156 sq ft 40 sq ft 170 sq.ft 1020cfhb 0.29 0.45 0.74 0.018 80 8 39.8** 80 Walla Glass Ceiling Infiltration ($) 114 sq ft 27 sq ft 129 sq ft 874cfhb 0.29 0.45 0.74 0.018 80 80 39.8* 80 Walla Glass Ceiling Floor over garage Infiltration (K)* 118 sq ft 20 sq ft 110 sq ft 110 sq.ft 660cfhb 0.29 0.45 0.74 0.26 0.018 80 . 80 39.8* 35* 80 Walls Glass Ceiling Infiltration (l)c 30 sq ft 14 sq ft 55 so ft 440cfnb 0.29 0.45 0.74 0.018 80 8 . 39.8** 80 Walls Glass Ceiling Floor over garage Infiltration (1)* 79 sq ft 9 sq ft 35 sq ft 35 sq.ft 280ofhb 0.26 0.45 0.74 0.26 0.018 80 8^ 39.8* 35 80 Walls Walls (adjoining garage) Glass Floor Infiltration (lH)b 267 sq ft 94 sq ft 50 sq ft 294 sq.ft 3715 cfhb 0.29. 0.391 0.45 0.018 80 35 80 . 80 Walls Glass (doors) Glass (windows) Floor Infiltration (1V$)* 166 sq ft 35 sq ft 20 sq ft 168 sq.ft 2140 cfhb 0.29 0.85 0.45 0.018 80 80 80 80 Walls Glass Door Floor Infiltration OH)* 96 sq ft 51 sq ft 18 sq ft 17 sq ft 125 sq.ft 1595cfhb 0.29. 0.39f 0.45 0.51 0.018 80 35 80 35 80 Walla Walls (adjoining garage) Glass Door Floor Infiltration (lH)k 82 sq ft 85 sq ft 9 sq ft 19 aq ft 30 sq ft . 383cfhb 0.29. 0.391 0.45 0.51 0.018 80 35 80 80 80 Walls Door Ceiling* Infiltration (2)1 39 sq ft 21 aq ft 87 sq ft U10cfhb 0.29 0.38 0.74 0.018 80 3809.8~4* 80 Walls Glass Doors Infiltration (1H)" Floor Gain adjoining rooms 167 aq ft 63 sq ft 2360 efU* 29 fta 0.29 1.13 0.51 0.018 0.81 45 45 45 45 45 Walls Glass Floor Infiltration (l)a 220 sq ft 8 aq ft 287 sq ft 2010 an 0.10 1.13 0.10 0.018 38 80 20 80 F1 G Heat Loss (Btu per hour) Totals (Btu per hour) 5520 1440 7410 2180 16,550 3620 1440 5000 1470 11,530 2650 970 . 3800 1260 2740 . 720 3240 960** 950 690 500 1620 630 8,680 8.610 3.440 1640 320 1060 320* 400 3,740 6200 1280p 1800 5400 14,680 3850 2380 720 . 3080 . 10,030 2220 700* 650 300 . 2300 6,170 1900 1160* 320 780 560 4,710 900 640 2560 1600 6,700 2180 2700 1010 1910 1060 -4420* 4,450 840 720 570 . 2890 6.020 ; TOTAL 103.310