Document DGQQzjpGdDEJeyd60m81Yy4Ea

192 CHAPTER 13 1959 Guide Table 20 .... Instantaneous Rates of Heat Gain Due to Transmitted Direct and Diffuse Solar Radiation by Unshaded Walls of 8-in. Hollow Glass Block of Types II, HI, IV, IVA and V Patterns MnrtMv A. TWhU 1? fmf Typ- i hy Tkes; p-TM-*--- Fosters for dear Ahnorphere* and 18 Dog Dedinatron, North [August ?} For 30, 40, and 50 Dog North Latitude Note To obfem total hsstaataneous heat goto odd adjusted Table 19 vatuat to the rafale 21 mfciat tiutuufuunou* Heat Gam Due to Tr as a Percentage of Type I Pattern Son flaw Typo II fattens Type tit fatten AM --. i 5 a.m. 6 7 8 9 10 U 7 pjn. 6 5 4 3 2 1 t PM -- . w, sw 100 100 100 100 100 100 100 100 N, NE, E,SE NE 100 100 95 95 90 90 95 90 95 85 95 . 95 100 95 100 100 NW W 100 90 90 90 90 95 95 100 SW S 100 100 100 100 90 95 100 100 s w, sw SE 70 70 70 70 65 65 70 65 60 65 70 65 70 65 65 70 70 70 70 70 70 70 70 70 75 N, NE, E SE NW w SW S 90 S Son Tksse AM --* i S a.m. 7 pan. 75 93 t PM --* Typo (V fattens Type IVA fattens N, NW, w, sw NE sSE N, NW, w, sw NE E SE S 55 55 55 55 55 55 55 55 N, NE, E.SE 45 45 45 45 50 55 55 55 NW 35 75 35 80 35 '60 30 40 25 30 35 30 45 35 55 50 w SW 55 55 55 55 60 50 40 45 S 55 55 55 55 55 55 55 55 N, NE, Ej SE 45 35 35 45 50 55 55 55 NW 35 40 65 85 90 55 100 115 W SW S Sun Tint l 5 a.m. 6 7. 8 9 10 11 12 7 p.m. 6 5 4 3 2 1 T PM - Type V Pattens N, NW, W, SW NE 60 35 60 35 60 35 60 50 60 80 60 70 60 60 60 60 N, NE, E,SE NW E 35 35 40 65 90 105 80 60 W SE 30 30 35 50 90 105 110 85 SW S 60 60 60 60 60 90 105* 115* Designation of Block Type III--Light Diffusing --Light Diffusion IVA--Light Diffusing $ * Reduea by 30% (or 30 dec N latitude only. ' simultaneous occurrence of. peak loads, is diversity. Typical of this is the case of a large department store where the air handling equipment serving a certain space must be sufficient to handle the load created by the throngs of people attend ing sales in that space. Under such a condition the number of people in other spaces is usually normal or below. While this means that the air-handling equipment for certain departments must be large enough to cope with the situation, the refrigeration equipment need be only large enough to handle the average maximum. If a system employing zone recirculating fans and a single central fan and Hehnmidifier were used, the saving would be reflected in the capacity of the central fan and dehumidifier. Another example of this diversity is found in an office building having restaurants and stores of certain types in the first story and basement. Cooling Load 193 Table 21.... Instantaneous Rates of Heat Gain by Convection and Radiation from Unshaded Wails of 8-in. Hollow Glass Block of Patterns Type I, II, 111, IV, IVA and V* For Clear Atmospheres and 18 Dag PocEncticn, North [August I) For 80 P Indoor Temperature Note For Mol instantaneous heal gam odd these values to values in Table 17, or Tabla 19 adjusted by Table 20 factor* Sun Tim Dry-bulb Fate. latitude Instantaneous Heat Gain its Btu per (hr) (*q M N NE Sf s sw w 6 7 8 9 10 11 12 2 .3 4 5 6 7 -8 9 74 -3 -3 -3 -3 -3 -3 -3 74 0 3 4* 3 -2 -2 -2 75 1 15 17* 13 -1 -1 -1 77 0 21 26* 21 1- 0 0 80 0 20 33 27 5 1 2 83 2 12 36 32 12 3 3 87 4 6 29 32 19 5 6 90 40 6 8 16 28 23 9 8 93 Degrees 8 10 14 14 26 25 12 94 North 9 10 15 11 25 37 28 95 11 11 16 11 21 44 41 94 11 11 15 11 16 45 44 93 11 10 13 10 13 43 42* 91 13 9 11 9 11 35 35* 87 11 . 7 8 7 8 19 21* 85 7 4 4 4 4 7 7 83 4 3 2 3 2 3 4 NW -3 -2 -1 0 1 3 5 7 9 11 17 30 35 29 15 4 3 Sun Tim Dry-Sulfa latitude SE S SW latitude SE S SW 6 7 8 9 10 11 12 1 p.m. 2 74 -3 -3 -3 -3 -3 -3 74 1 -2 -2 5 -2 -2 75 11 -1 -- 1 13 -1 -l 77 20 0 0 21 0 0 80 26 1 2 27 6 1 83 29 4 4 32 15 2 87 26 8 5 35 22 4 90 30* 18 12 7 50* 33 28 17 93 Degrees 10- ' 15 16 Degrees 23 31 31 94 North 11 16 30 North 12 32 39 3 95 4 94 5 93 6 91 7 87 8 85 9 83 12 14 39 12 13 43 11 11 41 . 10 9 32 6 6 15 446 333 11 28 43 11 20 44 10 12 43 9 10 36 7 7 23 4 4 10 333 * For types HI. IV, IVA sad V patterns end 30, 40 end 50 deg latitudes, multiply seat w&Q values (or 0, 7 sad 6 s.m. by 1.40, sad west wall values for 5, 0 and 7 pjn. by 1.25. * For N, NE. E, W and NW use 40 deg North Latitude values. At noon, when the restaurants and stores are crowded, the offices are below normal occupancy. Heat lag should be carefully considered in the cooling load calculations. In certain types of buildings the effect of solar radiation is still apparent several hours after the sun has shifted from that exposure. In other types having a much ,lighter construction, the heat gain due to solar radia tion decreases markedly with the passing of the sun. Some walls, warmed by the sun, may radiate heat long after the passing of the sun, thus requiring lower indoor temperatures to offset the radiant energy. Buddings have considerable heat storage capacity which can often be utilized to great advantage, and which has. provided an unexpected safety factor in many installations. If a space is kept below the design indoor temperature for some time, the interior walls, floors, furniture, and fixtures begin to assume the temperature of the space. Where the time is sufficient the' entire mass, 'rather than merely its surface, may reach the room temperature. Thus, when a space has been precooled below the design maximum ternperature for a period of time prior to the advent of the peak load, and the heat gain begins to increase to peak conditions, some of the increase is used in raising the temperature of the furniture, fixtures, etc., to the design conditions and the cooling load can be reduced accordingly. However, unless very accurate data with regard to the mass, surface, specific heat, etc., of the items within the space are available, due caution must be used in discounting the cooling load for this storage effect. In the absence of reliable data this allowance is often a matter of experience rather than calculation. ^