Document 5LKJ8j0QpKZZBEkxD93GXBOXz

280 CHAPTER 15 1946 Guide -100 3 90 Ui a-. 8'0 70 'Design temperature SUN TIME. AUGUST 1 Fig. 4. Outside Design Temperature Basis for Figs. 2 and 3 and 3 give the heat flow through the inside surface of roofs 6 with details of the construction of the roofs tested. The conditions for which these' results are given are: solar radiation for 40 deg north latitude on August 1 as given in Fig. 1, outdoor design temperature reaching a maximum,of 95 F as shown in Fig. 4, and an indoor temperature of 75 F. Due to devi ations in the tests from design temperature, solar conditions, and typical construction it is believed that the values from Figs. 2 and 3, as well as from Figs. 5, 6, 7, and 8 for walls, may be as much as 20 to 30 per cent below normal design expectations. Curves in Figs. 5, .6, 7 and 8 were prepared by the A.S.H.V.E. Lab oratory from tests made there and show the heat flow through the inside surface of three types of walls for various orientations 5.. The results are given for the following conditions: 90 per cent of the solar radiation given in Fig. 1 for 40 deg north latitude on August 1; outdoor design tempera ture reaching a maximum .of 95 F, as shown in Fig. 4, and an indoor tem perature of 78 F and 50 per cent relative humidity.... The heat flow shown in Figs. 2, 3, 5, 6, 7 and 8 is a combination of normal transmission and solar radiation-transmission and is the-total heat flow through the wall or roof. Due to. the heat capacity of walls and roofs there is a time lag 2 in the transmission of heat through them as shown by the curves. For the types of construction covered, in these ljgures arid for the conditions indicated, the heat flow through, the inside surface at any given, time can be read directly. ' ,For other types of con struction, the curves may be used as a guide in estimating the heat flow. Table 3. Time Lag in Transmission of Solar Radiation Through Walls and Roofs \Type and Thickness op Wau, or Roof Time Lag, Hours 1-in. yellow pine horizontal roof, water proofing, smooth blackiinish_____ 1 2-in. yellow pine horizontal roof, water proofing, smooth black finish 4-inl reinforced clav tile horizontal roof, water nroofinv. slav finish 2-in. gypsum horizontal roof, water proofing. slap finish Slate and slaters felt on 2J in. tongue and grooved yellow pine, sloped roof 4-imgypsum horizontal roof, water proofing, slag finish.._________ ____ _ m 2)4 2K 2H 4)4 6-in. concrete horizontal roof, water proofing, slap finish 5 1-in. concrete, 4-in. cinders, lM-in. concrete, water proofing, smooth black n finish:. Wood siding. 1-in. sheathing. 2 x 4 studs, lath and plaster 8, 2- Wood siding, 1-in. sheathing, 2x4studs (studding'space filled with insula tion) lath and plaster....................... ....... 5 4-in. bricky 1-in. sheathing, 2 x 4 studs, lath and Dlaster. .7 4-in. brick, 8-in. tile and plaster........................ l................ ,,.... lS^in. brick, plastered. -- . .... .......................... . . . ioh 12 : 9-ini brick, 3%-in. tile, 5)4-in. air space; 3)4-iiL tile and 134-in. plaster.... . 16 ' . HEAT PLOW - B.T.U. PER SQFT. PER HOUR Cooling load Fig. 5. Heat Flow-Time Relationship for Northern Exposed Walls Fig. 6. Heat Flow-Time Relationship fqr Eastern Exposed Walls Fig. 7. : Heat Flow-Time Relationship for Southern Exposed Walls'