Document YXaVDmk65VzeO9NbJmMeL4yk

292 CHAPTER 12 1952 Guide " Table 19.. Values op Y to be Used with Factors in Table 18 and Table 20 in the Determination op Instantaneous Rates op Heat Gain Due to Convection and Radiation fob Vabious Types op Single Glass and Combinations of Two Sheets' op Glass Spaced at i in. For Clear Atmospheres and 18 Deg Declination, North (August 1) Sun Time Values of Y in Btu per (hr)- (sq ft)* N NE E SE S ' SW W NW Horiz. 5 a.m. 6 7 8 9 10 11 . 12 1 p.m. 2 3 4 5 6 7 40 Degrees North Latitude 00 4 16 2 24 2 . 22 2 16 3 5. 33 33 3. 3 33 33 33 2 4 2 X 00 1 18 30 33 / 30 25 12 3 3 3 3 3. 2 1 0 0 9 20 25 29. 27 21 15 3 3 3 3 2 1 0 0 1 2 _ 2 8 14 18 19 19 16 10 4 2 1 0 0 1 2 2 3 3 3 12 22 27 30 29 23 14 2 0 -0 11 22 2. 2 33 33 33 3 .3 10 3 24 4 31 . 15 36 23 34 * 27 24 21` 33 0 3 11 21 32 37 42 45 44 41 35 26 17' 6. 1 Sun Time Latitude s sSE SW Sun Time Latitude SE SW 5 a.m. 6 7 8 - 9 10 11 12 1 p.m. 2 3 4 5 6 7 30b Degrees North Latitude 0 0 0. 5 a.m. 7. 1 . 1 6 18 2 2 7 22 2 2 8 24 3 3 9 2. .0 13 - 1 .0 1 22 2 2 28 3 2 30 13 . . 3 22 16 6 3 3 5 7 9 9 6 3 10 3 11 4 12 14 1 p.m. 21 . 2 50b Degrees North Latitude 31 27 20 9 3 20 25 27 25 22 3 5. 17 26 32 3 5 27 3 3 3 26 4 2 2 21 5 1 1 11 5 0 0 07 3 16 33 2 7 31 2 2- 26 1 1 17 007 * Values of 7 for 8 and 9 pm. are zero. b For N, NE, E, W, NW and horizontal use 40 deg North Latitude values. the corresponding Table 17 values. The total instantaneous heat gain is the sum of the gain due to transmitted solar, radiation and the gain by convection and radiation. ` The values given in Tables 20 and 21 are based upon an A.S.H.V.E. research paper20 to which the reader is directed for additional data. The values in Tables 20 and 21 may be used with fair precision for other pat terns of similar transmittance and surface characteristics. For example, the data for hammered glass may be used for glass having shallow, closely- ' spaced ribs or for glass having small, closely-spaced circular indentations. Because some patterns have distinct. orientation properties, no attempt has been made to give values for non-vertical glass. Design Tables for Glass Block Walls Tables 23 and 24 give design values of instantaneous rates of heat gain for sunlit walls of Type I pattern 8-in. hollow glass block for a solar de clination of 18 deg (see Table 22 for description of block patterns). These tables are based upon the solar intensity values for a clear atmosphere as given in Table 5. 'For solar energy transmittance data the reader is referred to reference 18. Table 23 presents values of transmitted direct Cooling Load -293 Table 20. Application Factors to Apply to Tables 17. and-. 19.to Obtain In stantaneous Rates of Heat Gain fob Vertical Single Sheets op Rolled Figured Glass -Having Normal Incidence Transmittances and Listed Thicknesses (Smooth Side Indoors, Figured Side Outdoors) J(See Table SI for Factors to Apply to Table 16 Values). Glass Pattern Normal Incidence .Transmittance Thickness, Inches Factor to Applt to Table 17 Hammered Hammered, etched both sides Deep ribs on } in. centers Hammered heat absorbing . Hammered heat absorbing, etched both sides 0.75 0.67 0.77 approx. 0.21 0.14 1.0(X) + 0.50(F)b' Hi 1.0(X) +0.65(Y)d i.0(X) +0.60 Y),' a l.om +i.i5(i9' H 1.000 + 1.40(F) * X values are.Table 17 values b Y values are Table 19 values c Use 0.40(F) for east and west glass Use 0.60( F) for east and west gift** * Use 0.35(F) for east and west glass Use 0.95( F) for south gift.*** Table 21. Instantaneous Rates, of Heat Gain Due to Transmitted Direct and Diffuse Solar Radiation by Unshaded Rolled Figured Glass- Multiply the Table 16 Values by These Percentage Factors For Clear Atmospheres and 18 Degrees Declination, North (August 1) For SO, Ifi, and B0 Degrees North Latitude Note: To obtain total instantaneous heat gain add adjusted Table 16 values to adjusted Table 17 values Instantaneous Heat Gain Due to Transmitted Solar Radiation as a Percentage op Single Sheet op Common Window Glass Sun Tims Hammered Hammered and Etched AM . ; N, NW W, SW NE* E SE s N, NW . W,SW NE E SE S 5 a.m. 6 7 8 10 11 .7 p.m. 6 5 4 3 2 1 80 80 85 70 80 80 85 85 75 80 60 '65 75 55 60 60 65 75 50 60 80 80 85 80 80 60 60 70 : 55 60 80 75 85 80 75 80 60 80 80 60 60 -60 55 65 55 60 50 55 55 50 80 65 75 75 65 60 55 50 55 50 80 80 60 70 65* 60 60 50 50 50 80 80. 80 60 65* 60 60 60 50 50 Sun Time 5 a.m. 9 7 p.m. 6 5 4 .3 2 1 Ribs.on i In. Centers Hammered Heat Absorbing 60 . 75 85 25 60 25 20 25 20 25 60 80 85 30 60 25 20 25 20 25 60 65 85 40 60 25 20 25 20 25 60 40 80 50 55 . 25 . 20 20 20 . 25 60 30 70 55 35 25 20 20 20 20 60 40 40 55 35 25 20 20 20 - 20 60 60 - 35 40 35b 25 25 20 20 20 60 60 60 35 45b . . 25, . 25 25 20 20 t PM-> N. NE NW W SW S E, SE N. NE NW `w ` SW S E, SE AM. 1 5 a.m. 8 10 11 12 7 p.m. 6 5 4 3 1 t PM-> Hammered and Etched Heat Absorbing N, NW W, SW NE E SE .8 20 15 15 10 20 20 . 15 15 10 20 20 10 15 10 20 20 20 20 10 15 10 20 10 10 10 10 15 10 10 10 20 20 10 10 10 20 20 20 10 10 N, NE NW W SW S E. SE * Decrease values 10 percent for 30 deg latitude: increase 15 percent for 50 deg latitude b Increase values 30 percent for 50 deg latitude