Document MMLBzE5qgvr9bMMZR5KkzkgO9

194 CHAPTER 13 1959 Guide Table 22 . -- Instantaneous Rates of Heat Gain Due to Transmitted Direct and Diffuse Solar Radiation by Unshaded Skylights of Hollow Glass Block of Types VI and VII Patterns For Char Atmotphero* and 18 Oeg Oecfinafion, North (Auguxf I) Not*: For total fattantoneam boot gain add thta ratuei to Table 23 vafoes in 6to par (hr) (cq ft)* Sun Tom 5 a.m. 6 7 8 7 p.m. 6 5 4 Typo VI North Latitude 30 40 50 001 3 .4 4 7 87 11 13 14 93 20 2 11 1 12 19 19 20 29 23 22 38 26 23 37 27 22 * Valaee for Type VI are for [nl ae aaeembtod. Velaee for Type Vll are far glaee Typo VTI North latitude 30 40 00 34 10 11 19 19 31 29 41 38 49 44 52 46 only. See text. 50 1 5 11 18 26 33 3839 Sun lime 5 a.m. 6 7 8 7 pjn. 6 5 4 93 10 2 11 1 12 Table 23 .... Instantaneous Rates of Heat Gain by Convection and Radiation from Unshaded Skylights of Hollow Glass Block of Types VI and VII Patterns For Clear Atmosphere and 18 Oep OacErrifiM, North (Aogod f) For 80 F Indoor finiii)iiunfiiio Wolgs For total imtontonaoui hoof gain, add these wsfaea to Table 22 vaftres____________ Inrtonfonoout Heal Gain in 8lw per (M {*q ft)* Sun T7me 5 a.m. 6 7 8 Typo VI North latitude 30 40 50 -9 -9 -9 -9 -9 -9 -9 -9 -8 -7 -5 -4 Typo VI/ North latitude 30 40 -9 -9 -9 -9 -9 -9 -7 -7 9 4 5524 10 14 14 13 11 11 11 21 21 19 *16 16 12 29 27 25 20 20 1 p.m. 2 3 4 34 32 29 25 23 37 34 31 27 26 37 35 32 28 28 34 32 29 26 25 5 29 28 26 24 23 6 22 22 22 20 20 7 14 14 14 13 13 * Valaee far Type VI are for pond ae arurmbled. Values far Type VU an for gbes Mn-e only. See text. 50 -9 -9 -9 -5 4 11 15 17 22 24' 25 22 22 19 13 Son Tine 6 7 8 9 10 11 12 2 3 4 5 6 7 Table 24 .... Approximate Corrections to Tables 13 and 21 for Deviations from Indoor and Outdoor Design Temperatures For aeh degroe the design room toeiperatare exceeds 80 F, mbfroct cor rection.* For eadi degree (ho deagn outdoor dry-bulb temperature exceeds 95 F, add correction." Apply these corrections to each value fa Table 13 or Table 21. Glass Typo Correction Btu per (hr) (sq ft) Single flat or rolled figured glass Doable fiat glass aod glass block 1.0 0.5 If tempenta b ksi than 80 F, add correction. b if temperature b km than 03 F, subtract correction. Where air-conditioning supply and return ducts pass through unconditioned spaces, there will be a transfer of heat from these spaces to the air in the ducts, even though these ducts are well insulated. An allowance should be made for (his heat gain and included in the heat estimate bo that air can be supplied at a temperature low enough to offset the rise caused by this heat gain (see Chapter 21). There will also be some heat gain to the air in ducts pairing through conditioned spaces, but since a cooling effect is produced in the space through which the duct paggp^ this is not a loss and usually can be compensated for by adjustment of air quantities between the various spaces. No comprehensive data are presently available for use in deagn load estimates to evaluate the interior load-lag Cooling Load Table 25___ Shade Factors for Various Types of Shading Type of Sbodfag Flaith on Side Expowd to Sun Canvas awning sides open Canvas awning top ana sides tight against building Inside roller shade, fully drawn* Inside roller shade, fully drawn* Inside roller shade, fully drawn* Dark or medium Dark or medium White, cream Medium Dark Inside roller shade, half drawn* Inside roller shade, half drawn* Inside roller shade, half drawn* Inside Venetian blind, slats set at 45 deg*1 Inside Venetian blind, slats set at 45 degb White, cream Medium Dark White, cream Diffuse reflecting aluminum metal Inside Venetian blind, slats set at 45 deg* Inside Venetian blind, slats set at 45 deg6 Outside Venetian blind, slats set at 45 degb Outside Venetian blind, slats set at 45 deg6* * extended as awning fully covering window Outside Venetian blind, slats set at 45 deg, extended as awn ing covering of window* Medium Dark White, cream White, cream White, cream 195 0.25 0.35 0.41` 0.62 0.81 0.71 0.81 0.91 0.56' 0.45* 0.65* 0.75' 0.15* 0.15* 0.43 Outside shading screen, solar altitude 10 deg Outside shading screen, solar altitude 20 deg Outside shading screen, solar altitude 30 deg * Outside shading screen, solar altitude, above 40 deg 0.46 0.35 0.24 * Roller ore assumed to be opoqoe. ft""* white may transmit considerable color radiation. Far white translucent shades fully drawn use 0 55 and (or half drawn use 0.77. b Venetian are folly drawn afa cover window. It is ?-----ri nt the occupant will adjust slats to prevent direct toys from peicritu between slats. If -*- ore fully Hrwr* (data set at 00 A-t) use same factors as used for roller shade fully drawn. * --i shade with wide Tim son may shine on window through sides of shade. Estimate the exposed portion of duo as unshaded. * Commensal shade, bronse. Metal slats 0 05 inches wide 17 per ineh and set st 17 dec ancle with horisontal. At tolar altitudes below 40 dec some direct solar rays are allowed lo pass between slots, and this amount becomes procreaively creater at lew solar altitudes. * aluminum +W- Slats 0.057 i~4>-- wide. 174 per inch, set et 17 dec and with horisooteL At solar altitudes below 40 dec eome direct solar rays are allowed to post between slats and this amount becomes progressively creater at low solar altitude. * From first paper in Reference 2$. effect, but several investigaters1^ " ** ** " have made a study of (he problem and. have presented many useful data:' Tables 9, 10, 12, 13, 17, 19, 20, 21, 22, and 23 are all based on instantaneous rates of heat transfer. Hence, practical judgment and experience offer the only basis of procedure. Until the needed data become available, it is recommended that the noncontinuous load be averaged over two or three hours during the time of mavimum load, when determining the total instantaneous cooling load where a large portion of the heat gain is radiant. This suggestion applies only to conditions near the time of maximum heat gain, as the heat stored within the structure would necessarily appear in the cooling load eventually; but if it appears at a time when the gain from outdoors is relatively low, the equipment will be able to maintain satisfactory conditions within the range of maximum capacity. LOAD FROM INTERIOR PARTITIONS, CEILINGS, AND FLOORS Whenever a conditioned space is adjaoent to another space in which a different temperature prevails, the transfer of heat through the separating structural section must be considered. Calculations are made according to the relation: where q = UiAi(th -- f<) Btu per hour. (6) ..Table 26 .... Length of Horizontal Projection Required for Shading Windows and Wails For Shading 10 Ft Down From Proportion For April It Through Sephnbw I Sun Time Projection fa Foot latitude 40 Deg 50 Deg AM--* 1 6 a.m. 7 8 9 10 11 12 6 p.m. 5 4 3 2 1 5 a.m. 6 7 8 9 10 11 12 7 p.m. 6 5 4 3 2 1 5 a.m. 6 7 8 9 10 12 7 p.m. 6 5 4 3 2 1 N NE E SE 17.4 a 5.6 * * * 2.0 11.2 17.4 13.8 0.6 6.3 10.8 9.7 ___ 3.3 6.3 7.1 1.1 3.1 4.7 -- -- -- 2.9 . 12.0 3.5 __ -- __ -- -- ' * 9.7 18.9 16.1 4.7 11 2 11.6 1.3 6.5 9.1 -- 3.1 6.5 -- -- 4.3 a- 8.4 * _1.6 9.4 19.7 18.9 -- 3.1. 12.8 14.3 _ 0.6 7.6 11.6 _ _ 3.7 8.7 -- -- -- 6.6 5 sw _ __ 0.9 -- 2.6 -- 3.6 -- 3.9 -- 4.1 0.9 4.1 2.9 __ ---- 1.8 -- 4.3 -- 8.4 -- 5.8 -- 6.1 2.2 6.3 4.3 _-- ---- 3.7 -- 6.6 -- 7.9 -- 8.4 0.6 8.7 3.9 9.1 6.5 U{ -- coefficient of overall heat transfer between the adja cent and the conditioned space, Btu per (hour) (square foot) (Fahrenheit degree). t P M --* N NW W sw s SE * Projection (motor than SO ft required. jfS