Part 1. Load Estimating | Chapter 3. Heat Storage, Diversity And Stratification

TABLE 8-STORAGE LOAD FACTORS, SOLAR HEAT GAIN THRU GLASS

WITH BARE GLASS OR WITH EXTERNAL SHADE24 Hour Operation, Constant Space Temperature

WEIGHT SUN TIMEEXPOSURE (lb per sq AM PM AM EXPOSURE(North Lat) ft of floor area) 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 (South Lat)

150 & over .17 .27 .33 .33 .31 .29 .27 .25 .23 .22 .20 .19 .17 .15 .14 .12 .11 .10 .09 .08 .07 .07 .06 .06Northeast 100 .19 .31 .38 .39 .36 .34 .27 .24 .22 .21 .19 .17 .16 .14 .12 .10 .07 .08 .07 .06 .05 .05 .04 .03 Southeast

30 .31 .56 .65 .61 .46 .33 .26 .21 .18 .16 .14 .12 .09 .06 .04 .03 .02 .01 .01 .01 0 0 0 0150 & over .16 .26 .34 .39 .40 .38 .34 .30 .28 .26 .23 .22 .20 .18 .16 .14 .13 .12 .10 .09 .08 .08 .07 .06

East 100 .16 .29 .40 .46 .46 .42 .36 .31 .28 .25 .23 .20 .18 .15 .14 .12 .11 .09 .08 .08 .06 .06 .05 .04 East30 .27 .50 .67 .73 .68 .53 .38 .27 .22 .18 .15 .12 .09 .06 .04 .03 .02 .01 .01 .01 .01 0 0 .01

150 & over .08 .14 .22 .31 .38 .43 .44 .43 .39 .35 .32 .29 .26 .23 .21 .19 .16 .15 .13 .12 .11 .10 .09 .08Southeast 100 .05 .12 .23 .35 .44 .49 .51 .47 .41 .36 .31 .27 .24 .21 .18 .16 .14 .12 .10 .09 .08 .08 .06 .06 Northeast

30 0 .18 .40 .59 .72 .77 .72 .60 .44 .32 .23 .18 .14 .09 .07 .05 .03 .02 .01 .01 .01 0 0 0150 & over .10 .10 .13 .20 .28 .35 .42 .48 .51 .51 .48 .42 .37 .33 .29 .26 .23 .21 .19 .17 .15 .14 .13 .12

South 100 .07 .06 .12 .20 .30 .39 .48 .54 .58 .57 .53 .45 .37 .31 .27 .23 .20 .18 .16 .14 .12 .11 .10 .08 North30 0 0 .12 .29 .48 .64 .75 .82 .81 .75 .61 .42 .28 .19 .13 .09 .06 .04 .03 .02 .01 .01 0 0

150 & over .11 .10 .10 .10 .10 .14 .21 .29 .36 .43 .47 .46 .40 .34 .30 .27 .24 .22 .20 .18 .16 .14 .13 .12Southwest 100 .09 .09 .08 .09 .09 .14 .22 .31 .42 .50 .53 .51 .44 .35 .29 .26 .22 .19 .17 .15 .13 .12 .11 .09 Northwest

30 .02 .03 .05 .06 .08 .12 .34 .53 .68 .78 .78 .68 .46 .29 .20 .14 .09 .07 .05 .03 .02 .02 .01 .01150 & over .12 .11 .11 .10 .10 .10 .10 .13 .19 .27 .36 .42 .44 .38 .33 .29 .26 .23 .21 .18 .16 .15 .13 .12

West 100 .09 .09 .09 .09 .09 .09 .10 .12 .19 .30 .40 .48 .51 .42 .35 .30 .25 .22 .19 .16 .14 .13 .11 .09 West30 .02 .03 .05 .08 .07 .07 .08 .14 .29 .49 .67 .76 .75 .53 .33 .22 .15 .11 .08 .05 .04 .03 .02 .01

150 & over .10 .10 .10 .47 .10 .10 .10 .10 .12 .17 .25 .34 .39 .34 .29 .26 .23 .20 .18 .16 .14 .13 .12 .10Northwest 100 .08 .09 .09 .57 .09 .09 .09 .09 .11 .19 .29 .40 .46 .40 .32 .26 .22 .19 .16 .14 .13 .11 .10 .08 Southwest

30 .02 .04 .05 .82 .08 .09 .10 .10 .13 .27 .48 .65 .73 .49 .31 .21 .16 .10 .07 .05 .04 .03 .02 .01North 150 & over .16 .23 .33 .47 .52 .57 .61 .66 .69 .72 .74 .59 .52 .46 .42 .37 .34 .31 .27 .25 .23 .21 .17 Southand 100 .11 .33 .44 .57 .62 .66 .70 .74 .76 .79 .80 .60 .51 .44 .37 .32 .29 .27 .23 .21 .18 .16 .13 and

Shade 30 0 .48 .66 .82 .87 .91 .93 .95 .97 .98 .98 .52 .34 .24 .16 .11 .07 .05 .04 .02 .02 .01 .01 Shade Equation: Cooling Load, Btu/hr = [Peak solar heat gain, Btu/(hr) (sq ft), (Table 6)] [Window area, sq ft]

[Shade factor, Haze factor, etc., (Chapter 4)] [Storage factor, (above Table at desired time)]

Bare glass-Any window with no inside shading device. Windows with shading devices on the outside or shaded by external projections are considered bare glass.

These factors apply when maintaining a CONSTANT TEMPERATURE in the space during the operating period. Where the temperature isallowed to swing, additional storage will result during peak load periods. Refer to Table 13 for applicable storage factors.

Weight per sq ft of floor-Room on Bldg Exterior (One or more outside walls) =

Room in Bldg Interior (No outside walls) =

Basement Room (Floor on ground) =

Entire Building or Zone =

With rug on floor-Weight of floor should be multiplied by 0.50 to compensate for insulating effect of rug.Weights per sq ft of common types of construction are contained in Tables 21 thru 33, pages 66 thru 76.

(Weight of Outside Walls, lb) + (Weight of Partitions, Floor and Ceiling, lb)Floor Area in Room, sq ft

(Weight of Partitions, Floor and Ceiling, lb)Floor Area in Room, sq ft

(Weight of Outside Walls, lb) + (Weight of Floor, lb) + (Weight of Partitions and Ceiling, lb)Floor Area in Room, sq ft

(Weight of Outside Wall, Partitons, Floors, Ceilings, Structural Members and Supports,lb)Air Conditioned Floor Area, sq ft