4 Cooling Load Calculation
4.1 Space Heat Gain and Space Cooling Load
Figure 3 Differences between Space Heat Gain and Space Cooling Load
4.2 Cooling Load Temperature Difference (CLTD) and Cooling Load Factor (CLF)
4.2.1 Cooling Load Temperature Difference
4.2.2 Cooling Load Factor
Table 1 Cooling Load Temperature Difference for Conduction through Window Glass
The values are calculated for an inside temperature (Ti) of 25.5oC and outdoor daily mean temperature (Tom) of 29.4oC.
Correct CLTD = CLTD + (25.5 - Ti) + (Tom - 29.4)
Table 2 Cooling Load Temperature Difference (40 degree North Latitude in July) for Roof
and External Walls (Dark)
The values are calculated for an inside temperature of 25.5oC and outdoor daily mean temperature of 29.4oC.
Correction values for 22 degree north latitude in July are as follows:
Wall: N NE E SE S SW W NW
+1.8oC +1.5oC -0.4oC -2.3oC -3.6oC -2.3oC -0.4oC +1.5oC
Table 3 Cooling Load Factor for Window Glass with Indoor Shading Devices
(North Latitude and All Room Construction)
4.3 Space Cooling Loads
4.3.1 External Cooling Loads
22.214.171.124 Solar Heat Gain through Fenestration Areas, Qfes
Table 4 Maximum Solar Heat Gain Factor of Shaded Area
Table 5 Maximum Solar Heat Gain Factor for Sunit Glass on Average Cloudness Days
Table 6 Shading Coefficient for Window Glasses with Indoor Shading Devices
a Shading coefficient with no shading device.
b Open weave means 40% openness, and closed weave indicate 3% openness.
Table 7 Overall Heat Transfer Coefficient for Window Glasses
126.96.36.199 Conduction Heat Gain through Fenestration Areas, Qfe
188.8.131.52 Conduction Heat Gain through Roofs (Qrs) and External Walls (Qws)
184.108.40.206 Conduction Heat Gain through Interior Partitions, Ceilings and Floors, Qic
4.3.2 Internal Cooling Loads
220.127.116.11 Electric Lighting
Table 8 Heat Gain from Occupants at Various Activities (At Indoor Air Temperature of 25.5 oC)
b Adjusted for latent heat of 17.6W person released from food.
18.104.22.168 Power Equipment and Appliances
4.3.3 Loads from Infiltration and Ventilation
Table 9 Summer Outdoor Design Dry Bulb And Wet Bulb Temperatures At 22 Degree North Latitude