When reviewing a Autodesk® 360 Energy Analysis in the Results and Compare dialog, this graph displays the number of hours per year that dry-bulb and wet-bulb temperatures fall within a certain temperature range. This range is sometimes referred to as a temperature bin.
Use outdoor dry-bulb temperatures (Tdb) and wet-bulb temperatures (Twb) to analyze whether the project may be a candidate for different low-energy cooling strategies, such as natural ventilation, economizers, or evaporative cooling systems.
Economizers save on cooling energy costs. If the thermostat calls for cooling and the outdoor air is cool and dry, the economizer circulates outdoor air through the building without requiring the air conditioning compressors to be used.
Evaporative cooling systems are effective as long as the outside air is dry enough. However, the potential for evaporative cooling decreases as the wet-bulb temperature of the outdoor air increases.
Night-time ventilation works well in hot, dry climates that experience large diurnal temperature swings. The building is ventilated at night and closed in the morning to retain the cool air.