Evaporative Cooling - Direct

Direct evaporative cooling introduces water directly into the supply airstream (usually with a spray or some sort of wetted media). As the water absorbs heat from the air, it evaporates. While this process lowers the dry bulb temperature of the supply airstream, it also increases its wet bulb temperature by raising the air moisture content.

While an evaporative cooling system can effectively reduce the required capacity of the mechanical cooling equipment, it usually does not eliminate the need for a conventional cooling coil (except in certain arid regions of the country). Additional static pressure typically around 0.2 to 0.3 inches water column is required by the air handling system whenever evaporative coils are used in conjunction with a conventional cooling coil.