Evaporative cooling in Europe. When and how much is it worth?

By 31st December 2020 only “nearly zero-energy” buildings shall be built. They are high energy performance buildings, where most energy is supplied by renewable sources (2010/31 EU Directive). New and energy retrofitted buildings usually demand more cooling than heating. Free cooling techniques can be usefully used in such buildings, varying the outside air flow by the air handling unit from the minimum (ventilation air flow) to the whole inlet air flow. The paper reports on the energy and economic analysis of
free cooling with direct and indirect evaporative cooling. The possible savings using such techniques with respect to traditional sensible heat recovery are evaluated in different European typical climates and different type of buildings. The analysis is based on hourly meteorological data (Typical Meteorological Year) taking into account also extra energy consumption for fans and pumps.