Purge ventilation, is high-airflow, manually operated strategy, particular used in studio apartments and student residential buildings. Night-cooling refers to the use of natural ventilation at night (through louvres for example) in order to purge excess heat and cool the building. Using a night time ventilation strategy, occupants have the power to reduce peak daytime temperatures by 2° to 3°.
Night-cooling or purge ventilation offers the potential to minimise or even avoid the use of mechanical cooling and improve the internal conditions in naturally ventilated buildings.
Good control of this strategy is required in order to achieve maximum free cooling whilst avoiding overcooling and the need for subsequent re-heating or thermal discomfort the following day.
The flows needed for this strategy are 10 times higher than those needed for basic ventilation. That’s why Night-cooling or purge ventilation is also referred to as intensive.