Ventilation efficiency

The ventilation efficiency describes the effectiveness of a given air flow ventilation in the occupied zone of a room. The ventilation efficiency is a characteristic parameter for ventilation systems , such as how the used room air or pollutants are removed from the room.

The air flow in the room has a major influence on the ventilation efficiency . It is fundamentally important that the required outside air does not flow past the occupied area unused in a short circuit, but replaces the existing room air. A distinction is made between three basic types of air flow: displacement, dilution and short-circuit flow. Of these types of flow, the displacement flow has the best ventilation efficiency and the short-circuit flow has the worst.

Ventilation systems

Displacement ventilation	Dilution ventilation / mixed ventilation	Short circuit ventilation

Ventilation efficiency ≤ 1	Ventilation efficiency ~ 0.5	Ventilation efficiency ≥ 0
Low-turbulence displacement ventilation is used, for example, with displacement ventilation or in paint booths and clean rooms .	Turbulent mixed ventilation is the most common system (offices, meeting rooms). However, the measurable ventilation efficiency is usually significantly lower in existing ventilation systems .	The air volume flow is hardly effective as an air exchange in the room .