Hybrid units in ventilation are those in which airflow can be produced naturally by gravity draft or produced mechanically by an electrically driven fan. These are mainly exhaust units.
The main advantage of hybrid fans in industry is that they require less space on the roof compared to rooftop fans and ventilators, if the designer decides touse both. This is important in the context of the increasing use of rooftops for the installation of photovoltaic panels.
Hybrid ventilation will also work well for buildings with high heat gains, but not very high, where sufficient gravitational drought for natural ventilation will not be generated on hot summer days. Examples of such buildings are buildings ofindustrial gas and air compressor stations, high-power transformer stations and engine rooms of small power units. For these and similar cases, hybrid ventilation has its justification and will probably be used more and more often.