Hybrid ventilation is a combination of natural and mechanical ventilation and exploits both systems as required. This entails either interchangeable periods of natural ventilation and mechanical ventilation, or a balancing of the two principles such that mechanical ventilation takes over when the external conditions so require. The result is an effective and energy-efficient ventilation solution that maintains healthy indoor climate and comfort.
In order to use a hybrid ventilation solution conditions for the use of natural ventilation must be in place.
There are three basic forms of hybrid ventilation
- Natural Ventilation + a VAV/CAV system
- Natural Ventilation + a decentralised system
- Natural Ventilation + extraction
The type of hybrid ventilation used depends on project requirements. NV Comfort™ and NV Advance™ can regulate both natural ventilation and mechanical ventilation in all three forms of hybrid ventilation system.
Note that whatever type of hybrid ventilation you choose, the same thermal comfort and air quality requirements as hold for other ventilation solutions in other buildings must be met.
The illustration shows how a fan can be used to increase airflow. In this example, the cross-ventilation principle is utilised as long as the wind speed is sufficient to create airflow inside the building. The window on the side of the building that faces the wind is opened less than the window on the sheltered side.
Where there is insufficient airflow in the building the fan operates to increase airflow. Insufficient airflow may be due to:
- low wind speeds or outdoor temperatures being higher than indoor temperatures
- the building structure preventing natural airflow
Hybrid ventilation solutions, like all other solutions that utilise natural ventilation, are based on the principle of providing healthy indoor climate and comfort, delivered with minimal energy consumption and at minimal cost.