Hybrid assistance fan

Optimising passive stack ventilation performances

The very low powered, low pressure VBP hybrid fan is designed to be installed in conjunction with Passive Stack Ventilation (PSV) systems, or low pressure Mechanical Extract Ventilation (MEV) systems (when used in “constant running” mode). A patented design feature of this fan is that the impellers do not interfere with airflow when not in use, thereby allowing the unhindered operation of natural passive stack ventilation when motorised assistance is not required.

The VBP hybrid fan only operates when the natural drivers of Passive Stack Ventilation (wind and thermal draught) are insufficient, as is sometimes the case on hot still days in summer. With the correct controls (such as a pressure sensor or wind gauge), the VBP guarantees satisfactory airflow all year round with the absolute minimum energy use. For this reason Hybrid Ventilation (which is also known as assisted Passive Stack or aPSV), is described as “best practice” by the Energy Saving Trust’s Good Practice Guide (GPG268).

The VBP is suitable for installation on buildings of up to seven storeys high.