Understanding Hepa filters

An appropriately specified Hepa filter can be used in mechanically ventilated spaces and recirculating systems to practically remove small airborne particulates. CIBSE Journal technical editor Tim Dwyer looks at what must be considered when integrating them into HVAC systems

Calculating Covid-19 risk according to activity and indoor space

A group of UK researchers has attempted to quantify the transmission risk of airborne Covid-19 infection according to activity and type of indoor space. Chris Iddon describes the methodology and how the risk of infection falls as ventilation rates are increased