This week’s question comes from Lara:
My rental has a bathroom right next to the kitchen. Can the ducting of the bathroom extractor and kitchen extractor be joined and vented out of the house together for HHS ventilation purposes?
Yes, so long as both extractor fans meet the size/capacity requirement (i.e. >150 mm diameter/exhaust capacity > 50 litres per second for anything
installed after 1 July 2019) and that you have the blessing of your installer. There is nothing in the standards that require each extractor to have
its own individual ducting for the purpose of external ventilation.