Are the pressure losses comparable in all-air and induction systems?
Yes. The pressure loss through the duct is what is important. It is therefore necessary to assess the two systems as complete installations, taking into account the AHU losses, filters, OA/RA path losses, the SA duct loss and then the VAV box and its duct and outlets or the induction terminal unit. No outlet loss is considered for the induction terminal unit as the pressure loss across it is supplied from the pressure at the nozzles. The losses between the VAV box, downstream duct and supply outlet will be very close to or higher than the induction terminal unit selected at 200Pa. The VAV boxes vary in their pressure losses depending on the type of box and what added features it has such as noise attenuation and reheat banks. Some makes with these two features, and the downstream duct and outlets, have considerably higher losses than a terminal unit. On the duct system, the route length will be very similar as will the Pa/m static loss. Therefore the total duct static loss will be simi
