The use of infrared controlled air terminals in an office building.

UK, CIBSE, 1996, , held , 29 September - 1 October 1996, Volume 2, pp 311-320. Demand controlled ventilation (DCV) allows close control of air quality whilst minimising ventilation heat losses. It is thus a powerful design option and may be preferred to conventional systems where temporal variations in occupant density are unpredictable. CO2 monitors are expensive, which restricts their use in feedback control to large open plan offices and auditoriums. Presence Controlled Ventilation (PCV) is a low cost form of DCV in which on/off switching of fans or air terminals is controlled by infra red detectors. PCV has successfully been used to ventilate modular offices, hotel rooms and toilet areas. However, most office buildings are neither constructed on a large open plan format nor fall into the category of modular buildings. A building with mixed modular and small open plan offices was partially fitted with PCV air terminals to assess their suitability in such office suites. The whole office suite was serviced by a single air handling unit for combined supply and extract. Indoor air quality and ventilation heat loss was measured for the building as a whole and for the branch fitted with PCV. Some drawbacks of the installed system were identified which significantly affected the payback period of the installation.