Evaluation of an IR-controlled ventilation system in an occupied office building.

The use of IR detectors to steer the ventilation is in principle an attractive approach for optimising the ventilation according to the occupants needs. In order to evaluate the performances under real conditions, one of the BBRI office buildings in Limelette (some 31 offices with in total 51 persons and a variable occupation load) was equipped with a mechanical supply ventilation system in which each terminal is controlled by an IR detector. During a two week period, the performances of the ventilation system were measured in detail (total air flow rate, functioning of each individual terminal, pressure control function, energy consumption, acoustical measurements,...). The paper presents first the concept of the ventilation system and some of the measured performances at component level. The overall performance of the system is then discussed as well as the impact of the building and ductwork airtightness. Finally conclusions and recommendations for further improvements are given.