Personal control and thermal comfort classification

Many thermal comfort standards (e.g. ISO 7730 and EN 15251) classify the thermal environment in 3 classes (A to C). The present classification approach suggest that buildings with tight, centralized temperature control are perceived as more satisfying than buildings with less tight, centralized temperature control. From field studies we know that it is not just the temperature design bandwidth that defines whether building occupants are satisfied with their thermal environment. A key factor to high occupant satisfaction is access to (adequate) personal control opportunities like room thermostats, operable windows and personal climatisation systems. But then: where is the aspect of personal control in today's thermal comfort standards? In this paper we present a proposal for a new thermal comfort classification scheme. Within the proposal a class A+ environment is described in terms of high degree of control over temperature and/or airspeed at workstation level, class A relates to a high degree of control over the thermal environment at room level; etcetera.