An adaptive thermal comfort policy for a geographically dispersed property portfolio; deciding when and where to air-condition in a warm climate zone

This paper describes a Thermal Comfort Policy recently developed for a client who owns a large portfolio of buildings in Australia. To date the client's decisions about where and when to install HVAC have been based on a static isotherm on the climate map of the region in which they operate, regardless of how well the building performs. The client's brief aims to shift air conditioning decisions onto a more rational footing, based on the climatic context, the building's thermal performance and occupants' thermal comfort. The solution we proposed was based on ASHRAE's 55-2010R adaptive model, with an exponentially-weighted running mean outdoor temperature for input. Of the three different metrics proposed for the diagnosis of systematic overheating, the simplest was finally selected by the client (>1 % of occupied hours annually during which indoor temperature exceeds the ASHRAE 55 upper limit (80% acceptability).