Applying a Comfort Model to Building Performance Analysis

This paper considers the application of comfort parameters as a mechanism for building performance analysis and control. It challenges traditional methods of evaluating zonal comfort through thermostatic dry-bulb temperature alone. It is realised that the ISO-7730 model offers several parameters – other than dry-bulb air temperature - that can be readily measured, possibly regulated, and changed, resulting in an outcome of improved comfort (ISO 7730, 2005). While the conventional ISO 7730 standard has been challenged as being conservative in its calculation, it is advantageous in cases where actual measurements of spaces are considered. This model is readily simulated with given input parameters through the ASHRAE 55 Comfort Tool (2004, 2017) or more recently by the CBE Comfort Tool (Hoyt et al. 2017).
A comfort cart built according to ASHRAE-55 standards together with thermal imaging surface temperatures can be combined in a comprehensive thermal performance analysis of a given space. These measurements can be applied as inputs to the ASHRAE 55 Comfort Tool (software) yielding a result in thermal comfort. Prior to this, a validation and tuning process between measurement and software output took place for a specific location in the space. It is then apparent that an exploration of changes within the ‘calibrated’ Comfort Tool software can be applied to make comfort improvements through alterations within the space. This paper is about demonstration and discussion in the development of a measurement and analytical process which is a systematic approach towards spatial comfort improvement.
Two houses were measured and analysed, over an extreme daytime period in Darwin, Australia. Improvement in overall thermal conditions of up to 35% and 59% were realised with the most reliable potential for thermal improvements found in surface temperature (mean radiant temperature), conditioning changes indicating between 32 – 38% overall comfort improvement in the building. Research on the energy-savings due to improvements in thermal conditions are however not presented and are highlighted as an important contribution to future research.