Development of a new metric to characterise the buildings thermal performance in a temperate climate.

The paper describes the development of a new metric to evaluate the thermal performance of residential houses for temperate climates, named the Adaptive Thermal Metric (ATM). The proposed ATM helps the evaluation of the thermal performance of an entire house by finding the internal air temperature of the building using Computational Fluid Dynamics (CFD) simulation then computes the fraction of time over which the internal air temperature of the house stayed within the 90% or 80% adaptive thermal comfort limits (designated ATM90 and ATM80 respectively). The adaptive thermal comfort approach allows inhabitants to choose an adequate range of internal air temperatures by implementing other adaptive practices such as changing clothes, opening windows, or using low energy solutions (e.g. fans) to adjust their thermal comfort level. The new metric uses temperature to assess a building's thermal performance. This differs from other commonly conventional approaches, which are established based on the amount of energy usage required to sustain an inhabitant's thermal comfort. To verify the modelling technique, the CFD simulated internal air temperatures were compared with the actual temperatures recorded for four full-scale housing test modules, each incorporating a different walling system. This comparison yielded an average accuracy of 93% at any given time for all simulated modules over the 12-month simulation period. Using the above CFD approach, the ATMs were calculated for each building test module over the studied period. The final results showed that the best thermal performance module was the Insulated Cavity Brick module (InsCB), followed by the Insulated Reverse Brick Veneer (InsRBV), Insulated Brick Veneer (InsBV) and Cavity Brick (CB) modules. These findings were accordant with both the house evaluation software used in Australia (i.e. AccuRate) and the earlier results on the walling systems research done by the University of Newcastle in Australia, which were used to assess the accuracy of the ATM. The results indicated that the ATM has the potential to be used as an alternative building evaluation technique to assess the overall building thermal performance in temperate climates. [ABSTRACT FROM AUTHOR]