Improving building fabric energy efficiency in hot-humid climates using dynamic insulation

New effective technologies and materials that have the potential to reduce energy demand with excellent energy efficiency and low environmental impact are urgently required in the Gulf Region. Dynamic insulation, which functions by recycling fabric heat loss back to the building, has been established theoretically and proven in pilot projects. It sets the green, low carbon benchmark for thermal insulation in buildings. This paper presents details of the Eco-Villa, its construction, how the performance of the villa was monitored, and the findings from the initial monitoring phase and the dynamic simulation model (DSM). The villa was tested in two modes, bypass (static) and dynamic. The static U value of the external envelop wall was estimated at 0.24 W/(m2·K) in bypass mode. The theoretical dynamic U value changed from 0.24 to 0.05 W/(m2·K) when the ventilation airflow was varied from 0 to 0.001 m3/(s·m2) (0 to 1 L/(s·m2)), with a further small reduction occurring when the flow rate increased beyond 0.001 m3/(s·m2) (1 L/(s·m2)). The design ventilation rate for the Eco-Villa was 0.0008 m3/(s·m2) (0.8 L/(s·m2)), which yielded a theoretical dynamic U value of 0.063 W/(m2·K) compared to a measured U value of 0.125 W/(m2·K). The reduction in the fabric conduction gain was found to be 41% whereas the estimate from the DSM was 38%. The results demonstrate the fabric energy efficiency improvements that can be achieved through the use of dynamic insulation.