Paper Conference

Proceedings of ASim Conference 2016: 3rd Asia conference of IBPSA-China, Japan, Korea


Thermal Decay and Energy Consumption Depending on Location of Slab Insulation in Underfloor Air Distribution System

H. Kwon, B. Yu, W. Lee, K. Lee

Abstract: Generally, Underfloor Air D1istribution (UFAD) system commonly applied to office buildings has many advantages over Ceiling Based Air Distribution (CBAD), including improvement of indoor air quality and energy saving. However, the thermal decay which is defined as the increase of the supply air temperature due to heat gain into underfloor supply plenum, can adversely affect the energy savings. Therefore, in this study, a thermal insulation was installed on the slab to prevent thermal decay and to improve cooling performance, and the effect of the insulation installation on the cooling energy consumption was analyzed. The result showed that the thermal decay was reduced by the installation of the insulation on the slab, and different effects were observed in individual cases. The energy consumption was reduced in the case where the insulation was installed on the slab, while no energy saving effect was found in the case where the insulation was installed under the slab. This indicates that an appropriate insulation installation location should be taken into account.
Keywords: Underfloor air distribution, Thermal decay, Supply plenum, Insulation, Convective heat gain