THE FEASIBILITY STUDY ON THE DYNAMIC INSULATION SYSTEM APPLIED TO WINDOW FRAMES OF DWELLING HOUSES

Abstract

In order to insulate buildings more efficiently, a lot of insulation methods have been proposed and successfully applied to the building envelope, including areas such as walls, windows and the others. However, it is also important to insulate the window frame efficiently because it usually exhibits the greatest heat loss. Authors purposed new dynamic insulation system at the window frames with an active ventilation function and a heat pump for heat recovery. This system is composed of three parts: window frames which use porous material for dynamic insulation, mechanical ventilation system, and heat recovery heat pump system. This paper describes a computational simulation study of the technical feasibility about the thermal insulation efficiency of porous material on the proposed system. First, the window frame was designed using a porous material such as the packed bed of particles (i.e. glass wool, mineral wool, aluminum particle, etc.). Then, to verify its thermal insulation efficiency, the temperature contribution of the window frame was evaluated using computer fluid dynamics with different coupled conditions, namely the indoor/outdoor pressure differences. In addition, to verify the condensation effect, the relative humidity in the porous material was calculated by outdoor condition such as air temperature, humidity ratio, indoor/outdoor pressure difference, and porosity dependence of insulation material. The calculated results show the thermal load was inversely proportional to the indoor/outdoor pressure differences. The condensation in the insulation material depends on the outdoor temperature, humidity ratio, and porosity.