Thermal insulation of cooled spaces in high rise residential buildings in Hong Kong

Abstract

Thermal insulation is seldom applied to the fabric of high rise residential buildings in Hong Kong. Where it is used, it is placed in the fabric component at the side that faces the outdoors or non-air conditioned spaces, such as kitchens, bathrooms and entrance lobbies. The paper reports on the results of an investigation into the effects of including a thermal insulation layer in the fabric components that separate cooled spaces from the outdoors and from non-air conditioned spaces. In the investigation, the effects of placing the insulation layer at the indoor side, in the middle and at the outdoor side, or the side of the adjacent non-air conditioned space, of the fabric components were evaluated and compared. For the doors, the insulation layer was always put between the two face panels. The detailed building heat transfer simulation program HTB2 was employed to calculate the yearly cooling loads and the maximum cooling demand in the year of two typical flats in a high rise residential building. The simulation predictions show that the highest reduction in the yearly cooling load, by 9.1%, and in the maximum cooling demand, by 10.5%, would be achieved when a 50 mm thick thermal insulation layer was placed at the indoor side of the walls that enclose the cooled spaces. However, increasing the thickness of the insulation layer beyond 50 mm and of the concrete layer to above 100 mm would only lead to insignificant further reductions in the yearly cooling load and the yearly maximum cooling demand.