Abstract
Considering the energy demand (ED) of 2.9 x 10(10) and of 2.9 x 10(10) MWh in the period between 2010 and 2020, China is one of the largest energy consumers when the world total ED in this period was equal to 14 x 10(10) and 15.46 x 10(10) MWh. By concentrating on the building sector, paraffin-based phase change materials (PCMs) are used to reduce ED associated with air conditioning. For building walls with a thermal resistance of 1.056 m(2).K/W and a thickness of 21.7 cm, paraffin C18 with a melting temperature of 22-27? was selected and added as a layer to all external walls of the building at thicknesses of 5, 10 and 15 cm. The Fourier equation for walls, the energy equation modified with the apparent specific heat method was developed to PCM enclosures to specify the temperature of the building transiently to determine its energy exchange across boundaries. According to the classification provided by ASHRAE, four areas in the first (very hot), second (hot), third (warm) and fourth (mixed) groups were selected and the effect of paraffin C18 on ED related to temperature regulation was discussed. In all four areas, paraffin C18 had an amazing effect. At a thickness of 5 cm for area-based ASHRAE types of 1, 2, 3 and 4, ED throughout the year fell sharply by 82.6%, 77.4%, 61.8% and 58.3%, respectively.