Application of passive solar design strategies for residential houses with different construction systems in NSW, Australia

Energy consumed in active heating, ventilation and cooling accounts for about 40 per cent of the total energy used in a typical Australian house. Passive solar design, by which one can take advantage of the natural climate, is found to be one of the key methods to minimise or even sometimes eliminate the need for active heating and cooling energy. The passive solar design includes consideration of the building orientation and careful design of the building envelope, such as roof, walls, windows, floor systems and thermal mass; with an overall aim of controlling the heat flow in or out of the building. The main aim of this study is to demonstrate the opportunity of energy conservation between houses with different construction systems that varies in thermal mass. A number of test houses, detached dwellings on a typical land area of 400 m2, were used to achieve the objective via parametric simulation of a series of scenarios. The simulation scenarios were based on different sub-flooring construction systems and walls. Integrated shading devices, thermal mass, orientation, and glazing, along with ventilation and infiltration rates, were considered in each scenario with different compositions. Internal air movement between the two floors of a two-storey house was simulated in each of the scenarios by calculating the air movement through the staircase. These analyses were carried out using commercially available off-the-shelf Building Energy simulation software called IDA Indoor Climate and Energy (IDA ICE). The energy saving values over the life span of the building were computed and compared between the standard houses which do not have passive solar design strategies and improved houses, which incorporate passive solar design strategies. The results show that the, improved houses are more energy efficient and cost-effective than standard houses over the considered life span of 50 years. Applying Passive solar and Energy Efficiency Design Strategies (PSEEDS) to old fibro and modern brick houses effectively reduced the total energy required for cooling and heating by 43% and 46%, respectively. Increasing the thermal mass of a house using, for example, a concrete slab for flooring and brick veneer walls, can significantly reduce the annual energy requirements of both standard and improved houses by 35% and 39%, respectively. Hence, a typical brick veneer house is more energy efficient than a typical fibro house. In addition, when a brick veneer house (which is a most common modern construction in Australia), is incorporated with PSEEDS, it is possible to reduce energy consumption by as much as 65% compared to a standard fibro house. In addition, the improved reverse brick veneer house performed better than the improved brick veneer system by 24%. The results obtained in this study indicate that the reverse brick veneer houses are more energy efficient than alternative construction systems over their lifetime