Multi-year (MY) building simulation: is it useful and practical?

This paper discusses a multi-year (MY) approach to building energy simulation and presents a pilot study in Hong Kong that investigates long-term building energy performance using MY weather data. Building energy simulations in the pilot study were carried out using the DOE-2.1E program. A set of 17 years hourly weather data (1979-95) was taken as the weather input to drive the simulation. It is found that the MY approach can provide more information for the analysis of long-term building energy performance and climatic properties. It can also remove the ambiguity of typical years and design weather in the present-day simulation approach. Although the MY approach has many advantages, its implementation does require great efforts since a lot more data and computations are involved. The availability of MY weather data is a critical limiting factor at present. To carry out MY simulation effectively, it is important to develop an efficient simulation process and new ways of interpreting simulation results. It is hoped that more thoughts can be stimulated to develop this approach for improving the accuracy and capability of building energy simulation.