Condensed weather data for heating calculation.

Two methods for reducing weather data are assessed and compared with respect to use for heating calculations. Degree days for calendar months, utility bill periods and without weekends were calculated and compared along with temperature 'bins' of various sizes using the CIBSE Example Weather Year. Wind velocity and solar radiation are also analysed with respect to degree days. Both methods, degree days and the bin method, are found to represent the actual weather conditions adequately for use in heating calculations.