New Weather Data for Thermal Building Simulation

Weather data used to simulate buildings' energy consumption and thermal indoor climate, the so-called Design Reference Year, DRY, was collected in the period 1975-1989 (Jensen and Lund, 1995).

This has given rise to concern in the consulting industry and among their customers that calculations of energy consumption and thermal indoor climate conditions are no longer sufficiently accurate because the climate has changed since weather data was collected and because climate change can be expected to increase in the future. It must also be borne in mind that the buildings that are being designed today are expected to stand for 100 years to come.

A new reference year for Denmark on the basis of new weather data from the period 1995-2009 has been prepared, thus taking into account the changes that have taken place in the outdoor climate since the previous DRY was developed. The preparation is based on the same principles as the previous DRY in terms of data selection and adjustment.

Weather data has been collected from the weather measuring station at DTU as well as purchased weather data on an hourly basis from nearby DMI measuring stations. This is due to the fact that there is the greatest versatility in solar radiation data from DTU, as e.g. also diffuse radiation and directional data are measured, while DMI's solar radiation data are only available as data for global global radiation.

The new weather data set consists of solar radiation, air temperature, humidity, wind speed and direction, as well as rainfall.