Simulating external longwave radiation exchange for buildings

- We improve the longwave exchange processes in the EnergyPlus simulation program.
- These covered other building surfaces, the ground and shading devices.
- Surfaces were coupled using a time lag, which is acceptable for short timesteps.
- This gives more accurate surface temperatures and hence energy demands.
- We found temperature changes of up to 6 °C, and energy demands differed by up to 20%.