Integrated Lighting and Thermal Simulation


Façade design directly affects the energy demand for heating, cooling, and, lighting, as well as the visual and thermal comfort of occupants. A good facade design can achieve a balance among these factors. With the development of dynamic façade and lighting technologies, the control strategies are now part of the façade design and the links between thermal and daylighting models become stronger than before. For any type of static or dynamic facades, the conflicting requirements of daylight provision, air-conditioning energy use and glare are always present. Therefore, I developed an integrated approach that considers all of the parameters.

The framework of the integrated analysis model in figure and it consists of a daylighting calculation module and a thermal calculation module. Inputs of the model consist of basic building description, weather information, and occupancy profile. Building description includes the dimensions of the studied space, orientation, window size and properties and shading properties. The model accepts three different formats of weather data inputs: TMY3 weather file, EnergyPlus weather file, or any type of measured data. Occupancy profile includes occupants’ position, occupants’ view direction, and occupants’ schedule. Shading and lighting control decision maker selects shades position and light dimming levels according to the weather information, or simulation results. For example, if we want to select the shading schedule based on hourly energy consumption, the decision maker would read and analyze both daylighting and thermal simulated results and send a command back to thermal and daylighting model to generate new results. This loop runs several times until it reaches an optimal value or a breaking point. An important parameter that links the daylighting model to the thermal model, especially when utilizing light dimming strategies, is the amount of lighting heat gains. The daylighting model calculates both illuminance distribution and interior solar radiation distribution, which is also an input of thermal model.