A large amount of building thermal mass is sometimes advocated as an energy saving measure in climate responsive building design, as it can contribute to a more stable indoor climate and store daytime solar energy gains to reduce heating demand during evening hours. Conversely, the thermal mass can also cause negative effects as the thermal inertia could prolong periods of overheating and reduce benefits of temperature setback regimes.
This doctoral research sets out to investigate the relative contribution of building thermal mass on heating energy consumption and thermal comfort for Belgian residential buildings. Multi-zone dynamic building simulations using EnergyPlus software are carried out in conjunction with Matlab pre- and post-processing to investigate a broad range of design variants. Unlike the simplified (quasi-) steady-state calculation tools which are commonly used to evaluate the building's energy performance during design stage, the dynamic whole building simulation tool is able to quantify the transient heat flow and storage effects.
The influences of thermal mass on energy consumption and thermal comfort are assessed in relation to other architectural design characteristics including building typology, thermal insulation, orientation, and window-to-wall ratio. The behaviour of the building occupant has proven to be an important parameter and therefore a detailed model for domestic occupant behaviour has been constructed which also represents the interactions of the occupant with the building, e.g. through the opening of windows.