Model of a sitting person acting as a heat source in the indoor environment

Heat plumes generated by heat sources, such as people, in ventilated and air-conditioned rooms may have a significant influence on the indoor air flow pattern; their momentum is comparable with that of air flow supplied by ventilation systems into occupied areas. Effective removal of heat gains can contribute to the reduction of energy need for cooling or mechanical ventilation. Computational fluid dynamics (CFD) simulations can be used in design and optimization of air distribution in rooms, providing that the computations are reliable (i.e. giving realistic results) and at the same time fast enough to enable comparison of alternative system solutions. This is why it is important to pay attention to simplified representation of indoor heat sources. The paper deals with CFD modeling of a heat plume generated by a person sitting in a confined space. The aim is to propose and test a new approach to simplified numerical modeling of heat sources, in order to reduce substantially the requirements for computing power and time without a significant influence on the results accuracy. The solution is based on the replacement of a heat source (thermal manikin in the current case) by a simple boundary condition. This simplification is elaborated in three variants and the results from simulations performed with all models are mutually compared.