This paper proposes that radiant temperature effects should be counted in energy simulation programs. This can be realized by using the operative temperature as the indoor design condition.Two solution methods are proposed to implement the concept into the ASHRAE heat balance method-one is a direct solution method and the other is the iterative method. The direct solution method saves computational time but requires delicate programming, whereas the iterative method needs minimal modification of any existing program based upon the heat balance method. The significance of the operative temperature control is illustrated by performing five case simulation studies, and it is shown that the method makes a significant difference when relatively large temperature differences exist between the room surfaces and the room air.

Units: Dual