The analysis of a dynamic control loop often requires the use of a room model. This paper discusses four simplified dynamic room models which in different ways take into account the thermal interaction between room air and surrounding walls. The room air is assumed to be fully mixed.

It is shown that the choice of the simplification level employed depends on how closely the long-term responses and steady-state values are to fit the actual room response. For modeling short-term dynamic responses, a simple time constant corresponding to the air change rate of the room is usually adequate and will lead to choosing conservati.ve control parameters.

An experimental procedure for determining typical parameter values is discussed.