Abstract: | The theory of optimal control is applied to intermittent heating. The general characteristics of the control are determined and their strategies compared with the performance of existing ‘optimum start controls’. Difficulties are identified particularly where the system includes more than one time constant. The existence of an ‘optimal stop’ control is established but its savings are shown to be small compared to ‘optimal start’. The ‘flywheel’ effect of the additional thermal inertia of heavyweight heating systems are then argued not to offer substantial savings. A general numerical technique is provided which enables the optimal heating strategy to be derived from a knowledge of the building response factor alone. The technique allows great flexibility in the type of constraints that can be imposed and an example is given of its application. |