Control and energy metering in low temperature heating systems

A new approach of temperature control and energy metering in low temperature heating (LTH) systems is presented. The required heat is supplied in terms of energy pulses by intermittent operation of the circulation pump. The control unit calculates the heat demand from external variables basically represented by the ambient air temperature. The parameters necessary for temperature control can be extracted when the heat transfer coefficient and the heat capacity of the floor construction are known. Furthermore, the control strategy opens for energymetering in LTH systems bymeans of the parameters heat carrier temperature and the duty cycle. Themethod is demonstrated to be at least accurate within 5%.