A method for dynamic compensation of central heating/cooling systems

From the control point of view, the heating and the cooling problems are the same, the sign of heat flow making the difference. The feedforward control of heating system relates the temperature of supply hot water to the temperature of the outdoor air. This relation is based on the global resistance of the heated building. However, the inertia of building is higher than the inertia of the heating system. As a result, the heat supplied to the indoor air of the buildings will have a lead lag comparatively with the heat lost by the building due to changes in the outdoor air temperature. In order to have a lesser lag between the heat supply and loss, a dynamic compensator is made by increasing the inertia of the outdoor air temperature transducer. The calculation of the inertia introduced is based on the statistically identified dynamic models of the heating and building systems. The response of the heating system after compensation is statistically better, although far from being perfect. The response is characterised by a smaller span and variance of the return secondary hot water temperature and the decreasing of the highest return temperature with about 10 degrees C.