The heating curve adjustment method

In apartment buildings with a collective heating system usually a weather compensator is used for controlling the heat delivery to the various apartments. With this weather compensator the supply water temperature to the apartments is regulated depending on the outside air temperature. With decreasing outside air temperature, the supply water temperature is increased because of the increase in the heat demand. The relation between the supply water temperature and outside air temperature is called the heating curve. After implementation these heating curves are usually set according to the design of the heating system. Often there is no check whether this setting is indeed correct in practice. Due to safety marges in the design, in practice often a some what lower heating curve is possible. Furthermore in practice adjustments on the heating curves are often used as an easy way to prevent complaints. Heating curves are for instance increased in case of complaints about too low inside air temperatures. The actual cause for the complaints is often not further investigated and the heating curve is often not set back and kept at an unnecessary high level in the future. The result of the above mentioned is that in a lot of situations the setting of the heating curve will not be the optimum for the specific building. This can, amongst other things, lead to thermal discomfort and unnecessary energy consumption. A method for determining the optimum setting of the heating curve in practice is developed by CSTB (France) [1]. With this method an easy and rational optimalisation can be obtained. Within the framework of the Sprint program of the European Community, this method is tested and improved by cooperation between CSTB (France), CSTC (Belgium), IBP (Germany), SINTEF (Norway) and TNO (the Netherlands) [2]. In this article the principle of this method, the performance of this method in practice and the benefits of using the method are described.