An algorithm for calculating the optimal reference temperature in buildings

In this paper we present an algorithm for calculating the reference temperature in the rooms of a building. The algorithm works in such a way as to properly reduce the reference temperature in the rooms when they are not occupied, and at the correct start time, before the rooms are occupied, recover the reference temperature back to the defined value. The algorithm is tested in six rooms of a simulated hotel building using the well-known TRNSYS software. Different occupancy regimes are considered in the various rooms, and simulations are performed for a period of 1 year using the weather data of the town of Portorož, Slovenia. The results obtained with the proposed algorithm are compared to the results achieved with a constant reference temperature setting. The comparison is made with regard to the energy consumed for the heating and cooling of the rooms, and taking account of the deviations from the allowed temperature rise time. In the rooms where the occupancy is not known in advance similar results can be obtained with the proposed algorithm as with the constant reference setting. However, in the rooms where the occupancy is known in advance, desired level of guest comfort can be preserved with the proposed algorithm with an approximately 10% lower energy consumption for the heating and cooling of the rooms than with the constant reference recovery time setting.