This chapter focuses on advanced tools for transient energy simulation of existing buildings. Budget constraints often hinder the possibility of implementing large-scale retrofit projects. As a consequence, designers must work out low-cost renovation, which asks for a deep knowledge of the current state of the buildings. Furthermore, the performances of heating plants in existing buildings can be enhanced through the improvement of the control of the system. These types of retrofit actions can be carried out with a limited budget, but asks for the availability of very accurate transient energy simulation tools, which can compare the current and the renovated scenarios. On top of them, cost–benefit analyses can be developed. In this chapter, a model of a small hospital is developed in the Dymola/Modelica environment. The high flexibility of the transient simulation model and the very good agreement between numerical estimations and measurements are shown. Then, one scenario regarding enhanced regulation of the heating system by means of a customized ambient temperature control system is developed, and the expected energy savings are estimated.
Part of the book: HVAC System