The objective of this emulator was to develop a procedural method and an emulator that could be used for the operational analysis and product development of heating and air conditioning equipment as well as its control systems and energy management software. The emulator will be used for research and product development purposes in the following ways - the analysis and testing of process dynamics, the development of supervisory control algorithms, the analysis and testing of unit control loops, and energy labelling of devices and systems. The project is a contribution to the International Energy Agency (IEA) Annex 17 project. An emulator consists of physical devices and simulation models of other devices. In this emulator, a heat production device (e.g., an oil boiler) is the physical device, as well as two water loops that represent heat distribution systems. The cooling of the water loops is carried out by two "cooling" heat exchangers. Furthermore, the system includes a domestic hot water system. A building and its interior and exterior loads are described by numerical models. Naturally, a part of the system (e.g., the heat distribution system) also can be numerically modelled. A control system can be a physical device or it can be a numerical model. The data processing system of the emulator consists of the following components - two personal computers, I/O devices, process control software, simulation software, and drivers. The simulation software has been installed in one of the computers and the process control software has been installed in the other one.KEYWORDS: computers, computer programs, testing, building services, heating, ventilation, air conditioning, controls, energy management, calculating.