Nobutaka Nishimura

Development of air-conditioning control algorithm for building energy saving

In office buildings, the requirement is that the room air-conditioning control system has to provide comfortable thermal feeling for the working people. While energy saving may sometimes conflict with comfort, it is possible to eliminate the wasteful use of energy associated with its overuse without prejudicing the comfort. The basic concept is that the target set values for the room temperature should be changed dynamically so as to suit the constantly changing room environment. The paper shows that the well-known comfort index PMV is useful for air-conditioning control systems aimed at both energy-saving and comfort.

Next generation HVAC system

The new HVAC (heating, ventilation and air conditioning) system for buildings is proposed. The key technology for the system is twin coil air handling unit (AHU) and its advanced control method. One coil is equipped to cool and to dehumidify the fresh air intake, and the other coil is for cooling circulated air. The deeply chilled water is necessary only for remove the moisture from the fresh air. The latter coil requires moderately cool water according to the HVAC load. Then 2 kinds of chilled water in terms of temperature should be prepared. The structure help saving the energy consumption for air-conditioning because the higher chilled water temperature means the better chiller efficiency (COP). Next, the advanced control method that is called dasiaAir-Water cooperation systempsila is introduced. The control system mainly focused on energy savings through changing the temperature of chilled water and supply air according to the HVAC load and weather conditions. In the paper, we introduce Next generation HVAC system with its control system and evaluation results of the system for the model-building simulator.