Most modern HVAC systems suffer from two intrinsic problems. First, inability to meet diverse comfort requirements of the occupants. Second, heat or cool an entire zone even when the zone is only partially occupied. Both issues can be mitigated by using personal comfort systems (PCS) which bridge the comfort gap between what is provided by a central HVAC system and the personal preferences of t...

Swedish nuclear plants are slowly being shut down as a result of a referendum in 1980. This was one starting point for the thermal energy storage (TES) expansion in Sweden. Now, the new EU directive on energy efficient buildings forces HVAC engineers and civil engineers to look for new methods to reduce electricity consumption and to improve energy performance in new and existing buildings. Thi...

Low-frequency high-voltage alternating-current (LF-HVac) transmission scheme has been recently proposed as an alternative solution to conventional 50/60-Hz HVac and direct-current (HVdc) schemes for bulk power transfer. This paper proposes optimal planning operation loss minimization in a multi-frequency system. In such system, LF-HVac grids are interconnected using back-to-back (BTB) converter...

Recent efforts to incorporate aspects of artificial intelligence into the design and operation of automatic control systems have focused attention on techniques such as fuzzy logic, artificial neural networks, and expert systems. The use of computers for direct digital control highlights the recent trend toward more effective and efficient heating, ventilating, and airconditioning (HVAC) contro...

Heating, Ventilation, and Air Conditioning (HVAC) systems are generally built in a modular manner, comprising several identical subsystems in order to achieve their nominal capacity. These parallel subsystems and elements should have the same behavior and, therefore, differences between them can reveal failures and inefficiency in the system. The complexity in HVAC systems comes from the number...

Residential and industrial buildings are significant consumers of energy, which can be reduced by controlling their respective Heating, Ventilation, Air Conditioning (HVAC) systems. Demand-based Ventilation (DCV) determines the operational times ventilation systems that depend on indoor air quality (IAQ) conditions, including CO2 concentration changes, occupants’ comfort requirements. The predi...

Most studies about the control, automation, optimization and supervision of building HVAC systems concentrate on steady-state regime, i.e., when equipment is already working at its setpoints. The originality current work consists proposing multi-HVAC from start-up until they reach setpoint, making transition to steady state-based strategies smooth. proposed approach works transient regime optim...

This paper presents an engineering application of optimization method for energy conservation in condenser water loop operation in HVAC (Heating, Ventilation and Air Conditioning) systems. Based on the analysis of component model characteristics and interactions within the cooling tower and between towers and chillers, an objective function, which minimizes the operating costs through optimal s...