Fuzzy control strategies to provide cost and energy efficient high quality indoor environments in buildings with high occupant densities

Since the oil crises of the 1970s building professionals have become increasingly aware of the effects of their design decisions on the energy consumption rates in buildings. Often this has led to strategies that have compromised aspects of human requirements such as thermal comfort or air quality. When this has been combined with an architectural approach that often takes little heed of local climate or custom the result has been uncomfortable buildings that are disliked by and have often affected the health of their occupants.

The comfort of building occupants is dependant on many environmental parameters including those provided by the building envelope, building environmental services and control systems. Inadequate design and control can lead to reductions of occupant comfort, energy efficiency and cost efficiency. To achieve a high quality internal environment with good energy and cost efficiencies, the interactions between the contributory factors must be taken into consideration. An examination of the notion of indoor environmental quality and the potential for control strategies and methodologies for this multivariate problem are considered within the contexts of energy efficiency and running costs. The use of fuzzy logic control is examined as a technical response to this dilemma. A high level fuzzy supervisor was used to make control decisions on the best course of action to achieve high levels of indoor environmental quality while taking into account effects on energy and cost efficiency. Simulation results indicated the potential for improvements in system operation.