The conversion efficiency of solar cells is dependent on the cell temperature and they perform better the colder the cells are. The paper discusses cooling of solar cells by providing solar cell modules with an air gap behind the modules. The stack effect in the air gap drives the ventilation flow in a hybrid ventilation system. Expressions for the bulk flow properties (volumetric flow rate, mass flow rate and temperature) are presented as a function of the geometry of the air gap and the location of the heat input (configuration factor).

Current thermal comfort standards and the models underpinning them purport to be equally applicable across all types of buildings, ventilation systems, occupancy patterns, and climate zones. A recent ASHRAE-sponsored research project (RP-884) critically evaluated this by statistically analysing a large thermal comfort field research database from 160 buildings scattered all over the would (n=22,000).

Demand Based Ventilation systems are potentially valuable in terms of energy saving in building with fluctuating occupation patterns. Most demand based ventilation systems are controlled by C02 measurement. However this approach cannot take account of other polluting elements found in indoor air. This paper will describe the results of a study of the indoor air quality in a recently built university library with continuous ventilation. The literature relating to typical levels of naturally occurring gases, volatile organic compounds and microbes, in indoor air is considered.

The UK government has signed the Kyoto Protocol and it has committed to reducing C02 emissions to 20% below 1990 levels by 2010. As buildings are responsible for approximately half of the UK C02 emissions, of which the domestic sector accounts for 50%, meeting this target will require a significant contribution from the domestic sector.

The inherent unreliability of the forces which drive natural ventilation can make such systems unattractive for the designer. Developing interest in mixed-mode ventilation is prompting difficulties in sourcing components suitable for ultra-low velocity flow generation in large ducts. This work examines the possibility of using air induction. A theoretical analysis generates equations which assist the designer in sizing a suitable inducer for ventilation purposes. Preliminary tests which verify the theory are described.

Unsteady wind effects can be important in natural ventilation, but their treatment requires knowledge of instantaneous surface pressure distributions which are extremely difficult to obtain. The paper describes a theoretical investigation aimed at determining the effects of unsteadiness and, perhaps more important, the conditions for which it may be worth accounting for them in the design process. For generality the study uses nondimensional parameters. The effects of unsteadiness on both mean and instantaneous flow rates are covered.

Recent years have seen increased use of natural ventilation, daylighting, and cooling techniques in UK buildings. This paper describes the design and operating concept of a large, naturally ventilated and illuminated city centre library for Coventry University in the UK. The novel design concept includes four lightwells acting as ventilation inlets, each of which is fed with fresh air from a plenum below the ground floor. A central lightwell and perimeter stacks draw air across each floor plate and provide air extract routes.

To develop guidance on effective ventilation strategies for buildings located in urban areas, it is necessary to have an understanding of the processes involved in the ingress of external pollution into buildings and its effect on indoor air quality. For naturally ventilated buildings, the combination of pressure forces and contaminant levels around the building is important in generating the level of internal contamination.

In this study, a mixed mode building, namely the Portland Building at the University of Portsmouth is considered. It combines both Natural Ventilation and conventional Heating Ventilating and Air Conditioning systems to maintain the internal comfort. The paper presents the development of Sof1 Computing models to predict the internal temperature in one of the offices using information from neighbouring rooms, corridor and the outside. To derive this model, the so called Adaptive Neuro Fuzzy lnference System method is used.