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Chapter 1 is a review of the literature concerning the study of volatile organic compounds in the atmosphere. It examines the basic chemistry of the atmosphere and the roles that organic compounds play in it. Also investigated are the methods of sampling and analysing the volatile organic compounds in the air, paying particular attention to the role of solid phase sampling. Chapter 1 also examines the role of volatile organic compounds on air quality. Chapter 2 describes the experimental procedures that were employed during the course of this research project. Chapter 3 examines a multi-method approach to the study of volatile organic compounds in urban and indoor air. The methods employed were capillary electrophoresis, high performance liquid chromatography and gas chromatography. Although good results were obtained for the various methods that were investigated Chapter 3 concludes that a more unified analytical approach is needed to the study of the air. Chapter 4 investigates the possibilities of using a unified approach to the study of VOC's. This is achieved by the development of an air sampling method that uses solid phase extraction cartridges. By investigating many aspects of air sampling mechanisms the results show that a simple yet efficient method for the sampling of VOC in air has been developed. The SPE method is a reusable, yet reliable method that by using sequential solvent desorption has been shown to exhibit some degree of selectivity. The solid phase that gave the best results was styrene-divinyl benzene however other phases were also investigated. The use of a single gas chromatography method was also investigated for the purpose of confirmatory identification of the VOC's. Various detection systems were used including MS and AED. It was shown that by optimising the GC's it was possible to get complimentary results. Also investigated was the possibility of compound tagging in an attempt to confirm the identity of several of the compounds found in the air. Chapter 5 is a theoretical discussion of the ways presenting the data obtained experimentally in an easy to understand way. Instead of targeting 7 or 8 compounds as being representative of air quality it is argued that by using a technique such as Air Fingerprinting, it is possible to show data that is indicative of the whole air sample. Using actual data it is possible to show the origin of the air sample in a simple yet effective way using air fingerprints. Also discussed is the Individual Component Air Quality Index, this is a method of quantifying air quality. By taking into account compound toxicity, atmospheric lifetime and UV exposure, the ICAQI, it is argued, is a technique that presents a more accurate picture of air quality. Chapter 6 concludes the thesis by drawing together the themes and issues that were raised.

The heating and cooling requirements after a shutdown period of the heating ventilating and air conditioning (HVAC) systems in buildings are studied through an analytical model. The parameters affecting the preconditioning and storage loads which are of particular importance are identified. A mathematical computer model is developed to facilitate the analysis of the shutdown loads. Zones are grouped in terms of heavy, medium and light weight construction for the study. For a specified zone, the ratio of the inside surface area to the outside exposed area, A(s)/A(w), is an important parameter in predicting the additional loads resulting from system shutdown. The computer model is validated with known computer programs, namely DOE-2, BLAST, and DARE-P. A simplification to the model is proved to be adequate for the study. The zones with similar weight characteristics and the same A(s)/A(w) ratio, prove to have the same temperature profiles during the shutdown period, provided that they are at the same ambient conditions. Design guidance and procedures for predicting the preconditioning and storage loads using the models are developed. In addition, the use of DOE-2 and ASHRAE weighting factor method for shutdown load predictions is demonstrated for generic and custom applications.

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