A comprehensive survey of industrial sites and heat recovery products revealed gaps between equipment that was required and that which was available. Two heat recovery products were developed to fill those gaps: a gas-to-gas modular heat recovery unit; a gas-to-liquid exhaust gas heat exchanger. The former provided an entire heat recovery system in one unit. It was specifically designed to overcome the problems associated with existing component system of large design commitment, extensive installation and incompatibility between parts. The unit was intended to recover heat from multiple waste gas sources and, in particular, from baking ovens. A survey of the baking industry defined typical waste gas temperatures and flow rates, around which the unit was designed. The second unit was designed to recover heat from the exhaust gases of small diesel engines. The developed unit differed from existing designs by having a negligible effect on engine performance. In marketing terms these products are conceptual opposites. The first, a 'product-push' product generated from site and product surveys, required marketing following design. The second, a 'market-pull' product, resulted from a specific user need; this had a captive market and did not require marketing. Here marketing was replaced by commercial aspects including the protection of ideas, contracting, tendering and insurance requirements. These two product development routes are compared and contrasted. As a general conclusion this work suggests that it can be beneficial for small companies (as was the sponsor of this project) to undertake projects of the market-pull type. Generally they have a higher probability of success and are less capital intensive than their product-push counterparts. Development revealed shortcomings in three other fields: British Standards governing heat exchangers; financial assessment of energy saving schemes; degree day procedure of calculating energy savings. Methods are proposed to overcome these shortcomings.

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The solar chimney allows natural ventilation to be achieved during periods when the wind velocities are low and the difference between internal and external air temperatures is minimal. The correct design of such building components requires that designers have appropriate design tools available to them that are both effective and easy to use. The aim of this project was to evaluate design tools currently available and if appropriate to provide a tool that would allow the effects of variations in key physical parameters to be evaluated. Two design tools are currently available to designers; zonal models and CFD programmes. Both of these were however found to be unsuitable for the evaluation of the performance of a solar chimney. Zonal models assume that the air within a zone is fully mixed which results in the effects of variations in physical parameters on the mass flow rate being incorrectly predicted. CFD programmes require validation of any models developed before confidence in the predictions can be established, it was found however that data for such validation was not available for realistic flow configurations. An experimental rig was designed and tested to ensure that the uncertainty in the data produced was both minimised and accurately quantified. A detailed review of the sensitivity of a CFD programme to model and input variables was undertaken allowing development of an appropriate model. Comparison of the results of the experimental investigation and CFD predictions showed that the CFD programme, utilising the ke turbulence model accurately predicted air flow rates through a solar chimney across a range of key physical parameter variations. Within the limits of the validity determined for the CFD model, a detailed parametric investigation was then undertaken. The result of the parametric investigation was the development of a design tool appropriate for the determination of the effects of variations of the key physical variables on the mass flow rate through a solar chimney.

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This study concerns an investigation into air movement and associated energy flows within the environment of a synthetic fibre producing factory. A multiplicity of airconditioning and ventilation systems were operated within the factory to provide a suitable atmosphere for the yarn, and also to allow some degree of comfort in hot production areas. Potential for improved operation of these systems was anticipated. Initial experiments showed certain anomalies and problems relating to air conditions and air movement; and an important facet of the production areas was identified as the regular partitioning created by the machine layout. A review of previous studies of building air flows indicated a lack of information relating to industrial and partitioned areas. Mathematical relationships for air flows were studied and the interactions of similar, closely spaced partitions were considered. A series of model scale tests using simple layouts supported a theory of interaction. The effect was substantial for wall type partitions and a considerable overestimation could result from the simple additive approach to determination of total resistance. At the factory a computer based monitoring scheme was designed and installed in order to establish environmental conditions and energy flows. The concept of "total thermal efficiency" was developed as a means of evaluating the performance of some of the air-conditioning systems. Considerable variations were evident between seasons and between systems; improvements being possible and recommended. Air flows were also investigated using Nitrous Oxide as a tracer gas. The effect of the internal partitioning combined with the high degree of ventilation and air-conditioning was to "compartmentalize" the spaces between the machines in the production areas, semi-isolating each from its neighbours. Thus, the results of the simplified model scale work could not be applied directly. However the isolation of the spaces offers potential for better systems operation by reducing air-conditioning requirements.

The UK Government has placed the need to reduce national energy demands and carbon emissions at the forefront of the political agenda, with a commitment made to meet EU targets of 20% reductions in greenhouse gas emissions and primary energy consumption, alongside a 20% improvement in overall energy efficiency, across all EU Member States, by 2020. Building performance has been identified as a key area where significant progress towards meeting these ambitions can be made. It is fundamental to ensure that the building fabric of a property functions correctly in order to achieve high levels of thermal effectiveness, which should result in lower energy demands and carbon emissions. However, research to date shows that a gap exists between predicted and actual performance levels. This research utilises the dwelling Heat Loss Coefficient (HLC) as a common output in design stage and post-construction evaluation techniques, that can be used to compare predicted and measured fabric performance. The Standard Assessment Procedure (SAP), coheating tests, air pressure tests and thermal imaging are used to evaluate in-situ buildings. Sensitivity analysis and controlled conditions experiments are utilised in order to investigate the reliability of the assessment techniques used. The key findings from the study include the demonstration, through novel coheating test, that post-installation mechanically ventilated heat recovery (MVHR) system efficiency levels can have a pronounced effect on the measured HLC, and, in conjunction with use of assumed theoretical efficiency levels, can cause divergence in theoretical and measured data of 10-15%. This can largely be resolved through correct design, installation and commissioning. Environmental conditions, both notional and site-specific, can also cause divergence in the HLC data, including wind speed (15%) and solar gains (10-26%). In addition, it has been shown that, when considering thermal bridging values, inaccurate calculation at the design-stage and poor attention to detail during construction could cause underperformance in this element by up to 50%. This is of significance as there are currently no mandatory procedures to assess post-construction compliance with thermal bridging levels specified within the UK Building Regulations.

The technology and applications of evaporative cooling to provide human comfort in buildings is not new and has been used in different places based on different methods and materials. Conventional air conditioning systems overshadowed the application of evaporative cooling for buildings despite their ozone layer depletion. Evaporative cooling using porous ceramic evaporators were experimentally investigated. Encouraging results in terms of temperature reduction and cooling effectiveness were reported. In this work also thermoelectric unit was integrated in to the evaporative cooling system containing porous ceramic evaporators. The warm inlet air cooled in the evaporative cooling chamber was passed over the hot-side fins of the thermoelectric cooling device to act as a better heat sink. Typical test results showed that the cold side temperature of thermoelectric unit was 5Deg.C lower and the hot side was 10Deg.Clower, respectively when operated on the wet and dry porous ceramics evaporative cooling chamber. Direct evaporative cooling is often associated with the rise in relative humidity which may result in uncomfortable feeling due to unwanted increase in moisture. Indirect evaporative cooling offers a solution but still requires improvements in the effectiveness. There is also need for using cheap and readily available materials for the construction, requiring simple fabrication technology without very complex engineering infrastructure. Most widely used common fibrous materials have very limited capillary effect. So a periodic water spray system with an automatic control is required for running the cooler which adds to the power consumption, rise in operation costs as well as construction and operational difficulties. As a compromise using horizontal arrangement was considered. Use of pump for supplying water required to moisten the evaporative cooling surface was eliminated. The system was constructed and tested under varying temperature, relative humidity and air flow rates. Results showed significant temperature reduction accompanied with acceptable increase in relative humidity. Temperature drop of 6-10Deg.C between the inlet and outlet temperatures of the product or supply air was recorded. Increase in relative humidity of the supply air was 6 - 10% less than the working air. Application of this novel system was demonstrated in the parasol self-cooling arrangement. The fibre tube vaporative cooler has the potential of cooling a building space to the acceptable comfort limits. The application of porous ceramics for building space cooling, integrating the system to be used as a heat sink and the use of horizontal fibre tubes for evaporative cooling are all novel ideas in this field of research. Other novel features also include the ability to minimise energy consumption by eliminating common methods of continuous water circulation.

No description available.