The traditional way to dehumidify the outdoor air in a heating, ventilating and airconditioning (ENAC) system is by cooling the air temperature down below the dew point.For this process a refrigeration system is necessary to realise these low temperatures.Nowadays the disadvantages of refrigeration systems are widely known. An alternativemethod to dehumidify the air is by separating the process of dehumidification and cooling.There are different ways to get low supply air temperatures for cooling the indoor spaces.

In the UK's temperate maritime climate, the need to air-condition a non-domestic building outside city centres should be the exception rather than the rule. Nevertheless, the potential clients for new or refurbished buildings, whether tenants or owner occupiers, are concerned about whether a non-air-conditioned building can deliver comfortable and productive working conditions, particularly in summertime.

Natural ventilation based on Passive-stacks are currently designed without incorporating heat recovery leading to wasteful heat loss. Heat recovery is not used because the pressure loss caused by conventional heat exchangers is large and could cause the ventilation system to fail. This paper presents laboratory investigation and computer simulation of a low pressure-loss heat recovery device for passive stack systems. It was found that the heat recovery effectiveness decreases with increasing stack velocity and heat recovery effectiveness of over 50% has been obtained in the experiments.

The majority of urban pollution is traffic related and often shows daily variations with peaks occurring at rush hours. Poor outdoor air quality can affect the IAQ of local buildings that ventilate with polluted air. This is particularly applicable to buildings where AHU air intakes are at low level and adjacent to busy roads. The effect of pollution peaks can be minimized by ventilation control and this paper presents potential control techniques for periods when outdoor air quality is poor.

Providing Quality for People has many aspects. Of these, one is providing buildings that give clients and users better value for their money. Another addresses the issues of preserving our heritage upon which our quality of life based. This paper describes how these can be achieved using the application of innovative design concepts supported by advanced analytical techniques. For the majority of archive repositories, storing as they do paper type material, environmental conditions of 60±5% and 15.5±2.5 °C are recommended by British Standard 5454.

A thermal simulation model and suitable weather data were used to generate design curves for the application of night ventilation cooling to office buildings. The work was carried out under the programme of the International Energy Agency (IEA) Annex 28 on 'Low Energy Cooling'. The generated curves show the potential reduction in internal peak day temperatures throughout the cooling season, the free cooling provided by night ventilation and the number of hours that a fan would run during the night for mechanical systems to achieve this free cooling.

Finding a solution to the problem of draughty buildings can be fraught with difficulty. Very often only the symptoms are apparent and the root cause can be difficult to identify. All too often a 'try and see' approach is adopted until finally, if luck prevails, a successful solution is found. The design team addressing the problem of a draughty mall at a shopping centre in Shrewsbury adopted a different approach. The possible causes were identified using site knowledge and Computational Fluid Dynamics. A 'blind' analysis of site data was then undertaken by an independent statistician ie.