cooling

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.

This paper critically reviews current and previous research into the use of displacement ventilation in commercial offices with and without supplementary static cooling devices. It also reports the findings of a preliminary study of a displacement ventilation technique that may increase the scope of application for displacemelllt ventilation systems without the need for supplementary static cooling.

There is increased interest in using chilled ceilings and beams for cooling in UK buildings, on account of their perceived advantages over traditional air or chilled water based systems. However, there is currently limited knowledge or experience of the use of chilled ceiling and beam systems in the UK, and there is no proper professional guidance. Designers are particularly concerned to avoid condensation occurring on the exposed cold surfaces that could cause a health problem or lead to the so-called "office rain" effect.

Air conditioning, as we know it, providing thermal comfort by mechanical means, first appeared in buildings about one hundred years ago. During that time it has had major influence on the evolution of the design buildings. This paper reviews the development of providing cool comfort in office buildings from the pre-active era of the middle of the 19th century through the rise of air conditioning in the mid 20th century to the current state of the art.

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.

This paper reviews several aspects of the performance of displacement ventilation: temperature distribution, flow distribution, contaminant distribution, comfort, energy and cost analysis, and design guidelines. Ventilation rate, cooling load, heat source, wall characteristics, space height, and diffuser type have major impacts on the performance of displacement ventilation.

Night cooling is an established technique allowing ventilation to take place at night with the intention of removing heat gains that have built up during the preceding day. By permitting the cool night air to flow through a building, heat is removed and a store of the cool air within the building fabric, furniture and fittings is achieved thus providing a cooling effect the following day.

This report is the third in a series produced for project 11621 "Night Cooling Control Strategies". The first report was a literature review of night cooling techniques, the second report detailed the results from case study buildings that were monitored in 1995 and this report includes the results of dynamic thermal simulation. APACHE thermal simulation software was used to model a basic representation of one of the case study buildings.