Publisher's Synopsis
Free cooling in the context of this document can be defined as "that amount of cooling which can be obtained from existing, additional or modified system components during low-ambient conditions and used to partly or wholly offset the load on mechanical refrigeration plant.";The objective of the research leading up to this report was to produce collective application-and-design guidance on these techniques, applicable to new and retrofit air-conditioning systems. Alternative methods of free cooling, such as fabric-energy storage, are covered in other BSRIA publications.;The free-cooling techniques detailed have been divided between water-side and air-side systems. The first half of the document deals with the water-side systems which make use of evaporative cooling towers. The second half deals with air-side systems which ensure the most efficient use of fresh and re-circulated air to cool a building.;The guidance offered is generally directed at two types of professional: firstly, the technically-aware building client/operator investigating ways to reduce energy usage; and secondly, the building services designer involved in selecting, evaluating and designing a free-cooling system.;Extensive use of schematics has been made throughout to highlight system configurations and principles of operation. Methods of control are described in detail and represented graphically in logic diagrams and psychometric charts. Numerous graphs are provided to demonstrate system economics and assist with the sizing of system components. Wherever possible, guidance is provided on plant costs and a worked example, demonstrating the energy savings for a common type of water-side system, has also been included.
