The work discussed here concerns the conditions of comfort obtained in a room cooled by a fan coil in relation to the form of air flow obtained. It is based both on practical experiment and on numerical simulation using CFD code. Combining these methods allowed a large number of configurations to be studied, in association with different operating conditions for the appliance. Using the results in combination enabled a relation to be established between the problem data, the device characteristics and the comfort conditions obtained.
One of the first sorption-supported air-conditioning systems ("Desiccative Evaporative Cooling Systems") in an industrial building in Germany was installed in a printing office in Waiblingen, a town in southern Germany. The circumstances for such a system showed to be optimal, as the printing office is equipped with its own co-generation system delivering a considerable amount of waste heat. The experiences made with the system in the hot and humid summer of 1995 were very positive.
Continuously rising energy costs, the demand for reduction of CO2-emission and theprohibition of CFC-containing refrigerants create a base for new concepts of air-conditioning(A/C) systems. A primary action must be the prevention of heat consumption and cooling loadby improvement of the building architecture. Additional the efficiency of the A/C process mustbe improved, in order to reduce the energy input.In most cases the target is to replace the dehumidification process, which normally is realizedby refrigerating cycles, by alternative systems.
Due to the lack of proper sensors for odours, the odour concept, involving the unitsolf and decipol, is of very little practical use with respect to automatic control of VAVsystems. However, the decipol level in a room may be predicted from the concentration ofCO2 and the amount of fresh air supplied. By using the CO2 level as a decisive variable ofthe occupant load within the room, the actual air quality (decipol level) can be predicted.Once the decipol level is known, it is compared to a given set point, thus enabling thecontroller to alter the air flow rate accordingly.
This study examines technical issues of residential forced-air space conditioning systems incorporating heating, ventilation and cooling in the context of increasingly energy efficient new housing. Current technologies and practices are reviewed and analyzed with a view to improvements. Potential existing and emerging technologies and strategies are examined. A comparison of conventional and improved design strategies are presented for a house with a 5 kW heating load.
Are air conditioned buildings better at filtering out external pollutants than their naturally ventilated cousins? A recent field study carried out by researchers at the BRE has yielded some surprising results.
A new method is proposed to appraise the relative energy efficiency of designs for new or refurbished buildings. Based on the development of an energy efficiency index, it is simple to use and understand, and requires no particular expertise. The method offers a straightforward determination of likely energy performance. It addresses the total power rating of plant installed to achieve specified indoor environmental conditions, and the monitoring and control equipment which manages that capacity.
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