Local exhaust ventilation systems are normally the most cost efficient method for controlling air pollutants and excessive heat. For many manual operations, capturing pollutants at or near their source is the only way to insure compliance with threshold limit values in the workers breathing zone. Local exhaust ventilation optimize ventilation airflow thus optimizing system costs especially where recirculation is not used.
Modeling of delivery efficiency was performed using three levels of combining measured and default input parameters and compared to measured data from seven manufactured homes. Using values based on all measured data provided modeled efficiency results that were closest to short-term coheat efficiency results. As individual measured parameters were replaced by estimated or default values suggested by the draft version of proposed ASH RAE Standard l 52P, the agreement with measured efficiency results worsened.
This study was initiated to determine the extent of cold temperature air leakage from operable windows available in todays marketplace and the impact that this has on the energy consumption of a house. During the heating season, changes in the window's leakage characteristics, as a result of thermal and pressure effects, were to be included. At two laboratories, air-leakage tests down to-30°C were performed on 35 windows, enough to reach some general conclusions about performance.
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.
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