States that it is difficult to achieve good mixing in a large space and that the usual methods to evaluate the ventilation system in such large spaces with the age of air measured by tracer gas is not often practicable. Proposes a new method to evaluate this ventilation, based on the normal step-down or decay method. A small control volume of tracer gas is used as opposed to filling the entire space. the local mean age of air is then measured in a study of the transient decay curve of the tracer gas concentration.
Steven Beckers and Pierre Lallemand conceived the refurbishment of the European Headquarters in the centre of Brussels. With a low-energy design, sensitive in its choice of materials, the building uses environmentally friendly strategies and meets all modern comfort and environmental standards.
Reviews the results of IRC research on some key factors that influence the performance of a ventilation system in large buildings. It discusses the effects of these factors and provides guidelines for operating the system efficiently. Improving the airtightness of older buildings will reduce air leakage and cold drafts, and help reduce energy use by improving the performance of ventilation systems.
A literature survey was conducted to identify measured airtightness values for various types of large buildings including Multi-Unit Residential Buildings (MURBs); offices; schools; commercial, industrial and institutional structures. Data was identified for 192 buildings in Canada, the United States, Great Britain and Sweden.
Large premises, such as airport tenninals or international conference centers, have high ceilings and large floor area. Most of passengers who use these facilities do not stay for a long time as they do in office blocks or residential housings, but occupy the buildings en masse for short periods of times.
In North America, there is an ongoing effort to repair the effects of corrosion in large boilers and pressure vessels. In recent years this work has been done from scaffolds erected in the boiler or vessel. The largest pressure vessels in British Columbia are known as Kamyr Digesters, and are found in Kraft pulp mills. The boilers are found in pulp mills across Canada and the USA, and in thermal power plants in east of the Rocky Mountains in Canada and across the USA. The scaffold structures are made up from 50 mm diameter steel columns and struts that are assembled with steel wedges.
This paper describes the development of a hybrid conditioning system that creates a comfortable indoor environment in a building. The operation of a variable-volume displacement conditioning system and a radiant cooled floor have been optimized to reduce the building load. Control strategies were developed that optimize energy consumption and contain moisture levels within specified limits. The development of conditioning-only occupied zones is shown and how the overall energy consumption is reduced. Its application in a large airport is described.