In this programme of work, methodologies for determining infiltration rates of large and complex buildings have been established. Theoretical considerations suggested that comprehensive information regarding interzonal air movements might be obtained from experimental techniques using multiple tracer gases. Field measurements to determine interzonal flows were carried out in office buildings using automated measurement systems developed for this purpose. Simpler techniques were found to be needed and were developed.
Discusses 11 strategies where methods and guidelines should be applied now by the building services engineer in designing new ventilation systems or retrofitting existing systems.
Treats major design and construction actions that can be taken in houses to limit conduction losses, increase heating performance, reduce energy losses through windows and provide adequate ventilation air - super insulation, high performance furnace or boiler, high performance windows and controlled ventilation. Discusses in some detail how controlling indoor air pollutants at source is the preferred approach to maintaining indoor air quality. Illustrates diagrammatically and explains how a house functions under natural ventilation conditions.
One of a series of articles focussing on problem areas in buildings. 1) Examines condensation risks in buildings. Treats condensation processes, water vapour input and movement, conditions for surface and interstitial condensation in walls and roofs. 2) Treats condensation avoidance in general, humidity control, controlling vapour flow, adding insulation, heating, mould. Illustrates numerous examples diagrammatically from various building types.
Development of infiltration and interroom airflow calculation methods, driven by a concern for indoor air quality have led to a computer simulation of interroom contaminant movement. The model, which assumes fully mixed room air, shows that open doorways provide rapid mixing between rooms in buildings using forced air heating. It also confirms that it is most energy efficient to remove the contaminant nearest its source. Detailed modeling of the variations in contaminant concentration within a room is not presently feasible for long term energy analysis simulations.
A computational procedure to predict expected rates of natural ventilation for buildings at the design stage is investigated. This procedure integrates three computational methods, namely one to predict temperature induced pressures, another to compute wind generated pressure distributions around buildings, and the third to analyse the networks of resulting air flows in buildings. Experiments show that these methods are valid. The three methods can be used not only for the prediction of natural ventilation, but also for many other environmental engineering applications, e.g.
The objective of this paper is to highlight the range of air infiltration and ventilation models that are available to the designer and to indicate the appropriate level of associated computer hardware that is necessary to support these modelling methods. The description begins with a discussion on simple empirical methods intended for basic design calculations. The applicability of these methods is discussed and some of their shortcomings are highlighted.
In order to obtain means for determining realistic convective heat transfer coefficients, a hierarchy of interacting and interdependent calculation methods have been developed by the authors. Both higher and lower level models have been used to develop and verify an 'intermediate level' computer code, which formed the basis for generating input convective heat transfer data for dynamic building models. The contribution considers the computation of convective heat exchange within three-dimensional, rectangular enclosures when buoyancy effects are significant.
One of the recent major developments to the ESP (Environmental System Performance) building/plant energy simulation package has been the integration of a technique capable of performing dynamic air flow analysis as part of the building thermal analysis, thereby permitting simultaneous dynamic modelling of energy and air flow within the building envelope. This paper briefly describes the model and its data requirements. It compares and discusses differences in zone energy requirements and temperature levels (obtained from ESP) when 1. applying traditional air changes rates and, 2.