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This handbook gives a comprehensive explanation of the theoretical and practical aspects of measuring important parameters for understanding air infiltration and ventilation within buildings. Discussed parameters include: airtightness of the building envelope and its component leakage paths; air exchange rates within a building and with the external environment; efficiency of the ventilation system; flow rates in the ventilation network. It has been designed so that material suited to differing levels of expertise is readily accessible.

Considerable developments in the area of computational fluid dynamics are currently taking place, especially in relation to refinements in calculation techniques. The objective of this report is to outline developments in building airflow analysis and to focus on some of the difficulties associated with this complex field of study. These include a brief synthesis of the relevant flow equations, the results of the AIVC's survey into the application of airflow codes for building airflow simulation, and summaries of selected public domain and commercial general purpose algorithms.

One of the aims of the Air Infiltration and Ventilation Centre is to encourage the collection and dissemination of air infiltration and airflow data as well as energy use data arising from programmes of research and experimental investigation. This task can be made much easier and more effective if the relevant test information and results are presented in a comprehensive and uniform manner.

The COMIS workshop (Conjunction of Multlzone Infiltration Specialists) was a Joint research effort to develop a multlzone Infiltration model. This workshop (October 1988 - September 1989) was hosted by the Energy Performance of Buildings Group at Lawrence Berkeley Laboratory's Applied Science Division. The task of the workshop was to develop a detailed multizone Inflitratlon program taking crack flow, HVAC-systems, single-sided ventilation and transport mechanism through large openings Into account.

The main objective of this report was to provide an introduction to the subject of contaminant removal effectiveness. Existing literature in this subject area is limited, and tends to be very difficult for a newcomer to understand. In recent years, a number of parameters have been defined in order to quantify contaminant removal effectiveness, but not all authors have used the same names or symbols for similar parameters, or derived them in the same way.

The main objective of this report was to provide a concise introduction into the subject of air change efficiency. Existing literature in this subject area is extensive, but it tends to be very detailed and is difficult for a newcomer to understand. Different authors also use different symbols and/or different definitions for the same concepts, which tends to confuse the reader. Little has been produced covering the basic ideas and concepts behind some of the terms used.

This document describes preliminary work towards validating models that predict airflow rates between several zones. It is preliminary in the sense that it examines the quality and definition of physical data needed for a more testing and thorough validation. The exercise has used a version of the multi-zone computer model developed by Walton at the National Bureau of Standards with some modifications to the treatment of wind pressure coefficients.

From a viewpoint of energy conservation air infiltration and ventilation have to be minimised. A certain amount of fresh outside air, however, has to be supplied to a building in order to maintain healthy and comfortable conditions for the inhabitants and to avoid structural damage. The optimisation of these adverse requirements will result in guidelines for minimum ventilation rates which are just large enough to meet the indispensable fresh air demand but small enough to avoid useless waste of energy.