The subtask 2 of Annex XX (Optimization of Air Flow Patterns Within Buildings) involved a research project called "Air Flows Through Large Openings In Buildings". The scope of this project was to test the range of validity of available algorithms, and where possible to develop new ones. This paper focuses on the new interzonal airflow studies which have been carried out in this frame.

We report on four new full scale experiments that were designed to measure the influence of wind on the ventilation and/or heat loss rates through single large openings: a) test-house with horizontal slit opening, set-up to measure internal pressures and the effect of air-compressibility (CSTB, France), b) attic with window ajar, set-up to measure long term ventilation rates with varying wind and temperatures (BBRI, Belgium), c) fully open window, set-up to measure ventilation rate and cooling as a function of time (BRE, UK) d) fully open window, set-up tomeasure cooling as a function of ti

The paper describes work on simplified design methods made in connection with the International Energy Agency programme "Air Flow Pattern within Buildings", Annex 20, subtask 1. It is shown that simplified models are able to indicate design values as the maximum velocity in the occupied zone and penetration depth of a non-isothennal jet in a room. The design according to throw of an isothermal jet is a fully developed method which has a sufficient level of accuracy when it is used in regular rooms.

The ability to accurately predict air movement and temperature distribution in spaces offers the potential for design engineers to evaluate and optimise room air distribution systems at an early stage, leading to improved thermal comfort and ventilation effectiveness. The computer models which are used for detailed analyses are based on computational fluid dynamics [1,2] and employ sophisticated numerical algorithms to satisfy the basic laws of physics. The programs are such that they are more complex and more difficult to use than those with which design engineers may be more familiar.

The International Energy Agency (IEA) task-sharing project "Air Flow Patterns within Buildings" was initiated in May 1988 for a duration of 3,5 years. Twelve nations contribute work and expertise and "share the task" specified in the project's objectives. This project and the AIVC belong to the same Implementing Agreement: The Energy Conservation in Buildings and Community Systems Program. As "Attachments" to the Implementing Agreement, they are called Annexes.

AIVC Conference proceedings. Contains 31 posters from the 12th AIVC Conference held in Ottawa, Canada, September 1991.

AIVC Conference proceedings. Contains 28 posters from the 12th AIVC Conference held in Ottawa, Canada, September 1991.

AIVC Conference proceedings. Contains 28 papers from the 12th AIVC Conference held in Ottawa, Canada, September 1991.

The use of independent people who visit the buildings is another approach to evaluating indoor air quality. Panels of 50 to 100 subjects have been used to evaluate the air quality in office buildings.

Accurate measurement of the positions of windows, skylights, vents, dampers, etc. has always been a problem for researchers. Often open/closed switches are used which do not indicate the degree of opening which has occurred. The use of Hall-Effect sensors to measure such positions was first proposed for monitoring residential passive air inlets.