There are certain conditions which are of interest when designing for natural ventilation ofcommercial buildings. These are:- summer cooling- indoor air quality in winter- night-time cooling.For the first two conditions it is necessary to determine the distribution of open areas to givethe desired distribution of flow rates. Since one is dealing with openings whose position andbasic geometry are known, the problem is relatively simple compared to general ventilationproblems.

This paper identifies the significance of pollution at five sites amongst the worst on the British mainland hence indicative of other polluted areas within Europe. Three sites are located in London and one each in Birmingham and Cardiff. The pollutants examined are NO2, SO2, O3 and PM10. Newly proposed DOE figures defining poor air quality have been used to re-examine the frequency of excess pollution episodes between 1992-1995. The results identify the most appropriate periods for natural ventilation of offices in urban areas in terms of the hour in a day and time of year.

Within the EU project NATVENT, which deals with the application of natural ventilation in office type buildings, one of the items to be studied was controlled air flow inlets. Natural air supply is a key part in the design of natural ventilation in offices. In cases these air supplies are designed in the wrong way one may expect complaints in terms of draft and stuffiness. Size and controls on inlets are vital elements in design. Controlled air inlets may help to overcome the problems of draft and stuffiness, and may contribute to an energy efficient design of the building.

Temperature and cooling demand in a room summertime are influenced by numerous factors,like internal gains, ventilation, solar gain, behaviour of occupants, thermal inertia of the roomand outdoor conditions (climate).The thermal environment and cooling demand summertime are often analysed using detailedcomputer programs, which take into account the factors mentioned above (among others).Often the overview, transparency and some of the physical insight is lost using these advancedcomputer programs.In a predesign phase of a project it is preferable to do simple calculations of the thermalbeha

Solar control devices placed in front of large building openings disturb air flow and theradiation transfer. Although solar radiation transfer through obstructed openings is arelatively well researched area, very little information is available regarding the air flowperturbations and daylighting alterations created by external solar control devices. Thepresent paper reports a series of experiments aiming at investigating natural ventilationand daylight phenomena associated with the use of specific shading devices.

NiteCool was developed under the Energy Related Environmental Issues in Buildings(EnREI) DOE Programme and is designed especially for the assessment of a range of nightcooling ventilation strategies. The program is based on a single zone ventilation model and isconfigured to analyse a 10m x 6m x3m cell of an office building. It is intended to be used atthe early stages in the design process to help the designer to make informed decisions on theconstruction, opening configuration and operation of the building.

The concept of 'build tight - ventilate right' requires minimising air infiltration through theenvelope of a building and then providing adequate ventilation in a controlled manner tosatisfy the fresh air requirements of occupants. This paper describes a simple-to-use designtool (PC based and in spreadsheet format) for predicting the airtightness of office buildingenvelopes either at the design stage or before a major refurbishment.

An extensive experimental program on single sided natural ventilation was carried out within the frame of PASCOOL EC research project. Within the frame of these activities, four single sided natural ventilation experiments were carried out in a cell test, a full scale outdoor facility. Experimental data were used as input for numerical simulations that were carried out using air flow calculation tools based on network modeling as well as computational fluid dynamics (CFD). Finally, fuzzy logic techniques were used to predict the air velocity profile in the middle of the opening.

Four types of heat-pipe heat recovery systems were tested for application in passive stackventilation. The effects of fin shape, pipe arrangement and air velocity on the heat recoveryeffectiveness were investigated. The air velocity was found to have a significant effect on theeffectiveness of heat recovery; the effectiveness decreasing with increasing air velocity.The pressure loss coefficient for heat pipe units was also determined.

We examine conditions under which the natural forces of wind and buoyancy may beharnessed in order to provide ventilation for cooling. Steady-state, displacement flows drivenby combined buoyancy and wind forces are simulated at small scale in the laboratory using aPerspex box to represent a generic room or single-spaced building. Density differencesnecessary to simulate the stack effect are produced using fresh and salt water solutions. Windflow is simulated by placing the box in a flume tank; the flume produces a flow of water pastthe box and this flow is used to represent the wind.