BRE have experimental data for the flows found in Passive Stack Ventilation (PSV) ducts from a test house in Garston. These data cover different duct diameters, number of bends and roof terminals, all measured over a variety of weather conditions. In the first part of this paper the data are analyzed to separate temperature and wind effects, and to see how well they fit well to the expected model of duct flow. The second part gives a comparison of the same data with predictions from the single zone ventilation model BREVENT.

The adequate ventilation of houses is essential for both the occupants and the building fabric. As air-tightness standards increase, background infiltration levels decrease and extra ventilation has to be designed into the building. Passive stack ventilation has many advantages - particularly when employed in low cost housing schemes - but it is essential that it performs satisfactorily. This paper give the results from monitoring two passive stack ventilation schemes.

The UK factory stock is predominantly naturally ventilated. Measurements performed in this class of building have indicated that air infiltration rates in factories are usually excessive in relation to occupants' requirements for health and safety, resulting in an energy penalty. As part of a project to investigate construction options for energy efficient industrial buildings, three factories of different cladding construction types were designed and then built at Aberarnan, South Wales.

Ventilation of the void below suspended timber floors is necessary to prevent dampness, which leads to wet and dry rot. The air flow beneath such a floor has been investigated for a range of ventilator hole positions, using a full-sized test room. The variations in heatlosses with ventilation rate have been measured, for floors with and without insulation. The use of radiation barriers in place of conventional thermal insulation was found to cut down the heat losses significantly at low ventilation rates, but was not so effective at higher rates.

The system of decentralized apartment ventilation has been successfully used for several years in multiple-storey apartment construction in the Federal Republic of Germany. With this tried and tested system, the individual apartments are vented into a common exhaust shaft with decentralized apartment ventilating fans. The special designs of the individual fans ensure a constant volume flow of the outgoing air in the individual apartments, in spite of the large pressure variations into the outgoing air conduits. Non-returnflaps prevent a back flow of the outgoing air.

Terminals are used on all types of ventilation system exhausts, often to prevent rain water and animal entry, but also to prevent wind induced flow-reversal and enhance wind induced updraught. There are many different terminal designs available displaying a wide range of characteristics. This report discusses a terminal testing and rating method. The tests highlight terminal wind performance as well as terminal resistance to the exhaust flow. The terminals are ranked according to loss coefficients and wind performance which allows them to be matched more closely to system requirements.

Ventilation and air conditioning systems mainly use fossile primary energies as gas, oil and coal for the heating and cooling processes. Air conditioning means heating and humidifying the supply air during the winter season and cooling and dehumidifying the supply air in the summer season. For these summer operations the supply air in general is cooled down lower than the dew point in order to dehumidify the air by condensation. Afterwords the supply air is reheated again to reach the required temperature level for room inlet.

User experiences of the workings of a ventilation system have often been pretty disheartening. Draughty, too hot, noisy, too stuffy are some of the verdicts which in many cases have been confirmed by objective measurements. Often the complaints are due to the air flows not being appropriate to the room. This in turn can be due to adjustment difficulties or to the flow balance in different branches of the system being affected by residents tampering with the supply or exhaust air terminal device settings.

A Test House at EA Technology, Capenhurst, has been refurbished to provide a ventilation test facility. The house was required to meet the following requirements: - A high standard of air tightness - Insulation to current Building Regulations or better - Incorporation of several ventilation systems - Comprehensive instrumentation The original timber frame front and rear facades of the house were replaced with brick and block construction. All internal floors, ceilings and partitions were replaced and the external walls replastered.

The aim of the study was to identify methods for the renovation of ventilation systems in domestic buildings which are 3 - 8 storeys high. Three typical buildings were selected and the problems in ventilation were examined. The designers made their proposals for repairs and the research team analyzed the solutions and made improvements. The special problems compared with new buildings included less airtight building envelopes and leakages in existing ventilation ducts.