Hybrid ventilation systems may consist of a combination of natural ventilation for air supply and a mechanical exhaust system. The quality level of thermal comfort is influenced by e.g. the way of air supply, the heating system at the facade and internal heat loads. This article deals with these parameters and their influence on the indoor climate based on research in climatic chambers.
By now hybrid ventilation systems are being used successfully in many projects. Three projects will be used to create a picture of the way in which the hybrid ventilation system has been used and of the experience with it. It can be concluded on the basis of these projects that hybrid ventilation is readily applicable and has a positive effect on comfort.
States that the poor indoor air quality of US schools has become a real concern for students, parents and educators. This article discusses why the problem exists. A second article is to cover source management and mechanical controls, and a third will provide a summary and list addional resources. States that modern schools are differently designed; buildings used to be able to handle small, common rainwater leaks without growing mould because they were constructed of masonry, steel, ceramics and plaster.
The brief for this university campus design required a low energy building for the business school and the education faculty, with a wide variety of room sizes and functions. The work included ensuring that the European Commission (Thermie programme) and the British Ministry for Energy DTI financed the low energy strategy. The energy strategy is based on a well-insulated building, a low energy ventilation system, passive solar energy gain, using direct daylight, using a building-integrated photovoltaic system. The buildings are very compact and well insulated.
Describes a cooling design using ground water to prevent overheating in London's underground train network. More conventional air conditioning is unusable because of the problem of exhausting the excess heat. However the proposed system would require moderate extra ventilation for the carriages. Rising groundwater is a major problem in London, and remains at 12 deg. C year-round. Temperatures in summer in tube trains is as high as 28 deg. C in the tunnels rising to 34 deg. C in the crowded trains. The groundwater is passed through heat exchangers in the tunnels which cool the air.
To ensure good indoor air quality in buildings, filters are installed in the ventilation ducts. These filters cause a pressure drop in the ducts, so that increased power to the ventilation fans is required to maintain the flow of fresh air. To reduce this problem, the Norwegian company, Interfil, developed a new energy efficient filter in 1995. This filter has been carefully tested in recent years. The test results show that, compared to ordinary filters, the new filters could reduce fan power by about 10%, while maintaining indoor air quality.
Nightsky, an innovative night roof spray storage cooling system, provides chilled water to in-slab tubing and fan coils. Passive cooling delivery from the slab cools the building in parallel with the 'active' chilled-water fan coils. Delivering a significant fraction of the building's cooling requirements via the floor slab allows that size of the forced-air delivery system to be reduced. NightSky is most appropriate for large, low-rise buildings that have low-slope roof areas.
States that car park ventilation systems not only have to control the exhaust gases emitted by vehicles but take into account possible fuel spillages and the venting of smoke in the event of a fire. Explores ways of checking for compliance.
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