PR2008

Energy efficient building means automaticallyextra attention to energy efficient ventilationand air tight building. At this moment there area number of new innovative domesticventilation systems in the market as analternative for the common MVHR systems.The types of systems range from advancednatural and hybrid systems to balanced hybridsystems. All these systems can combine a lowenergy consumption with a good indoor airquality and thermal comfort and guarantees onreliability and performance. A prerequisite forthis is a good design and especially a goodconstruction and commissioning.

Conventionally, the flow rate of a crossventilatedbuilding is predicted by using theorifice equation. When the opening is small,flow becomes like infiltration through cracks, itis useful. However, the flow rate could beunderestimated when the orifice equation isapplied to the cross-ventilated flow throughlarge openings. The goal of this research is topropose the prediction method of the flow rateof a cross-ventilated building by considering thepower balance inside the whole stream tube.

Prediction and visualisation of wind flow andpollutant dispersion in urban, densely built areasis necessary for city planners and engineers inorder to regulate and monitor successfully thelocal air quality. Wind vortices, low pressurezones and channelling effects may affect theventilation characteristics of street canyonsunder different meteorological conditions. Inthis respect physical and mathematical modelsare employed which are able to provide insightinto passive cooling techniques for buildingslocated in densely built up areas.

The present research was aimed at the definitionof a design hypothesis for the construction of apharmaceutical warehouse in a hot humid areaof southern Sudan. The candidate hypotheseswere based on an existing prefabricated singlestoreypitched-roof steel stiuctural systems 18 mlong and 9 m wide and had to be constsuctible ata low cost and using local materials. At climaticlevel, the goal was that daily d.b. temperaturesnot exceeding 27-28 "C were reached bypassive of very low-energy means, which wasnot easy to achieve in the given conditions.

There is an obvious and indisputable need for anincrease in the efficiency of energy utilization inbuildings. Heating, cooling and lightingappliances in buildings account for more thanone third of the world's primary energy demand.In turn, building stock is a major contributor toenergy-related environmental problems.

Recently, dampness in buildings has beenindicated to be associated with occupants' healthdamages such as allergies. In particular mold inindoor air is considered to be a significant riskfactor of health. The indoor concentration ofmolds becomes higher with mold growth on thesurfaces of wall, floor, ceiling and so on.However, mold growth in the concealed spaces:inner wall spaces, beam spaces and crawlspaces, can not be ignored as one of theemission sources.

Development of a unique measuring unit for airflow volume within the vertical shaft of naturalventilation system with solar chimney with theresults of laboratory test and on-sitemeasurement is presented. As it was considerednecessary to make a continuous, siniultaneousmeasurement of a fluctuating air flow within thevertical shafts towards solar chimney, thesimple measuring unit was devised. This unitconsists of pressure detector and data logger tobe installed at several locations. First therelationship between the air velocity and thepressure difference was obtained in thelaboratory test.

On-site air flow measurements of domesticventilation systems with using funnel type airflow measurement instrument which isgenerally used in Japan, has been reported themeasurement difficulties due to the terminaldevices' installed location, the existence offurniture in the vicinity or skill of the measurer.Hence investigations on the measurementmethod, which has lesser influences of thedisturbance, have been needed. Therefore, thisstudy compares on-site air flow measurementwith funnel method and pressure differencemethod which is considered as on of thesolution.

Subtask B of the IEA-ECBS Annex 44"Integrating Environmentally ResponsiveElements in Buildings" deals with thedevelopment and the optimisation of integratedbuilding elements. The results of two modelbuildings exemplify the impact of buildingconcepts and user behaviour on the operation ofthe building. The analysis shows that innovativebuilding concepts and elements, which to someextent are being realised at the moment, need totake into account system integration andintelligent planning in order to achievesatisfactory results.

Tall buildings have traditionally been sealed andmechanical ventilated. In recent years advanceshave been made allowing the natural ventilationof tall buildings for a part of the year. Themotivation has been both energy savings andoccupant comfort. The projects realized thus farwork on the mixed mode principle. Naturalventilation is employed for a proportion of theannual period. However under certain wind andexternal temperature conditions mechanicalsystems take over.