In predicting flow rate of a cross-ventilatedbuilding, discharge coefficients obtained fromthe connected value of resistance coefficient ofopening based on the chamber method, and thewind pressure coefficients from a sealedbuilding are usually used. This method canpredict the flow rate well for the case of smallopenings. For the large openings, however, it iswell known that flow rate could beunderestimated because these are not based onactual condition.

The purpose of this study is to clarify thecharacteristics of airflow around building roofand to provide the guidelines for design ofnatural ventilation by chimney.

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.

Measurements and smoke tests show that thequadrants of a Windcatcher with a positivepressure across them act as supply ducts, whilethose with a negative pressure across them actas exhaust ducts.

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.

If thermal insulation and solar control ofbuilding envelopes are appropriately made forindoor thermal environment control, then themoderate air current becomes relativelyeffective for thermal comfort especially inresidentional buildings in summer seasons.To clarify the ways of natural ventilation withsufficient thermal insulation and solar control,we examined four cases of natural ventilation.We use an experimental house designed withthe concept of symbiosis in Tsukuba for tendays in August, 2007.

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.

This paper presents a study of solar chimneysusing a Phase Change Material (PCM)integrated into the heat absorber of the solarchimney. Solar chimneys have recently beenused as natural ventilation devices in buildingsin order to improve the quality of indoor airand provide a comfortable environment for theinhabitants. The advantage of a solar chimneyis that it depends on solar energy rather thanelectricity for generating ventilation. However,it is unstable as a ventilation system since itsventilation rate is directly affected by the solarradiation.

The case study of a nursery school of Bologna isa pilot example of how hybrid ventilationsystems can be embedded in architecturallysignificant buildings. This paper hasinvestigated the operating condition of thispeculiar design to make sure that designhypothesis were accomplished. To do this, afteran ovewiew of local climatic conditions andsensors recent data, a CFD simulation has beenmade to compare theoretical and real behavior.

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.