wind

We describe a novel modeling technique, based on Duhamel's theorem, to study the effects of time-varying winds on radon transport in soil near buildings. The technique, implemented in the model RapidSTART, reduces computational times for transient, three-dimensional, wind-induced soil-gas and radon transport by three to four orders of magnitude compared with conventional finite-dierence models.

The identification of effective factors in the historical formation of architecture can help develop architecture and its various aspects (Mofidi, 2005). These factors may be classified in the groups of cultural, historical and climatic. Specifically, the application of the native and traditional basis of past architecture can be highly significant for the improvement of contemporary architecture (Fathy, 1986).

Top down natural ventilation systems, usually referred to as ‘windcatchers’, have been used recently in modern non-domestic buildings in the UK. These systems combine inlet and outlet into a single roof mounted terminal, which is split into sections. Literature exists on theoretical, scale modelling and wind tunnel tests to evaluate the performance of the systems; however there is a scarcity of performance in-use tests. This paper presents the results of air exchange rate tests using the tracer gas decay method carried out in three operational buildings with windcatchers.

The wind speed and wind direction affected concentration of indoor radon in seven houses, which arelocated in three region of southern Finland. In the case of houses (B - F) which are built on upperslope of a permeable esker, according to the analysis of covariance the highest concentration of indoorradon, 20 - 33% over grand mean, was observed when wind (v?0.4 m.s-1) direction was perpendicularthe esker, leading to increasing pressure of soil gas and consequently to increased radon entry andconcentration.

In the scope of the EU supported project RESHYVENT, the possible integration of Renewable Energy Solutions (RES) into hybrid ventilation systems has been analysed. The focus has been on solar and wind applications to substitute the use of fossil fuel. The feasibility of the investigated options depends on the ventilation concept the RES is integrated into, the location of the building geographically, placement of the RES in the building and on the urban environment.

In that study, two air supply devices were investigated in order to simulate the characteristic of natural wind. The paper demontrates that the simulated natural air movement had an acceptability, for the subjects exposed, higher than the artificial air movement. With simulated natural air movement comfort may improve with energy saving in warm climates.

The provision of adequate naturally generated airflow is a vital component of energy-efficienthealthy buildings. Increasing densification in cities of today acts as a dominant influence onthe wind regime, diverting and obstructing natural wind flow to unpredictable levels.Localized air movement is often inadequate and vastly different from regional magnitudes anddirections and cannot be used as the basis of design.

A combined windcatcher and light pipe (SunCatcher) was installed in the building of theSchool of Construction Management and Engineering in the MSc Seminar Room (2N09).Monitoring of indoor environment in real weather conditions was conducted to evaluate theperformance of windcatchers in the room and to conduct occupant survey. External weatherconditions and internal indoor environment and air quality indicators were recorded. Thetracer gas decay method using SF6 was used to establish the air change rate for variousconditions.

Measurements of wind speed and wind direction, air temperature inside and outside an urbancanyon also infrared radiation in buildings have been measured on summer 2001 in Athens, in fivedifferent urban canyons, in the frame of Urbvent project. Urban canyons with different geometricalcharacteristics and orientation were placed in five different neighborhoods in Athens.Measurements took place in four different height levels inside each canyon, in the facades ofthem, also in the top of each canyon.

The focus of project Web has been the development of wind enhancement and integration techniques which improve the annual energy yield per installation by concentrating the low to moderate wind speeds (2-5 m/s).