AIVC - Air Infiltration and Ventilation Centre

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Experimental Investigation of the Impact of Environmental Conditions on the Measurement of Building Infiltration, and its correlation with Airtightness

The air infiltration of a building, which fundamentally depends on its airtightness, can be a significant contributor to its heat loss.  It can also be affected by other factors such as external terrain, leakage distribution, sheltering factor and environmental conditions. The infiltration rate of a detached UK house was monitored for 2 months in early 2018 using constant concentration and decay tracer gas methods under various temperature and wind conditions.

Wind-induced pressure coefficients on buildings dedicated to air change rate assessment with CFD tool in complex urban areas

The paper presents a numerical methodology to assess the natural ventilation. UrbaWind is an automatic computational fluid dynamics code. It was developed to model the wind in urban environments. The turbulence modelling, namely the dependence of turbulence length on the distance from wall, and the model constants were calibrated in order to reproduce with good agreements flow separation around buildings walls and pressure coefficient field on façades. Numerical results match well with the experiments: separation patterns and pressure field on walls in dense urban areas.

Short-term prediction of weather parameters using online weather forecasts

While people need to know tomorrow’s weather to decide suitable activities and precautions, so do the “intelligent” building management systems. The accuracy of the short-term prediction of the ambient conditions is particularly import for the development  of predictive control strategies.

Natural ventilation strategy potential analysis in an existing school building

Natural ventilation is increasingly considered a promising solution to improve thermal comfort in buildings, including schools. However in order to support its planning and implementation, quantitative analysis on airflow paths and heat-airflow building interactions are needed. This requires an adequate accounting of both internal effects, from building layout and structure, and external forcings from atmospheric factors.

The Impact of Urban Wind Environments on Natural Ventilation

The aim of this paper is to illustrate the impact of urban wind environments when assessing the availability of natural ventilation. A numerical study of urban airflow for a complex of five building blocks located at the University of Reading, UK is presented. The computational fluid dynamics software package ANSYS was used to simulate six typical cases of urban wind environments and to assess the potential for natural ventilation. The study highlights the impact of three typical architectural forms (street canyons, semi-enclosures and courtyards) on the local wind environment.

Revisiting Internal Pressure Dynamics in a Single Opening Enclosure Ventilated by Wind

This paper describes a re-analysis of internal pressure and building ventilation in a single-opening enclosure ventilated by winds. The dynamics of internal pressure is governed by a nonlinear oscillation equation. An alternative semi-nonlinear approach is proposed for obtaining the amplitude and phase shift of the periodic motion, the resonant frequency and resonant amplitude. Our new approach reproduced two of the commonly used existing linearization results.

Effects of variable wind speed and direction on radon transport from soil into buildings: model development and exploratory results

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 Role of Wind and Natural Ventilation in the Vernacular Architecture of Zavareh

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).

Windcatchers in Modern UK Buildings: Experimental Study

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.

How did wind affect the radon entry into seven detached houses

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.