natural ventilation

In this paper the effectiveness of retrofitting strategies in a sunspace attached to a one-storey building has been investigated. Natural and hybrid ventilation, air-tight glass partitions, awnings and increased thermal mass retrofitting scenarios were implemented, mainly for the Greek climate. Window openings and sensor-controlled fans were used to create a controllable and secure environment. Combined ventilation and thermal simulation were applied, taking into account all the related physical phenomena, such as ventilation, infiltration and solar radiation.

Past research (ASHRAE RP-884) demonstrated that occupants of naturally ventilated buildings are comfortable in a wider range of temperatures than occupants of buildings with centrally controlled HVAC systems. However, the exact influence of personal control in explaining these differences could only be hypothesized because of the limits of the existing field study data that formed the basis of that research. The objective of ASHRAE RP-1161 was to quantitatively investigate how

In so far as natural ventilation system is totally dependent on local weather conditions and building facade elements, housing ventilation cannot be permanently guaranteed. This paper offers a computational flow simulation (CFD) which can be used to analyze housing ventilation under different buildings and weather conditions.

The aim of this paper is to give an overview of the work carried out during three years with URBVENT project and to present its main issues: - to provide methodologies and accompanying software tools to assess the potential and feasibility of natural ventilation - to design optimal openings for efficient naturally ventilated buildings.The different partners of this project are: five European University laboratories, two technical centers and one industrial company.

In this paper "the ventilability chart" concept is presented and the methodology for drawing it for whatever space is illustrated: its aim is to check the effectiveness of natural ventilation in ensuring comfort levels related to the indoor air quality.Three case studies of calculation of air exchanges by naturally ventilation in typical office room are presented.Through the ventilability charts here proposed, it is possible to determine the conditions under which natural ventilation can be properly used instead of mechanical ventilation.

In this paper, different types of local housings have been classified (housing with two facades, housing with two facades in angle or in corner, housing with facade and interior patios, housing with an only facade, embedded housings, in several heights) with the aim of defining the natural ventilation's parameters for them. Then simulations can be made with the selected types along with the validation of results.

In Norway and Sweden's schools, hybrid or natural ventilation with ground-coupled fresh air intake ducts (or culverts) is the popular way of conditioning air.The ground-coupled ducts are normally made of concrete and easily accessible for inspection and cleaning; they can be divided into two parts: the air-intake culvert and the air-distribution culvert. Measurements show that the use of ground-coupled ducts along with a suitable airflow regulation is a guarantee that the supply air is colder than room air.

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.

During the construction of Dhoby Ghaut Station on the MRT North-East line a 10-storeycommercial development was completed. The facade is a vented cavity of a triple glazedconstruction comprising of an Insulated Glazed Unit, cavity blind with natural ventilation, anda single internal operable glazed layer. This type of facade technology has been used inEurope; however, its relevance in tropical climates where buildings are cooling-dominatedneeds to be carefully considered.

The objectives of the present work are to use computational fluid dynamics (CFD) to studythe airflow pattern and to evaluate the effectiveness of the passive cooling design of theproposed Jurong General Hospital (JGH) using natural wind. The complex three-dimensionalCFD model is used to assess the environmental conditions at the deep podium inside the JGHcomplex with prevailing wind conditions in Singapore, corresponding to the monsoon(November-February) and hot (March-October) seasons.