ventilation strategies

High-quality data obtained from three-dimensional Particle Tracking Velocimetry (3D PTV) is pivotal for indoor environment engineering when designing ventilation strategies or monitoring airborne pollutants dispersion in inhabited spaces. A new method is proposed to link multiple 3D PTV systems, positioned side by side so that the entire measuring volume can be covered. An algorithm is developed to establish a link between the particles' trajectories calculated by each 3D PTV system.

Situated 1º North of the equator, Singapore has a year-round hot and humid climate with temperatures in the range of 25 and 32º C and relative humidity around 70%.  In view of these environmental conditions, there is really no need for “Heating (or simply “H”) in the traditional Heating, Ventilating and Air-Conditioning (HVAC) terminology.  Consequently, the term Air-Conditioning and Mechanical Ventilation (ACMV) is used in the local industry.

Ventilation air may be provided in buildings by means of natural or mechanical strategies. When a HVAC system is installed, thermal comfort and indoor air quality (IAQ) may be controlled with higher precision. However, especially between the 70s and the 90s, mechanical ventilation systems have been installed on formerly naturally ventilated buildings without providing any control for natural ventilation.

One of the most commonly used strategies to reduce the heating demand in low energy buildings is reducing the leakage level of the building envelope. Dedicated ventilation systems are then installed to compensate for the reduced air change rate in an energy efficient way. Most occupants, however, operate their ventilation system at very low flow rates. Together with the emission of bio-effluents, linked to the presence of the occupants, moisture production related to household activities is one of the most important sources of indoor air pollution in dwellings.

In this article we compare to ventilation strategies to heat a “passive house” office building using only the ventilation system. Two ventilation strategies with supply air temperature above and below the current room temperature were compared through a cross over experiment. A questionnaire was used to measure the perceived health and well being. Both strategies documented very good indoor climate with highly positive scores on the questionnaire.

Releases of airborne chemicals can rapidly affect wide areas, leading to exposures that may adversely affect public health. A strategy of sheltering indoors has often successfully protected public health, but in some cases it has been ineffective. This paper explores the role of ventilation as one of a number of factors that affect shelter effectiveness.

A good level of thermal insulation and an adequate thermal capacity of the building envelope are essential to achieve good energy performance. Many studies have been conducted about this topic, mostly focused on the reduction of energy losses, peak load control and energy savings. Nevertheless, very few studies were realized addressing both insulation and inertia of the building envelope in a thermal comfort perspective, and taking into account the combined effect of different ventilation strategies.

A potential conflict may exist between energy saving and good indoor climate. The present project is phase 2 of a 5-year research programme consisting of four phases, the objective of which was to develop energy efficient ventilation strategies that will provide both healthy and comfortable indoor climate and reduced energy consumption when compared to present standard.

This paper discusses the application of a new strategy approach for the room air conditioning. The basis of the classification is different aims or ideas of the temperature, gas, particle, humidity distributions and room air flow patterns that can be created within a room. A certain strategy can be applied by using different system combinations of room air distribution, exhaust, heating and cooling methods and their control. The realization of an ideal strategy is also dependent on the operating parameters and internal sources.

The multi-storey blocks which constitute the main type of building in Greek urban environments, have certain common characteristics. Those characteristics include the overall building dimensions and geometry, internal room dimensions, the materials used both in building construction and insulation, the size and the arrangement of the openings on the facades, the arrangement of the balconies, the position and dimension of the staircase etc.