The influence on ventilation efficiency in typical dwelling with floor-based displacement ventilation

The characteristics of the climate in Taiwan are high temperature and humidity. In order to solvethese basic problems in dwellings, a meteorological station was established in Fulong(northeastern part of Taiwan) to document the detailed microclimatic information of indoor andambient environments during 4 years. According to the hydrodynamics and thermal mechanics,the new ventilation strategy was developed with the thermal mass cooling-down systemconstructed as the porous floor in a full-scale climate chamber.

Relative influence of boundary conditions on the indoor air quality of a displacement ventilated room

In the indoor air quality (IAQ) assessment of ventilated enclosures it is useful to know therelative influence of key boundary conditions on the personal exposure and ventilationeffectiveness, for instance as a source of information on where to allocate the greatest effortin the design phase. CFD is used to predict ventilation effectiveness and personal exposure tocontaminant sources in a displacement ventilated room subject to variation of several keyboundary conditions.

Influence of geometry of thermal manikins on concentration distribution and personal exposure

A number of different thermal manikins have been applied in literature to experimentallystudy the indoor environment. These manikins differ in size, shape and level of geometriccomplexity ranging from simple box or cylinder shaped thermal manikins to humanlikebreathing thermal manikins. None of the reported studies, however, deals with the influenceof geometry of the thermal manikin.

A thermal comfort study on displacement ventilation in the tropics

This paper presents the performance of a displacement ventilation system in a thermalchamber with tropical subjects. The chamber is served by an Air-Conditioning andMechanical Ventilation (ACMV) system in either Mixing or Displacement Ventilation modes.In the experiments, tropical subjects were surveyed with respect to their thermal sensationsunder different room conditions in either displacement ventilation or mixing ventilation.Objective measurements such as room air temperature, air velocity and relative humidity weremeasured at different heights in the chamber.

Estimating performance of thermal displacement HVAC systems using heat balance-based simulation programs

This paper will address the shortcomings of typical heat balance-based HVAC design and analysis software when applied to thermal displacement ventilation (TDV) system design. The performance characteristics of thermal displacement systems that lead to inaccurate calculations from heat balancebased programs are discussed. Finally, the paper presents an approach for estimating the performance of TDV systems using existing heat-based calculation tools that responds to most of the significant differences between overhead mixing systems and thermal displacement systems.

Déplacement d'air - Assainissement et rafraîchissement des ambiances industrielles (Air displacement - Cleaning and cooling of industrial surroundings)

One of the major means of air diffusion for air conditioning equipment is the displacement ventilation. The stack effect is used by introducing at a very low speed, in the lower part of the room, some air whose temperature is close to the one of the desired atmosphere.

Air flow and particle control with different ventilation system in a classroom

Istis normally assumed by designers that all pollutants in a displacement ventilation system follow the buoyant air flow into an upper zone, where they are evacuated. But studies have shown that it is not always true and that concentrations of pollutant particles can be found in the breathing zone. This study aims at designing a ventilation system that will minimize the respirable airborne particle in that breathing zone.

Energy savings potentials in air conditioning of industrial buildings Einsparpotentiale bei des Klimatisierung von Industriehallen

Using results from dynamic simulations, the article compares the energy consumption for the air conditioning of an industrial building with mixing and displacement ventilation.

Floor heating and displacement ventilation

A question raised about displacement ventilation, is whether floor heating can be utilised without disturbing the thermal stratification in the room. See Figure 1.Q?Figure 1 Too much floor heating may destroy displacement ventilationThis paper deals with the possibilities and limitations to floor heating with displacement ventilation. This paper shows that floor heating can be utilised with displacement ventilation for both industrial and non-industrial premises for normal airflow rates and normal floor heating rates.

Underfloor & displacement. Why they're not the same

This article aims at precising the difference between Underfloor air distribution (UFAD) and Displacement Ventilation (DV) systems, though they both use supply air delivered into a room or space from an access floor.This article presents each system with its different way of working in applications for commercial buildings.