Experimental and numerical analysis of a hybrid-ventilated room

This study was undertaken in IEA ECBCS Annex 35 to model a hybrid-ventilated room and to implement control strategies. An experimental cell was designed and simulations were performed after having adjusted the thermal models to experiments. The hybrid ventilation proved more performant than traditional ventilation systems.

Transport of microbes from crawl space to indoors

The concentration of fungal spores is higher in the crawl space than inside houses. Domestic mechanical exhaust ventilation systems may create air flow between crawl space and base floor through leaks. This study used data from eight buildings to develop a model providing relation between indoor and crawl space fungal spores concentrations. Results show that the correlation between the fungal spores in the crawl spaces and indoors depends on the size range of microbe species.

Combined ventilation flow in buildings driven by combined natural and mechanical forces

This paper demonstrates that the distribution and area of ventilation openings affects significantly the air flow rates in a hybrid ventilation system.

Measurement, explanation and prevention of particle deposition near ceiling induction outlets

The deposit of particles on ceilings close to ventilation outlets is mainly caused by the features of mixed ventilation, turbulence and induction. This study aims at solving that annoying problem of particle deposition, for the ventilation industry. The development of a clean outlet is eased thanks to a new experimental approach using an optical technique (in so far as the experimental technique and the CFD calculations are too inefficient).

Reducing bartenders' exposure to ETS by a local ventilation - field evaluation of the solution

Restaurant workers have a high risk to be exposed to environmental tobacco smoke (ETS) in their work. In Finland the latest tobacco Act has set more stringent requirements for the smoking in restaurants. Despite of the tightened legislation most of the restaurant employees are still continuously exposed to ETS. Ventilation techniques enable significantly to reduce employees exposure to ETS in hospitality facilities, where smoking is permitted.

Experimental charaterisation of thermal plumes in confined ventilated spaces

This paper presents the behaviour of a thermal plume combine with a forced ventilation. A method to locate the position of the thermocline in a ventilated room is shown. It also gives and compares the results obtained by means of a solutal simulation on an hydraulic model and from full-scale experiments in a climatic chamber.

Relationship of SBS-symptoms and ventilation system type in office buildings

This paper provides a summary of current knowledge about the associations of ventilation types in office buildings with sick building syndrome symptoms. Most studies completed to date indicate that relative to natural ventilation, air conditioning, with or without humidification, was consistently associated with a statistically significant increase in the prevalence of one or more SBS symptoms, by approximately 30% to 200%.

Barriers to improved ventilation in production housing

In addressing the goals of energy-efficiency and indoor air quality (IAQ) in homes, industry teams in the U.S. Department of Energy's Building America program are installing mechanical ventilation systems in tight homes. A variety of designs - some simple and inexpensive, some more sophisticated - have been demonstrated. The advanced designs provide more consistent ventilation over time, more uniform ventilation among rooms, and source control measures that reduce the air-change requirement.

The evaluation of HVAC systems and indoor air quality of high-rise appartments

Although most of the apartments adopt state-of-the-art convenience facilities, since they have become the most popular housing type in Korea, they depend on natural ventilation for HVAC systems, as traditional floor heating systems (Ondol) are used. On the other hand, the indoor environments of the apartments have become more important, because people stay longer in a room and the room environment is polluted, because of various kinds of interior materials. Accordingly, some apartments apply air conditioning systems using AHU and ventilation systems using heat exchangers.

Decentralized building automation and hybrid ventilation at ING HQ's

This paper describes the hybrid ventilation system of a new office building (650 employees) in Amsterdam (The Netherlands) equipped with a decentralized building automation and individual controls.

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