A PMV (predicted mean vote) index is often adopted to assess the thermal comfort conditions of thermal moderate environments, but to prevent problems when monitoring or controlling HVAC equipment a fuzzy adaptive controller has been introduced. That paper gives a description of the method along with the presentation of simulation results .
The IAQ characteristics and the corresponding health symptoms and thermal sensation of the occupants of child care centers in Singapore under 3 different ventilation strategies are reported. The 3 child care centers studied were centrally air-conditioned and mechanically (ACMV) ventilated (Case A), naturally ventilated (Case B) and hybrid (natural and air-conditioning) ventilated (Case C).
Integration of building components and ventilation systems is an effective way to control thermal loads, especially cooling loads. The key point of the system which has been studied in this paper is a special hollow building slab which allows the penetration of variable ventilation air flows. The ventilation rate may be adjusted following a specific control strategy, in order to activate the thermal mass of the slab, and enhance the free cooling effect in the night time.
The key principle of this work is that intermittent ventilation is equivalent to continuous ventilation if the pollutant exposure to an individual in the space is the same in both cases.
There are two ways for unbalanced return air to produce moisture and mold problems during hot and humid weather : - the increased entry of outdoor air that substantially increases indoor relative humidity. - a negative pressure can draw moist air into wall cavities causing a moist interstitial microclimate, if indoor humidity is relatively low in the conditioned space.To prevent the creation of moisture and mold problems, properly sized return ducts should be provided.
Protecting immune suppressed patients from construction generated airborne opportunisticinfectious agents is essential during their hospitalization. During modernization of thehospitals 32-bed bone marrow transplant unit (BMTU), an empty intensive care unit wasretrofitted to BMT ventilation criteria. Filtration, pressurization and room air exchangecriteria were required at 12/h. A condensate particle counter and a digitalpressure gauge were used to assess these criteria.
This paper investigates the pollutant distribution patterns in a ‘negative pressure’ isolation room by means of objective measurement and CFD modelling. The isolation room has two air supply diffusers and two extract grilles mounted in the ceiling. Numero
A cubic experimental chamber with 2.5m of sides was designed to measure the impact of the ventilation on particle concentration. Particles of 0.3 - 15µm diameter were used. Two ventilation parameters were studied: the ventilation rate (0.5 and 1.0 ach) an
Research partners of 10 different countries are developing a computer tool in the framework of IEA ECBCS Annex 36, which helps decision makers to include the most energy-efficient and economic technical retrofit measures into the retrofit of their educational buildings.
The control industry integrates more and more recent innovations, especially on the sector of communication networks (bus), control (fuzzy logic, neural networks...) and informatics (hard-and software) for the development of Building Automation and Control Systems of HVAC plants. These complex control strategies are now being implemented on ventilation systems (hybrid systems, mechanical systems, etc) to satisfy energy and environmental issues.
Login