Influence of air flow patterns in a room on evaporation and humidity distribution around a heated wet cylinder.

Air flow patterns in rooms can roughly be classified as one of three types: Displacement flow, source flow and mixed flow. Displacement flow in its original meaning is only used in special applications like clean rooms. Mixed flow is generally found in air-conditioned spaces, source flow which is frequently also called "displacement flow" is the usual type of flow in naturally ventilated spaces. This type had become more and more common in air-conditioned spaces in recent years.

Measuring and modelling moisture and temperature beneath a suspended timber floor.

Temperature and relative humidity have been measured in a BRE test house to investigate the vapour content in the void beneath the timber floor. The void can be ventilated naturally or by means of a fan supplying or extracting air. The results show that air flow into and out of the void is stack dominated. The fan needs to supply or extract large volumes of air in order to disrupt this. Measurements and modelling have shown that the vapour content in the void is generally dependent on the level in external air, and that the contribution from the ground is usually small by comparison.

Dynamic water vapour sorption: measurement and modelling.

The objectives of thisinvestigation were to examine the dynamic water vapour sorption offurnishing materials and to compare the experimental results withpredictions obtained from the Moisture Admittance Model. Dynamic sorption measurementswere carried out for common building materials. The measurements were made by placingspecimens of the materials in a humidity chamber and varying the ambient humidity between46% and 90% RH at constant 22C. The weight of the specimens was monitored in situduring this procedure.

Numerical study on air-conditioned indoor airflow by dynamic large eddy simulation.

The aim of this research is to apply dynamic Large Eddy Simulation (LES) to predicting the complex turbulent flow field in an air-conditioned room. LES is a method to calculate turbulent flows where only the small-scale (subgrid-scale) motions are modelled and the large-scale (grid-scale) motions are computed directly. Recently, a dynamic subgrid-scale model has been developed that can evaluate a model coefficient dynamically. This paper presents a numerical simulation of LES with a dynamic mixed subgrid-scale model of a flow field in an air-conditioned room model.

Prediction of the indoor air quality trend in a dwelling in the Mediterranean climate.

The purpose of this study was to evaluate the indoor air quality parameters in a residentialdwelling using information from the field. The subject was a typical example of the modernItalian dwelling stock, built in the 1980s in a residential area in the northernpart of Rome.The dwelling was constructed from pre-cast panels using industrial building techniques. Thewindows were steel-framed and painted. Airtightness was measured to obtain the ACH (airchanges per hour) at 50 Pa pressure difference, and ELA (equivalent leakage area).

Velocity and temperature prediction in an office room with furniture.

The paper presents results from the numerical modelling of the flow field in an existing ventilated office room. The numerical procedure is based on the 3D Reynolds equations closed by the k-e turbulence model and an equation for temperature solved by the finite volume method. The boundary conditions are set in accordance to detailed measurements of the velocity distribution in the air supply diffuser. The established complex flow conditions in the room, which are due to the presence of furniture and buoyancy forces, are presented.

Comparison of modelled and measured tracer gas concentrations in a multizone building.

Few detailed comparisons of modeled ad measured pollutant concentrations in multizonebuildings have been published. The COMIS air flow and contaminant transport modelpermits simulation of the effects of building and HVAC operation, as well as the influence ofthe local meteorology, on air flows within the building. We have recently used this model tosimulate the release of a gas-phase tracer in a three-story, multi-room building located atDugway Proving Ground, Utah, USA.

Simulation of indoor air quality in an office building floor: a first case study.

In order to evaluate the impact on indoor air quality of different installation and ventilation strategies, the modelling of indoor air pollutant transfer has been developed in the CLIM2000 software (thermal and airflow code). Then, these models have been used to simulate the evolution of indoor air pollution in an office building floor for a week in winter under different ventilation strategies. The selected pollutants are CO2, CO, NO2 and HCHO and the sources are outdoor pollution for all pollutants and occupancy for CO2. So far, humidity has not been taken into account.

An intermediate model to predict thermal comfort and air quality in a building.

In this paper, a zonal model used to predict the air movement, temperature distribution and airquality in a room is presented. It is based on a rough partitioning of the room: it is anintermediate approach between one-node models (that consider an homogeneous temperaturein each room, and, for that reason, do not permit to predict the thermal comfort in a room) andCFD models (that require great amount of simulation time). Where plumes, jets or thermallayers occur, air flow is described by empirical laws.

School ventilation - gymnasiums in primary schools.

The main objective of this study was to determine the ventilation demand for a gymnasium inthe primary school based on verified metabolic rate.Norwegian guidelines recommend 6.0met as the activity level to be used when calculating the outdoor air flow rate in a gymnasium.Younger pupils have a lower body mass and metabolic capacity than adults, and their demandfor ventilation is therefore lower. The metabolic rate has been assessed by measuring thepupils emission of the dominating bioeffluent CO2 during intensive gymnastic activity.

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