Experimental and numerical VOC concentration field analysis from flooring material in a ventilated room

The aim of this study is to analyse the impact of volatile organic compounds emissions from asolid flooring material on the concentration field in a ventilated room. A field study has beenconducted in the CSTB experimental house MARIA. Measurements were performed in a testroom recently equipped with a flooring material made of pine wood and under controlledventilation conditions. a-Pinene was selected as tracer from flooring VOC emissions. Velocityand temperature fields are measured in different points of the room.

The ups and downs of airflow in building ventilation

Almost all existing analysis methods for building ventilation airflows, such as the simpleanalytical methods, multi-zone methods and computational fluid dynamics (CFD), give onlyone unique solution for one set of identical input parameters when started with zeroinitialization or zero initial conditions. This can be shown to be incorrect in some situations.Multiple stable solutions are found in some very simple buildings, which indicate that thebuilding airflows are of a nonlinear dynamical system.

Modelling of indoor concentrations of ultra-fine particles based on laboratory measurements

The objective of the present study is to apply and test a mathematical model for thedetermination of the strength of various indoor sources of ultra-fine particles (UFP), and thesink effect for such particles. The model is intended for further development in order to createa tool capable of predicting the concentrations of fine and ultra-fine particles in a room. Inputdata to the model are the ventilation rate, emission rates of ultra-fine particles from differentindoor sources and properties describing sink effects. Laboratory measurements of 10 indoorsources (e.g.

Periodic heat transfer analysis: an analytical tool in modeling of non-airconditioned multi-zone buildings

This paper presents a transient periodic heat transfer analysis of non-air-conditioned multizonebuildings taking into account the effects of heat fluxes through various facades ofbuildings including windows, air ventilation and infiltration, furnishings and ground heatconduction. A user-friendly computer software has been developed for the above mentionedpurpose. The validity of the analysis and the building simulation software has been checkedby comparing the results with those obtained by running commercial software SUNCODE forthe same input data.

Thermal and airflow behaviour of buildings model reduction

We describe the implementation of a model reduction tool within a software dedicated tothermal and airflow simulation. The goal is to allow the use of more detailed models. Wecompare experimental results and simulations results. We show the usefulness of the balancedreduction model for thermal and airflow simulation.

Prediction of indoor sol-air temperature in an atrium space with a vertical distribution

This study suggests a computer model capable of predicting thermal environment of an atriumand calculating indoor sol-air temperature, which can evaluate the influence of heat loads thatthe atrium space puts on the adjoining rooms. The computer model is based on zonal modelcombined with the solar radiation model using the Monte Carlo method and ray-tracingtechnique. The accuracy of computer model was validated through scale model test and fieldmeasurement. The average relative error of solar radiation model for predicting solar radiationintensity in atrium space was 11.8%.

Development of human thermoregulation model JOS applicable to different types of human body, sex and age

The numerical thermoregulation model JOS was developed. In this model, the influences ofbody size, sex and age on thermoregulation were reflected on physiological parameters of thethermoregulation model. The whole body model has 17 body segments, each consisting oftwo layers for core and skin. In addition, it is possible to alter its height, weight, sex, age,body fat percentage, basal metabolic rate and cardiac index. In the limbs of this model, thedetailed vascular system was considered, including deep artery and vein, superficial vein andarteriovenous anastomoses (AVA).

Adaptive comfort theory applied to office buildings

There has been much debate over the use of steady-state and adaptive thermal comfortmodels. Many researchers have suggested that the former model is better suited to buildingswith full HVAC systems whilst the latter is better suited to naturally ventilated buildings. Thispaper suggests that the most appropriate form of thermal comfort model is dependent on theadaptive opportunity available to building occupants, regardless of climate control strategy.Some results from a series of field studies carried out in the UK as part of a doctoral thesis arepresented.

PMV-derived productivity model as a tool to assess productivity loss

A novel PMV index based productivity model is derived and it is used to estimate the effectsof different thermal conditions on productivity. Past research findings are used as inputs in thecreation of this productivity loss model. The PMV equation is useful to predict productivityloss that is due to the rate of change in thermal conditions. Using the model prediction, thetheoretical maximum level of productivity occurs when the PMV value is -0.21. Admitting a30% productivity loss in typing-task, the model predicts PMV value ought to be at least+0.63.

Practical thermal sensing measurement and neural-thermal comfort index

The primary purpose of heating, ventilating and air-conditioning (HVAC) system is to makeoccupants comfortable. Without real-time practical measurement and method to determinehuman thermal comfort, it may not be feasible that the HVAC system can provide humancomfortable all the time. This paper presents a practical measurement and model to determinehuman thermal comfort index for feedback control. The proposed model is developed basedon the original thermal comfort index called predicted mean vote (PMV) index by applyingfeed-forward neural network model.

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