A learning machine approach for predicting thermal comfort indices

Human thermal comfort is influenced by psychological as well as physiological factors. Several comfort indices, such as PMV, PPD, TSENS, ET*, DISC, and SET* (see nomenclature) have been developed. These indices attempt to correlate human thermal comfort with environmental conditions. This paper describes the use of a learning algorithm "support vector machine (SVM) learning" for prediction of the thermal comfort indices. The SVM is an artificial intelligent approach that can capture the input/output mapping from the given data.

A review of evidence linking ventilation rates in dwellings and respiratory health - A focus on house dust mites and mould

This paper reviews the literature for evidence of links between ventilation rates in dwellings and moisture related respiratory health with a particular focus on house dust mites (HDM) and fungal growth. There is general consensus that a link exists between ventilation rates in dwellings and respiratory hazards (for example HDM). There is also general consensus of a link between these respiratory hazards and respiratory problems, but it is not clear to what extent hazards cause ill-health.

A simplified model to estimate natural ventilation flows for simple dwelling layouts

The paper presents a procedure to estimate natural ventilation flow rates through buildings. The principle is to assume that the flow paths are known and that the whole building is an association of ducts that can be coupled either as series or parallel configurations. The equivalent characteristic airflow vs pressure curve is then established. The main driving force is the pressure difference on faades, expressed via their respective pressure coefficients, together with an appropriate reference wind velocity. A thermal (stack) component may be added to establish the final pressure values.

A ventilation system integrating a buried-pipe technique with multi-purpose windows

This paper introduces a ventilation system that combines buried-pipes with multi-purpose windows with the aim of finding an energy efficient, environment-protecting and low-cost way to improve the indoor environment. In this system, buried pipes serve as air-conditioners and multi-purpose windows serve as draught, sound and heat protective devices, in addition to acting as ordinary windows. Further benefits include protection from noise, dust, and insects as well as protection against intruders, thus providing a safe, healthy and comfortable indoor environment.

Air Movements through Horizontal Openings in Buildings - A Model Study

A building contains a number of large openings, such as doors and staircases. When the temperature of the spaces connected by these openings differs, the difference in density will cause air movements through them.Horizontal air movements through vertical openings in buildings, such as doors and windows are wellinvestigated while studies of air movements through horizontal openings, such as stairwells are less frequent and therefore this work focuses on this case.

Analysis of contaminant remowal efficiency assessment in a ventilated room

This paper reports a critical analysis of the assessment of contaminant removal efficiency. Measurements have been carried out in a ventilated room equipped with a pine wood floor, which emits Volatile Organic Compounds (VOCs), considered as air pollutants in this paper. Thereafter, Computational Fluid Dynamics (CFD) simulations are performed. CFD results are compared to measurements to check their accuracy. Moreover, air quality within the ventilated room is numerically analysed via indices.

Analysis of Spot Cooling in an Underground Subway Station

Railway platform spot cooling has become an increasingly attractive means to improve thermal comfort conditions of existing subway stations. This paper presents a systematic approach to evaluate the effectiveness of platform spot cooling. The subway environment is first analysed by a simple onedimensional network model, which is able to estimate the bulk air temperature from the available spot cooling. The localized effects of spot cooling are then investigated using CFD.

Application of a Thermal Manikin to Evaluate Heat Loss Rates from People caused by Variations in Air Velocity and Air Temperature

Heat loss monitoring from a thermal manikin was undertaken representing an occupant in a classroom during a lesson period of 80 minutes in which the room temperature was increased from 21 to 24C for various airflow velocity configurations. A group of subjects was exposed to various conditions of temperature and airflow rate so that the impact of these variations on their surface/skin temperature could be determined. It was found that skin temperature remained stable and close to 34C for all conditions of exposure.

Book review - Ventilation effectiveness - REHVA guidebook

The aim of that guidebook (74 pp), published by REHVA is to provide a clear analysis of the definitions of ventilation effectiveness and to present case study examples

Comparison of a CFD fire model against a ventilated fire experiment in an enclosure

The definition of a good indoor climate is important to the success of a passenger rail coach, not only because it will decide its energy consumption and thus influence its sustainability but also because good comfort for long journeys is essential. A survey in a coach investigating the thermal and air quality environment was undertaken. The intention is to use the results to optimise the control of the ventilation system to provide an indoor climate that passengers will find comfortable.

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