AIVC - Air Infiltration and Ventilation Centre

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A Case Study of Quantitative Energy Efficiency of Personalized Ventilation in the Tropics

This paper provides information of energy efficiency potential of Personalised Ventilation (PV) systems used in conjunction with a secondary Mixing Volume (MV) air-conditioning system in the tropics. The energy consumption and the acceptability of PV at selected combinations of indoor ambient temperatures of 26 C and PV air supply temperatures of 20 or 23 C, is compared with that of sole mixing ventilation in which the indoor air temperature was controlled at 23 C.

Thermal Sensation of Tropically Acclimatized Subjects under Fixed Air Flow of Personalized Ventilation

Thermal sensation of tropically acclimatized subjects performing sedentary tasks under personalized ventilation (PV) was explored in this study. The study was conducted in an Indoor Air Quality (IAQ) chamber, which is capable of simulating typical office conditions in Singapore. An experimental design involving interventions in indoor ambient temperature, PV supply temperature and PV supply airflow rate, introduced blind to subjects, was conducted.

Segmental Equivalent Temperature Determined by Means of a Thermal Manikin : A Method for Correcting Errors due to Incomplete Contact of the Body with a Surface

The segmental equivalent temperature determined by means of a thermal manikin is often correlated with the local thermal sensation of people and is used for indoor environment assessment. It is also used to assess performance of heated/cooled/ventilated car seats, etc. However, the body of the thermal manikins used at present is not as flexible as the human body and is divided into body segments with a surface area that differs from that of the human body in contact with a surface. The area of the segment in contact with a surface will depend on the shape and flexibility of the surface.

Modelling of Temperature Fields in Heated Rooms

The contribution deals with the research on temperature fields in rooms heated in differentways at heating-up as well as in steady state conditions. The investigations are being carried out byphysical modelling with the use of interferometry, numerical modelling as well as measuring real rooms by thermocouples. The results show that interferometric research of two-dimensional temperature fields can be used for modelling in smaller heated rooms, in cars and various air-conditioned boxes. Numerical modelling seems to be more effective and can be used in wider range of application.

An analytical model for the airflow in a ventilated window with known surface temperatures

This paper presents an analytical model for predicting the air flow and velocity in an open vertical air channel due to natural convection. It can be used in the study of ventilated windows and double-faade systems, which are arousing interest as an energy-efficient means of providing fresh air, daylight and solar radiation to rooms. Unlike most previous work in this field, it proceeds from known surface temperatures instead of known surface heat flux.

Zonal model based on airflow partitioning

We present in this paper an advanced formulation of zonal models for calculating room airtemperature and airflow distributions. It is based on a new way of sub-dividing the room usings the Octree method. It allows us to obtain a partitioning based on airflow patterns. The behaviour of the room is represented by the connection of SPARK calculation objects according to its partitioning. The SPARKs objects represent sub-zones of the room or interfaces between sub-zones. We developed an automatic generator of zonal models.

CFD Codes Efficiency Case Study: Ability to Perform Numerical Simulations in the Refrigerated Compartment of a Foodstuff Transportation Vehicle

The purpose of the present work is to describe the ability of the advanced computer packages(CFD codes) to perform numerical simulations of general refrigeration engineering problems. The case study concerns the modelling of three-dimensional turbulent airflow with thermal buoyant effects and air temperature distribution in the refrigerated compartment of a perishable foodstuff transportation vehicle.The numerical predictions obtained with three commercial codes (PHOENICS, FLUENT and CFX) and an academic one are evaluated and compared with experimental data.

Industrial Grille Applied to Zoning Room Air Conditioning Strategy - Performance Prediction by CFD-simulation

Zoning room air conditioning strategy is based on the idea of controlling the conditions of one zone by supply air and, at the same time, utilizing the stratification of temperature and contaminants in another zone. The aim of this study was to assess the ability of CFD-simulation to predict the supply air flow pattern and the overall performance of the system. The study was based on a series of laboratory experiments and corresponding CFD-simulations.

Comfort simulation of a double-deck train coach using CFD analysis

Within the last years CFD has become an essential tool to investigate and optimize concepts of train coaches during an early design stage to achieve best results without major modifications of the final design. The simulation of the current railroad double deck coach gives some special challenges because of the complex channel system and the different boundary conditions on each floor. First the air duct including the outlet vents is investigated and optimized. The results are used as boundary condition for the simulation of the passenger's compartment.

Comparison of temperature measurement methods for the evaluation of the thermal environment in vehicles

A new standard, ISO/DIS 14505 is under preparation, dealing with the assessment of the thermal environment in vehicles, based on the equivalent temperature. The scope of this paper is to demonstrate the different results obtained when evaluating the thermal environment inside a vehicle, using the three well known parameters, air temperature, operative temperature and equivalent temperature. The tests were carried out in the winter season during heat-up of the vehicle cabin.