Thermal performance of a local bench heating system for churches

Within the European project - Friendly Heating - a local heating system is designed. The main goal is not to heat the monumental churches themselves, in order to prevent damage to valuable art works and the building itself. The idea is to provide a thermal comfort zone for the people in the pew using radiant heat sources. Measurements in a climate room are used to a) evaluate the local climate created by the bench heating system and b) evaluate the CFD model. The results will be used in ongoing research on the prediction of the indoor climate in a church under real climate conditions.

Experimental Investigation of Three Types of Clean Room Diffusers using Particle Image Velocimetry and Laser Doppler Velocimetry Techniques

The main purpose of this paper is to evaluate the main fluid mechanics parameters in the exit region of three different terminal systems commonly used for controlled environments such as clean rooms or operating theatres. Three different types of diffuser were tested i.e. a diffuser grid, a square ceiling diffuser and a swirling radial discharge diffuser. The paper presents results obtained experimentally which were carried out in order to study the flow characteristics of isothermal jets issuing from such devices.

Modeling of Ceiling Fan Based on Velocity Measurement for CFD Simulation of Airflow in Large Room

This study examines the way of utilizing a ceiling fan for airflow control in a large air-conditionedroom. Although it seems that CFD simulation is useful in predicting the airflow around a ceiling fan, modeling of a ceiling fan as a body of rotation is very complicated. Therefore, in this study, airflow of a ceiling fan is modeled as boundary conditions of air velocity data measured near the ceiling fan.

CFD Simulation and Measurements in Near Zone of a High Induction Swirl Diffuser

This article describes CFD simulation results and measurements using a swirl diffuser. Thediffuser is able to provide relatively low velocities within the occupied zone while supplying high airflow rates. The flow pattern produced by the air diffuser was validated by measurements with a flow rate of 133 l/s and 4 C lower temperature than ambient air. Turbulence was modelled using the RNG k- e model with additional swirl modification.

About the validity of turbulence models for the computational fluid dynamics of a non-isothermal developing plane jet in aiding mixed convection regime

A comparative study between experiments and numerical simulations in the developingzone of a non-isothermal plane vertical jet is presented. Low velocity airflow, in aiding mixedconvection regime, discharging from a large rectangular nozzle in a quiescent medium at a highertemperature is considered (Re = 4220).The "Reynolds-Averaged" Navier-Stokes equations (RANS) are solved with two codes, the CFD code Fluent and the Aquilon code, including different turbulence models.

Improved interpretation and validation of CFD predictions

The mean velocity in rooms predicted by CFD simulations based on RANS equations differs from the mean (in time) magnitude of the velocity, i.e. the mean speed, in rooms measured by low velocity thermal anemometers with omnidirectional sensor. This discrepancy results in incorrect thermal comfort assessment by the CFD predictions as well as incorrect validation of the predicted velocity field. In this paper the discrepancies are discussed and identified, and a method for estimating the mean speed based on the CFD predictions of mean velocity and kinetic turbulence energy is suggested.

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.

How ambient environment effects the migration of particulate matter?

The paper reviews the effect of environmental parameters on the migration of particulate matter. Themethodology involves simultaneous monitoring of particulate matter using dust monitor at indoor and outdoor locations along with the ambient environmental conditions. The study is of great significance as Particulate Matter (PM) has been reviewed in terms of particle count, which is more significant as compared to particle mass. In this paper, the variation of Indoor (PM) /Outdoor (PM) calculated on the basis of count are studied as a function of ambient wind speed, temperature and humidity.

Thermal sensation and comfort with five different air terminal devices for personalized ventilation

Thirty human subjects participated in experiments with five different air terminal devices forpersonalized ventilation operating at two levels of room air temperature within the range prescribed instandards for thermal comfort, namely 23C and 26C. The subjects actively used the possibility to change the airflow rate and to adjust the positioning of the air terminal devices in regard to the airflow direction. The individual control provided allowed subjects to maintain thermal neutrality with the systems studied, except one, named Headset at the higher room temperature of 26C.

Measured occupancy levels in Swedish offices

In order to accurately design and analyze demand controlled volume ventilation systems, theoccupancy level in the room must be known. The occupancy level corresponds to the length of time people occupy a room. Since there is a lack of data for occupancy levels in regards to offices, this study reports on measured occupancy levels for three cell offices in Sweden. The same occupancy sensors were used as those found on the ventilation systems. The results showed that the occupancy level for an office was as low as 11.2%.