European research project RE-VIS, daylighting products with redirecting visual properties

The European RTD project REVIS, Daylighting products with redirecting visual properties (contract JOE3- CT98-0096), started in October 1998 and was completed by the end of 2000. The project was coordinated by TNO. The presentation highlights the objectives, means and some of the main results.

Inaccuracies in standard meteorological low-speed wind data.

States that zero and low wind speed occurrences are often overestimated in standard meteorological data for use by HVAC engineers because of the use of the robust, rotating cup anemometers. Therefore the data would be expected to underestimate wind-driven natural ventilation as well as pollution dispersal. A comparison of rotating cup and ultrasonic anemometers carried out for this study indicated that the former can indicate zero wind speed over many hours in the day when speeds up to 1.5 m/s can be present.

Indoor air quality handbook.

Dynamic thermal performance of concrete and masonry walls.

Modem, massive building envelope technologies (masonry and concrete systems) are gaining acceptance by builders today. All U.S. thermal building standards, including ASHRAE 90.1and90.2 and the Model Energy Code, are linked to the steady-state clear wall R-value. They also have separate requirements for high mass walls. Very often, only steady-state R-value is used as a measure of the steady-state thermal performance of the wall. This value does not reflect the dynamic thermal performance of massive building envelope systems.

Quantifying ventilation needs in Local Authority housing - a case study.

A Tool Kit was developed to assess indoor air quality. The Tool Kit was designed to be robust, reliable, universal and to provide data that could be linked with other studies assessing health, social factors and building conditions for any given locality. A case study using the Tool Kit to assess 116 Local Authority houses is described.

The discharge coefficient - experimental measurement of a dependence on density contrast.

At sufficiently high Reynolds numbers, the discharge coefficient Cd associated with a sharplycontracting flow through a square-edged opening is, in general, taken to be constant.

Experimental testing of a homogeneous tracer pulse technique for measurement of ventilation and air distribution in buildings.

A number of single tracer gas techniques (decay, step-up, homogeneous constant emission,inlet pulse and homogeneous pulse) suitable for measuring the local mean ages of air in multizonebuildings exist, each having their advantages and drawbacks. The characteristics of thedifferent available techniques are compared from theoretical and practical points of view. Thehomogeneous pulse technique has not been experimentally validated before. This techniquerelies on pulses of tracer gas being injected into the different zones in amounts, which areproportional to the zone volumes.

Airflow through louvers: an experimental and CFD study.

In this study a series of parametric laboratory measurements were made of the velocitiesoutside, ve, and inside, vi, a full-scale louver positioned in a rectangular opening located in avertical wall forming part of a 1m x 1m x 2m deep model room. The louver parametersexamined, for external incident wind speeds from 0.6 to 2.5 m/s, included louver blade depth(L), aperture (d) and distance from the louver in to room (Rd). For this initial study the bladesof the louvers for each experiment were horizontal with an inclination angle ? of 0.

A report on the radon measurement in a single family house.

This paper presents the results of a series of measurements made in an occupied family house. Long and short-term measurements of the concentration of radon gas in the cellar and other living areas of the house were carried out. Subsequently a mechanical ventilation system was installed in the cellar and operated in both supply and extract mode with different air change rates. Further measurements of radon concentrations were carried out along with other physical parameters.