A new facility for the study of ventilation in buildings has been recently developed at the University of Basilicata (Potenza, Italy). This facility consists in a Controlled Ventilation Chamber (CVC), with an overall size of 2.4*2.4*3.0 m (the length may be extended to 4.2 m) . The CVC is divisible in two parts with a connecting door and is equipped with four grilles from which air can be immitted or extracted. A variable speed fan can adjust a flow rate of 0 to 10 ach.

A new European norm for measuring the heat transfer rate of radiators is under discussion [ CEN TC 130 ]. This testing can be done either in a closed chamber with cooled walls or in a open chamber with a controlled air supply. The air flow pattern around a typical radiator is calculated for both types of chambers. The calculation is done with the program PHOENICS, a finite volume program that solves the conservation equations for mass, momentum and energy. For turbulence, the k-E model is used with the Lam-Bremhorst correction for low Reynolds numbers.

An investigation has been carried out using computational fluid dynamics methods to study the performance of an air curtain at the door of a heated building. A number of operating conditions have been studied and observations are made on the effectiveness of infiltration control and energy use. Comparisons are also made with previously published design data and results from an accepted infiltration analysis. It is shown that the calculation method generates plausible and very detailed results which conform well to physical interpretation.

This paper presents some of the early theoretical work conducted within the framework of a research program aimed at analysing the interaction between gas-fired domestic appliances and the indoor environment in terms of energy consumption, indoor air quality and operational safety. A simplified multizone mathematical model has been developed, which is capable of analysing the thermo-fluid dynamics behaviour of the building + appliance + chimney system.

An appropriate way to identify the most efficient ventilation systems and improve their design is to use design codes for ventilation rates. These rates are strongly influenced by spatial and temporal fluctuations in wind pressure on the facade and roof. The influence of the effects of wind on ventilation was studied using a model which includes air compressibility, together with the pressure field measured on a model in a boundary layer wind tunnel. The simulation results obtained are analyzed using a design code.

This paper treats the structure of models for predicting interzonal airflow and contaminant dispersal in buildings. It will discuss the mathematical structure of such models, the use of modem data structures, the application of structured program techniques and the use of object-oriented structures for the development of users interfaces and building description processes.

Ventilation efficiency may be defined as the capability of a given ventilation system to achieve the best balance between indoor air quality and energy conservation requirements:

This paper describes the use of tracer-gas techniques to measure airflow in a rectangular duct and a HVAC system. Experimental procedures are discussed for the application of the constant injection, pulse injection and decay techniques using N2O andSF6 as tracer gases. This paper also describes a new tracer-gas system with variable sampling speed which was used to measure the decay of tracer-gas concentration. A comparison is presented between tracer-gas measurements and those made with a pitot tube and a hot wire anemometer.

This paper discusses three methods for measuring interzonal air movements in two zone buildings: 1. initial injection of one tracer into a single room, 2. repeated injection of one tracer in two rooms, 3. initial injection of two tracers in two rooms. The description of these methods includes an outline of the theoretical background, the presentation of suitable injection strategies and algorithms for the evaluation of the concentration profiles.

This paper describes the activity on Air Infiltration and Ventilation of the research group of "Dipartimento di Energetica" in Politecnico of Turin. The group formed in 1988 and only at the beginning of 1990 it began to work on multizone flow analysis. The aim of the group is to set up an apparatus for air infiltration measurement comparable to those of other countries; up to now only measurements using decay technique were made in laboratory in a scale-model which represents a two-zone system.