English

The influence of the Reynolds number on low speed flow (essentially incompressible flow) is discussed. A first set of literature is reviewed to identify effects of low Reynolds number on flows in rooms. Methods of incorporating low-Reynolds-number effects in existing turbulence models are surveyed.

Air Infiltration in Norwegian buildings has been an unknown parameter. This paper is based on results from measurements in nine different buildings in Norway. The measured parameters have been: infiltration envelope air humidity and temperatures on theinside and outside of the building. The infiltration has been measured continuously with tracer gas using the constant concentration method. In addition air tightness measurements and thermography have been carried out to establish the dimensions and the locations of the major leaks.

IEA Annex 23 has been established in order to attempt to resolve these difficulties in relation to multizone air flow modelling. These models are used to evaluate the air flow between individual rooms or zones as well as the rate of inflow andoutflow of air from buildings. This approach is especially important for evaluating the adequacy of ventilation, predicting pollutant transport and evaluating airborne heat transfer between zones. Such models therefore have vital applications in both energy and air quality related analysis.

The scope of the task 2.2 is to provide an algorithm simulating the behaviour of the inhabitants with respect to the openings of doors and windows. The purpose of this report is to present the status of the work carried out by Scartezzini and his colleagues at the LESO-EPFL in this task on May 15th 1989.

The proposed task addresses the measurement methods using several tracer gases to measure the air flow rates between several zones of a building and between these zones and the outside air. If the building has N zones, there are N(N+1) unknown flowrates, which can be measured simultaneously using N different tracers. In so-called active methods the sampling of the atmospheres of the zones is made an active way, that is using either a mechanical pump or a manually actuated syringe or bag.

Inhabitants may influence the indoor air quality and air flow patterns within buildings in several ways: a) through windows and doors openings; b) through action on mechanical ventilation systems (fans on and off, dampers closed and open, etc); c) creating extra-flow patterns through their own heat, when moving or using portable fans; d) through their activity, inhabitants are an important (but not the only one) source of pollutants. Some of these influences are of great importance (e.g. a and b) or might be negligible, as c) in some cases.

The objectives were a) to evaluate performance of air flow models in predicting air velocity, temperature and contaminant concentrations; b) to evaluate applicability of models as design tools; c) to produce guidelines for their use. All the work is addressed to a single zone. It includes both numerical simulations and experiments for given configurations.

In this paper information is provided about ways to model the boundary conditions near the radiator for use in the flow simulation program. Due to lack of time the modelling is restricted to the thermal behaviour of a single plane radiator as selected in 'R.I. 1.4 : Selection of radiator'. Ways to model the flow near the radiator with e.g. hot and cold wall jets have not been investigated.

In this paper a proposal has been made for the identical testroom configuration, which should be used for the measurements and numerical simulations of the identical test cases. The proposal includes the positions of the measuring points in the testrooms. I have used the collected data of testrooms from several participants and the agreements made at the second expert meeting in Warwick. Unfortunately it was not possible to find common testroom dimensions for all participants, so alternative dimensions for some participants are also given.