OPTIBAT: a real scale cell in simulated climatic environment for multizone air flow patterns in buildings.

One of the main problems about air flows pattern studies remains the experimental validation of numerical codes developped for interzone air flow and polluant diffusion prediction. A few years ago, CETHIL developped a real scale experiment made of a 88m² dwelling built in our laboratory hall in a controlled climatic environment. This experimental tool allows a full control of outdoor climatic conditions: air temperature, relative humidity, pressure drop can be controlled on the six faces of the cell: OPTIBAT is thus a reference tool for multizone air flow measurement techniques, and experimental data sets available for validation of numerical models. The first phase of this experimental projet allowed us to determine air leakage characteristics of indoor and outdoor walls of the cell. The second element required for the validation of multizone air flow codes is the knowledge of all the interzone air flows. The vast majority of the air flow measurements made to date have involved multiple tracer gas techniques. Using the OPTIBAT facility, we have first used only one tracer gas to determine all the air flows. The present paper describes the experimental cell and gives the first results about air flows measurements using tracer gas technique. The interzone air flows are computed using two methods. Each method is completed by an error analysis which defines the uncertainty of each result. Both methods give the same results.