A humidity controlled exhaust fan have been tested during the winter season 1991/2. The test have been carried out in a detached one storey house with a flat roof. The relative humidity (RH) have been measured in the following modes: * natural ventilation only* wall mounted fan, setpoint 70% RH, and natural ventilation * fan in the exhaust duct, setpoint 70% RH.The relative humidity levels have been monitored in the shower room and in the other part of the dwelling. The temperatures have been measured in the exhaust duct and in four places in the dwelling.
The ventilation rate in a building depends on many things, one of which is the air temperature. The air temperature in turn depends in part on the ventilation rate. The effects of this relationship are generally overlooked in both thermal and ventilation models. To study this effect a model has been developed which integrates the models GAINE and SILONA developed at CSTB. This allows the prediction of the natural ventilation rates caused by the actual temperatures in the building.
Modern one-family houses in Scandinavia built before 1980 are often naturally ventilated and heated by electric baseboard heaters. The overall supply of fresh air is often inadequate during the heating season in many of these houses. Long periods of time individual rooms might get too little fresh air. The performance of a natural ventilation system is very much dependant upon the overall airtightness and the distribution of the airtightness of the building and the weather.
Experiments were carried out in four naturally ventilated offices to measure the indoor environmental parameters such as air velocity, turbulence intensity and air temperature at three vertical levels, Air change rates for various indoor and outdoor climates were detetmined. The concentration of carbon dioxide in the room was monitored. Subjective assessment was made to evaluate the thermal comfort and indoor air quality in the offices. The effect of opening windows and doors on the indoor comfort conditions was also investigated.
This paper deals with the problem of the weather influence on ventilation rate for naturally ventilated buildings with purpose provided openings and vertical shafts. Hitherto, it has not been possible to predict the ventilation rate or to extrapolate it for other weather conditions than the measured ones, without performing a heavy calculation exercise by means of running a computer program. In the paper a prediction as well as an extrapolation procedure is outlined . The procedures are based on generalised output data from a single zone infiltration and ventilation model (AIDA).
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