Abstract: A ventilator comprising a cylindrical housing the intake of which is connected to a coaxial cylindrical conduit of smaller diameter, an electric motor axially mounted in the housing, of small diameter relative to that of the housing, and on the shaft of which is fixed a wheel consisting of blades, each having a shape that all the cross-sections of a blade through planes parallel to the axis of the housing are parallel to said axis and the vanes orienting the air stream, integral with the inner side of the housing, distributed at the periphery of the housing and each including at least a curved part which, located on the side of the housing intake, is housed in an annular space comprised between the housing and the virtual cylindrical surface extending the air intake.

Abstract: According to this method, the number of movements of the occupants of each premises is counted for a given time, a datum related to the activity of the occupants and to their number is deduced from this, and this datum is used directly to vary the air flow cross section and consequently the flow rate of the ventilation device of the relevant premises, in the same direction as the measured activity.

Abstract: This method consists in supplying the various rooms of the premises with air under stable low pressure using a relatively high-pressure fan, in feeding the fan, on the one hand, using fresh air, and, on the other hand, using recycled air, that is to say air that has been displaced by the fan and not let into the premises, and in regulating the respective proportions of fresh air and recycled air so that the proportion of fresh air increases and the proportion of recycled air decreases when the ventilation requirements increase, and so that the proportion of fresh air decreases and the proportion of recycled air increases when the ventilation requirements decrease, so that the delivery rate of the fan is kept almost constant.Application to systems for controlled mechanical ventilation of premises.

Abstract: A method for adjusting an opening cross section of an air inlet into a premises involves sensing the amount of water vapor contained in the air inside of the premises and the amount of water vapor in the air outside of the premises. The opening cross section is adjusted on the basis of at least one of a difference between the amount of water vapor sensed the inside and outside the premises so that the opening cross section increases when the difference increases and independently of the amount of water vapor in the air outside the premises. A device for adjusting an opening cross section of an air inlet into a premises includes two chambers in communication respectively with the air outside and with the air inside the premises, the chambers being separated from one another by a heat exchanger, which is impervious to water vapor.