The modern accessories provide three types of opening of shutters of a window: raspashnoe, folding and slot-hole.
At raspashnom cold air directs to a floor, as a result there are the draughts which are hazardous to health.
At folding opening cold air at first gets to a ceiling zone where mixes up with warm, and uniform enough circulation of air streams is indoors created.
Slot-hole opening provides the dosed out receipt of fresh air, as a matter of fact, there is soft, but an effective ventilation of a premise.