摘要 |
FIELD: construction industry. ^ SUBSTANCE: invention refers to the field of construction industry, namely to construction of windows or doors. Framed block contains folding-type frame, box, at least one air duct between inner and outer sides of framed block, at least one device in air duct for restriction of air flow with turning, in relation to bearing element hard-mounted on frame, surface restrictor installed with possibility of movement between open position, in which restrictor opens air duct, and closed position, in which restrictor at least partially closes air duct. Restrictor is designed in such a way that it is in open position while rate of air flow through air duct is below limit value. ^ EFFECT: provision of maximum free from draft ventilation of framed block upon simultaneous air change between its inner and outer sides. ^ 25 cl, 19 dwg |