Abstract: A ventilator (10) has a housing (12) including an apertured wall portion (14) an exterior weather hood (16) and a cover portion (18). A rotatable flap (42) is pivotally mounted to the apertured wall portion (24). The cover portion (18) contains a reticulated foam filter (120). The cover portion (18) is removable from the apertured wall portion (14) for servicing or replacement of the filter (120).

Abstract: A vented frame (1) includes an air passage of L-shaped section having a horizontal portion (8) and a vertical portion (9). A ventilator (7) is inserted into the vertical portion and comprises an elongate main body with first and second openings (10), (11) diametrically opposed to one another. A closure member controls the passage of air through the ventilator. The ventilator consists of two parts which are separable from one another and, once installed, the lower of the two parts can be replaced or repaired, while the other part is left in place.