Abstract: An air exchange fan comprises: a frame with an opening, a helicoid housing with an air suction inlet disposed in the frame, an air blower disposed in the housing, and, an elongated circuit board box mounted at the air suction inlet side of the housing; a silencing plate is mounted above the outer peripheral of the inlet, and has a streamlining structure formed by outwardly expanding from the inlet in an axial direction of a rotation axis of the air blower, the rotation axis of which being served as the center, within a range that is from a tongue of the housing to a location with a 90 degrees angled from the tongue in a direction opposing to the rotation direction, and has a curved chamfered shape which mates with the peripheral shape of the inlet. A circuit board box for such air exchange fan is also disclosed.

Abstract: A centrifugal fan having a sound reduction effect for noises in a wide frequency range is provided. The centrifugal fan comprises a motor to which an impeller is connected, a casing which surrounds the impeller and which has a bell-mouth-like suction port, and a bell-mouth-like orifice which has a suction port being concentric with the suction port of the casing and having a diameter as large as that of the suction port of the casing, in an outer shell, providing a plurality of protrusions in a resonant space surrounded by the orifice, the casing, and the outer shell, and providing depressions which are formed so as to be interposed between the protrusions.

Abstract: Disclosed is a ventilator with an illuminating unit and a human sensor, which includes a ventilator body and a cover. An air inlet, a lamp shield and a human sensor are provided in the cover. The lamp shield and the air inlet are mounted at the center of the cover while the human sensor is mounted at the periphery of the cover, and the installation orientation of the cover is changeable.

Abstract: An assembly of pipe hood and pipe unit for a ventilating fan, comprising a front cover, a rear cover and a pipe unit, characterized in that: a baffle is vertically provided in the pipe unit to divide the pipe into an air inlet pipe and an air outlet pipe on the left and right sides respectively; a partition plate is vertically provided in the rear cover corresponding to the baffle to divide the space enclosed by the front cover and the rear cover into an air inlet side and an air outlet side on the left and right sides respectively; an external air inlet opening and an external air outlet opening are provided on the outer side of the rear cover on the left and right sides respectively; an internal air inlet opening and an internal air outlet opening are provided on the inner side of the rear cover on the left and right sides respectively; an air inlet passage and an air outlet passage are formed in parallel to each other on the left and right sides respectively.

Abstract: A multifunctional ventilating fan comprises a machine body, a panel provided with an air inlet and an air outlet. The machine body includes a first area, a second area, and a third area separated by several partition plates. The first area is provided with a first heat exchanger and a ventilating blower. A exhaust port of the ventilating blower is communicated with the outdoor. The second area is provided with a second heat exchanger and a circulating blower. The third area is provided with a compressor. The air inlet of the panel is communicated with the first area to form a first air path. The air inlet of the panel, the first area, the second area and the air outlet of the panel are communicated in turn to form a second air path. A first valve is provided in the second air path for isolating the first area so that a third air path is formed by the air inlet of the panel, the second area and the air outlet of the panel communicated in turn.

Abstract: A ventilation fan unit with a heater, including: a frame with an opening provided at the underside of the frame; a cover having an air outlet and an air inlet provided at the opening of the frame; a snail-shaped casing with an air exit provided in the frame; a circulating fan enclosed in the snail-shaped casing; and a heating portion including a spiral heater mounted at the air exit of the snail-shaped casing, wherein the heating portion is communicated with the circulating fan through the air exit, wherein an axis of a spiral shape of the heater is in parallel with a rotation axis of the circulating fan, wherein the rotation axis of the circulating fan is located obliquely above the axis of the spiral shape of the heater.

Abstract: A temperature protection device for a brushless DC Motor, wherein a thermal fusing type protector is provided at a depression formed on a casing of the plastic-packaged brushless DC Motor. In this way, the thermal fusing type protector can be provided conveniently at a position where the casing temperature is highest after plastic packaging, and if the protector is fused due to high temperature, it can be replaced easily.