Abstract: A fan includes a motor, two frames, an impeller and a housing assembly. The two frames are coupled with an outer periphery of the motor and are engaged with each other by way of fastening. Each of the two frames includes one groove. The impeller is connected to the motor and is driven to rotate by the motor. The housing assembly houses the impeller and includes first and second housing parts. The first and second housing parts are engaged with each other by way of fastening. A protruding lip is provided on one of two end faces of the first housing part which is relatively adjacent to the motor. Another protruding lip is provided on one of two end faces of the second housing part which is relatively adjacent to the motor. The protruding lip and the other protruding lip are engaged with the grooves of the two frames.

Abstract: An air exchanging device according to the invention is mounted to a wall. An inner side of the wall is the indoor space, and an outer side of the wall is the outdoor space. The wall has an installation hole. The air exchanging device includes a housing, a first fan unit and a second fan unit. The housing has a compartment. The housing has a first through-hole, a second through-hole and a third through-hole. The first fan unit is received in the compartment and includes a first air inlet intercommunicating with the second through-hole, and a first air outlet intercommunicating with the first through-hole. The second fan unit is received in the compartment. The second fan unit includes a second air inlet intercommunicating with the third through-hole, and a second air outlet intercommunicating with the second through-hole.

Abstract: A low vibration fan including a housing, a driving member and a fan wheel is provided. The housing has an outer frame and a base, wherein the outer frame has two openings, a positioning rim, and a guiding channel linking the two openings, wherein the base couples with the positioning rim, and wherein a radial buffer gap is formed between an outer periphery of the base and an inner periphery of the positioning rim. The driving member is mounted on the base. The fan wheel couples with the driving member rotatably. Accordingly, the radial buffer gap can largely reduce the vibration transmitted from the base to the outer frame.