A filter assembly structure and a water heater including the same are provided. The filter assembly structure includes a filter housing coupled to an inner surface of a base panel provided in a case of a water heater, and including a flow space formed together with the inner surface of the base panel and an entrance to communicate with the flow space, and a filter assembly detachably assembled with the filter housing and including an air filter to filter air introduced through an air inlet provided in the base panel. The filter assembly is provided in a slide structure and inserted into or separated from the filter housing through the entrance.

An air cleaner includes a case, an air inlet, an air outlet, a grill covering the air inlet to filter airborne oil droplets, a fan to suction air through the air inlet and discharge air out of the air outlet, a roll filter provided between the grill and the fan to filter oil mist, and a filter roller to cut the roll filter. The roll filter includes a roller and a filter sheet wound around the roller, and the filter sheet may be unwound to extend behind the grill. When the filter sheet becomes dirty, the roll filter is further unwound so that a clean section is provided behind the grill, and the filter cutter may cut off the dirty section. During cutting, a clamp holds down the filter sheet. The case includes a slit through which the dirty section of the filter sheet passes for discarding.

An air cleaner includes a case, an air inlet, an air outlet, a grill covering the air inlet to filter airborne oil droplets, a fan to suction air through the air inlet and discharge air out of the air outlet, a roll filter provided between the grill and the fan to filter oil mist, and a filter roller to cut the roll filter. The roll filter includes a roller and a filter sheet wound around the roller, and the filter sheet may be unwound to extend behind the grill. When the filter sheet becomes dirty, the roll filter is further unwound so that a clean section is provided behind the grill, and the filter cutter may cut off the dirty section. During cutting, a clamp holds down the filter sheet. The case includes a slit through which the dirty section of the filter sheet passes for discarding.

An air cleaner includes a case, an air inlet, an air outlet, a grill covering the air inlet to filter airborne oil droplets, a fan to suction air through the air inlet and discharge air out of the air outlet, a roll filter provided between the grill and the fan to filter oil mist, and a filter roller to cut the roll filter. The roll filter includes a roller and a filter sheet wound around the roller, and the filter sheet may be unwound to extend behind the grill. When the filter sheet becomes dirty, the roll filter is further unwound so that a clean section is provided behind the grill, and the filter cutter may cut off the dirty section. During cutting, a clamp holds down the filter sheet. The case includes a slit through which the dirty section of the filter sheet passes for discarding.

An air cleaner includes a case, an air inlet, an air outlet, a grill covering the air inlet to filter airborne oil droplets, a fan to suction air through the air inlet and discharge air out of the air outlet, a roll filter provided between the grill and the fan to filter oil mist, and a filter roller to cut the roll filter. The roll filter includes a roller and a filter sheet wound around the roller, and the filter sheet may be unwound to extend behind the grill. When the filter sheet becomes dirty, the roll filter is further unwound so that a clean section is provided behind the grill, and the filter cutter may cut off the dirty section. During cutting, a clamp holds down the filter sheet. The case includes a slit through which the dirty section of the filter sheet passes for discarding.

An air cleaner includes a case, an air inlet, an air outlet, a grill covering the air inlet to filter airborne oil droplets, a fan to suction air through the air inlet and discharge air out of the air outlet, a roll filter provided between the grill and the fan to filter oil mist, and a filter roller to cut the roll filter. The roll filter includes a roller and a filter sheet wound around the roller, and the filter sheet may be unwound to extend behind the grill. When the filter sheet becomes dirty, the roll filter is further unwound so that a clean section is provided behind the grill, and the filter cutter may cut off the dirty section. During cutting, a clamp holds down the filter sheet. The case includes a slit through which the dirty section of the filter sheet passes for discarding.

An air cleaner includes a case, an air inlet, an air outlet, a grill covering the air inlet to filter airborne oil droplets, a fan to suction air through the air inlet and discharge air out of the air outlet, a roll filter provided between the grill and the fan to filter oil mist, and a filter roller to cut the roll filter. The roll filter includes a roller and a filter sheet wound around the roller, and the filter sheet may be unwound to extend behind the grill. When the filter sheet becomes dirty, the roll filter is further unwound so that a clean section is provided behind the grill, and the filter cutter may cut off the dirty section. During cutting, a clamp holds down the filter sheet. The case includes a slit through which the dirty section of the filter sheet passes for discarding.

An air cleaner includes a case, an air inlet, an air outlet, a grill covering the air inlet to filter airborne oil droplets, a fan to suction air through the air inlet and discharge air out of the air outlet, a roll filter provided between the grill and the fan to filter oil mist, and a filter roller to cut the roll filter. The roll filter includes a roller and a filter sheet wound around the roller, and the filter sheet may be unwound to extend behind the grill. When the filter sheet becomes dirty, the roll filter is further unwound so that a clean section is provided behind the grill, and the filter cutter may cut off the dirty section. During cutting, a clamp holds down the filter sheet. The case includes a slit through which the dirty section of the filter sheet passes for discarding.

A round filter element has a filter medium body flowed through by a fluid to be purified in radial direction relative to a longitudinal axis of the filter medium body. The filter medium body radially encloses an inwardly positioned flow space. An end disk is arranged at an end face of the filter medium body. The end disk has a shaped body axially delimiting the inwardly positioned flow space. The end disk has a sealing disk arranged externally at the shaped body, wherein the sealing disk covers the shaped body and the end face of the filter medium body. The shaped body has a receiving depression that is flow-tight relative to the inwardly positioned flow space. The sealing disk has a receiving opening aligned with the receiving depression of the shaped body. The receiving depression and the receiving opening can receive a support element of a filter housing.

A round filter element has a filter medium body flowed through by a fluid to be purified in radial direction relative to a longitudinal axis of the filter medium body. The filter medium body radially encloses an inwardly positioned flow space. An end disk is arranged at an end face of the filter medium body. The end disk has a shaped body axially delimiting the inwardly positioned flow space. The end disk has a sealing disk arranged externally at the shaped body, wherein the sealing disk covers the shaped body and the end face of the filter medium body. The shaped body has a receiving depression that is flow-tight relative to the inwardly positioned flow space. The sealing disk has a receiving opening aligned with the receiving depression of the shaped body. The receiving depression and the receiving opening can receive a support element of a filter housing.