Abstract: A water heater especially for bathroom includes a hair filter (1), a water self pumping pump (2), a heat exchanger (3), a water valve (5), a controller (6), an operator (7), three water flow resistance amplifiers (8) and a waste water tank (9). The heat exchanger can recover the heat from the waste water during bathing and preheat cold water. The waste water tank can reuse the waste bath water for flushing toilets. Said parts are assembled by pipes and electric circuits and arranged on the proper position in the bathroom.

Abstract: A grill unit having a plurality of grill pipes, each grill pipe having two ends; water tanks connected to both ends of the grill pipes to supply water to the grill pipes; and soundproofing covers positioned around both ends of the grill pipes that are inserted into the water tanks. The grill unit allows water contained in grill pipes to continuously flow in any one direction, and prevents the generation of noise caused by water vapor discharged from the grill pipes to the water tanks.

Abstract: The invention describes a method and apparatus for controlling the temperature of the floor of a cooking oven by utilizing a recirculating primary heat transfer fluid made to flow through a heat exchanger located in an oven floor. After traveling through the oven floor and absorbing heat, the primary fluid travels to an external liquid-to-liquid heat exchanger wherein the primary fluid transfers heat to a secondary circulating heat transfer fluid. The primary fluid is then recirculated through the oven floor to maintain the floor at a predetermined temperature. The heated secondary fluid may then be utilized for other processes such as in the conveyor belt washing tank of the oven, or it may be discarded. The primary heat transfer fluid may be a thermal oil having a boiling point substantially in excess of 212.degree. F., and having other properties designed to prevent the corrosion, plugging, and fouling of the heat exchanger located in the oven floor. The second fluid is preferably water.