Abstract: A water heater with reduced nitrogen oxides output utilizing NO.sub.x reducing water conduits to cool a laminar flame and thereby reduce production of nitrogen oxides, The water heater has a partially aerated burner using a partially premixed combustion method to produce the laminar flame wherein a plurality of NO.sub.x reducing water conduits are disposed above the partially aerated burner in such a manner that water is supplied from a cold water conduit or a hot water conduit of the water heater into the plurality of NO.sub.x reducing water conduits through a water introducing portion by means of branching or serial connections. The water absorbs heat while flowing through the plurality of NO.sub.x reducing water conduits and is returned to the cold water conduit or the hot water conduit through a water receiving portion by means of and branching or serial connections.

Abstract: An electric vacuum cleaner comprises a main body having an electric blower and a dust collecting chamber, a triac controlling the electric blower, a floor nozzle coupled to the main body, a pressure sensor sensing the pressure in the vicinity of a suction port of the electric blower, a current sensor sensing the current in a rotary brush driving motor of the floor nozzle, and a microcomputer. The microcomputer performs a fuzzy inference on the outputs of the pressure sensor and the current sensor to determine the duty cycle of the blower control triac on the basis of the result of the inference. By doing this, supply of power to the electric blower in accordance with the condition of a floor surface is realized.