Aspects of the invention relate to water heaters including a water storage tank having a top wall, a bottom wall, and a side wall extending between the top wall and the bottom wall; a combustion chamber extending below the bottom wall of the water storage tank and a heat exchanger configured to receive combustion gases and to transfer heat to water in the water storage tank. The heat exchanger includes a first pass flue extending through the water storage tank and a plurality of second pass flues coupled to receive combustion gases from the first pass flue. The second pass flues extending through the water storage tank and having a straight top portion, a curved bottom portion, and a longitudinal axis residing in a plane. The curved bottom portion of the second pass flues exits the water storage tank through at least one aperture defined in the side wall of the water storage tank.

A fluid heating system for heating a production fluid using a thermal transfer fluid, the production fluid being contained in a vessel includes an electric blower configured to receive ambient air and electrical input power and to provide output source air, a combustion system configured to receive the source air from the electric blower and to receive fuel and to provide the thermal transfer fluid, a heat exchanger configured to receive the thermal transfer fluid from the combustion system and configured to provide heat exchange from the thermal transfer fluid to the production fluid, and to provide output exhaust gas, and wherein the electric fan provides a predetermined volume flow rate of the output source air at a predetermined blower efficiency such that the fluid heating system has a Bulk Heat Flux of at least about 14.7 kBTU/Hr/ft.sup.2 and a Pressure Drop of at least about 0.7 psi.

A method for operating a water heater appliance includes determining a set temperature of the water heater appliance. The method also includes monitoring a temperature proximate to a lower heating element of the water heater appliance with a first temperature sensor of the water heater appliance and monitoring a temperature proximate to an upper heating element of the water heater appliance with a second temperature sensor of the water heater appliance. When the monitored temperature proximate the lower heating element is less than a first temperature threshold and the monitored temperature proximate the upper heating element is less than a second temperature threshold, the method includes turning the lower heating element on. When the monitored temperature proximate the upper heating element is equal to the set temperature, the method includes turning the lower heating element off. A related water heater appliance is also provided.

Floating marinized water bath vaporizer utilizing a slosh chamber having reduced water surface area to reduce the effects of wave created which the vaporizer is in motion, and systems utilizing such vaporizer, and to methods of making and using such vaporizer.

A heating assembly for heating a liquid storage tank includes a heat exchanger tank supported in one wall of the storage tank to extend into the storage tank in contact with liquid stored therein. The heat exchanger tank contains a heat exchanger fluid therein which is heated by a burner tube extending through the heat exchanger tank whereby heat is only transferred to the liquid in the storage tank through the heat exchanger fluid. A controller actuates the burner head of the burner tube to maintain temperature of the heat exchanger fluid between upper and lower temperature limits. The operation of the burner head is interrupted in response to temperature of the liquid in the storage tank exceeding an upper limit, or fluid level in the heat exchanger tank being below a lower limit as determined by respective sensors.

A blower assembly is attached to a water heater having an exhaust opening, the assembly includes a tank cap attached to a tank of the heater. A recess surface formed in the exterior surface of the cap. A member has a first surface that is connected to the tank cap to form a cover plenum between the cap and the member. The blower includes a motor, an air moving member connected to the motor and a blower housing having an interior containing the fan. The blower housing has an input opening that communicates the blower housing interior with the member output opening. The blower housing, the member and the tank cap provide an exhaust gas flow path from the exhaust opening of the heater through the cover plenum, through the blower housing interior and out the output opening.

A fluid heating system including: a pressure vessel; an assembly comprising: a heat exchanger core including a second inlet and a second outlet; a first conduit having a first end connected to the second inlet of the heat exchanger core and a second end disposed outside of the pressure vessel; a second conduit having a first end connected to the second outlet of the heat exchanger core and a second end disposed outside of the pressure vessel; and a blower in fluid connection with the first end of the first conduit, wherein the fluid heating system satisfies the condition that a Bulk Heat Flux between the first end of the first conduit and the first end of the second conduit is between 45 kW/m.sup.2 and 300 kW/m.sup.2, and wherein the Pressure Drop between the first conduit and the second conduit is between 3 kiloPascals and 30 kiloPascals.

Process heaters and associated methods of processing with ultra-low pollutant emissions are provided. The process heaters and methods utilize a heat exchange tube having disposed therein a radiant permeable matrix burner at a first end of the tube. The tube further includes a thermally insulated insert disposed adjacent the radiant burner opposite an oxidant-fuel mixer that feeds the burner. The process heaters and methods act to reduce emissions of CO and NOx.

An exhaust duct includes an upper duct being open at opposite ends thereof and a lower duct being open at a tip end thereof. One end of the upper duct is connected, inside an enclosure of a water-heating device, to an exhaust adaptor disposed on the enclosure, and an opposite end of the upper duct communicates with the tip end of the lower duct. The upper duct is connected to the lower duct so as to be slidable along a reference direction in which the lower duct extends from the tip end of the lower duct, and the upper duct is configured to be separated from the exhaust adaptor by sliding along the reference direction.

A method for operating a water heater appliance includes determining a set temperature of the water heater appliance. The method also includes monitoring a temperature proximate to a lower heating element of the water heater appliance with a first temperature sensor of the water heater appliance and monitoring a temperature proximate to an upper heating element of the water heater appliance with a second temperature sensor of the water heater appliance. When the monitored temperature proximate the lower heating element is less than a first temperature threshold and the monitored temperature proximate the upper heating element is less than a second temperature threshold, the method includes turning the lower heating element on. When the monitored temperature proximate the upper heating element is equal to the set temperature, the method includes turning the lower heating element off. A related water heater appliance is also provided.