Abstract: Heat is transferred from a first fluid to a cooler second fluid with a heat exchanger having heat exchanger tubes in which the cooler second fluid flows, preferably in a counterflow to the first fluid. The heat exchanger tubes are arranged in more than three rows of heat exchanger tubes. The first fluid proceeds successively downstream through such rows in heat-transfer relationship with the heat exchanger tubes. Each downstream row of heat exchanger tubes has less throughput area for the first fluid than an adjacent upstream row of heat exchanger tubes as among at least the first three rows of heat exchanger tubes in the direction of flow of the first fluid. Each downstream row of heat exchanger tubes may have less heat exchanger tubes than an adjacent upstream row of heat exchanger tubes as among at least the first three of the rows of heat exchanger tubes in the direction of flow of the first fluid.

Abstract: A methods and apparatus for exhausting flue products and removing condensate from a combustion of air/gas mixtures provide a condensate collecting pan for flue products. That pan is provided with an inlet for flue products and condensate, and with an outlet for flue products spaced from that inlet. That inlet is provided with a larger cross-section for flue product and condensate flow than the outlet. A space is provided in the pan for a flow of flue products from the inlet at a substantially even velocity across the larger cross-section of the inlet to the smaller cross-section outlet. Condensate collecting in that space is removed from the pan.

Abstract: Air pollution from combustion of air/gas mixtures is reduced effectively and reliably at a porous burner providing flames with a downstream reaction zone where the ignition of the air/gas mixture initiates. The porous burner is loaded with the air/gas mixture sufficiently, such as at from 1000 to 2500 kWm.sup.-2 or 2200 to 5500 Btu/sqin-hr, to locate the downstream reaction zone at a downstream surface of the porous burner, while the air/gas mixture is provided with sufficient excess air, such as more than a quarter of excess air, for the flames to burn blue. In a typical combustion of that air/gas mixture, less than 20 ppm of NO.sub.x are produced. A related method loads the porous burner with the air/gas mixture at from 1000 to 2000 kWm.sup.-2 or 2200 to 4400 Btu/sqin-hr, while providing that air/gas mixture with more than about forty-five percent of excess air for the flames to burn blue. That combustion of the air/gas mixture including its excess air produces less than 10 ppm of NO.sub.x.

Abstract: The reflectivity of a porous burner matrix is enhanced in order to enhance burner performance, capacity and capability. More specifically, a porous matrix is coated with a layer of a material, such as gold, having a higher reflectivity than the porous matrix by itself, and gas-flow pores of the porous matrix are preserved in that layer. A burner has a porous matrix and a porous coating on that porous matrix including a porous layer of a material, such as gold, having a higher reflectivity than the porous matrix by itself.

Abstract: A fluid valve has a valve housing defining a corner and having a valve housing cover opposite that corner. That valve housing and cover enclose a valve chamber therein. A fluid inlet or outlet is in the valve housing cover. First and second valve seats for further fluid inlets or outlets are in first and second sides, respectively, of the corner in the valve chamber. A flapper is in that chamber for selectively closing the first valve seat and alternatively the second valve seat. A flapper actuator is in the corner of the valve housing. There may be an expansible valve closing member for each valve seat. Such expansible valve closing member may have an aperture paralleling that valve seat. A pilot valve may be at the expansible valve closing member for closing its aperture. Opening of the valve is initiated by moving the pilot valve away from the aperture in the expansible valve closing member, and such opening of the valve is completed by pulling the expansible valve closing member away from its valve seat.

Abstract: A control for a spa and swimming pool pump and heater assembly with diverter valves, includes a selectively actuable pump and spa heater actuator or relay having a first latching circuit, and having a separate first unlatching switch or relay contact, a selectively actuable pump and pool heater actuator or relay having a second latching circuit including the first unlatching switch or relay contact, and having a second unlatching switch or relay contact in the first latching circuit. The control also includes a diverter valve actuator in parallel to one of the pump and spa heater actuator or relay and pump and pool heater actuator or relay.

Abstract: A fluid valve has a valve housing defining a corner and having a valve housing cover opposite that corner. That valve housing and cover enclose a valve chamber therein. A fluid inlet or outlet is in the valve housing cover. First and second valve seats for further fluid inlets or outlets are in first and second sides, respectively, of the corner in the valve chamber. A flapper is in that chamber for selectively closing the first valve seat and alternatively the second valve seat. A flapper actuator is in the corner of the valve housing. There may be an expansible valve closing member for each valve seat. Such expansible valve closing member may have an aperture paralleling that valve seat. A pilot valve may be at the expansible valve closing member for closing its aperture. Opening of the valve is initiated by moving the pilot valve away from the aperture in the expansible valve closing member, and such opening of the valve is completed by pulling the expansible valve closing member away from its valve seat.

Abstract: A plurality of baffles for adjacent finned tubes of a heat exchanger wherein a first fluid flows in the finned tubes and a second fluid of a different temperature flows past the finned tubes in heat transfer relationship therewith, include a baffle for each adjacent pair of finned tubes. A first flow path for second fluid extends in between baffles at one of the finned tubes, and a second flow path for second fluid extends in between baffles at an adjacent other of the finned tubes. The second flow path is larger between baffles at the other finned tube than the first flow path between baffles at the one finned tubes, and the second flow path is longer along baffles at the other finned tube than the first flow path along baffles at the one finned tube.

Abstract: A wind-resistant heating appliance has a housing with air inlet openings for sustaining combustion generating flue products inside that housing which also has an outlet for flue products. The heating appliance has a top structure above that outlet and the housing. A top wall of that top structure is penetrated with exhaust openings for flue products along opposite edges of that top structure. The outlet between the housing and the top structure is provided with a transverse outlet channel inside the top structure and has opposite ends open at the exhaust openings adjacent the opposite edges of the top structure. That transverse outlet channel is solidly enclosed along its top, sides and bottom between the opposite ends, except for the outlet between the housing and the top structure. The exhaustion of flue products in various wind conditions is further aided by increasing the speed of flue products passing through the outlet from the housing to the transverse outlet channel.

Abstract: Methods and apparatus for controlling equipment for operating a spa, provide electrical controls for controlling such equipment, a manual stationary control for manual user operation of these electrical controls, and a manual remote control including a hand-held wireless remote control unit for manual user operation, at least from inside the spa, of the electrical controls operable by the manual stationary control. The manual stationary control is maintained activated for continued manual user operation of the equipment through the electrical controls manually from a control location while the manual remote control remains activated for manual user operation of the equipment through the electrical controls interchangeably with the manual stationary control from the control location and with the hand-held wireless remote control unit at least from inside the spa.