An oil boiler includes an outer container having openings at opposite ends, a combustion chamber that covers an opening at an upper end of the outer container and in which a combustion reaction occurs, a lower cover that covers an opening at a lower end of the outer container, a plurality of flue tubes to heat heating water flowing in the outer container by guiding combustion gas, a burner including a fuel nozzle that sprays fuel, an air nozzle that injects air, and a spark plug that ignites a mixture of the fuel and the air, and a flame tube part that defines a tube space by surrounding a partial space in which the mixture is ignited, the flame tube part including a flame tube having an open lower end and a recirculation hole formed through the flame tube such that the combustion gas is introduced into the flame tube.

A system and apparatus for precision temperature control of thermal bead baths used in biological laboratories to heat biological samples is disclosed. The system has an insulated outer shell and an inner shell sealed together to form a recirculation pathway. The inner shell has an air extraction port opening into the recirculation pathway and at least one air injection port opening into the recirculation pathway. A fan is in the recirculation pathway and is positioned to draw air through the air extraction port. At least one thermal sensor is connected to a control and is disposed in close proximity to one of the air injection ports. Beads used in thermal bead baths are placed in a mesh basket inside the inner shell. The fan draws air from the inner shell through the beads and into the recirculation pathway, where the air is heated by a thermal element. The air flows past the thermal element and through the air injection ports back into the inner shell.

A heating system including at least one louver coupled with the housing of a heater including a blade and end caps on the blade for holding each louver in a fixed position during operation of the heater assembly, but also releasing the louver for adjustment in positioning relative to the axis of rotation of the louver to change air flow direction or other characteristics as desired.

A dryer includes a centrifugal impeller, a motor configured to rotate the impeller about a rotation axis which crosses a plane including a blowing axis, and a heater. The impeller is accommodated in a portion including a pair of side surfaces, each of which crosses the rotation axis, and an air inlet defined in at least one of the side surfaces. The impeller includes blades that are annular with the rotation axis as a center. The heater is supported on plate-shaped portions extending in a plurality of directions from the blowing axis in a cross-section perpendicular or substantially perpendicular to the blowing axis. A rear edge of each of the plate-shaped portions with respect to the blowing axis extends in a direction which crosses radially outer edges of the blades with respect to the rotation axis when viewed along the blowing axis.

The heat exchanger comprises at least one gas flow channel, at least one water flow channel, and a metal wall delimiting the gas flow channel from the water flow channel. The at least one water flow channel comprises a number of consecutive parallel straight segments. Two consecutive parallel straight segments are separated by a wall and by a U-turn comprising an upstream section and a downstream section. The upstream and the downstream sections are defined as the sections of the U-turn delimited on the one hand by the plane of the wall separating the two consecutive parallel straight segments; and on the other hand by the plane through the end section of the wall separating the two consecutive parallel straight segments, the plane which is parallel with the width direction of the water flow channel and which is perpendicular to the plane of the wall separating the two consecutive parallel straight segments. In at least two U-turns the upstream section has a volume that is at least 20% lower than the volume of the downstream section.

A water heater insert device positioned within an electrical showerhead or as a standalone liquids heating device. The water heater insert optimizes heat transfer by channeling water through a channel of a spiral or zigzag form where a deployed heating element supplies thermal energy. The channel maximizes water contact while minimizing the space. A temperature limiter adds protection against scalding.

A flue shield is described for use within HVAC systems and inside of a combustion chamber. The flue shield can be installed around the burner and within the combustion chamber to help dissipate heat that builds up as a result of the combustion of gas and air. Extensions from the flue shield extend through holes in the combustion chamber and into tubes of a heat exchanger. An air gap is created between the flue shield and the inner surfaces of the combustion chamber and heat exchanger tubes. Installation of a flue shield provides better efficiency than insulation solutions, reduces stresses on the heat exchanger, and provides safety benefits.

A flue shield and mesh baffle are described for use within HVAC systems and inside of a combustion chamber. The shield or baffle can be installed around the burner and within the combustion chamber to help dissipate heat that builds up as a result of the combustion of gas and air. An air gap is created between the flue shield and the inner surfaces of the combustion chamber and heat exchanger tubes. A mesh baffle can provide heat insulation and noise dampening. Installation of a flue shield or mesh baffle provides better efficiency than insulation solutions, reduces stresses on the heat exchanger, and provides safety benefits.

A heat exchanger device for a heater a motor vehicle, having a housing with at least one fluid channel disposed therein, with a fluid inlet and a fluid outlet, an element generating an alternating magnetic field, and at least one, preferably metallic, flat heating element around which a fluid can flow on one or both sides, whereby at least one further flat heating element is provided, which is configured to divide the at least one fluid channel into subchannels. A heater with a heat exchanger device is also provided.

A fuel-fired furnace incorporates specially designed fuel/air mixing and combustion structures. The fuel/air mixing structure is of a mixing sound-attenuating design and comprises a venturi having a perforated sidewall portion and being surrounded by a noise-damping housing chamber communicating with the interior of the venturi via its sidewall perforations. During use of the mixing structure, air is flowed through the venturi in a swirling pattern while fuel is transversely injected internally against the swirling air. The combustion structure comprises a burner box housing into which the fuel/air mixture is flowed, combusted, and then discharged as hot combustion gas into and through the heat exchanger tubes. The fuel/air mixture entering the burner box housing initially passes through a non-uniformly perforated diffuser plate functioning to substantially alter in a predetermined manner the relative combustion gas flow rates through the heat exchanger tubes.