A method for controlling a gas furnace that performs a heating operation by receiving a first heating signal; calculating a certain heating capacity smaller than a maximum heating capacity of the gas furnace, according to the first heating signal; and operating a heating of the gas furnace with the calculated certain heating capacity. The calculating of the certain heating capacity includes calculating the certain heating capacity according to a difference between an intake air temperature sucked into the gas furnace and a reference temperature.

A portable gas water maker comprises a water maker body with a shell having a hollow structure. A water inlet communicating with the shell and used for injecting water into the shell is formed at an upper end of the water maker body. The water maker body is inverted U-shaped, so that the lower half part of the water maker body is divided into a left cavity and a right cavity. One group of Peltier semiconductor assemblies is arranged in each of the left cavity and the right cavity. A front-end semiconductor and a rear-end semiconductor in each group of Peltier semiconductor assemblies are connected through a wire. The group of semiconductor assemblies in the left cavity is used for generating electricity, and the group of semiconductor assemblies in the right cavity is used for refrigeration.

A gas furnace is provided. The gas furnace includes a combustion part in which a fuel gas is burnt to generate a combustion gas, a heat exchanger having a gas flow path through which the combustion gas flows, a blower configured to blow air around the heat exchanger, and an inducer configured to discharge the combustion gas from the heat exchanger. The heat exchanger includes at least one single path in which a single gas flow path is formed a single-multiple return bend configured to communicate with the single path and convert a flow direction of the combustion gas, and at least one multiple path having a plurality of paths that communicate with the single-multiple return bend and form multiple gas flow paths.

A connected-type hot-water supply system includes hot-water supply apparatuses connected in parallel and a control means. The control means sets one main hot-water supply apparatus and sub-hot-water supply apparatuses, and performs leveling control of cumulative loads of the hot-water supply apparatuses by setting the main hot-water supply apparatus based on sequential rotation among the hot-water supply apparatuses. The control means includes a failure sign response mode in which it is determined whether there is a failure sign respectively for components of the hot-water supply apparatuses, and when a component of a part of hot-water supply apparatuses is a failure sign component determined to have a failure sign, a main use time of a hot-water supply apparatus having the failure sign component is increased, and the main use time is a main use time of serving as the main hot-water supply apparatus in the leveling control.

A furnace for a heating, ventilation, and air conditioning (HVAC) unit includes a heat exchange tube configured to flow combustion products therethrough and place the combustion products in a heat exchange relationship with an air flow directed across the heat exchange tube. The furnace also includes a burner assembly fluidly coupled to a first port of the heat exchange tube and configured to generate the combustion products directed into the heat exchange tube via the first port, and a draft inducer blower fluidly coupled to a second port of the heat exchange tube and configured to draw the combustion products through the heat exchange tube. The burner assembly is higher in position than the draft inducer blower relative to a base of the HVAC unit.

A furnace for a heating, ventilation, and air conditioning (HVAC) unit includes a heat exchange tube configured to flow combustion products therethrough and place the combustion products in a heat exchange relationship with an air flow directed across the heat exchange tube. The furnace also includes a burner assembly fluidly coupled to a first port of the heat exchange tube and configured to generate the combustion products directed into the heat exchange tube via the first port, and a draft inducer blower fluidly coupled to a second port of the heat exchange tube and configured to draw the combustion products through the heat exchange tube. The burner assembly is higher in position than the draft inducer blower relative to a base of the HVAC unit.

A heat exchanger for heating a fluid flowing through a pipe using a combustion gas includes: a body including open upper and lower ends and having a space formed therein to allow the combustion gas to pass therethrough; a combustor formed in an upper portion of the space in which combustion of the combustion gas occurs; a heat exchange portion formed below the combustor and provided with a heat exchange pipe configured to heat an internal fluid by using the combustion gas; and a heat return pipe provided outside the space so as to be in contact with an outer surface of the body, wherein the combustor and the heat exchange portion may be unitarily formed, and the body in which the combustor is formed includes a concave portion protruding concavely inward so as to correspond to a shape of an outer circumferential surface of the heat return pipe.

A heat exchanger for heating a fluid flowing through a pipe using a combustion gas includes: a body including open upper and lower ends and having a space formed therein to allow the combustion gas to pass therethrough; a combustor formed in an upper portion of the space in which combustion of the combustion gas occurs; a heat exchange portion formed below the combustor and provided with a heat exchange pipe configured to heat an internal fluid by using the combustion gas; and a heat return pipe provided outside the space so as to be in contact with an outer surface of the body, wherein the combustor and the heat exchange portion may be unitarily formed, and the body in which the combustor is formed includes a concave portion protruding concavely inward so as to correspond to a shape of an outer circumferential surface of the heat return pipe.

The present subject matter relates to a smoke tube boiler including: a mix chamber, a heat exchanger, a firing rod assembly, a sealing means, and an air-cooled cooling means and a water-cooled cooling means.

The present subject matter relates to a smoke tube boiler including: a mix chamber, a heat exchanger, a firing rod assembly, a sealing means, and an air-cooled cooling means and a water-cooled cooling means.