A system comprising a main circuit for routing a flow of heat transfer liquid out of a thermal storage to at least one outer heat exchanger and back to the thermal storage again, a main circulation pump configured to force the heat transfer liquid through the main circuit, a temperature sensor configured to measure the temperature of the heat transfer liquid, and a controller configured to control the main circulation pump based on temperature readings of the temperature sensor such that a calculated Reynolds number for the flow of heat transfer liquid is constant at a predetermined target Reynolds number over at least a primary temperature range.

A system comprising a main circuit for routing a flow of heat transfer liquid out of a thermal storage to at least one outer heat exchanger and back to the thermal storage again, a main circulation pump configured to force the heat transfer liquid through the main circuit, a temperature sensor configured to measure the temperature of the heat transfer liquid, and a controller configured to control the main circulation pump based on temperature readings of the temperature sensor such that a calculated Reynolds number for the flow of heat transfer liquid is constant at a predetermined target Reynolds number over at least a primary temperature range.

A gas furnace according to an embodiment of the present disclosure includes: a mixer for mixing air and a fuel gas, which are introduced through an intake pipe and a manifold, respectively, to form a mixture; a mixing pipe through which the mixture, having passed through the mixer, flows; a burner assembly for producing a combustion gas by burning the mixture having passed through the mixing pipe; a heat exchanger through which the combustion gas flows; an exhaust pipe through which an exhaust gas, as the combustion gas having passed through the heat exchanger, is discharged outside of the gas furnace; and an inducer for inducing a flow of a fluid through the intake pipe, the mixer, the mixing pipe, the burner assembly, the heat exchanger, and the exhaust pipe. In this case, the mixer has a front end connected to the intake pipe, a rear end connected to the mixing pipe, and a side surface connected to the manifold.

A heating system is configured to produce heated fluid. The system includes a source of primary fluid, a diffusing structure comprising an outlet structure out of which the heated fluid flows, at least one conduit coupled to the source and the diffusing structure and configured to introduce to the diffusing structure the primary fluid, and an intake structure coupled to the diffusing structure and configured to introduce to the diffusing structure a secondary fluid accessible to the system. The heated fluid includes the primary and secondary fluids.

A heating system is configured to produce heated fluid. The system includes a source of primary fluid, a diffusing structure comprising an outlet structure out of which the heated fluid flows, at least one conduit coupled to the source and the diffusing structure and configured to introduce to the diffusing structure the primary fluid, and an intake structure coupled to the diffusing structure and configured to introduce to the diffusing structure a secondary fluid accessible to the system. The heated fluid includes the primary and secondary fluids.

Example furnaces and methods related thereto include a burner box including at least one burner configured to combust a fuel/air mixture. In addition, the furnace includes a first blower including an inlet nozzle having an air inlet and fuel inlet. The inlet nozzle is configured such that operation of the first blower is to pull air and fuel into the inlet nozzle to produce the fuel/air mixture at a fuel/air ratio that is configured to produce flue products having less than 14 Nano-grams per Joule of nitrogen oxides when combusted. Operation of the first blower is configured to push the fuel/air mixture into the burner box. Further, the furnace includes a heat exchanger assembly fluidly coupled to the burner box through a vestibule, and a second blower configured to pull the flue products through the heat exchanger assembly.

Example furnaces and methods related thereto include a burner box including at least one burner configured to combust a fuel/air mixture. In addition, the furnace includes a first blower including an inlet nozzle having an air inlet and fuel inlet. The inlet nozzle is configured such that operation of the first blower is to pull air and fuel into the inlet nozzle to produce the fuel/air mixture at a fuel/air ratio that is configured to produce flue products having less than 14 Nano-grams per Joule of nitrogen oxides when combusted. Operation of the first blower is configured to push the fuel/air mixture into the burner box. Further, the furnace includes a heat exchanger assembly fluidly coupled to the burner box through a vestibule, and a second blower configured to pull the flue products through the heat exchanger assembly.

According to various aspects, exemplary embodiments are disclosed of blow through direct fired heaters including evaporator coils and/or energy recovery ventilation.

According to various aspects, exemplary embodiments are disclosed of blow through direct fired heaters including evaporator coils and/or energy recovery ventilation.