Heating system including a refrigerant boiler

A heating system comprising:

• a refrigerant boiler including a heat source for heating a refrigerant from a liquid state to a vapor state, a boiler outlet and a boiler inlet, a first section and a second section arranged in counterflow manner with respect to flue gas flow from the boiler;
• a heat exchanger in fluid communication with the refrigerant boiler, the heat exchanger including an upper manifold having a heat exchanger inlet coupled to the boiler outlet, a lower manifold having a heat exchanger outlet coupled to the boiler inlet and a plurality of tubes connecting the upper manifold and the lower manifold, wherein refrigerant passes from the upper manifold to the lower manifold via gravity;
• a liquid-vapor separator positioned between the first section and the second section, a vapor portion of the liquid-vapor separator being coupled to an inlet of the heat exchanger, a liquid portion of the liquid-vapor separator being coupled to an inlet of the first section;
• a fan moving air over the heat exchanger to define supply air for a space to be heated;
• a first valve downstream of the boiler controlling flow of vapor refrigerant to the heat exchanger inlet;
• a second valve upstream of the boiler controlling flow of liquid refrigerant to the boiler inlet;
• and a controller for selectively opening and closing the first valve and second valve to control flow of refrigerant between the boiler and heat exchanger;
• wherein in a first state the first valve and second valve are closed, the controller opening the first valve in response to at least one of temperature and pressure in the boiler.

A heating system comprising:

• a refrigerant boiler including a heat source for heating a refrigerant from a liquid state to a vapor state, a boiler outlet and a boiler inlet;
• a heat exchanger in fluid communication with the refrigerant boiler, the heat exchanger including an upper manifold having a heat exchanger inlet coupled to the boiler outlet, a lower manifold having a heat exchanger outlet coupled to the boiler inlet and a plurality of tubes connecting the upper manifold and the lower manifold, wherein refrigerant passes from the upper manifold to the lower manifold via gravity;
• a fan moving air over the heat exchanger to define supply air for a space to be heated;
• a first valve downstream of the boiler controlling flow of vapor refrigerant to the heat exchanger inlet;
• a second valve upstream of the boiler controlling flow of liquid refrigerant to the boiler inlet;
• and a controller for selectively opening and closing the first valve and second valve to control flow of refrigerant between the boiler and heat exchanger;
• wherein the boiler includes a first section and a second section arranged in a counterflow manner with respect to flue gas flow from the boiler, the second heat exchanger section including a tray for collecting flue gas condensate and a condensate drain coupled to the tray;
• and a liquid-vapor separator positioned between the first section and the second section, a vapor portion of the liquid-vapor separator being coupled to an inlet of the heat exchanger, a liquid portion of the liquid-vapor separator being coupled to an inlet of the first section.

A heating system comprising:

• a refrigerant boiler including a heat source for heating a refrigerant from a liquid state to a vapor state, a boiler outlet and a boiler inlet, a first section and a second section arranged in counterflow manner with respect to flue gas flow from the boiler;
• a heat exchanger in fluid communication with the refrigerant boiler, the heat exchanger including an upper manifold having a heat exchanger inlet coupled to the boiler outlet, a lower manifold having a heat exchanger outlet coupled to the boiler inlet and a plurality of tubes connecting the upper manifold and the lower manifold, wherein refrigerant passes from the upper manifold to the lower manifold via gravity;
• a liquid-vapor separator positioned between the first section and the second section, a vapor portion of the liquid-vapor separator being coupled to an inlet of the heat exchanger, a liquid portion of the liquid-vapor separator being coupled to an inlet of the first section;
• a fan moving air over the heat exchanger to define supply air for a space to be heated;
• a first valve downstream of the boiler controlling flow of vapor refrigerant to the heat exchanger inlet;
• a second valve upstream of the boiler controlling flow of liquid refrigerant to the boiler inlet;
• and a controller for selectively opening and closing the first valve and second valve to control flow of refrigerant between the boiler and heat exchanger;
• a sensor detecting an operational parameter of the refrigerant boiler;
• a flue gas fan directing flue gas over a boiler heat exchanger of the refrigerant boiler;
• and
• the controller for controlling at least one of the heat source of the refrigerant boiler and the flue gas fan in response to the sensor;
• wherein the flue gas fan is one of a two speed fan, a variable speed fan, and multiple fans, controlled by the controller in response to the sensor.