Abstract: A device that heats/cools air includes a heat exchanger that contains hydronic fluid; a blower that moves air over and/or through the heat exchanger; a pump that circulates the hydronic fluid; a first vessel that contains hydronic fluid under pressure, air, a sealed first opening, a second opening that allows the hydronic fluid to exit the first vessel, a third opening that allows the hydronic fluid to enter the vessel, and a fourth opening; a second vessel that contains hydronic fluid at atmospheric pressure, a sealed first opening, and a second opening in communication with the first vessel, wherein the second vessel is in communication with the fourth opening; a valve that allows hydronic fluid to flow from the second vessel to the first vessel when pressure inside the first vessel decreases below zero psig, and prevents hydronic fluid from flowing from the first vessel to the second vessel.

Abstract: A device that heats/cools air includes a heat exchanger that contains hydronic fluid; a blower that moves air over and/or through the heat exchanger; a pump that circulates the hydronic fluid; a first vessel that contains hydronic fluid under pressure, air, a sealed first opening, a second opening that allows the hydronic fluid to exit the first vessel, a third opening that allows the hydronic fluid to enter the vessel, and a fourth opening; a second vessel that contains hydronic fluid at atmospheric pressure, a sealed first opening, and a second opening in communication with the first vessel, wherein the second vessel is in communication with the fourth opening; a valve that allows hydronic fluid to flow from the second vessel to the first vessel when pressure inside the first vessel decreases below zero psig, and prevents hydronic fluid from flowing from the first vessel to the second vessel.

Abstract: An electronic expansion valve (EEV) is operated by a motor controlling a variable restriction valve in which a liquid refrigerant enters at a high pressure and exits at a reduced pressure. The motor controls the depth of a tapered needle which, as extended, penetrates multiple fixed orifices, aligned in series. Additional fixed orifices, downstream of the fully extended needle, provide further restriction and management of refrigerant flashing. Depending on the desired operating range, the following elements may be controlled: needle length, diameter, and taper; diameter, thickness, and relative elevation of each orifice; response and maximum torque provided by the motor; and geometry of the valve enclosed volume.

Abstract: An electronic expansion valve (EEV) is operated by a motor controlling a variable restriction valve in which a liquid refrigerant enters at a high pressure and exits at a reduced pressure. The motor controls the depth of a tapered needle which, as extended, penetrates multiple fixed orifices, aligned in series. Additional fixed orifices, downstream of the fully extended needle, provide further restriction and management of refrigerant flashing. Depending on the desired operating range, the following elements may be controlled: needle length, diameter, and taper; diameter, thickness, and relative elevation of each orifice; response and maximum torque provided by the motor; and geometry of the valve enclosed volume.