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US 10,704,816 B2Granted
Liquid transfer pump cycle
AssigneeLennox Industries Inc.
InventorsCarl T. Crawford, Robert B. Uselton
Life of this patent
Estimating the term…
Abstract
A method of initiating a low-energy cooling mode using a controller of an HVAC system includes measuring a temperature of ambient air proximal to a condenser coil and determining whether the temperature of the ambient air proximal the condenser coil is less than a temperature threshold. If the temperature of the ambient air is less than the temperature threshold, the HVAC system is configured to operate in a low-energy cooling mode. In the low-energy cooling mode, the controller opens a first bypass valve to allow a refrigerant to bypass a compressor and the compressor is powered off. The HVAC system is operated until a cooling demand has been met.
Claims19
An HVAC system configured to provide low-energy cooling, the HVAC system comprising:
- an evaporator coil comprising an evaporator coil inlet and an evaporator coil outlet;
- a condenser coil comprising a condenser coil inlet and a condenser coil outlet, the condenser coil outlet being coupled to the evaporator coil inlet, the condenser coil comprising:
- a primary cooling path coupled to a first collector;
- a secondary cooling path coupled to a secondary cooling path inlet;
- and
- a first cooling-path outlet coupled to the secondary cooling path inlet via a first collection tube to direct a refrigerant to the secondary cooling path from the first collector of the primary cooling path, wherein the first collection tube bypasses a second primary cooling path inlet and a second primary cooling path outlet;
- a first bypass valve comprising a first bypass valve inlet coupled to the evaporator coil outlet and a first bypass valve outlet coupled to the condenser coil inlet;
- a liquid pump comprising a liquid pump inlet coupled to the condenser coil outlet and a liquid pump outlet coupled to the evaporator coil inlet;
- a thermal expansion valve coupled between the liquid pump and the evaporator coil inlet;
- a second bypass valve disposed in parallel with the thermal expansion valve between the liquid pump and the evaporator coil inlet;
- and
- an HVAC controller configured to:
- measure a temperature of ambient air proximal to the condenser coil;
- determine whether the temperature of the ambient air proximal to the condenser coil is less than a temperature threshold;
- responsive to a determination that the temperature of the ambient air is less than the temperature threshold, configure the HVAC system to operate in a first cooling mode by opening the first bypass valve to allow the refrigerant to bypass a compressor and powering off the compressor;
- and
- operate the HVAC system in the first cooling mode.
14 more elements
A method of initiating a low-energy cooling mode using a controller of an HVAC system, the method comprising:
- measuring a temperature of ambient air proximal to a condenser coil, the condenser coil comprising:
- a primary cooling path coupled to a first collector;
- a secondary cooling path coupled to a secondary cooling path inlet;
- and
- a first cooling-path outlet coupled to the secondary cooling path inlet via a first collection tube to direct a refrigerant to the secondary cooling path from the first collector of the primary cooling path, wherein the first collection tube bypasses a second primary cooling path inlet and a second primary cooling path outlet;
- determining whether the temperature of the ambient air proximal the condenser coil is less than a temperature threshold;
- responsive to a determination that the temperature of the ambient air is less than the temperature threshold, configuring the HVAC system to operate in a first cooling mode, wherein configuring the HVAC system to operate in the first cooling mode comprises:
- opening a first bypass valve to allow the refrigerant to bypass a compressor;
- opening a second bypass valve to allow the refrigerant to bypass a thermal expansion valve that is coupled to an evaporator coil of the HVAC system;
- and
- powering off the compressor;
- operating the HVAC system in the first cooling mode;
- determining, responsive to the operating, if a cooling demand has been met;
- responsive to a determination that the cooling demand has been met, turning the HVAC system off;
- and
- responsive to a determination that the cooling demand has not been met, measuring the temperature of the ambient air.
13 more elements
A method of initiating a low-energy cooling mode using a controller of an HVAC system, the method comprising:
- measuring a temperature of ambient air proximal to a condenser coil, the condenser coil comprising:
- a primary cooling path coupled to a first collector;
- a secondary cooling path coupled to a secondary cooling path inlet;
- and
- a first cooling-path outlet coupled to the secondary cooling path inlet via a first collection tube to direct a refrigerant to the secondary cooling path from the first collector of the primary cooling path, wherein the first collection tube bypasses a second primary cooling path inlet and a second primary cooling path outlet;
- determining whether the temperature of the ambient air proximal the condenser coil is less than a temperature threshold;
- responsive to a determination that the temperature of the ambient air is less than the temperature threshold, configuring the HVAC system to operate in a first cooling mode, wherein configuring the HVAC system to operate in the first cooling mode comprises:
- opening a first bypass valve to allow the refrigerant to bypass a compressor;
- powering off the compressor;
- closing a check valve to direct the refrigerant through a liquid pump;
- and
- opening a second bypass valve to allow the refrigerant to bypass a thermal expansion valve;
- operating the HVAC system in the first cooling mode;
- determining, responsive to the operating, if a cooling demand has been met;
- responsive to a determination that the cooling demand has been met, turning the HVAC system off;
- and
- responsive to a determination that the cooling demand has not been met, measuring the temperature of the ambient air.
14 more elements
Dependencies are inferred from the claim text.