Method for refrigerant pressure control in refrigeration systems

A method for controlling refrigerant pressure in an HVAC system comprising:

• providing a closed loop refrigerant system comprising a compressor, a condenser and an evaporator, the condenser having a header arrangement capable of distributing refrigerant to a plurality of refrigerant circuits within the condenser and capable of selectively isolating at least one of the circuits from refrigerant flow;
• providing at least one valve arrangement capable of controlling refrigerant flow into and out of at least one of the circuits that can be selectively isolated from refrigerant flow;
• measuring refrigerant pressure at a predetermined location in the refrigeration system;
• isolating at least one of the circuits from refrigerant flow, in response to the measured refrigerant pressure;
• selectively drawing refrigerant from the at least one refrigerant circuit isolated from refrigerant flow into the refrigerant system to increase the refrigerant pressure in the refrigerant system;
• selectively drawing refrigerant into the at least one refrigerant circuit isolated from refrigerant flow from the refrigerant system to decrease the refrigerant pressure in the refrigerant system;
• and
• repeating the steps of measuring and isolating until the measured refrigerant pressure is sufficiently adjusted with respect to the predetermined pressure.

A heating, ventilation and air conditioning system comprising:

• a compressor, an evaporator, and a condenser connected in a closed refrigerant loop;
• a refrigerant pressure sensor to measure refrigerant pressure, the refrigerant pressure sensor being disposed at predetermined location within the system;
• the condenser including a plurality of refrigerant circuits, a first valve arrangement and a second valve arrangement;
• the first valve arrangement arranged and disposed to selectively isolate one or more of the refrigerant circuits from flow of refrigerant;
• wherein the first valve arrangement is further arranged and disposed to increase the refrigerant pressure in the closed refrigerant loop by selectively drawing refrigerant into the closed refrigerant loop from at least one of any refrigerant circuits isolated from flow of refrigerant;
• wherein the first valve arrangement is further arranged and disposed to decrease the refrigerant pressure in the closed refrigerant loop by selectively drawing refrigerant from the closed refrigerant loop into at least one of any refrigerant circuits isolated from flow of refrigerant;
• and
• wherein the second valve arrangement is arranged and disposed to draw refrigerant into or out of the one or more isolated refrigerant circuits of the condenser in response to the measured refrigerant pressure to maintain a predetermined system pressure.