System and control method for a self-contained marine air conditioner unit

A method for controlling a marine air conditioning unit, comprising:

• the marine air conditioning unit including:
• a base plate having one or more mounting holes;
• a main unit supported on the base plate comprising an evaporator, a compressor, a compressor driver, a condenser, an electronic expansion valve, a blower, a plurality of temperature and pressure sensors, and a condensation pan operatively coupled together;
• the blower configured for drawing indoor air from a room of a boat through the evaporator;
• the compressor located on a refrigerant line connecting the condenser to the evaporator to compress refrigerant flowing therethrough;
• the electronic expansion valve located on the refrigerant line configured to operate as a flow regulator to create a pressure difference between the condenser and the evaporator;
• a water pump fluidly connected to the condenser and configured for circulating water into the condenser to absorb heat from the refrigerant, wherein the water pump circulates the water from a body of water in which the boat is floating;
• and
• a controller configured to constantly receive, respond to, and, using an algorithm, analyze sensor information from multiple sensors including the plurality of temperature and pressure sensors positioned within the main unit, based on the sensor information the controller determines a precise amount of refrigerant to pass to the evaporator, and the controller transmits a control signal to adjust the electronic expansion valve to control the precise amount of refrigerant to pass to the evaporator;
• the method for controlling the marine air conditioning unit comprising:
• performing an initial diagnostic safety check;
• detecting an intake air temperature of the air;
• detecting a compressor off temperature of the compressor;
• determining whether a difference between the intake air temperature and the compressor off temperature meet a first threshold value;
• adjusting the compressor off temperature when the difference does not exceed the first threshold value;
• operating the compressor when the difference exceeds the first threshold value;
• operating the electronic expansion valve based on the control signal to adjust the electronic expansion valve;
• and
• continuously monitoring and obtaining, by the controller, data including:
• a low pressure measurement from a low pressure sensor located on a low pressure portion of the refrigerant line;
• a valve open ratio from the electronic expansion valve;
• an evaporator outlet temperature;
• compressor driver data;
• and
• electronic expansion valve driver data.