Sensor circuit for detecting refrigerant and related method

A sensor circuit, comprising:

• a float sensor including
• a float housing having an opening on a first side wall, the float housing being configured to contain a liquid,
• a float located in the float housing and configured to rise or fall based on a level of the liquid in the float housing, and
• a switch connected to the float and configured to transmit an air-conditioner shut-down signal when the liquid in the float housing rises to a predetermined height;
• a three-way connection pipe connected at a first end to the first side wall of the float housing such that the liquid and first air can flow from the overflow pipe into the float housing through the opening;
• and
• a refrigerant sensor connected to a third end of the three-way connection pipe and configured to detect a level of refrigerant in third air formed at least in part by the first air in the three-way connection pipe,
• wherein
• an opening from the third end of the three-way connection pipe is located above the predetermined height.

A method of detecting refrigerant, comprising:

• passing overflow water and first air from a drain pan in an air conditioner to a float sensor;
• diverting a portion of the first air to a refrigerant sensor to form at least part of second air in the refrigerant sensor after the air exits the drain pan;
• determining at the refrigerant sensor that a level of refrigerant in the second air is above a concentration threshold;
• and
• transmitting a leakage signal from the refrigerant sensor after the refrigerant sensor determines that the level of refrigerant in the second air is above the concentration threshold.