Direct evaporative cooling system for data center with fault detection

A method for sensor fault detection for a first sensor that measures a first condition and a second sensor that measures a second condition, wherein equipment is operable to affect the first condition and the second condition, the method comprising:

• generating expected values for the first condition and corresponding expected values for the second condition using a physics-based model that defines a physics-based relationship between the first condition and the second condition;
• and
• triggering a sensor fault in response to determining that measured values for the first condition deviate from the expected values for the first condition and measured values for the second condition track the expected values for the second condition;
• and
• abstaining from triggering the sensor fault in response to determining that the measured values for the first condition deviate from the expected values for the first condition and the measured values for the second condition deviate from the expected values for the second condition.

A method for sensor fault detection for a first sensor that measures a first indoor air condition and a second sensor that measures a second indoor air condition, the method comprising:

• determining an expected relationship between the first indoor air condition and the second indoor air condition based on thermodynamic principles;
• evaluating first measurements of the first indoor air condition from the first sensor and second measurements of the second indoor air condition from the second sensor to determine whether the first and second measurements satisfy the expected relationship between the first indoor air condition and the second indoor air condition;
• triggering a fault in the first sensor or the second sensor in response to determining that the first measurements from the first sensor and the second measurements from the second sensor do not satisfy the expected relationship between the first indoor air condition and the second indoor air condition;
• and
• performing, in response to the fault, one or more of cleaning, moving, or replacing the first sensor or the second sensor.