Question 447General Subjects - Assistant Engineer

The correct answer is B) 0.5 inches of water column. This pressure drop across an air conditioning filter is indicative of a need to replace or clean the filter as appropriate. The recommended maximum pressure drop for an air conditioning filter is typically around 0.5 inches of water column. If the pressure drop exceeds this value, it indicates that the filter is becoming clogged and needs to be cleaned or replaced to maintain proper airflow and system efficiency. The other answer choices are incorrect because 0.1 inches of water column is too low, 1.0 inches of water column is too high, and 5.0 inches of water column is significantly too high and would indicate a severely clogged or obstructed filter that could potentially damage the air conditioning system.