The day I got my first air balancing hood, many of my beliefs about the air conditioning industry changed drastically. For the first time I was able to measure how a system worked, and it wasn't pretty. The design concepts I had been taught were badly bruised, and the certainty I had about the comfort and efficiency I was providing to my customers was swept away. At the end of the day I went home nervous and confused.
It took years of study and practice and hundreds of thousands of measurements to learn and then simplify the testing and reports that could reveal to homeowners the sorry operating state of their air conditioning and heating systems.