IAQ: Measurement and Verification (Metrics)

New Development 1/8/2021: Texas A&M Students Design Rapid COVID-19 Detection System

Is it possible to control a mechanical or chemical process without metrics? Yes, but how will you know how successful you are or how effective the process is without comparing the ‘before’ and the ‘after’?

Is it possible to drop devastating bombs over an enemy without a sophisticated guidance system? Yes, because bombs have a way of destroying intended targets and unintended targets, alike. Generals prefer a precision guidance system that can calculate a bombs trajectory with pinpoint accuracy. The amazing Norden bombsight of WW2 dramatically improved the effectiveness of our bombers.

An operator can observe the damper shaft rotating but is the correct volume of ventilation air up to specifications and codes?

The CEO of one hospital customer understood the value of code compliance. The first HVAC system to which we added an airflow measuring station served the ER waiting room, arguably the most dangerous room of a hospital.

Upon commissioning the updated control system, the technician observed rotation of the outdoor air damper shaft but there was no indication of airflow in either the open or closed positions of the damper shaft. The problem was the damper. When the hospital was constructed, a contractor wedged an incorrectly sized rectangular damper into the air duct. At some time the powerful damper actuator sheared the small bolts on the drive blade. No one knows for how many years there was no fresh air ventilation into that ER waiting room.

Long-term data is a powerful ally in a courtroom and could make the difference between a costly out-of-court settlement and a finding for the defendant in a civil lawsuit. Before a jury hears the arguments in a civil trial, the parties of a dispute undergo the discovery process. Well-maintained HVAC equipment supported by science and long-term data can be useful to the defendant’s position.

The overarching value of metrics is public confidence.

Back in 2010, an owner of a Toyota Prius claimed he could not stop his car as it reached over 90 mph. The car owner was unaware the manufacturer had built in to the car’s control system a long-term log that recorded operator actions. As reported by ABC News, “… electronic data from Sikes’ car showed that he had applied the brakes and the accelerator alternately at least 250 times…the data indicated Sikes was actually trying to keep the car in motion rather than stop it“.

Data is the building owner’s friend and a comfort to occupants of the building.


Published by John White

A lifetime (over 50 years) of experiences with automation and control systems ranging from aerospace navigation, radar, and ordinance delivery systems to the world's first robotic drilling machine for the oil patch, to process-control systems, energy management systems and general problem-solving. At present, my focus is on self-funding HVAC retrofit projects and indoor air quality with a view to preventing infections from airborne pathogens.

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