Ventilation Inspection Checklist

The reason this document insists on a measurement rather than an inspection is that a ventilation system gives almost no outward sign of underperforming. A fan that runs, a grille that moves air when you hold a hand under it and a unit that has had its filters changed on schedule all look exactly the same whether the system is delivering its design figures or sixty percent of them. There is no alarm, no fault and usually no complaint that anybody connects to ventilation, because the symptoms of too little fresh air read as tiredness, headaches and stuffiness and get attributed to the work rather than the building. The gap opens slowly through a combination of fouled coils, leaking duct joints, dampers drifting from their set positions, filters at the top of their pressure drop and a building whose occupancy rose after the system was commissioned. Each one costs a few percent, none of them is visible, and the only way to find the total is to put a calibrated instrument in front of a terminal and compare the reading with the figure on the design drawing. The grading of duct cleanliness follows the same logic from a different direction. A written description is not evidence of anything, because the next inspector will describe the same duct differently and no two reports can be compared. Three fixed grades, spelled the same way every time, turn an opinion into a measurement that trends: a duct that was Acceptable last year and Requires cleaning this year has told you something specific, and it has also given whoever holds the budget a date rather than a recommendation.

Thirty one of forty two terminals within tolerance is seventy four percent, and it is the number nobody would have had without a meter. The building was not complaining in any way that had been attributed to ventilation, every air handling unit had been serviced, and a quarter of the terminals were delivering materially less than they were designed to. That is the ordinary condition of a system that has never been remeasured, and it is worth a great deal to know because it converts a vague sense that the building is stuffy into a list of locations with figures against them. The two inaccessible dampers are a different kind of finding and they are the reason this document reports two numbers rather than one. Sixteen of eighteen dampers tested would read as eighty nine percent, which sounds like a good result and is the wrong way to think about it: there is no partial credit on a fire damper, and two that nobody can reach are two that have never been proved to close. Boarded over in a ceiling void during a refit, they will stay untested through every future inspection until somebody funds the access panels, which is why the action carries a named owner and a date rather than a recommendation. For the plant behind the air, use the HVAC maintenance checklist, and for the water side of the same building the cooling system inspection checklist.

Seventy four percent airflow compliance and sixteen of eighteen dampers tested are both poor results, and only one of them can be improved gradually. Airflow is a genuine percentage: every terminal brought back toward its design figure is a real improvement, the building gets measurably better as the work progresses, and a program that lifts the figure from seventy four to ninety across a year has delivered something worth having at every point along the way. A fire damper does not work like that. It spends its entire life doing nothing at all, and it is called upon once, in the only circumstance where it matters, where it either closes or it does not. There is no partial performance and no gradual benefit, which means a count of dampers tested is not a score to be improved but a list of specific references, each of which is either proved or outstanding. Combining the two into one headline figure is therefore not a simplification but a loss of the only information that could not be recovered later, and it reliably flatters the result, because the airflow number is large and granular and the damper number is small and binary. The template keeps them apart for that reason, sends the second to a different named person, and asks for an action with an owner and a date against every damper nobody could reach. What this page does not cover is the air itself, the carbon dioxide, humidity and occupant complaints that describe what people are actually breathing. That is the indoor air quality checklist, a separate survey with separate instruments, and the two read best together.