Outdoor Air / Ventilation Calculator
Work out the outdoor air each space requires, room by room, to ASHRAE 62.1 and IMC Table 403.3.1.1 – and get it back as a table you can drop onto the mechanical plans.
Ventilation is calculated per person and per square foot, and the two are added rather than one replacing the other. Occupancy category is the input that moves the answer most: the same floor area as an office and as a conference room produces very different rates, because the second assumes people packed far more densely.
What the plan reviewer checks
Reviewers usually check the occupancy categories against the plan’s own room names before they check the arithmetic. Label rooms the way the code table labels them and most comments never get written.
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Every mechanical, electrical, plumbing, and fire sheet your reviewer needs — a fixed quote in 24 business hours, first sets in as few as 5 working days, and city comments answered until your permit is issued.