Ventilation & Indoor Air Quality Calculator
Calculate required fresh-air ventilation by occupancy and area to ASHRAE 62.1.
Estimate to ASHRAE 62.1 ventilation-rate procedure. Actual design also accounts for system efficiency and zone air distribution. Demand-controlled ventilation, which trims fresh air toward real occupancy, can cut the energy of over-ventilating empty spaces. A puniq audit sizes it to your building.
About this tool
Good indoor air quality is part comfort, part health, and part energy. ASHRAE 62.1 sets the baseline: the fresh outdoor air a space needs depends on both how many people are in it and how big it is. This calculator applies that ventilation-rate procedure so you can size, or sanity-check, the fresh air for any zone in seconds.
Enter the floor area, the occupancy, and the space type. We combine the per-person rate (Rp) and the per-area rate (Ra) for that space to give the required outdoor air in L/s, then convert to CFM and break it down per person and per square metre.
Why this matters in the Gulf
In GCC heat, every litre of outdoor air must be cooled and dehumidified, so over-ventilating an empty room is paid for twice. The fix is not to under-ventilate: it is demand-controlled ventilation, which uses CO₂ and occupancy signals to deliver exactly the fresh air a space needs, when it needs it. A unified, vendor-neutral controls layer is what lets ventilation, cooling, and occupancy talk to each other.
Frequently asked
What is the ASHRAE 62.1 ventilation-rate procedure?
It sizes outdoor air as the sum of a per-person rate (Rp, for the people) and a per-area rate (Ra, for the building materials and finishes): required air = Rp times occupancy plus Ra times floor area.
Why does the rate change by space type?
People and surfaces emit different loads in different uses. A classroom packs more people and activity per square metre than an office or lobby, so its per-person rate is higher.
What is demand-controlled ventilation?
A control strategy that modulates fresh air to real occupancy, usually via CO₂ sensors, instead of running a fixed maximum all day. It maintains air quality while cutting the energy of cooling unneeded outdoor air.
Is this a substitute for a mechanical design?
No. It is a planning estimate for the base outdoor-air requirement. A full design also accounts for ventilation efficiency, duct distribution, and filtration. A puniq audit ties it to your actual systems.
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