eng.HVAC-fresh-air-ventilation Calculator
Calculates required HVAC fresh air ventilation rate from occupancy, floor area, and ASHRAE 62.1 standard requirements. ASHRAE 62.1 minimum ventilation is 20 cfm/person + 0.12 cfm/ft² — CO₂ concentration above 1,100 ppm indicates inadequate ventilation.
Inputs
- Occupants
- Count of items or occurrences.
- Floor Area M2
- Two-dimensional surface extent (m²). For complex shapes, break into simpler sub-shapes and sum.
- Qp L S Person
- Amount per unit of time or per unit quantity. Check the denominator before interpreting.
- Qbz L S M2
- Two-dimensional surface extent (m²). For complex shapes, break into simpler sub-shapes and sum.
- Ez
- Reference formula or conversion factor shown for context.
Results
- breathing zone OA Vbz (L/s)
- The value at the specified point or condition.
- outdoor air supply Vot (L/s)
- Reference formula or conversion factor shown for context.
- outdoor air supply (m³/hr)
- Reference formula or conversion factor shown for context.
- air changes per hour ACH (3m ceiling)
- Sample size or count used in the calculation.
- Vbz = n·Rp + Az·Ra (ASHRAE 62.1)
- Sample size or count used in the calculation.
- compliance
- Sample size or count used in the calculation.
zone outdoor number fresh engineering