ASHRAE 62.1 Outdoor Air Ventilation Calculator

Indoor Air Quality & Ventilation: Calculate Breathing Zone outdoor air ($V_{bz}$), zone intake airflow ($V_{oz}$), and primary outdoor air fraction ($Z_p$).

Space Occupancy & Geometry

Occupancy Category (ASHRAE 62.1 Table 6-1):

Floor Area $A_z$ (ft²):

Design Population $P_z$ (people):

Air Distribution & Supply

Air Distribution Configuration ($E_z$):

Primary Supply Air $V_{pz}$ (CFM):

Ceiling Height $H$ (ft):

Outdoor Air Compliance Output

Required Outdoor Air ($V_{oz}$)

-- CFM

Breathing Zone: -- CFM

Outdoor Air per Person

-- CFM/person

Ventilation ACH: -- /hr

Primary OA Fraction ($Z_p$)

-- %

Fraction of supply air

Rate Contributions

People Component: -- CFM

Area Component: -- CFM

ASHRAE 62.1 VRP Principles:

• $V_{bz} = R_p \cdot P_z + R_a \cdot A_z$. Outdoor air delivered to zone: $V_{oz} = V_{bz} / E_z$.

• Floor displacement ($E_z = 1.2$) purges contaminants upward, reducing required intake airflow compared to ceiling diffusers.

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ASHRAE 62.1 Outdoor Air Ventilation Calculator

Space Occupancy & Geometry

Air Distribution & Supply

Outdoor Air Compliance Output

Frequently Asked Questions