HVAC Air Change Out Frequency (minutes)

Minimum Ventilation Air Exchange Rates in Breathing Zone per. ANSI / ASHRAE Standard 62.1

HVAC Systems & Components

Per. ANSI / ASHRAE Standard 62.1 - Breathing Zone Outdoor Airflow. The outdoor airflow required in the breathing zone (Vbz) of the occupiable space or spaces in a ventilation zone shall be not less than the value determined in accordance
withThe following are general recommendations for total volume of air change out for selected type indoor air spaces.

Outdoor Airflow Required in Breathing Zone Calculator

Outdoor airflow required in the breathing zone calculator

Eq. 1

V_bz = R_p P_z + R_a A_z

Where

A_z = zone floor area, the net occupiable floor area of the ventilation zone, ft² (m²)
P_z = zone population, the number of people in the ventilation zone during use

R_p = See table calculator
R_a = See table calculator

General Ventilation Rates (no references)

HVAC Space Definition	Air Change Out Frequency (minutes)
Assembly Halls	3-10
Auditoriums	4-15
Bakeries	1-3
Boiler Rooms	2-4
Bowling Alleys	2-8
Dry Cleaners	1-5
Engine Rooms	1-1.5
Factories (General)	1-5
Forges	1-2
Foundries	1-4
Garages	2-10
Generating Rooms	2-5
Glass Plants	1-2
Gymnasiums	2-10
Heat Treat Rooms	0.5-1
Kitchens	1-3
Laundries	2-5
Locker Rooms	2-5
Machine Shops	3-5
Mills (Paper)	2-3
Mills (Textile)	5-15
Packing Houses	2-15
Recreation Rooms	2-8
Residences	2-5
Restaurants	5-10
Retail Stores	3-10
Shops (General)	3-10
Theaters	3-8
Toilets	2-5
Transformer Rooms	1-5
Turbine Rooms	2-6
Warehouses	2-10

Source ANSI / ASHRAE Standard 62.1 - Breathing Zone Outdoor Airflow

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