In order to deliver enough outside air to each zone, ASHRAE Standard 62.1 Ventilation Rate Procedure considers both people-related and area-related sources of contamination. To help engineers determine the outdoor air required to counter act these contaminates and achieve good Indoor Air Quality (IAQ), the standard includes a table of Occupancy Categories. Each Occupancy Category included in Table 6-1 the following information:

  • People Outdoor Air Rate (Rp) in cfm/person and L/s person

  • Area Outdoor Air Rate (Ra) in cfm/ft2 and L/s m2

  • Default Occupant Density in People per 1000 ft2 or per 100 m2

  • Air Class

For zones that will be exhausted the information is slightly different and is included in Table 6-2:

  • Exhaust Rate per Unit in cfm/unit and L/s unit

  • Exhaust Rate per Area in cfm/ft2 and L/s m2

  • Air Class

On the platform, each Occupancy Category (144 total!) is preloaded and can be selected via the Room Template or directly on the Ventilation Calculation Table. Values for the outdoor air rates and exhaust air rates will be loaded into the project.

Tip: for unlisted occupancy Section 6.2.1.1.1 recommends using an occupancy category that is most similar in occupant density, activities, and building construction. There is also an optional Custom category available that allows for custom definition.

Looking for ASHRAE Standard 170 Space Functions? Check out this article

Table of available Occupancy Categories

Occupancy Category

Outdoor Air per Person

cfm/person | L/s person

Outdoor Air per Area

cfm/ft2 | L/s m2

Animal exam room (veterinary office)

10 | 5

0.12 | 0.6

Animal imaging (MRI/CT/PET)

10 | 5

0.18 | 0.9

Animal operating rooms

10 | 5

0.18 | 0.9

Animal postoperative recovery room

10 | 5

0.18 | 0.9

Animal preparation rooms

10 | 5

0.18 | 0.9

Animal procedure room

10 | 5

0.18 | 0.9

Animal surgery scrub

10 | 5

0.18 | 0.9

Large-animal holding room

10 | 5

0.18 | 0.9

Necropsy

10 | 5

0.18 | 0.9

Small-animal-cage room (static cages)

10 | 5

0.18 | 0.9

Small-animal-cage room (ventilated cages)

10 | 5

0.18 | 0.9

Art classroom

10 | 5

0.18 | 0.9

Classrooms (ages 5 to 8)

10 | 5

0.12 | 0.6

Classrooms (age 9 plus)

10 | 5

0.12 | 0.6

Computer lab

10 | 5

0.12 | 0.6

Daycare sickroom

10 | 5

0.18 | 0.9

Daycare (through age 4)

10 | 5

0.18 | 0.9

Lecture classroom

7.5 | 3.8

0.06 | 0.3

Lecture hall (fixed seats)

7.5 | 3.8

0.06 | 0.3

Libraries

5 | 2.5

0.12 | 0.6

Media center

10 | 5

0.12 | 0.6

Multiuse assembly

7.5 | 3.8

0.06 | 0.3

Music/theater/dance

10 | 5

0.06 | 0.3

Science laboratories

10 | 5

0.18 | 0.9

University/college laboratories

10 | 5

0.18 | 0.9

Wood/metal shop

10 | 5

0.18 | 0.9

Bars, cocktail lounges

7.5 | 3.8

0.18 | 0.9

Cafeteria/fast-food dining

7.5 | 3.8

0.18 | 0.9

Kitchen (cooking)

7.5 | 3.8

0.12 | 0.6

Restaurant dining rooms

7.5 | 3.8

0.18 | 0.9

Break rooms

5 | 2.5

0.06 | 0.3

Coffee stations

5 | 2.5

0.06 | 0.3

Conference/meeting

5 | 2.5

0.06 | 0.3

Corridors

|

0.06 | 0.3

Occupiable storage rooms for liquids or gels

5 | 2.5

0.12 | 0.6

Barracks sleeping areas

5 | 2.5

0.06 | 0.3

Bedroom/living room

5 | 2.5

0.06 | 0.3

Laundry rooms, central

5 | 2.5

0.12 | 0.6

Laundry rooms within dwelling units

5 | 2.5

0.12 | 0.6

Lobbies/prefunction

7.5 | 3.8

0.06 | 0.3

Multipurpose assembly

5 | 2.5

0.06 | 0.3

Banks or bank lobbies

7.5 | 3.8

0.06 | 0.3

Bank vaults/safe deposit

5 | 2.5

0.06 | 0.3

Computer (not printing)

5 | 2.5

0.06 | 0.3

Electrical equipment rooms

|

0.06 | 0.3

Elevator machine rooms

|

0.12 | 0.6

Freezer and refrigerated spaces (<50°F [10°C])

10 | 5

0 | 0

Manufacturing where hazardous materials are not used

10 | 5

0.18 | 0.9

Manufacturing where hazardous materials are used (excludes heavy industrial and chemical processes)

10 | 5

0.18 | 0.9

Pharmacy (prep. area)

5 | 2.5

0.18 | 0.9

Photo studios

5 | 2.5

0.12 | 0.6

Shipping/receiving

10 | 5

0.12 | 0.6

Sorting, packing, light assembly

7.5 | 3.8

0.12 | 0.6

Telephone closets

|

0 | 0

Transportation waiting

7.5 | 3.8

0.06 | 0.3

Warehouses

10 | 5

0.06 | 0.3

Breakrooms

5 | 2.5

0.12 | 0.6

Main entry lobbies

5 | 2.5

0.06 | 0.3

Occupiable storage rooms for dry materials

5 | 2.5

0.06 | 0.3

Office space

5 | 2.5

0.06 | 0.3

Reception areas

5 | 2.5

0.06 | 0.3

Telephone/data entry

5 | 2.5

0.06 | 0.3

Birthing room

10 | 5

0.18 | 0.9

Class 1 imaging rooms

5 | 2.5

0.12 | 0.6

Dental operatory

10 | 5

0.18 | 0.9

General examination room

7.5 | 3.8

0.12 | 0.6

Other dental treatment areas

5 | 2.5

0.06 | 0.3

Physical therapy exercise area

20 | 10

0.18 | 0.9

Physical therapy individual room

10 | 5

0.06 | 0.3

Physical therapeutic pool area

|

0.48 | 2.4

Prosthetics and orthotics room

10 | 5

0.18 | 0.9

Psychiatric consultation room

5 | 2.5

0.06 | 0.3

Psychiatric examination room

5 | 2.5

0.06 | 0.3

Psychiatric group room

5 | 2.5

0.06 | 0.3

Psychiatric seclusion room

10 | 5

0.06 | 0.3

Speech therapy room

5 | 2.5

0.06 | 0.3

Urgent care examination room

7.5 | 3.8

0.12 | 0.6

Urgent care observation room

5 | 2.5

0.06 | 0.3

Urgent care treatment room

7.5 | 3.8

0.18 | 0.9

Urgent care triage room

10 | 5

0.18 | 0.9

Auditorium seating area

5 | 2.5

0.06 | 0.3

Courtrooms

5 | 2.5

0.06 | 0.3

Legislative chambers

5 | 2.5

0.06 | 0.3

Libraries

5 | 2.5

0.12 | 0.6

Lobbies

5 | 2.5

0.06 | 0.3

Museums (children’s)

7.5 | 3.8

0.12 | 0.6

Museums/galleries

7.5 | 3.8

0.06 | 0.3

Places of religious worship

5 | 2.5

0.06 | 0.3

Sales (except as below)

7.5 | 3.8

0.12 | 0.6

Barbershop

7.5 | 3.8

0.06 | 0.3

Beauty and nail salons

20 | 10

0.12 | 0.6

Coin-operated laundries

7.5 | 3.8

0.12 | 0.6

Mall common areas

7.5 | 3.8

0.06 | 0.3

Pet shops (animal areas)

7.5 | 3.8

0.18 | 0.9

Supermarket

7.5 | 3.8

0.06 | 0.3

Bowling alley (seating)

10 | 5

0.12 | 0.6

Disco/dance floors

20 | 10

0.06 | 0.3

Gambling casinos

7.5 | 3.8

0.18 | 0.9

Game arcades

7.5 | 3.8

0.18 | 0.9

Gym, sports arena (play area)

20 | 10

0.18 | 0.9

Health club/aerobics room

20 | 10

0.06 | 0.3

Health club/weight rooms

20 | 10

0.06 | 0.3

Spectator areas

7.5 | 3.8

0.06 | 0.3

Stages, studios

10 | 5

0.06 | 0.3

Swimming (pool and deck)

0.48 | 2.4

Common corridors

0.06 | 0.3

Dwelling unit

5 | 2.5

0.06 | 0.3

Table of Exhaust Only Occupancy Categories

Occupancy Category

Exhaust Air per Area

cfm/ft2 | L/s m2

Exhaust Air per Unit

cfm/unit | L/s unit

Animal imaging

0.9 | 4.5

Animal operating rooms

3 | 15

Animal postoperative recovery room

1.5 | 7.5

Animal preparation rooms

1.5 | 7.5

Animal procedure room

2.25 | 11.3

Animal surgery scrub

1.5 | 7.5

Large-animal holding room

2.25 | 11.3

Necropsy

2.25 | 11.3

Small-animal-cage room (static cages)

2.25 | 11.3

Small-animal-cage room (ventilated cages)

1.5 | 7.5

Arenas

0.5 | 2.5

Art classrooms

0.7 | 3.5

Auto repair rooms

1.5 | 7.5

Barber shops

0.5 | 2.5

Beauty and nail salons

0.6 | 3

Copy, printing rooms

0.5 | 2.5

Darkrooms

1 | 5

Educational science laboratories

1 | 5

Janitor closets, trash rooms, recycling

1 | 5

Kitchenettes

0.3 | 1.5

Kitchens - commercial

0.7 | 3.5

Locker rooms for athletic, industrial and health care facilities

0.5 | 2.5

All other locker rooms

0.25 | 1.25

Shower rooms (continuous exhaust)

20 | 10

Shower rooms (noncontinuous exhaust)

50 | 25

Parking garages

0.75 | 3.7

Pet shops (animal areas)

0.9 | 4.5

Residential kitchens (continuous exhaust)

50 | 25

Residential kitchens (noncontinuous exhaust)

100 | 50

Soiled laundry storage rooms

1 | 5

Storage rooms, chemical

1.5 | 7

Toilets - private (continuous exhaust)

25 | 12.5

Toilets - private (noncontinuous exhaust)

50 | 25

Toilets - public (continuous exhaust)

50 | 25

Toilets - public (noncontinuous exhaust)

70 | 35

Woodwork shop or classroom

0.5 | 2.5

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