Rates of Outdoor Supply Air

Recommended rates of outdoor make up air in some common types of rooms - banks, assembly halls, hotels and many more. Smoking and air supply rates

Air Shifts

Air shift is the number of times the air in a room is replaced by supply air per hour and can be expressed as

n = q / V (1)

where

n = air shifts (1/h)

q = supply air to the room (m³/h)

V = room volume (m³)

Example - Air Shifts

The air supply to a room with volume 10 m³ is 5 m³/h. The air shifts can be calculated

n = (5 m³/h) / (10 m³)

= 0.5 1/h

Recommended Supply Air to some typical Rooms

Type of Building and Room		Air Shifts - n - (1/h)	Supply Air flow (l/s per m² floor area)	Supply Air Flow (l/s)
Animals	Sheep			3 per animal
	Horses			40 per animal
	Hens			3 per animal
	Cows			100 per animal
	Chickens			2 per animal
	Pigs, sow			60 per animal
	Piglet			15 per animal
Apartments				15 per person
Assembly halls		5 - 10		10 - 15 per person
Auditoriums				10 - 15 per person
Bakeries	Production		8
Bakeries	Pastry room		6
Banks	Service		2 - 3
	Archive		1
	Staff		2 - 3
Baths		5 - 8		15
Barber Shops				10 - 15 per person
Bars				15 - 20 per person
Beauty Shops				10 - 15 per person
Bowling Alleys				10 - 15 per person
Cafeterias			4	10 - 15 per person
Cinemas/Theaters		5 - 10		7 - 10 per person
Chemist's shops	Sterile room		15
	Laboratory		15
	Packing room		4
	Store		1
Churches			2	10 per person
Clubhouses				15 - 20 per person
Cocktail Lounges				15 - 20 per person
Computer Rooms				10 - 15 per person
Court Houses				10 - 15 per person
Dance halls				15 - 20 per person
Dental Clinics, Offices				10 - 15 per person
Department Stores (cfm/Sq.Ft)			0.3
Dining Halls				10 - 15 per person
Drug Shop				10 - 15 per person
Engine rooms		4
Exhibition halls			10 - 20
Fire Stations				10 - 15 per person
Garages		5 - 6	> 1
Hospitals	General			15 per person
	Therapy		9
	Operating theater		14
	Autopsy		9
Hotels	Reception			15 - 20 per person
Hotels	Room		3
Industries	Factory			10 - 20 per person
	Carpenter work shop		2 - 5
	Car repair shop		4
	Car repair shop, exhaust outlet			60 - 80 per car
	Mechanical work shop		3 - 4
	Welding		12 - 15
	Assembly		4 - 5
Jails				10 - 15 per person
Jewelry Shop				10 - 15 per person
Libraries				10 - 15 per person
Lift Shaft (Lift Car)			8 - 10
Lunch Rooms, Luncheonettes				10 - 15 per person
Municipal Buildings				10 - 15 per person
Museums				10 - 15 per person
Smithies			6 - 7
Kitchens	Small	20 - 40
	Large	10 - 20
	< 7 m²			15
	> 7 m²			20
	Industrial in general		25 - 30
	Gas ovens			550/m² outside wall
	Electric ovens			300/m² outside wall
	Grill table			400/m² outside wall
	Frying pan			300
	Boiling pan 100 l			100
	Boiling pan 200 l			200
	Coffee machine			60
	Refrigerated cabinet		7 - 10
	Cooling and freezer room		0.3 - 0.5
	Store		2 - 4
Laundries		10 - 15
Lavatories		5 - 10		10
Night Clubs				15 - 25 per person
Malls				10 - 15 per person
Motels				15 - 20 per person
Offices	Module	3 - 8		10 - 20 per person
	Landscape			10 - 20 per person
	Conference room			15 - 30 per person
	Lecture room			10 - 20 per person
	Dining hall			15 - 25 per person
	Staff, changing clothes		8 - 12
	Dining room		8 - 10
	Resting room			15 per person
Police Stations				10 - 15 per person
Post Offices				10 - 15 per person
Precision Manufacturing				10 - 15 per person
Restaurants		5 - 10	10	10 - 15 per person
Retail Stores (cfm/Sq.Ft)			0.3
Schools	Classroom		4 - 5	10 - 15 per person
Shops				10 - 15 per person
Shopping Centers				10 - 15 per person
Sports halls			3 - 4
Supermarkets				10 per person
Swimming pools		5 - 10
Taverns				10 - 15 per person
Town Halls				10 - 15 per person

1 dm³(liter)/s = 10^-3 m³/s = 3.6 m³/h = 0.03532 ft³/s = 2.1189 ft³/min (cfm) = 13.200 Imp.gal (UK)/min = 15.852 gal (US)/min = 792 Imp. gal (UK)/h

Smoking or Not Smoking versus Recommended Supply Air

Smoking has a dramatic impact on required make up air (Chartered Institution of Building Service Engineers, CIBSE Guide B2):

Level of Smoking	Proportion of occupants that smoke (%)	Supply Air (liter/s person)
No smoking	0	8
Some smoking	25	16
Heavy smoking	45	24
Very heavy smoking	75	36

Recommended Residential Air Ventilation

Recommended outdoor air supply according ASHRAE 62.2:

Air Flow (cfm)
Floor Area (ft²)	Bedrooms
Floor Area (ft²)	0 - 1	2 - 3	4 - 5	6 - 7	> 7
< 1500	30	45	60	75	90
1501 - 3000	45	60	75	90	105
3001 - 4500	60	75	90	105	120
4501 - 6000	75	90	105	120	135
6001 - 7500	90	105	120	135	150
> 7500	105	120	135	150	165