Outdoor Supply Air Rates
The rates of outdoor make-up or supply air in the table below can be used as a guideline in the design of ventilation systems.
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 (m 3 /h)
V = room volume (m 3 )
Example - Air Shifts
The air supply to a room with volume 10 m 3 is 5 m 3 /h . The air shifts can be calculated
n = ( 5 m 3 /h ) / ( 10 m 3 )
= 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 m 2 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 | ||
| 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 | ||
| 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 m 2 | 15 | |||
| > 7 m 2 | 20 | |||
| Industrial in general | 25 - 30 | |||
| Gas ovens | 550/m 2 outside wall | |||
| Electric ovens | 300/m 2 outside wall | |||
| Grill table | 400/m 2 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 dm 3 (liter)/s = 10 -3 m 3 /s = 3.6 m 3 /h = 0.03532 ft 3 /s = 2.1189 ft 3 /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 (ft 2 ) | Bedrooms | ||||
| 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 |
Related Topics
• Ventilation
Systems for ventilation and air handling - air change rates, ducts and pressure drops, charts and diagrams and more.
Related Documents
Air Change Rate
Calculate air change rates - equations in imperial and SI units.
Air Change Rates in typical Rooms and Buildings
Fresh air (make up air) rquirements - or recommended air change rates (ACH) for typical rooms and buildings like auditoriums, kitchens, churches and more.
Heat Recovery Efficiency
Classification of heat recovery efficiencies - temperature efficiency, moisture efficiency and enthalpy efficiency - online heat exchanger efficiency calculator.
Outdoor Makeup Air
Acceptable indoor air quality and required make up air.
Pollution Concentration in Rooms
Concentration of a pollution in a limited space as a room depends on the amount of polluted material spread in the room, supply of fresh air, outlets positions and construction, principles used for supply and outlet from the space.