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 (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 | ||
| 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 m2 | 15 | |||
| > 7 m2 | 20 | |||
| Industrial in general | 25 - 30 | |||
| Gas ovens | 550/m2outside wall | |||
| Electric ovens | 300/m2outside wall | |||
| Grill table | 400/m2outside 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 | ||||
| 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
Design of 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.
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.
Recommended Air Change Rates for Different Room Types
Fresh air (make up air) rquirements - or recommended air change rates (ACH) for typical rooms and buildings like auditoriums, kitchens, churches and more.