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FAN SELECTION AND AIR CHANGE RATE BY NEIGHBORHOOD

FAN SELECTION AND AIR CHANGE RATE BY NEIGHBORHOOD

02-04-2022 00:48

Example of air flow calculation by space:

For example; we have a paint shop that is 20 meters wide and 15 meters long, and the ceiling height is 3 meters.

(Our air change rate in paint shops is minimum 30, maximum 60 times.)

Minimum air flow calculation: width x length x ceiling height x 30 ( m2xhx30 )( 20 x15 x 3 x 30 ) = 27,000 m3/h

Maximum air flow calculation: width x length x ceiling height x 60 ( m2xhx60 )( 20 x15 x 3 x 60 ) = 54,000 m3/h

Finding the average: 27,000m3/h + 54,000m3/h / 2 = 40,500 m3/h (our average air flow in a paint shop will be 40,500 m3/h)

Unit Conversions: (1 cfm = 1.7m3/h) - (1 i/s = 3.6m3/h) - (1 mmsS = 9.8Pa) - (1m3/h = 3.600m3/sn) - ( 1kw = 1000 Watt ) - ( 1 Hp = 0.74569 Kw ) - (1 Kw = 0.371 Hp )

AIR CHANGE RATES PER HOUR FOR VENTILATION BY LOCATION
TYPE OF LOCATION	NUMBER OF AIR CHANGES PER HOUR
FURNACE WORKSHOPS (MELTING AND HEAT TREATMENT FURNACES)	30-60
PAINTING WORKSHOPS	30-60
PROCESSING WORKSHOPS	6 – 10
BANKS	2 – 4
HOTEL BARS	4 – 6
LAUNDRIES	20-30
OVENS	20-30
OFFICES (*)	4 – 6
CAFETARIES AND CAFETARIES BARS	10-12
CARGO WAREHOUSES (GENERAL)	6 – 10
SHIP HOLD CARRYING FOOD LIKE MEAT, EGGS, ETC.	10-20
CANTEENS	4 – 6
DARK ROOMS IN PHOTO STUDIOS	10-15
MUSHROOM GROUPS (MUSHROOM GROWING PLACES)	10-20
CINEMAS (*)	10-15
COMMERCIAL KITCHENS or SCHOOL KITCHENS	15-20
HOME KITCHENS	10-15
CHURCHES	½ – 1
FACTORIES (GENERAL)	6 – 10
FOUNDRY	20-30
FRUIT BARRENTS ON SHIPS	20-30
GARAGES (AUTO REPAIR SHOPS)	6 – 8
MEETING ROOMS (*)	4 – 6
HOSPITALS	4 – 6
LABORATORIES	4 – 6
SINK	10-15
SWIMMING POOLS	20-30
PIG HOUSES	6 – 10
POULTRY HOUSES	6 – 10
RESIDENTIAL NEIGHBORHOODS	1 – 2
RESTAURANTS	6 – 10
BANQUET HALLS	6 – 10
BILLIARD HALLS	6 – 8
BOILER ROOMS	20-30
CLASSES	2 – 3
CLUB HALLS	8 – 10
DANCE HALLS (*)	6 – 8
MACHINE ROOMS	20 - 30
LOUNGE HALLS ON SHIPS	10-20
DYE SHOP	30 - 60
THEATRES (*)	10-15

NOTES:
Air exchange rates as high as 8 allow the pollutants normally emitted by humans to be removed. Larger air exchange rates allow both heat and vapors to be removed in regions with temperate climates. In hot climate regions, the number of air exchanges should be at least doubled.
(*) In areas where smoking is allowed, it is appropriate to double the air change numbers.

AIR FLOW (Q)	:	It is the amount of air transferred by the fan per unit time. It is commonly expressed in units of m³/h, m³/s or CFM.
		1 m³/h = 3600 m³/s
		1 CFM = 1.7 m³/h
NUMBER OF CYCLES (N)	:	It is the rotational field speed that occurs in the stator in one minute. It is commonly expressed in units of rpm or Rpm.
PRESSURE (P)	:	When a fan transfers air through a closed volume (such as air ducts), the air is exposed to the air per unit area. It is the force that acts in the opposite direction to the flow. It is expressed as Pa or mmSS in fan characteristic curves.
		1 Pa = 1N/m²
		1mmSS = 9.8Pa
STATIC PRESSURE (Ps)	:	In the channel where the air flow is, the friction force on the inner walls of the channel and the equipment placed in the channel These are the forces acting on a unit area due to the effects of the flow obstruction (damper, silencer, vent, filter, etc.).

DYNAMIC PRESSURE (Pd)	:	It is the force acting on a unit area due to air flow velocity.
TOTAL PRESSURE (PT)	:	It is the sum of static and dynamic pressures.
		PT = Ps + Pd
SOUND LEVEL (dB)	:	Fans emit sound waves due to vibration during operation. These emitted sound waves are transmitted from the fan. decreases with distance as you move away.
INPUT POWER (W)	:	It is the power that the motor draws from the network. Its unit is W or kW.
		1 HP = 0.75 kW
TEMPERATURE (T)	:	Ambient conditions: temperature not more than +40°C, altitude not more than 1450 m (inclusive) and relative humidity not more than 95% standard environmental conditions are accepted.
		The most important factor in the resistance of insulating materials used in the winding insulation of asynchronous motors is temperature. In order to facilitate the selection of suitable insulators in practice, insulators are divided into classes in the standards. Asynchronous motor windings are generally in B, F and sometimes H insulation class.

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