Calculation of Poultry House Ventilation
Air exchange area and calculation of fans in a poultry house
Air exchange area m3/minute = Length width height
For example
Air exchange area m3/minute = 120m×12m×03m
| Air exchange area m3/minute = 4320 m3 |
No. of fan needed for air exchange =
Air volume m3/minute Air exchange capacity of Fan
Standards
- Fan with diameter of 1.2m = 566 m3/minute
- Fan with diameter of 1.0m = 283 m3/minute
- Fan with diameter of 91 cm= 255 m3/minute
For example
No. of fan needed for air exchange = Air volume m3/minute ÷ Air exchange capacity of Fan
No. of fan needed for air exchange = 4320 ÷ 566 =7.6 or 8 Fans
| No. of fan needed for air exchange = 08 fans |
Calculation of space for Cooling Pad in poultry house(m2) =
(Fan air exchange Capacity m3/minute × Number of fans)÷ Air Speed through cooling pad m3/minute
Standards
- For 100mm (10cm or 4-in) thick Pad,
use ( 1.27m/s or 76m/minute )(250fpm)
- For 150mm (15cm or 6-in) thick Pad,
use ( 1.91m/s or 114/minute ) (375fpm)
For example
Cooling Pad area m2
= (Fan air exchange Capacity m3/minute × No. of fans)÷ (Air Speed through cooling pad m3/minute)
Cooling Pad area = (566 × 8 )÷114 = 39.7m2 Or 40m2
*It means 20m2 (2m in width and 10 m in length) on each side of the house
| Cooling Pad area in m2 = 40m2 |
The number of fans Needed to exchange required air velocity
=(Required Air velocity m/s ) ÷{ Fan capacity ÷ (width × Height ×60) }
Standard Air velocity
Rearing ˃ 2.03 meter per second (m/s) OR 400 Feet per minute (fpm)
Production ˃ 2.54 meter per second (m/s) OR 500 Feet per minute (fpm)
For example
The number of fans Needed to exchange required air velocity =
(Required Air velocity m/s ) ÷{ Fan capacity ÷ (width × Height ×60) }
No. of fans Needed to exchange required air velocity =(2.03) ÷ { 566 ÷(12×03×60} =7.8 fans
| No. of fans Needed to exchange required air velocity = Fans 8 |
Minimum Ventilation Calculation For Fan Timer Setting
Standards
Minimum ventilation per bird
| Age | Cubic meter per hour (CMH/Bird) | Cubic feet per minute (CFM/Bird) |
| 01-08 weeks | 0.16 | 0.10 |
| 09-15 weeks | 0.42 | 0.25 |
| 16-35 weeks | 0.59 | 0.35 |
| 35- depletion | 0.76 | 0.45 |
For example
Bird Age = 20 weeks
Number of Birds = 10,000
Minimum ventilation fan = 1 × 91 cm =255 m3/minute × 60 =( 15300m3/hr )
Using a 5 minutes cycle timer
Calculate the minimum Ventilation ?
Step:1
Ventilation rate = (Minimum ventilation per bird) ×( Number of Birds)
Ventilation rate= (0.59 cmh) ×(10,000) = 5,900 cmh (cubic meter per houre)
Percentage time the fans needed to be run for
Step:2
Percentage time = (Total ventilation needed) ÷ (Total capacity of fans used)
Percentage time =(5,900cmh) ÷ (15,300) =0.39 or 39%
| Percentage time =39% |
*It means if a 5 minute timer is used, the run timer required would be then 39% of 5 minutes ,or 117 seconds
( or fan should be 24 sec on and 36 sec off for each minute)
For example
Bird Age = 01 weeks
Number of Birds = 10,000
Minimum ventilation fan = 1 × 91 cm =255 m3/minute × 60 =( 15300m3/hr )
Using a 5 minutes cycle timer
Calculate the minimum Ventilation ?
Step:1
Ventilation rate = (Minimum ventilation per bird) ×( Number of Birds)
Ventilation rate= (0.16 cmh) ×(10,000) = 1600 cmh (cubic meter per houre)
Percentage time the fans needed to be run for
Step:2
Percentage time = (Total ventilation needed) ÷ (Total capacity of fans used)
Percentage time =(1600cmh) ÷ (15,300) =0.10 or 10%
| Percentage time =10% |
*Assuming a 05 minute cycle timer, the run Timer required would then be 10 % of 05 minutes ,or30`seconds
Ventilation standers for Layers
