Ventilation of poultry houses involves managing temperature, humidity, and air quality for optimal bird performance. There are different ventilation systems for different weather conditions, including minimum ventilation for winter, tunnel ventilation for summer, and transitional ventilation for moderate weather. Key aspects of ventilation management include housing/ventilation systems, static pressure, controlling humidity, and calculating the appropriate number and placement of fans.

1. Management of flock
in hot and cold
weather

2. Important aspects
• Housing and Ventilation Systems
• Controlling humidity
• Static Pressure
• Temperature

3. Ventilation
Ventilation means moving the right amount of air at the right time
and in such a way to manage temperature, humidity and other
environmental factors for optimum bird performance

4. Housing and Ventilation
Systems
• There are two basic types of ventilation system:
•Natural Ventilation • Also known as “open-
sided”, “curtain-sided”, or “natural” houses. • Fans may be
used inside the house to circulate and move air.
•Power Ventilation (Controlled/Closed
environment housing) • These houses usually have either solid
sidewalls or curtains that are kept closed during house
operation. • Fans and inlets are used to ventilate the house.

5. Objectives of Ventilation
 Maintain uniform temperature
 Provide fresh air
 Remove undesirable gases
 Remove moisture
 Keep the litter dry
 Keep uniform condition in the house

6. Ventilation
o For ventilation purposes weather can be divided into three
types:
 Winter
 Summer
 Moderate weather

7. Ventilation
 Winter :
Minimum ventilation
 Summer:
Tunnel ventilation
 Moderate weather:
Transitional ventilation

8. Minimum ventilation
Achieving the correct operating negative pressure to ensure
incoming air is drawn at high speed up towards the apex of the
roof is critical.
Air inlets should be opened a minimum of 5 cm (2 in) and opened
inlets should be distributed evenly around the house.
Evaluating bird behavior and house condition is the only real way
to determine if minimum ventilation settings are correct.

9. Minimum Ventilation System

10. Minimum Ventilation Fan
1. Number of birds in the house
2. Body weight
3. Cfm per Kg.
4. Fan Capacity

11. Minimum Ventilation Fan
No. of birds X B.W. X cfm ÷ Fan capacity
30000 X 1.8 X 0.5 ÷ 9000 = No. of fans
= 3

12. Tunnel ventilation
Tunnel ventilation is used in warm to hot weather or where
large birds are grown.
Cooling is achieved through high-velocity airflow.
Care should be taken with young birds which are prone to
wind chill.

13. Tunnel ventilation

14. Transitional ventilation
• Transitional ventilation is a temperature driven process which
removes excess heat from the house when the temperature
increases above the desired set point.
• Transitional ventilation is used when the outside air is too
cold and/or the birds are too young for tunnel ventilation to
be implemented.
• Evaluating bird behavior is the only real way to determine if
Transitional ventilation settings are correct.

15. Transitional ventilation

16. Transitional ventilation

17. Transitional Ventilation Fans
Vol. of House x 40 % ÷ Fan Capacity = No. of Fans
162000 x 40 % ÷ 22500 = 2.88 = 3

18. Ventilation of Poultry House
STANDRD DIMENSIONS
• Length 450 ft
• Width 45 ft
• Height 8 ft

19. Pad Cooling System
• In pad cooling systems, cool air is drawn through a water
soaked filter (cooling pad) by the tunnel ventilation fans.
• Cooling pads should be installed at the opposite end of the
house to the tunnel fans.
• Half of the total cooling pad area should be installed on each
sidewall

20. Pad Cooling System

21. Pad Cover

22. Static Pressure
• When we run the exhaust fans a negative pressure is
created inside the house. To measure the difference of
outside and inside pressure we use the term ‘Static
Pressure’. It is mentioned in Pascal or inches.

23. Static Pressure Calculation
• 1 inch water Colum = 249 pascals
• Width of house in meter ÷ 249
• = 14 ÷ 249
• = 0.056 iwc

24. Controlling humidity
• The main aim of controlling relative humidity is maintaining
dry friable litter.
• Moisture is produced by the heating system, drinking system
and the birds.
• To reduce relative humidity, the only option is to increase the
air temperature
• Approximately for every 1 ℃ we heat the air, the relative
humidity of the air is reduced by 4.5%.

25. Relative Humidity and
temperature
Moisture holding capacity of air at certain temperature.
• Relative humidity is the ratio of the partial pressure of water
vapor to the equilibrium vapor pressure of water at a given
temperature.
Temperature is measured in C or F.

26. Fan Calculation
• Volume of House
• Cross Section of House
• Desire Air Velocity
• Fan Capacity

27. Fan Calculation
Volume of House = Length x Width x Height
= 450 x 45 x 8
= 162000 cub. Ft
Cross Section of House= Width X Height
45 X 8 = 360 sq. ft
• Length of the house are recommend (length + 50-75) 500
ft/min
Fan Capacity
• 18000 cfm
• 22500 cfm

28. Fan Calculation (1)
NUMBER OF FANS=
Cross Section x Air Velocity ÷ Fan Capacity
360 x 500 ÷ 22500 = 8

29. Fan Calculation (2)
Volume of House ÷ Fan Capacity = No. Fans
162000 ÷ 22500 = 7.2
= 8

30. Side wall Fan spacing
Length of house ÷ (No. of fans X 2) = feet from wall
400 ÷ ( 3 X 2 ) = 67 ft
67 X 2 = 134 ft

31. House With Curtains