The document discusses the benefits of closed environment (CE) housing for poultry compared to open housing. CE housing allows for greater control over ventilation including air entry points, speed, and direction of airflow. This control enables maintaining optimal temperatures and air quality for birds. CE housing can achieve higher stocking densities and production. It also helps control costs by precisely managing minimum ventilation, transitional ventilation, and hot weather ventilation using fans and inlets. However, CE housing requires an airtight, well-insulated structure and properly designed ventilation system to realize its full benefits.

1. www.poultryindia.co.in | www.poultryprotein.com | www.poultryrecipes.co.in

2. Environmental Control Housing :
Myths and Reality
 Benefit of Closed Environment Housing
 Stocking Density
 Bird Requirements
 The House
 Ventilating
 Closed Environment House “Limits”
Sponsors

3. Benefit of Closed Environment Housing
• Bird performance/production revolves around bird
comfort and air quality.
• Bird comfort and air quality depend on how well you
can control air flow into and through the house.
• How much control you have depends on the house
and the ventilation system.
• You will ALWAYS have more CONTROL in Closed
Environment (CE) houses
• CE houses give you CONTROL of how you ventilate
the birds
Sponsors

4. With Closed Environment housing we can control:
• Where the air will enter.
• How it will enter (fast, slow).
• In what direction it will travel.
• How much will enter (and be removed).
• At what speed it will travel over the birds.
This is crucial for achieving bird comfort.
Sponsors

5. OH vs CE – Questions To Ask Yourself
• Am I getting maximum performance/production?
• Does my performance/production drop at certain
times of the year?
• Am I utilising my house floor area to its extent?
• Am I getting the maximum kg/m² from my house?
• How much does late heat stress mortality cost me?
• Is my FCR where I want it to be?
• Is my heating cost too high?
Above answers will be influenced by ventilation
Sponsors

6. Recommended Stocking Density
The following is an example of recommended stocking
density in hot climates:
• CE – 30kg/m²
• Open house – 20-25kg/m² (poor ventilation)
These densities can vary depending on relative
humidity.
Sponsors

7. Bird Requirements
• Warm floor during brooding
• Good temperature control (actual and effective)
• Good air quality (oxygen)
• No temperature fluctuations
• No drafts (in cold weather)
• No environmental stresses
• It doesn’t matter what type of housing you have!
• These are the bird requirements and somehow you
must provide them
• Closed environment houses are better equipped to
provide this Sponsors

8. The House
• Good ventilation system starts with a “good” HOUSE.
Closed Environment (CE) houses should be :
• Well sealed
– Air tight
– Minimal air leakage
• This allows control over where and how air will enter
• New houses should be “pressure tested” before final
payment is made
• This does NOT mean that older houses can’t be
upgraded Sponsors

9. Well Sealed vs Poorly Sealed
Sponsors
 

10. Poorly Sealed
Sponsors



11. The Roof
Properties of a good chicken house roof (open or
closed environment)
1. Insulation (polyurethane, polystyrene, glass wool)
– Keeps heat in during winter
– Minimises radiant heat during the summer
1. Radiant barrier
– Reflective layer to deflect radiant heat away from the
house
1. Protection against thermal bridging
– “Steel-on-steel” contact in the structure
Sponsors

12. The Roof
Sponsors
Outer roof sheet
Structural steel
Sun
Heat radiates into the house
You cannot ventilate radiant heat away

13. The Roof
Sponsors
Outer roof sheet
Inner roof sheet
Structural steel
Insulation Insulation
Sun
Heat radiates into the house

14. Thermal Bridging
Sponsors

15. Thermal Bridging
Sponsors

16. Minimum Ventilation
• Minimum ventilation is when the house temperature
is at, or below, the required house set temperature.
• It is a time when we are heating the house.
• At the same time we must introduce a bare minimum
amount of air to maintain air quality.
• We need to control moisture levels in the house.
• We must keep the birds warm, comfortable, and with
good air quality.
Sponsors

17. Minimum Ventilation – Open Houses
• Curtain management is crucial.
• Air entering through the curtain drops to the floor.
• Problems :
– Stress on the birds
– Increased heat consumption
– Wet litter
• If you open too much, the temperature goes down.
• If you open too little, air quality deteriorates.
Sponsors

18. House Leakage
Sponsors
Cold floors, stressed chicks, wet litter,
heater activated
Wasted Heat

19. Air Leakage
Sponsors

20. Minimum Ventilation – CE House
• Operates with “negative pressure”.
• Pressure differential is used to control how the air
enters the house.
• The air travels away from the birds into the heat
accumulated in the roof.
• No air movement at bird level – bird comfort.
• Re-uses the heat from heaters and birds.
• Reduces heating costs.
• WE determine how much air enters the house, not
the outside wind.
• Can increase stocking density.
Sponsors

21. Minimum Ventilation
Sponsors
High air speed in roof area
Air speed at bird level < 0,25m/s

22. Sponsors

23. Transitional Ventilation – Open Houses
• Outside temperature is higher than required set
point.
• Curtains are opened more than minimum ventilation.
• If there is a prevailing wind, then need to be careful.
• If there is no wind, then birds may soon start to get
too hot.
• Amount of air flow and cooling on the birds depends
on outside wind.
Sponsors

24. Transitional Ventilation – CE Houses
• Using fans and side inlets, WE control how much air
enters the house.
• Large volume enters away from the birds.
• Bird comfort is regulated by the number of fans
being used (controlled).
• As temperature increases, more fans can be used to
keep the birds comfortable.
Sponsors

25. Hot Weather Ventilation
• When ambient temperature is higher than the
required set point.
• Along with high temperature may be high RH.
– This is probably the most dangerous weather condition.
• The birds are hot and panting (stress).
• Activity/growth/production may decrease.
• There may be mortality.
• THE BEST CHANCE OF SURVIVING HOT, HUMID
CONDITIONS IS AIR MOVEMENT, AIR EXCHANGE.
Sponsors

26. Hot, Humid Weather – Open Houses
• Stocking density is often decreased in hot season.
• Curtains may be fully opened.
• Circulation fans may be used.
– These fans only cover certain area of the house
– House conditions are very uneven
– Usually they just recirculate the hot, humid air
• Spray cooling used along with circulation fans.
• Not all the birds experience the same cooling/relief.
• System has a limited house air exchange rate.
Sponsors

27. Hot, Humid Weather – CE Houses
• Liveability depends on air speed and air exchange.
• Can create high air speed (3+ m/s).
• Can exchange all the air in the house in 30-40sec.
• This will be uniform across all the birds.
• Birds can tolerate higher RH if air speed is high.
• Evaporative cooling pads can reduce temperature.
• During tunnel ventilation we need to control bird
effective temperature.
– dry bulb temperature, RH, air speed, bird age, density.
Sponsors

28. Wind Chill Example
Sponsors
0.5 1.0 1.5 2.0 2.5 3.0
Air Velocity (m/s)
8.0
5.5
1.0
9.0
6.5
4.5
2.0
WindChill(°C)
3.5

29. Cooling Potential
Sponsors
ΔT = Maximum cooling possible
Dry Bulb Wet Bulb

30. CE House Reality
• Closed environment houses can/should be used in all
climates around the world.
• The more extreme the climate (hot, cold, high RH)
the greater the need for Closed Environment.
• India :
– 0°C; 45°C; high rainfall; high humidity
• CE housing does NOT guarantee good
results/performance/production.
• It is just another MANAGEMENT TOOL to help you
manage your flock.
Sponsors

31. CE House “Limits”
• House must be :
– Well sealed (air tight)
– Well insulated
• Ventilation system must be designed correctly
– Heating capacity and distribution
– Side wall inlets for transitional ventilation
– Side wall fans for minimum ventilation
– Fans for tunnel ventilation
– Pad area
• This depends on pad thickness
• Depends on flute angle of the pad Sponsors

32. Transition Ventilation Inlets
Sponsors

33. Pad Flute Angles
Sponsors

34. CE House “Limits”
• Bad house design
– Owners who design their own house from “internet info”
– Equipment companies that don’t know their business
• Over complicated ventilation control systems
– There is NO need for the controller to be complicated.
– There is NO such thing as a controller that does not have
to be adjusted during the flock.
– Beware of equipment companies that tell you they will
program the controller and you won’t need to change it!!
– Keep the control system simple to understand and use,
making sure it can still do what you need it to do.
Sponsors

35. CE House “Limits”
• Lack of education and training.
– There are new concepts in CE houses.
– Farmers must be educated about the principles.
– They must understand how the control system “thinks”.
– They must know how to manage this to achieve bird
comfort.
Sponsors

36. Bernard Green
Green Environmental Services
Consultant
Email:
bernard@greenenviro.co.za
Phone: +27 82 412 5821
Skype / LinkedIn / Twitter /
Etc.:
Contact
Sponsors