Further measuring and monitoring

• House tightness (see Ventilation How To 02; How To…Measure Air House Tightness)
  • Measure before flock placement or when suspected issues occur (e.g. if house pressure decreases, litter quality deteriorates, or bird behavior changes)
  • Use a smoke test (outside the house) to show air entry or turn lights off and stand in dark to see where cracks are.

• Measuring fan capacity (see Ventilation How To 03; How To…Measure Fan Capacity)
  • Measure revolutions per minute (RPM) using a digital tachometer and compare to manufacturers specifications
  • Refer to manufacturers performance data (pressure vs fan capacity)
• Air speed (cross ventilation)
  • Use smoke test or cassette tape method to determine if air speed is sufficient to reach the peak of the roof. tunnel ventilated house)
• Tunnel ventilation (see Ventilation How To 05; How To…measure average air speed in a
  • Measure in 3-4 places across width of house at bird level
  • Measure approximately 10-30m (33-100 ft) away from tunnel fans
  • Use Average

Key maintenance management

• Check system operation;
  • check alarm systems; there should always be an alarm system that is independent of the control system.
  • check auxiliary electricity generator.
  • check curtain operation if using open-sided housing.
  • check electrical panel and its elements.
  • calibrate inside and outside sensors every flock.
  • make sure outside temperature sensors are never in direct sun.
  • check fogger and pad cooling systems.
  • check fans are in good working order.
  • check inlets are calibrated to open uniformly.
  • check air pressure sensor tubes are not blocked and the tube to the outside is not affected by wind.
  • calibrate the pressure sensor reading.

• Check water quality; a reduction in the physical/chemical quality of water (for example due to contamination or periods of hot weather) will have a negative impact on filter condition where water cooling systems are fitted.
• Clean all water filters and replace if necessary.
• Check that temperature and humidity sensors for foggers are protected from water. Water (and/or dust) on the surface of the sensor will reduce sensor accuracy and may affect operation of the ventilation and cooling systems.
• Clean evaporative cooling pads and/or foggers. Remove inlays and clean sediment, replace worn elements.
  

• Have spare parts available (such as fan belts, pump spares filters etc.) in case of breakdowns.
• Complete fan maintenance checks:

• Cooling pad / pump maintenance.
  • Make sure the sump is covered.
  • Empty sump a minimum of once every 2 weeks (more often may be needed depending on water quality).
  • Completely dry the cooling pad out once a day.
  • Keep pads shaded if possible (make sure that air flow to the pad is not restricted).
  • Use recommended products to control algae.
  • Clean filters weekly and test air flow regularly.
  • Ensure water pipe drip holes are not blocked.
  • Follow the pad manufacturers maintenance recommendations.

Key management tasks

• Routinely record environmental and air quality parameters.

• Check position of sensors. They should be:
  • at bird height
  • evenly spread along length of house
  • out of direct line of heating system
  • located out of direct sunlight - outside temperature sensors located out of direct sunlight.

• Manually verify the accuracy of electronic sensors controlling automatic systems once per week.
• Regularly remove dust and feathers from, screens and fan blades, light traps, and louvers. A build-up of dirt will significantly reduce ventilation efficiency.

Open or curtain-sided housing

For more information on ventilation in open or curtain-sided houses please refer to the document: A Guide to the Management of Open-Sided Houses.

Broilers vs breeders

• For breeders reducing house temperature during feeding until 2 hours after feeding can help to dissipate excess heat and reduce dust – exact temperature reduction should be determined by monitoring bird behavior.
• Be aware that air flow may be different in a breeder house than in a broiler house due to additional equipment such as slats and nests.

Useful calculations

Minimum ventilation

Ventilation Rate

• Minimum ventilation [m³/hr] = number of birds x ventilation rate per bird [m³/hr/bird]
• Minimum ventilation [cfm] = number of birds x ventilation rate per bird [cfm/bird]

Cycle Timer

• ON time = (min vent [m³/hr] x cycle time [sec]) ÷ (total min vent fan capacity [m³/hr])
• ON time = (min vent [cfm] x cycle time [sec]) ÷ (total min vent fan capacity [cfm])

Note: cycle time = ON + OFF time