Combi tunnel ventilation
“Your Perfect Climate” throughout the whole year
Different ages of pigs have different temperature requirements:
- Sows require 18°-20° Celsius
- Piglets in the farrowing unit requires 35°-28° Celsius depending on age and house design
- Weaners require from 28° to 20° Celsius depending on weight
- Finishers require from 22°-16° Celsius depending on weight and floor layout
The impact of heat stress on finishers:
- Increasing respiratory rate
- Extending body contact to the floor (for cooling)
- Drinking more water
- Avoid physical contact with other pigs
- Increase evaporative heat loss by wallowing behaviour
- Feed intake declines
Heat stress converted into productivity loss:
- 35% of feed energy is used for growth (!)
- 20% for maintenance, 20% for heat and 25% for urine and faeces.
- When feed intake declines, it has a big impact on average daily gain (ADG):
Winter – inlets and fans
During winter, the farm sections are equipped with variable regulated air inlets (wall / ceiling) and air outlets (exhaust) through variable speed controlled fans. This ensures that the incoming (cold) air is mixed with warm room air before it reaches the animal zone. The air inlets ensures optimal climate in the animal zone throughout the cold period.
When the outdoor temperature is about 1°-4° Celsius colder than the optimal room temperature for the pigs, the ventilation system will gradually move into tunnel mode. This period is called “transition phase” where air inlets are open and shutters and/or curtains start to open.
Summer – tunnel ventilation
When room temperature exceeds the comfort zone the ventilation will switch into tunnel mode. This will ensure that all incoming air enters the building in one end and exits the building in the other end. Exhaust fans extracts air and ensures optimal air speed above the skin of the pigs (chill effect).
When the room temperature is 26° Celsius the air speed created by tunnel ventilation will reduce the effective temperature felt by the pigs with 6,5° Celsius. That means the temperature felt by the sows and finishers will be 19°-20° Celsius, ensuring the optimal production results.To maintain high productivity it is essential to cool down the pigs in warm periods. Previously, circulation fans were used to cool down the pigs in warm periods. However, this is far from ideal for all the pigs in the building and the pig producer will not get equal growth rate among all the pigs. From a health point of view it is ideal to operate with all in/all out production and to have the best use of the house all pigs must have the same growth rate. Tunnel ventilation will secure the same air speed and the same cooling effect and growth rate in the whole house.
Hot summer – Tunnel ventilation + CELdek® pads
During hot summer periods the effect of wind speed will not be effective enough to cool down the pigs. When there is only a little difference between room temperature and skin temperature the effect of wind speed is not enough to maintain high production results. If the room temperature is 31° Celsius the tunnel system will only reduce the effective temperature felt by the pigs with 3.7° Celsius. Therefore, additional cooling is required – the solution is to install CELdek® evaporative cooling pads.
As an example, when the outdoor temperature is 32° Celsius and the relative humidity is 50% the CELdek® pads can easily cool down the incoming fresh air to 26° Celsius and as mentioned before the wind speed from the tunnel can give a chill effect of 6.5° Celsius so the temperature felt by the pigs will be 19°-20° Celsius. This is optimal temperatures for sows and finishers, and the high productivity in the farm can be maintained.
In climate zones where the periods with high temperatures of 24°-35° Celsius it is necessary to cool down the air with CELdek pads before the air enters the house.