Seeking energy-efficiency in pre-conditioning inlet air for setters and hatchers
Written by Gerd de Lange, Senior poultry specialist Pas Reform
Hatcheries are found in a variety of climates, from the hot, humid tropics of South East Asia to hot, arid zones in the Middle East or the changeable climates of Central Europe or the USA. Typically, external temperature and relative humidity are subject to seasonal changes (e.g. rainy season, very cold winters) or even a day and night rhythm. The challenge is to establish whether outside air is directly suitable for incubation - and if not, how to make it fit for that purpose.
To a certain extent, setters and hatchers can deal with climatic variations to inlet air, although most incubator manufacturers specify the climate conditions under which their equipment will perform at its best.
Untreated, inlet air can be:
- Too cold: this may lead to low temperature uniformity and, especially if occurring early in incubation, an extended hatch window;
- Too warm: during late incubation in the setter and certainly in the hatcher, this will overwork the water cooling system, produce excessive condensation and ultimately wet floors, which will cause eggs close to the floor to become too cold;
- Too dry: humidification (rotating disc, nozzles) in the incubator may compensate for this, but will cause cold spots due to localised evaporation;
- Too humid: this may cause difficulties in achieving sufficient egg weight loss during incubation, which can only partially be compensated for by a higher ventilation rate and might ultimately lead to reduced hatchability and poor chick quality.
The example below shows a realistic range of climate specifications for setter and hatcher inlet air:
Example of climate requirements for setter and hatcher inlet air * Above 70% RH increases the risk of fungal growth.
For hatcheries at sea level, dew point specifications can also be converted to a specific humidity of 8.2 – 13.8 g water/kg of air. There are several Mollier Diagram/psychometric chart-based climate calculation tools available online to help make these calculations.
Conditioning outside air to inlet specifications is not without cost, as demonstrated in the following two...
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