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Condensation point = dew point
Condensation point = dew point
Condensation point
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The condensation points of eggs (sweating) at certain levels of relative humidity (RH) outside the storage room. Example 1: in a setter room of 25°C with 50% RH, eggs will ‘sweat’ when they are taken from a storage room where the temperature is set below 14°C. Example 2: eggs with a temperature of 27°C set in a warm incubator at 38°C and with 55% RH will stay just below the condensation point. This is why it is important to allow the eggs to acclimatise properly before setting them in the incubator. The setter room is usually a little colder than 27°C.
Dew point determination based on temperature and humidity values
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Dew point temperature (°C) 10 20 30 1 80% 55% 30% Relative humidity (%) 15 20 25 30 35 40 Air temperature (°C)
The moment that condensation occurs depends on the temperatures inside and outside the storage room combined with the relative humidity. It is a natural phenomenon that cold air can hold less moisture (water vapour) than warm air. When warm, moist air cools down it reaches a certain temperature referred to as the condensation point or dew point. At that moment the water vapour in the air condenses to form liquid droplets (dew). The highest risk of condensation (sweating) occurs when eggs are moved from the colder storage room/trailer to the relatively warmer environment of the receiving area at the hatchery. Unloading the eggs from a plane onto a loading platform at a ‘hot and humid’ airport is also a critical moment. 2 The air that comes into contact with the eggshell cools quickly. The moisture in this air condenses on it as soon as the condensation point is reached. Condensation on the eggshell creates favourable conditions for bacteria and moulds to multiply and carries the risk of the egg contents being contaminated by pathogen absorption through the pores in the shell. You can calculate the condensation point based on the temperature and relative humidity values. The Mollier diagram is a commonly used tool, but there are also many handy calculation apps available.
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Condensation, or sweating, on the eggshell surface. Cooled eggs will sweat if they suddenly come into contact with warm, moist air. You will see condensation form if a glass of cold drink poured straight from the fridge is placed in warmer surroundings. This is exactly what happens with hatching eggs too.
