Cooling is an entirely natural process as most birds will get off the nest at least once a day and leave the eggs unheated for a significant time.
Recent research (please scroll down for more information) has also shown that hatch rates can actually increase significantly as a result of cooling.
For this reason Brinsea has now incorporated a cooling option in all their Advance models of egg incubators for 2012. This feature turns the incubator's heater and low temperature alarm off for a selected period but keeps the fan running. After the cooling period is complete the incubator reverts to normal temperature and the alarm is automatically reset.
The new cooling feature turns the incubator’s heater and low temperature alarm off for a selectable period but keeps the fan running. After the cooling period is complete the incubator reverts to normal temperature and the alarm is automatically reset. The cooling function is optional and the user can select cooling periods of 60, 120, 180, 240, 300 and 360 minutes with fixed 24 hour intervals. The default setting is that cooling is set to off.
F. Bogenfurst, Pannon University of agriculture, Hungary. 1997. Experiment showed the increase in hatch rate of geese eggs with periodic cooling. Concluded ‘Incubation results improved with periodic cooling’.
We have assessed the available research and recommend that smaller poultry, waterfowl and game bird eggs are cooled for 2 hours each day and larger eggs (e.g. duck and goose) are cooled for 3 hours each day from day 7 through to 2 days before they are due to hatch (the same point that automatic turning would normally be turned off). Cooling is not recommended for parrots and birds of prey because the results of cooling for these species haven’t yet been established. This cooling feature is an option which can be enabled to improve your hatch rates.