Why is 102 Lethal?

[Poulets De Cajun]

Why is it that if I have my thermometer on a block of wood in the STILL AIR incubator, and it reads 102, it is right on and not considered lethal temps.

But if I have that same thermometer on a block of wood in the CIRCULATED AIR incubator, and it reads 102, it is considered DANGEROUSLY close to lethal temps?

I realize that there is no air movement in the still air, therefore temperatures will be lower towards the bottom and higher towards the top, but if the thermometer is laying level with, or just below the tops of the eggs and reading 100, wouldn't they develop just fine?

Can there be that much temperature different in the 1 inch height of my eggs?

 

[horsejody]

Because in a circulated bator the temp is pretty consistent throughout. In a still air the temps are higher at the top then the bottom. At the the level of the top of the egg the temp is 102. On the floor it is cooler. Right in the middle of the egg it is 100. Yes, that little bit of height makes a huge difference.

 

[Poulets De Cajun]

I realize there is temperature "layering", but can there be that many layers in one inch of an egg?

 

[horsejody]

Quote:
Yes. People have been hatching successfully in still air incubators for many years using the 102 at the top of the egg method to prove it.

 

[walkswithdog]

I've not found 102 in still air to be lethal. But I've gone to circulated now in everything but my lone homemade hatcher.

I start worrying in still air when it goes over 104 and stays there for any period of time. 105-108 is even worse.

But people have had hatches after temp spikes over 110.

Sometimes it's just dumb luck. Consistency is better than hope but some of the time hope works.

 

[PurpleChicken]

I seem to recall a thread here where someone said the Egyptians
used to incubate at 104.

 

[AHappychick]

I once put 2 of the same thermometer in a still air one ontop of eggs and one on the grate, they were off my several degrees. The one on top was about 102 while the one on bottom read 98.something

 

[DANNY]

102 IS NOT LETHAL. IN FACT I ALWAYS RUN MY INCUBATORS HOT DUE TO INACCURACIES IN THERMOMETERS, THERMOMETER LOCATION AND HOT AIR MOVEMENT. I ALWAYS LET THE EGGS TELL ME HOW I AM DOING. IF THEY ARE OUT AND READY TO GO IN THE BROODER IN 21 DAYS I AM GOOD. IF THEY HATCH A LITTLE EARLY I AM A LITTLE TOO HOT. IF THEY ARE HATCHING LATE I AM TOO COOL AND IN TROUBLE BECAUSE THEY TEND TO PIP AND DIE AND HATCH FOR 2 OR 3 DAYS. ALL LAST YEAR MY GQF READ 102.4 WITH IT HANGING IN THE WINDOW AT THE TOP. ITS ALWAYS HOTTER AT THE TOP BECAUSE ITS RIGHT IN FRONT OF THE HEATING COIL AND HEAT RISES. I HAVE BEEN HATCHING BIRDS FOR ALMOST 40 YEARS AND HAD THE BEST HATCHING SEASON EVER LAST YEAR SINCE I STARTED LETTING THE EGGS TELL ME INSTEAD OF DEPENDING ON INACCURATE THERMOMETERS ETC.