A common question we often get is this: What is an appropriate temperature range for my incubator?
We all know that the target temperature for incubating most bird eggs is 99.5 degrees F. But we also know that getting an incubator to stay at exactly 99.5 degrees is just about impossible. Egg incubators naturally have a temperature range that occurs as the thermostat controls the power going to the heating system. In an on/off thermostat, the power turns completely off and then back on at full power. As the heater cools down and then heats back up there is a delay before the air inside the incubator starts feeling the effect of the heating and cooling cycle. This results in the temperature range that you will see as you monitor the thermometer in your incubator. Even in a proportional style thermostat there is still a temperature range, though it is often less.
So what is an appropriate range? It turns out that that is a pretty tough question to answer because it depends on several things. A better question is, “What is a good cycle time?” The cycle time is the time it takes the incubator to go from the highest temperature (during the heating cycle) to the lowest temperature (during the cooling cycle). Let’s discuss that a bit.
Let’s say, for example, that your highest point is 102.5 degrees and your lowest is 96.5 degrees. This gives us a total range of 6.0 degrees. That seems huge and really bad. However, if the cycle time is fast enough, this range would be just fine. But wait, if my eggs reach 102.5 degrees that’s really bad, right? Yes, that is correct. But we have to remember that the air inside your incubator is warming and cooling much, much faster than your eggs. So if the temperature cycles between that high and low temperature within just a couple of minutes, your eggs have experienced almost no temperature change. The key is to get the AVERAGE temperature really close to 99.5 degrees and then make sure that the cycle time is short enough so the eggs stay very close to that average. Most incubators will cycle between the high and low points within just a couple of minutes and that is very appropriate for keeping the eggs at the average temperature.
Another example would be a high temperature of 101.0 and a low of 98.0. But with a cycle time of 15 minutes. The average is still 99.5 degrees and the range is only 3 degrees. That’s better, right? Well, no. The cycle time is pretty long and gives the eggs a lot of time to heat and cool. The eggs in the first scenario would be better off than this second scenario.
We have found that keeping the cycle time short and then ensuring that the average temperature is very close to 99.5 degrees is the best way to ensure your eggs have the best opportunity for a great hatch.