How to Control Humidity Without a Hygrometer When Incubating Chicken Eggs

The humidity within an incubator is directly affected by the outside humidity. Humidity changes with the seasons, and it can be hard to maintain a high humidity within an incubator during the first two months of the year, because the humidity in the room will be low. Conversely, it is difficult to prevent the humidity within the incubator from going too high during June and July. The surface area of water within your incubator will influence the humidity. By increasing the water surface, you can increase the humidity in the incubator.

Things You'll Need

  • Incubator
  • Two small bowls
  • Water
  • Wet/dry thermometer
  • Wet/dry thermometer conversion table
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Instructions

    • 1

      Place a wet/dry thermometer in the incubator. A wet bulb thermometer incorporates a cotton wick that is immersed in water. Water that is soaked up by the wick evaporates and thereby cools the wet side of the thermometer.

    • 2

      Place a small bowl on the floor of the incubator and fill it with warm water. The surface area of the bowl will influence the humidity, with a larger surface area creating a more humid environment. The depth of the container is unimportant.

    • 3

      Calculate the humidity by taking the difference between the wet and dry bulb temperatures and looking at the corresponding figure on the conversion table that is supplied with the wet/dry thermometer to gauge humidity. If the humidity in your incubator is high, very little moisture will evaporate from the wick and the wet bulb temperature will not be much lower than the dry bulb thermometer reading. The humidity within your incubator should be between 60 and 65 percent for the first 18 days of incubation.

    • 4

      Place a second small bowl into the incubator during the last three days of incubation as the humidity needs to be much higher and the additional water surface will be required. The humidity within the incubator during these last three days prior to hatching needs to be between 80 and 85 percent.