I am in the process of building an incubator from a small fridge. I am using the bottom section as an incubator with articulating trays and the upper freezer section for hatching. This should allow me to run three different sets at a time. I have digital controllers for both sections and did a test run tonight with nothing but an empty cabinet. The temp stabilized between 99.1 and 99.5 within about 15 min. I had planned on adding some containers of sand to help balance out temp swings and provide a little security for short power outages. Temp swing does not look like its going to be an issue because if I open the door and let it drop 5-6 degrees it's back to a stable temp in just a couple of minutes. Is their a recommended formula for how much mass to add for a given volume of space in an incubator? And if I do add thermal mass does it create more of a liability than it's worth should an overheat situation occur? I plan on doing my first set on Monday or Tuesday so I can have chicks during my daughters visit Thanksgiving week. The incubator will be able hold about 90 eggs at any given time. I have around 4 dozen eggs to choose from on my desk ready to go. and will probably try to do three sets of 20 next week. Any last minute advice would be appreciated.
Seeing how you are using digital controllers with an insulated cabinet, I don't think there would be a need for additional thermal mass. Thermal mass may help if you were having problems with temp stability, but it does not sound like you are. As far as a power outage or overheating scenario I'm not sure . Good luck with your hatching.
