I'm looking for a way to maintain a constant temperature of 110°F in a medium-sized camping cooler. The temperature needs to be fairly constant for as long as 30 days, so the heat source needs to be efficient and not prone to burning out. Putting a light bulb in the cooler does work, but it's not very cost effective because bulbs burn out, and also are not especially efficient heat generators.
If I put a gallon jar of water in the cooler, and heat the water with a fish tank heater to 95°F, how warm will the air in the cooler get? Fish tank heaters will not go beyond 95°F, since I guess there are no fish wanting warmer water than that. The lid is not airtight (there is just enough gap at the handle for an electric cord to pass), but airflow from the cooler is minimal. Where would I find formulas that model this kind of thing? Thanks for your help.
Byron