Max temperature for fermentation fridge

Does anyone know what is likely to be a safe maximum operating temperature for a converted freezer to fermentation chamber? A friend needs to hold his collected honey at 52C for 24 hours before putting it in jars. I was concerned that my freezer components or maybe refrigerant might be damaged going that high. Also wonder if my 40W heater might be a bit undepowered for the job.

Your main worry is the local temp directly around the heater. You don’t want the plastic right next to the heater to melt. This is highly dependent on your heater, less so on control logic.

You could use heating belts to put the heat source right next to the beer, and away from the fridge wall.

For keeping steady state in a fridge, 40W is more than enough. If you want significant (52*C) heating, your upper boundary is dictated by melting fridge plastic and heater placement.

Thank you Bob. Will give it a go and keep an eye on the area around the heater.