How does repeatetly moving food from freezer to fridge and back every day affect it? My fridge and freezer makes noise to the point that it is hard for me to sleep (even with earplugs) so I have began to shut off the power to the fridge and freezer during the night. My fridge is set to 1 degree celsius and my freezer is set to -18 degrees celsius.
When I go to sleep I move all the fridge items such as milk, cheese, butter, meat, kefir to the freezer and shut the power off for 9-12 hours when I sleep. When I wake up again, I turn the power back on, wait about an hour or so and put my items back in the fridge. The freezer temperature when I turn the power back on is around 3-4 degrees.
I don't feel ill when I eat the food, all I have noticed is ice crystals in the milk and that the cheese is a bit harder to slice. I am wondering about the long term effects of this process, both the food safety aspect and the quality of the foods. Is there any food items that are less safe to do it with?
I assume you have no food that needs to be kept frozen. If you do that's your greatest concern.
If, as suggested by your measurements, the fresh food never gets above the recommended maximum fridge temperature, the quality is going to suffer, possibly quite a lot, but the safety shouldn't, within the use by dates.
You may be able to keep the quality better by leaving the food in the fridge, but transferring a lot of ice from the freezer. I'd freeze several large plastic bottles, about 3/4 full of water, when the freezer is running, and move those into the fridge when you turn it off, leaving the food in there. Refreeze the next day. This is the approach used in many camping coolers, and it sounds like you have the ability to ensure the temperature doesn't get too high.
If it's so noisy that it's keeping you awake through earplugs, even if it's right next to your bed, that is quite likely to mean it's on its way to failing completely. The fact that your freezer is warming so fast is probably partly the unfrozen food going in and partly that it's empty of frozen stuff. It may also be a further sign of imminent failure.