Overview
While staying at a resort in Hawaii, I noticed the following label on our minifridge:
We are happy to provide this mini refrigerator for your convenience. Please keep in mind that the temperature setting is at a level to keep your beverages cool and refreshing. Please know that because perishable food items will not be safely chilled at this temperature setting for future consumption, the hotel cannot be responsible for loss or replacement of these food items. We appreciate your understanding and cooperation.
While I understand that electricity is more than twice as expensive as the country average and is mostly non-renewable, I’d still rather use a little bit more electricity and be able to keep food below 8ºC (45ºF) with a target of 5ºC (40ºF), per food handling standards.
Using my handy portable thermometer, I found that the refrigerator was at a toasty 20ºC (67ºF), which isn’t enough to keep food safe.
Preparing to adjust the temperature
Looking inside most hotel minifridges, you’ll not find an adjustment dial. This is because it’s on the back, like the picture above. Before you start adjusting the refrigerator, you should check to see if the cooling panel (evaporator) is covered with frost. If you find that it is, I’d recommend unplugging the fridge and letting it sit for a few hours to defrost. Doing that makes the unit more efficient at cooling, which saves power and reduces the number of times that the compressor has to turn on while you’re trying to sleep.
Choosing the right setpoint
Once you’ve defrosted and plugged back in the fridge, it’s time to turn it on and adjust the temperature. If you twist the dial completely to the coldest setting (the farthest that the dial can turn clockwise), it will be below freezing and may not be what you want unless you’re keeping ice cream or the like. While the most efficient way to find the right set point is to do a binary search, I opted to slowly move it a few degrees at a time from cold because nobody has time for food poisoning, certainly not me.