A commercial refrigerator will keep food cold for a very long time, but if you’re not sure how long it can last without power, you can use a thermometer to determine the temperature. It is also a good idea to have a large block of ice in the freezer. This can help prevent food from thawing and can even keep it cold for 24 hours.
Depending on the model, a commercial refrigerator can stay cold for four to six hours, and a freezer can keep food for a day. It’s best not to open the freezer door if there’s no power, but leaving the vents open in case it starts working again can help extend the time your food stays frozen.
One of the factors that determines how long a commercial refrigerator will stay cold without power is its insulation. Modern refrigerators are better insulated than their older counterparts, so they can keep food cold even when there is no power. In the event of a power cut, a full fridge will stay cold for at least 48 hours, and a half-full freezer can keep food cold for two days.
To keep food safe, the temperature inside a refrigerator should be around 40 degrees Fahrenheit. The temperature inside a freezer should be around 0 degrees Fahrenheit. When the internal temperature rises above this temperature, bacteria can multiply and cause foodborne illness. Some ways to keep food cold longer are to use block ice, dry ice or a cooler. Frozen gel packs also work well to keep food cold.