Why Freezing Occurs
Household refrigerators are designed to operate in a room temperature environment and therefore do not have heating elements or the ability to warm the refrigerator compartment.
As the temperature outside the refrigerator lowers, the compressor runs less frequently. If the outside temperature drops to approximately 40 F, the compressor stops running altogether. If the outside temperature drops below freezing, the refrigerator temperature will continue to drop until it equals the surrounding temperature. This will cause liquids to freeze, bottles to burst and many foods to spoil.
The following graph shows what happens to the refrigerator temperature as the outside temperature drops. Notice that with Fridgeguardian, the temperature inside the refrigerator never drops below freezing.

How it Works
Just place Fridge Guardian inside your refrigerator, run the power cord across the door seal and plug it into any 110VAC outlet. If the temperature inside the refrigerator ever approaches freezing, a built-in thermostat will turn on a low wattage heater and circulating fan. The precision thermostat will maintain the refrigerator temperature above freezing but below the normal refrigerator setting. This feature prevents the refrigerator compressor from turning on unnecessarily. Fridge Guardian protects against freezing down to -30 F and can remain installed all year round.
Typical Installation