Fridge Freezer Facts

The ideal refrigerator temperature

The main purpose of a modern refrigerator is to slow down the growth of harmful bacteria and the purpose of a freezer is to stop bacteria in it's tracks by it freezing completely solid.

Therefore you need your refrigerator to be very cold, but not cold enough to freeze things. This temperature is somewhere between 35 and 38 degrees F (1.7 to 3.3 degrees C)

The frost-free refrigerator

In old refrigerators frost forms around the coils that cool the freezer. This frost can get 6 inches thick.

Frost forms when water vapour inside the fridge freezer hits these cold coils. The water vapour then condenses and turns to liquid water just like the water on widowsills in single glazed houses.

The same thing happens on the ice cold fridge freezer coils, except that when the water condenses onto the coils it immediately freezes solid.

A frost-free freezer has three main parts:

• Timer
• Heating coil
• Temperature sensor

At around six hours intervals the fridge freezer timer turns on the heating coil. The heating coil is wrapped around the freezer coils.

The heater melts the ice off the coils. When all of the ice is gone, the temperature sensor senses the temperature rising above 32 degrees F (0 degrees C) and turns off the cooling coils heater.

Heating the cooling coils takes energy, and it also moves the food in the freezer through temperature changes so it is not ideal but much better than a fridge/freezer full of ice.