Welcome to Frost Free Fridge Freezers Guide: we're proud to offer you a comprehensive source for everything you need to know about frost free fridge freezers.

Frost free fridge freezers have been around for quite a few years now and their operation remains a mystery to quite a few people. Let's unravel that mystery.

Cooling Theory
Cooling is a way to store food that keeps food safe to eat by using cold temperatures to reduce the number of bacteria -- the colder the temperature, the slower the bacteria population grows, and the slower food spoils. Centuries ago, root cellars kept vegetables and smoked meats available to year round. The original iceboxes of the late 1800s simply used ice to cool the food. Electricity for refrigerators came into use the beginning of the 20th century, and allowed the addition of freezer compartments. Today, technology provides us with many different types of household appliances that cool food.

Avanti 10.0 Cu. Ft. Frost Free Fridge / Freezer

Refrigerators
The basic refrigerator or "fridge" has two components: a compartment lined with thermal insulation and a heat transfer system. A fridge compartment is made to maintain a temperature slightly above the freezing point of water, around 37-41 degrees F (3-5 degrees C), an optimal temperature for storing perishable food for several days beyond its normal spoilage time.

Freezers
A freezer works in the same way, but it maintains its interior temperature well below the freezing point of water, about 0 degrees F (?18 degrees C). Frozen food will remain edible longer than food kept in the refrigerator compartment, but frozen food must be thawed before it can be eaten, and some types of food do not react well to the process of freezing and become inedible upon being thawed -- one example is celery, a food with a lot of water contained within microscopic cells. Meat, however, reacts well to being frozen -- it can be kept for weeks and still be edible when thawed.

A freezer can be part of a refrigerator or an entirely separate unit. The separate units can be upright, like a refrigerator, or prone, like a chest that opens from the top. Separate commercial freezer units are usually upright, while domestic ones are prone. Attached freezer units are well-integrated into the body of the refrigerator, with the freezer compartment either above, below or to the side of the less cool fridge compartment. An attached freezer compartment is usually one-third to one-quarter the size of the fridge compartment.

Temperature Control
One of the mysteries of the combo fridge/freezer units is how two different temperatures can be maintained. The answer is not two thermostats, except, perhaps in the most expensive models with separate controls. Most fridge/freezer units have only one thermostat to keep the entire interior cool. Though the heat pump is the device that removes the heat from the air within the unit for both the fridge and the freezer, it's fans circulate the cold air throughout the interior. The freezer compartment is both where the thermostat is located and where the initial flow of cold air from the heat pump is circulated. Ducts than channel the cold air into the fridge compartment where there is an inlet that leads back to the heat pump.

When the thermostat in the freezer compartment senses the temperature is too high, the thermostat turns on both the compressor of the heat pump and the fans. Fans circulate the cold air throughout the freezer compartment. The temperature control knob for the fridge compartment controls only a set of dampers that determine the amount of air leaving the freezer and entering the fridge.

The cold air picks up heat from the food, cooling the food. The circulation of the air brings the heat to the heat pump, which transfers the heat outside the compartments via the refrigerator coils on the back of the machine. When the temperature in the freezer drops to a proper level, the thermostat there turns off the compressor of the heat pump and the fans. The temperature in the fridge compartment does not affect the thermostat in any way.

The best setting for the two temperature controls, of which we now know only one is directly connected to a thermostat, is one where the fridge setting is Max Cool and the freezer setting is a low enough temperature that the food will be stay frozen, but not be damaged by freezer burn.

In the next section we'll give a look at the main features of frost free fridge freezers, in order to help you find the product most suited to your needs and expectations.