May 5


How Does a Freezer Work? Explained

By Robin Hatch

May 5, 2021

A freezer is one of the best appliances. It helps to preserve our food and keep cool treats like ice cream fresh for a hot summer day. Freezers are often paired with the refrigerator, as they both help to keep food cool. But how does a freezer work?

By compressing and depressurizing, refrigerators produce warm air which circulates for food to be fresher. A refrigeration unit helps retain food by extinguishing heat inside. Similar to fridges, a fridge uses an evaporation technique when keeping food fresh.

In this article, we’re going to show you how freezers work and how you can keep your food frozen before eating.

What Are the Different Parts of a Freezer?

Generally, freezers are composed of four major components: condensing coils and compressors, sonic tubes, and evaporators. This part works in tandem with the heat in the freezer chamber by moving cool air through it.

It’s your responsibility to create the ideal environment in your freezer that will ensure that your food stays frozen for a long time. The following lists each component as well as the function summary that should help you understand their functions.

How Does a Freezer Work Step by Step?

Freezer on a refrigerator

Now we understand the four key components of the freezer and how vapor compression plays a crucial role. A freezer absorbs warm food and circulates cold air in its interior to keep temperature favorable for long-term storage and to reduce waste in storage.

Condenser Coils

The refrigeration system of a typical freezer consists of three parts. An electric freezer compressor pushes the refrigerant through the first coil and this pushes it through the expansion valve into the second coil. Because pressures are lower, the refrigeration evaporator evaporates and the heat supply provides cooling. Molecular biology says evaporation is an endothermic process absorbing heat.

The freezer coils transfer heat from the inside of the freezer to the exterior keeping the appliance cool for the storage of food and beverages. The coil is usually constructed of copper, which is extremely hot, and the coil is usually found inside the freezer. Freezer coils are important components of heat transport that keep your food frozen.

This coil helps circulate refrigerants throughout a refrigerator, changing the heat and pressure, and helps cool and freeze the food inside the appliance. The coils are also used for keeping food frozen at an optimal temperature so it will not freeze.

Why Freezer Refrigerant Is Important

Even though there are several refrigerant properties, if we look at the situation from an environmental perspective, we can see that the most important ones are ozone depletion potential (ODP), global warming potential (GWP), and level of flammability. 

Since the refrigerant stays inside the refrigeration system, why are ODP and GWP considered necessary? Refrigeration systems all tend to leak. These leaks may occur through contraction and expansion at welds in refrigerant piping, systems recharging, or during the freezer’s eventual disposal. The lower the ODP and GWP numbers are, the less risk to nature.

Modern refrigerants have an ODP of zero, making them perfectly safe for the Ozone layer. Still, if you’d like to know what refrigerant your freezer is using, check the nameplate of your unit – it should be noted.

I suggest you always use an EPA-certified refrigerant reclaimer when you finally dispose of your freezer and then ensure that natural refrigerants cool the replacement fridge/freezer.

How Does A Freezer Stay Frost-Free?

Because freezers mainly use converting the liquid into a liquid refrigerant, you’d certainly expect a frost inside, but this remains frost-free. The secrets of that are in the heating coils. Freezers have an alarm that turns on the heater every six hours. The chamber stays cold during the freezing time.

The heating coils lie between the condensers and the freezers and are often bundled between them. As ice melts from coils the process continues until the whole ice has been removed from them.

It may be helpful if you use ice in ice boxes and containers. Until the ice has settled on the freezer wall next to the cooling coil, it can affect airflow and reduce cooling efficiency. This means condensing must work harder which wastes energy.

The working theory of deep freezers is that the coil absorbs the air around the coil and does nothing if ice or freezing is covered. Defrosting regularly is important and some freezer models feature automatic defrosting.

Common Freezer Problems

Setting The Temperature High

Freezer on a refrigerator

Store food at, or colder than, 0 degrees F (-18 degrees C), so don’t try to save money by setting it a little warmer to avoid requiring a chisel for the ice cream, say. This belief may cost you far more in the long run.

Freezer temperature sensors will make sure it stays below freezing cold, but you need to double-check it in case something hit it by accident.

This could result in a higher temperature.

Freezing Food For Too Long

Label your food well, as we discussed earlier, and perhaps even rotate the items if you have a large freezer, so you forget nothing until you discover it years later.

Losing Small Items Like Herbs and Chili Peppers

You might want to dedicate a freezer-safe container into which all small objects are placed and never overlooked.

Whenever cooking, I consider the possibility that freezing might be required, and if it is, I do so as soon as the food cools. This seals in the most flavor possible.

Keeping The Freezer Nearly Empty

You might think this will save power costs, but it does just the opposite. Frozen food helps cool the freezer box, whereas the empty area will not retain cold as efficiently as the food can and requires more cooling.

Despite carefully packing the freezer according to date, types of food, etc., We should take care never to close any vents off, as this will undoubtedly lead to extra running costs and could lead to repairs being required by yourself later.


Circulating cold air inside the freezer will only be at the proper temperature if the freezer works properly.

The temperature sensor will regulate the warmer air inside of the freezer, but it needs to be able to work freely. The heat transfer process by the evaporator coils, where the freezer removes heat is a typical refrigerator process. The freezing cycle in modern freezers works by setting the temperature and forgetting about it.

Be sure to check on your freezers often especially if you’re getting frost-bitten food.

Robin Hatch

About the author

For over a decade, Robin has been a real estate agent, interior design specialist, and mother. Through her trials and tribulations, she wanted to create the perfect website to help you save money and make your home look beautiful.

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