How Does a Freezer Work?

Whether it’s a chest freezer in the basement or an upright freezer in the kitchen, these appliances are designed to keep temperatures well below freezing, safeguarding the freshness and nutrition of our stored items. But how exactly do freezers work, and what’s the difference between chest and upright freezers? Let’s dive in and find out.

The Basics of Freezer Operation

At its core, a freezer operates on the principles of thermodynamics and refrigeration. The main goal is to remove heat from the interior of the freezer and dissipate it outside, creating a cold environment inside. Here’s how this process works step by step:

1. Refrigerant Circulation

A freezer relies on a refrigerant, a special fluid that can easily transition between liquid and gas states. The refrigerant will also readily absorb a significant amount of heat as it changes from liquid to gas. These properties allow refrigerant to remove heat (or cool down) the inside of the freezer.

This refrigerant circulates through a sealed system of tubing, coils and components, starting in the compressor.

2. Compression and Heating

The compressor compresses the refrigerant gas, increasing its pressure and temperature. The hot, high-pressure gas then moves to the condenser coils.

3. Heat Dissipation

The condenser coils, typically located at the back or bottom of an upright freezer, release the heat from the refrigerant into the surrounding air.

The condenser tubing in a chest freezer is located inside the cabinet between the outer cabinet walls and the inner freezer liner. Locating the condenser tubing between in inner liner and out cabinet wall allows the condenser to heat up the cabinet and area surrounding the inner liner to drive out moisture.

As the refrigerant cools, it turns into a high-pressure liquid.

4. Cooling and Expansion

The liquid refrigerant flows through an expansion valve or capillary tube to prepare the refrigerant for effective heat absorption in the evaporator.

The expansion valve or capillary tube lowers refrigerant pressure and limits the amount of refrigerant liquid entering the evaporator, which will allow liquid refrigerant to efficiently expand, evaporate into a gas and absorb heat as the refrigerant travels through the evaporator.

5. Absorbing Heat Inside the Freezer

The cold refrigerant passes through evaporator coils inside the freezer. Here, it absorbs heat from the freezer’s interior, cooling the air and lowering the temperature below freezing.

In an upright freezer, the refrigerant travels through an evaporator with cooling fins and a fan that circulates air across the fins and throughout the freezer.

In a chest freezer, the evaporator is a series of refrigerant tubes that travel through the space just outside the inner liner of the freezer. Some upright freezers use a similar process for cooling the inside of the cabinet by running refrigerant tubes through permanently placed shelves inside the freezer.

6. The Cycle Repeats

The warmed refrigerant returns to the compressor, and the cycle begins again.

Chest Freezers vs. Upright Freezers: How They Differ

Both chest and upright freezers use the same fundamental refrigeration process, but their designs and layouts influence their performance, efficiency, and usability.

Chest Freezers

Design

Chest freezers are horizontal and open from the top like a large box.

As noted above, the condenser runs through the space between the outer cabinet and the inner freezer compartment liner – next to the outer liner.

The evaporator tubing runs through the same space, but is positioned next to the inner freezer compartment liner.

Advantages

• Energy Efficiency: Chest freezers tend to be more energy-efficient because cold air stays inside when the lid is opened (cold air sinks and doesn’t escape easily).
• Better Temperature Consistency: With fewer temperature fluctuations, chest freezers are ideal for long-term storage.
• Cost-Effective: Chest freezers often have a lower upfront cost compared to upright models.

Challenges

• Space Utilization: Items are stacked, making it harder to organize and access specific foods.
• Footprint: They take up more floor space, which might not suit all homes.
• Must be Manually Defrosted: Because a chest freezer doesn’t have a compact evaporator with a defrost heater and automatic defrost system, you’ll need to manually defrost the freezer at least yearly.

Upright Freezers

Design

These freezers stand vertically and feature shelves and compartments for organized storage.

The evaporator is typically positioned in a compartment behind the back of the rear freezer compartment liner and a fan blows cooling air throughout the freezer compartment.

Advantages

• Accessibility The vertical design and shelves in an upright freezer make it easier to locate and access food.
• Smaller Footprint: They take up less floor space, fitting neatly in kitchens or smaller rooms.
• Aesthetics: Upright freezers often blend better with other kitchen appliances.
• Automatic Defrost: Upright freezers typically have an automatic defrost system so you don’t need to manually defrost an upright freezer.

Challenges

• Energy Use: Opening the door lets cold air spill out, causing the freezer to work harder to maintain its temperature.
• Cost: Upright freezers tend to be more expensive than chest freezers.

Energy Efficiency Tips for Freezers

• Keep It Full: Freezers run more efficiently when full, as the cold items help maintain a consistent temperature.
• Seal Check: Inspect door seals regularly to ensure they’re airtight. If you find door or lid seal damage, replace the seal. If you’re unable to replace the door or lid seal yourself, schedule freezer repair and we’ll replace the seal for you.
• Location Matters: Place your freezer in a cool, dry area away from direct sunlight or heat sources.
• Defrost as Needed: For manual defrost models, remove ice buildup to maintain efficiency.
• Schedule Professional Maintenance: Annual professional freezer maintenance will keep your freezer operating efficiently and prevent unexpected breakdowns. The freezer will also last longer when you have it professionally maintained yearly. If you encounter problems with your freezer, schedule freezer repair service quickly to avoid food spoilage and further damage to the freezer.

Freezers, whether chest or upright, rely on a simple yet effective refrigeration process to keep your food fresh.

Choosing between a chest and upright freezer depends on your storage needs, space, and budget.

Understanding how these appliances work helps you use them more effectively.