Food Kitchen Tools & Products Kitchen Appliances How Does a Refrigerator Work? Here's the science behind how your food stays cool. By Nicole Sforza Nicole Sforza Nicole Sforza is a former senior editor at Real Simple and Home Magazine with more than 15 years of experience. Today, she is is the executive editor of Yahoo Lifestyle, Commerce. Highlights: * Former vice president of marketing at Underbuilt.com * Author of three books: "Mrs. Meyer's Clean Home," "You're So Invited: Panic Less, Play More, and Get Your Party On," and "Domino: Your Guide to a Stylish Home" Real Simple's Editorial Guidelines Updated on July 31, 2024 Fact checked by Isaac Winter Fact checked by Isaac Winter Isaac Winter is a fact-checker and writer for Real Simple, ensuring the accuracy of content published by rigorously researching content before publication and periodically when content needs to be updated. Highlights: Helped establish a food pantry in West Garfield Park as an AmeriCorps employee at Above and Beyond Family Recovery Center. Interviewed Heartland Alliance employees for oral history project conducted by the Lake Forest College History Department. Editorial Head of Lake Forest College's literary magazine, Tusitala, for two years. Our Fact-Checking Process In This Article View All In This Article How Does a Refrigerator Work? How Does a Freezer Work? How Does a Fridge Water Dispenser Work? Frequently Asked Questions Photo: Karen Moskowitz/Getty Images The fridge is one of the best inventions to grace our kitchens. Before refrigerators as we know them existed, people relied on natural sources such as streams and caves, community cooling houses, or iceboxes, and households weren't able to keep as much perishable food on hand. The first home electric refrigerator was invented in 1913 by Fred W. Wolf (following several scientific developments from others in the preceding century), and it has revolutionized the way we store and preserve food. How do these important appliances work? Keep reading to learn more. The Best Way to Organize Your Fridge (and How to Keep It Organized) How Does a Refrigerator Work? In the refrigeration cycle, there are five basic components: refrigerant, which continually alters between a gaseous and a liquid state; a compressor; the condenser coils (on the outside of the fridge); the evaporator coils (on the inside of the fridge); and an expansion device, located between the condenser and evaporator coils. Here's how they interact to cool your food. 1. Refrigerant gas gets heated and pressurized. The compressor, a motor usually located at the bottom or back of your fridge, draws in refrigerant gas from inside the fridge, compresses it to increase the heat and pressure, then pushes it into the condenser coils. 2. The condenser coils turn the refrigerant into a liquid. As the hot gas flows through the condenser coils, it cools down, becoming a liquid. The heat from the gas is released into the surrounding air. (That's why the back of your fridge can feel warm.) 3. The expansion device lowers the pressure. The refrigerant liquid passes into the expansion device, a kind of valve that lowers its pressure dramatically. This pressure drop causes the liquid to expand, transforming it into a liquid/vapor state, and also has a cooling effect. 4. Refrigerant removes heat from inside the fridge. Now the cold, low-pressure refrigerant travels into the evaporator coils, where it absorbs warm air from inside the fridge, cooling down the space around your food. During the process, the refrigerant boils and evaporates, turning into a gas. 5. The refrigerant gas flows back into the compressor. And the cycle starts again! How Does a Freezer Work? Victoria Kotlyarchuk/Getty Images Freezers use the same technology as refrigerators, but they maintain a lower overall temperature. Freezers typically run at or below 0°F, while refrigerators typically run at 40°F. Fridges and freezers work better when they're well stocked. That's because the cold or frozen food items help maintain the cold temperatures and keep other items cool too. However, you shouldn't overfill either compartment—maintaining room for airflow is important to keep your machine running properly. Here's the Best Way to Store Food in the Freezer How Does a Fridge Water Dispenser Work? Your fridge is connected to your home's cold-water supply line. When you press the water dispenser's paddle or button, you activate a series of switches that open valves and allow water to flow through tubes inside the fridge and out the dispenser's spout. Some models include a filter, which removes particles and contaminants as the water passes through it, as well as a reservoir (a kind of tank, often behind the crisper drawers), which helps keep water cool. Frequently Asked Questions Why is my fridge not cold? Often there's a quick and easy fix, like reorganizing the food in the fridge so you don't block air vents, setting the thermostat to the right temperature, or cleaning the door gaskets so the doors seal properly. Dirty condenser coils (the ones on the outside of the fridge) are another common culprit. If they're blocked with grease or dust, they don't cool the refrigerant as effectively. Check your manual for the best way to clean them; you may need to do so every two or three months. You may also have a stuck or broken condenser fan, evaporator fan, or compressor, or you may need to move your fridge to a spot with better airflow around it. If you can't easily ID or solve the issue, call a pro! What happens to the fridge when the power goes out? The refrigeration cycle shuts down during a power outage (electricity drives the entire process, after all). Food starts to go bad if the fridge temp rises above 40°F, but the good news is that food should stay safe for up to four hours without power, according to the USDA, as long as you avoid opening the doors, which will cause cold air to escape and warm air to flow in. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit