Complete Guide: How To Turn A Fridge Into A Freezer

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Complete Guide: How To Turn A Fridge Into A Freezer

Can you turn a fridge into a freezer? Yes, you can, but it needs changes. It’s a DIY appliance conversion. It takes work and parts. A fridge works in the Refrigerator temperature range, usually above freezing. A freezer needs the freezer operating temperature, much colder. Modifying refrigerator thermostat control is key for this project. It is important to know that changing a fridge this way is not simple. It might cost more in the long run than buying a freezer. It can also cause problems with how well it works and how long it lasts.

Why Think About Making a Fridge a Freezer?

People sometimes want to change a fridge into a freezer. Why? Maybe they have an old fridge they don’t use much. They might need a freezer for extra food storage. Buying a new freezer costs money. They might think changing the fridge is cheaper.

Also, maybe they need a freezer of a certain size or shape. A fridge they have might fit the space better than a standard freezer you can buy. It could be a specific type of fridge, like a small dorm fridge or a specific under-counter model.

But it is important to know that changing a fridge is not like flipping a switch. It needs some work and some extra parts. It also changes how the fridge works. It can make it use more power.

How Coolers Keep Things Cold (A Simple Look)

To see if we can make a fridge a freezer, we first need to see how they work. They both use a system called the refrigeration cycle explanation. It’s like a loop.

Think of a special liquid or gas inside the pipes of the fridge. This is called refrigerant. This stuff moves heat from inside the fridge to outside the fridge.

Here is how it works simply:

1. Taking Heat Away: Inside the fridge, there are cold pipes (the evaporator). The liquid refrigerant goes into these pipes. It turns into a gas. When it turns into a gas, it takes heat from the air inside the fridge. This makes the inside cold.
2. Moving the Gas: A part called the compressor is like a pump. It pushes the refrigerant gas. This gas is now warm because it took heat from inside. The compressor squeezes this gas. This makes it even warmer and raises its pressure.
3. Letting Heat Go: The warm, high-pressure gas goes into pipes on the outside of the fridge (the condenser). Here, the gas cools down and turns back into a liquid. As it turns back to liquid, it lets go of the heat it picked up from inside. This heat goes out into the room. That’s why the back or side of a fridge feels warm.
4. Starting Again: The liquid refrigerant then goes through a small valve or tube. This drops its pressure. Now it is ready to go back inside, turn into a gas again, and pick up more heat.

This cycle repeats again and again. It keeps the inside of the fridge cold.

Why a Regular Fridge Is Different From a Freezer

A fridge and a freezer work the same way with the refrigeration cycle explanation. But they are built for different jobs. The main difference is the temperature they keep.

• Refrigerator temperature range: A normal fridge keeps food cold, but not frozen. The temperature is usually between 35°F and 40°F (1.7°C and 4°C). This range keeps food fresh for a while.
• Freezer operating temperature: A freezer keeps food frozen solid. This stops food from going bad for a very long time. The temperature needs to be 0°F (-18°C) or colder.

To keep things this much colder, freezers are made differently:

• Stronger Compressor: Freezers usually have a stronger compressor. This compressor is made to work harder and run longer. It needs to move more heat out to get the temperature down to 0°F and keep it there. A fridge compressor is built for a temperature range that is much warmer. It does not need to run as hard or as long.
• More Insulation: Freezers have thicker walls and doors. They have much more insulation inside. This adding insulation to appliance helps keep the super cold air in. It stops warm air from the room from getting in. This helps the freezer stay cold without the compressor running all the time. Fridge insulation is thinner because the temperature difference between inside and outside is not as big.
• Different Refrigerant (Sometimes): Some older freezers might use a different type of refrigerant than some fridges. The type of refrigerant affects how cold the system can get and how well it works at very low temperatures.
• Thermostat: The thermostat in a fridge is made to turn the compressor on and off to stay in the refrigerator temperature range. It cannot be set to keep the freezer operating temperature of 0°F or lower.

So, a standard fridge is not built to work like a freezer. Its parts are not strong enough for the much colder job.

Steps for Changing a Fridge into a Freezer

Changing a fridge into a freezer mainly involves getting the inside temperature much lower. The standard way people try this DIY appliance conversion is by using an external temperature controller. They usually do not change the compressor or the internal pipes because that is very hard and needs special skills and tools.

Here are the general steps and things to think about:

Checking Your Fridge First

Before you start, make sure the fridge you want to use works well as a fridge. Is the compressor running? Does it get cold inside? Is the door seal in good shape? A fridge that is already having trouble will not work for this project. It needs to be in good working order. Clean it out completely.

The Main Part: An External Temperature Controller

This is the most important part for modifying refrigerator thermostat function. You cannot use the fridge’s built-in temperature dial. It cannot make the fridge cold enough. An external temperature controller for custom freezer use is a separate device.

• How it Works: This device has a temperature sensor (a probe) that you put inside the fridge. You set the temperature you want on the controller (like 0°F or -18°C). You plug the fridge into the controller, and you plug the controller into the wall. The controller watches the temperature inside. When the inside gets too warm (above your setting), the controller turns the fridge’s power on. The fridge starts cooling. When the inside gets cold enough (at or below your setting), the controller turns the fridge’s power off.
• Why It’s Needed: This lets you tell the fridge to try and get much colder than its own thermostat allows. It fools the fridge into running more often and trying to reach a lower temperature.
• Setting It Up: The temperature controller for custom freezer projects often comes with simple instructions. You usually just hang the probe inside the fridge space. Make sure it is not touching the walls or any items that might be warmer or colder than the air. You plug the fridge cord into the controller’s outlet. Then plug the controller into the wall outlet.

Making It Colder: The Compressor’s Job

Here is where the big problem comes in. You are asking the fridge’s compressor to do a job it was not made for.

• Working Harder: To get the temperature down to 0°F (-18°C), the compressor has to work much harder and run for much longer times than it does when keeping things at 40°F (4°C).
• Is It Strong Enough?: Many fridge compressors are not built for this kind of hard, long-term work. They might get too hot. They might wear out very quickly. Trying to make a fridge work at the freezer operating temperature puts a lot of stress on the compressor.
• Limited by Design: The compressor, the pipes (evaporator and condenser), and the amount of refrigerant in a fridge are all sized to keep temperatures in the Refrigerator temperature range. They are not made to easily reach and hold true freezing temperatures in a large space.

You cannot easily change the compressor yourself. This needs special tools, knowledge about refrigeration gases, and is very dangerous. So, when doing this DIY appliance conversion, you are relying on the existing fridge compressor. This is the biggest gamble and reason why this project might fail or not work well.

Keeping the Cold In: Adding More Insulation

A fridge has some insulation, but not as much as a freezer. When the inside is 0°F (-18°C) and the room outside is 70°F (21°C), there is a very big temperature difference. Warm air will try much harder to get in.

• Why Add Insulation?: Adding insulation to appliance surfaces helps slow down the heat from getting inside. This means the compressor does not have to run as often to keep the temperature down. This saves energy. It also reduces how much frost builds up inside.
• Where to Add It: You can add insulation to the outside of the fridge. Think about the sides, the top, and the door. You could use sheets of foam insulation board. Cut the pieces to fit the sides, top, and door. You can tape them on using strong, wide tape. Be careful not to block the air vents or the compressor area at the bottom.
• Important Note: Do not add insulation inside the fridge. This can mess up the air flow. It can also be a problem with food safety if the material is not meant for being near food. When adding insulation to appliance exteriors, ensure it doesn’t trap heat around the compressor or condenser coils.

Adding insulation is part of trying to make an energy efficiency appliance modification. Without enough insulation, the converted fridge will likely use a lot more electricity than a real freezer.

Sealing the Door

A good door seal is very important for any cold appliance. For a freezer, it’s even more important. A bad seal lets warm, moist air leak into the cold space constantly.

• Checking the Seal: You can check the door seal by closing the door on a piece of paper. If you can easily pull the paper out, the seal might be bad in that spot.
• Fixing or Replacing: If the seal is bad, you might need to clean it well. If it is old and hard, you might need to replace it. This can be tricky depending on the fridge model. A good seal is key to keeping the freezer operating temperature steady and reducing frost.

Handling Frost and Water

Freezers are built to handle frost better than fridges. When warm, moist air gets into a very cold space, the water in the air freezes very fast. This makes frost or ice build up on the inside walls or the evaporator coils.

• Frost Buildup: A converted fridge might build up frost very quickly, especially if the door seal isn’t perfect or if you open the door often. Thick frost makes the appliance work much harder and use more power. It also takes up space.
• Defrosting: Most fridges are “auto-defrost” but work differently than auto-defrost freezers. Or they are manual defrost. You will likely need to defrost a converted fridge by hand more often than a real freezer. This means turning it off, letting the ice melt (make sure you have towels ready for the water!), and drying it out before turning it back on.

Putting It Together (Step-by-Step Guide)

Okay, if you want to try this DIY appliance conversion, here are the steps you would generally follow. Remember the warnings about risks!

Get What You Need

• A working fridge
• An external temperature controller for custom freezer use (make sure it can handle the power draw of the fridge’s compressor)
• Maybe some foam insulation boards and strong tape (optional but recommended)
• Tools: knife to cut foam, measuring tape, maybe a screwdriver.

Set Up the Temperature Controller

1. Read the instructions for your specific temperature controller.
2. Place the temperature probe inside the fridge space. Some have a suction cup, some clip onto a shelf wire. Put it in the air, away from walls or food.
3. Plug the fridge power cord into the outlet on the controller.
4. Plug the controller’s power cord into the wall outlet.

Add Insulation (If You Choose)

1. Measure the sides, top, and front of the door of the fridge.
2. Cut the foam insulation board to fit these areas. Make sure not to cover any vents, the compressor area at the bottom back, or where the door hinges or latches.
3. Use strong tape to stick the foam pieces onto the outside of the fridge. Seal the edges well with tape.

Check the Door Seal

1. Clean the door seal and the surface it touches on the fridge body.
2. Use the paper test all around the door. If the paper pulls out easily anywhere, try to fix the seal or consider replacing it if possible for your fridge model.

Set the Temperature and Wait

1. Set the desired temperature on your external temperature controller. Aim for 0°F (-18°C) for true freezing.
2. Close the fridge door.
3. Let the fridge run. It will take many hours, maybe even a full day, for the temperature inside to drop down to freezer operating temperature.
4. Check the temperature on the controller display after several hours and then after 24 hours to see if it is reaching and holding the target temperature.
5. Do not put a lot of warm food into it right away. This will make the temperature go up and could cause problems.

Monitor Performance

Keep an eye on the temperature inside. Check for fast frost buildup. Listen to how often and how long the compressor is running. If it seems to be running almost constantly, it might be too much for the compressor, or you need better insulation/seal.

Important Warnings and Things to Know

Making a DIY appliance conversion like turning a fridge into a freezer comes with significant risks and downsides. It is crucial to understand these before you start.

Is the Compressor Strong Enough?

This is the biggest question. As discussed, the compressor in a fridge is sized for a different job. Forcing it to work constantly at much colder temperatures can make it overheat and burn out. If the compressor breaks, the fridge is useless. Replacing a compressor is very expensive and not a job for most people. The likelihood of the compressor failing early is high with this modification.

Wasting Power

A converted fridge is very likely not an energy efficiency appliance modification. It will almost certainly use much more electricity than a standard freezer of the same size.

• Why it Uses More Power:
  • The compressor is less efficient at the lower temperature range it’s trying to work in.
  • It has to run more often and longer to keep the super-cold temperature.
  • The thinner insulation lets more heat leak in, making the compressor work harder to fight it.
• Cost Over Time: The extra cost on your electricity bill can quickly become more than the cost of buying a new, efficient freezer.

Food Might Spoil

If the modified fridge cannot consistently stay at or below the freezer operating temperature of 0°F (-18°C), your food is at risk. Temperatures that go up and down, or stay above freezing, can cause food to thaw partly and refreeze, harming its quality. Worse, if it stays above freezing for too long, bacteria can grow, making the food unsafe to eat. The external temperature controller helps, but if the fridge physically cannot reach or hold the temperature because of the compressor or insulation, your food is not safe.

Short Life for the Fridge

Putting this much stress on the fridge’s components, especially the compressor, will likely shorten its lifespan greatly. A fridge that might have lasted many more years could fail in a year or two after being converted.

Voiding Warranties

If your fridge is still under warranty, making this kind of change (modifying refrigerator thermostat control, adding insulation to appliance) will almost certainly cancel the warranty. If it breaks, you cannot get it fixed for free.

Safety First!

• Electrical Risk: Only use an external temperature controller designed for appliances. Do NOT try to change the internal wiring of the fridge itself. This is very dangerous and can cause electrical shocks or fires.
• Refrigerant: The gas inside the fridge is under pressure. It can be harmful if released. Never try to cut pipes or mess with the sealed cooling system.
• Stability: Make sure the appliance is stable and on a level surface. Adding external insulation might change its balance slightly.

Looking at Other Choices

Before you go ahead with turning a fridge into a freezer, think about these other options. They might be safer, work better, and save you money in the long run.

Buying a Real Freezer

This is often the simplest and best choice.

• Designed for the Job: A real freezer is built from the ground up to reach and hold freezer operating temperature. It has the right compressor, the right amount of refrigerant, and thick insulation.
• Energy Efficient: Modern freezers are much more energy efficient than trying to force a fridge to be a freezer. They use less power to keep food frozen. This saves you money on electricity bills over time. It is a true energy efficiency appliance modification from the start.
• Reliable: Freezers are made to run at freezing temperatures for many years. They are less likely to break down from the stress of the cold compared to a converted fridge.
• Proper Features: Real freezers have features like better door seals, ways to manage frost (auto-defrost or easier manual defrost), and inner baskets or shelves designed for frozen items.
• Cost: While a new freezer costs money upfront, prices for small or chest freezers can be quite low, especially during sales or if you buy used.

Thinking About Chest Freezers

Chest freezers are another type of freezer. They open from the top.

• Chest Freezer Conversion: Sometimes people talk about “chest freezer conversion,” but this usually means converting them for a different use, like making them into a cold storage unit for drinks (a kegerator or beverage cooler). This involves making them warmer than freezer temp, using a similar external controller method as described for a fridge. It is the opposite goal! Turning a chest freezer into a colder freezer is not usually the goal as they are already freezers.
• Benefits of Chest Freezers: They are often more energy efficient than upright freezers because the cold air doesn’t fall out when you open the door. They can often hold more food for their size. They tend to be very reliable.

Comparing a DIY fridge conversion to buying a chest freezer, the chest freezer is almost always the better option for long-term, reliable, and efficient frozen storage.

Energy Use: Converted Fridge vs. Real Freezer

Let’s talk more about energy efficiency appliance modification. When you convert a fridge, you are trying to make it work outside its design limits.

• Fridge Design: Fridges are designed to cycle on and off to keep a temperature around 38°F. The compressor runs maybe 30-50% of the time depending on how often the door is opened and the room temperature.
• Freezer Design: Freezers are designed to cycle on and off to keep a temperature around 0°F. They have thicker insulation and a compressor built for this lower temperature. They might run 40-60% of the time depending on use and room temperature, but they do it more efficiently at that temperature.
• Converted Fridge Reality: A converted fridge has a compressor working outside its ideal temperature range. It has thinner insulation than a freezer. This means the compressor will likely run much more often, maybe 70-90% of the time, or even constantly in a warm room. It is fighting hard to keep that very low temperature while letting a lot of heat leak in.

The result is often a big jump in electricity use. This negates any potential savings from not buying a freezer. It’s not a smart energy efficiency appliance modification. It’s usually the opposite.

Finishing Up: Is It Worth It?

So, can a fridge be converted to a freezer? Yes, using an external temperature controller for custom freezer settings and perhaps adding insulation to appliance exteriors can make the inside temperature drop below freezing.

But is it a good idea? For most people, no.

• Pros: Maybe you can use an old fridge you already have. It might fit a specific space better.
• Cons:
  • High risk of the fridge compressor failing quickly.
  • Much higher electricity bills compared to a real freezer (poor energy efficiency appliance modification).
  • Food safety concerns if the temperature is not kept steady at the freezer operating temperature.
  • Lots of frost buildup requiring frequent manual defrosting.
  • Voiding the fridge’s warranty.
  • The total cost over a few years (higher electricity, potential repair/replacement) is usually more than buying a new, efficient freezer.

While the DIY appliance conversion of modifying refrigerator thermostat control with an external unit is possible, the fundamental design differences between the Refrigerator temperature range and the freezer operating temperature mean a fridge is simply not built for the job.

Unless you have a very specific, temporary need and understand all the risks and potential extra costs (especially in electricity), buying a proper freezer, like a chest freezer conversion unit (meant as a freezer!) or an upright freezer, is almost always the more practical, reliable, cost-effective, and energy-efficient choice for long-term frozen storage.

Frequently Asked Questions (FAQ)

Q: Can a fridge really be converted to a freezer?
A: Yes, it is physically possible to make the inside temperature go below freezing using an external temperature controller, but it requires significant modifications and comes with risks.

Q: What temperature should a freezer be?
A: The standard freezer operating temperature is 0°F (-18°C) or colder to keep food safely frozen long-term.

Q: Will a converted fridge use more electricity than a real freezer?
A: Almost certainly yes. A converted fridge is not designed for the lower temperatures, making it far less energy efficient than a purpose-built freezer. This is not a good energy efficiency appliance modification.

Q: Is it safe for food?
A: Only if the converted fridge can consistently maintain the freezer operating temperature of 0°F (-18°C) or below. If the temperature goes up and down, food safety is at risk.

Q: What’s the hardest part about converting a fridge?
A: The main limitation and risk is the fridge’s compressor. It is not designed to run constantly at freezing temperatures and may fail quickly.

Q: What is the typical refrigerator temperature range?
A: A standard refrigerator usually keeps food between 35°F and 40°F (1.7°C and 4°C).

Q: Do I need to change the refrigerant?
A: No, this is highly technical, dangerous, and not part of the common DIY appliance conversion using an external controller. The existing refrigerant and system are used, which is why the compressor limit is a factor.

Q: How does adding insulation to appliance surfaces help?
A: Adding insulation helps keep the cold inside the converted fridge, reducing how hard the compressor has to work to maintain the freezer operating temperature, which can slightly improve energy efficiency.