Converting a freezer into a high efficiency fridge is a relatively cheap and simple DIY project.
All you need is a standalone freezer (chest freezer or upright freezer) and a new refrigerator thermostat. The freezer can be old or new. And new refrigerator thermostats can be purchased online for around $30 or less.
Please Note: we do not sell or support this upgrade. The following guide is provided as a free online resource by Reduction Revolution.
These are the components found in a typical refrigerator thermostat kit.
Convert a Freezer Into a Fridge for Massive Energy Savings
I've converted both a small and large freezer into energy efficient refrigerators using this simple thermostat retrofit method.
I achieved the best results converting a brand new ~100 litre ALDI upright freezer into a drinks fridge. Electricity consumption for this fridge (after the conversion) stabilised at just over 50 Wh per day. That's about $5 per year in electricity costs.
At the other end of the spectrum, I converted a relatively large ~20 year old upright freezer into a refrigerator. The results were still fairly impressive, with usage averaging around 250 Wh per day. This is still about 75% less energy than a regular upright fridge or fridge / freezer combination.
See Also: How Much Power Does a Fridge Use?
Here's a review from a past customer who completed an upgrade using the guide on this page:
The thermostat is going great! It turned a chest freezer into a beer fridge, and life hasn't been better. It was relatively easy to install (having never done anything of the sort before), and it's keeping everything lovely and cold, even at the lowest setting. I will definitely recommend your product to the envious friends of mine who are looking at creating their own beer fridge. - David R.
Freezer to Fridge - How & Why Does It Work?
The reason this upgrade works so well is simple: insulation.
Have a look at your refrigerator at home, and then look at the freezer compartment. You will notice that the insulation thickness for the freezer is about twice that of the fridge.
When you raise the temperature inside a freezer to that of a refrigerator, the compressor hardly needs to do any work to keep the contents cold. In fact, once you have converted your freezer into a fridge you will notice that the compressor only switches on for a few minutes each hour. Compare that to a regular fridge where the compressor might be on for around 20 to 30 minutes per hour.
For best results, convert a chest freezer into a chest refrigerator. Cold air sinks, so each time you open a 'chest refrigerator' virtually no chilled air is lost.
Freezer to Fridge Conversion - Installation Guide
WARNING: Converting a freezer into a fridge involves working with the electrical wiring of the thermostat. In practical terms all you need to do is unplug the old thermostat and plug in and mount the new one (no actual wiring, crimping or soldering is required). However, if you are not confident in completing this upgrade you should seek the assistance of a qualified tradesperson.
STEP 1) Turn off the freezer at the wall and un-plug the power cord.
STEP 2) Locate the thermostat housing. Take note of how the existing thermostat is wired. Remove it and slowly pull the capillary tube wire out of the freezer.
An example of where to find the existing thermostat on you freezer.
STEP 3) Carefully unravel the new thermostat’s capillary tube (silver wire) and insert as much as possible into the freezer through the same slot that you just removed the old one. Be careful not to bend or kink the wire – it's fragile.
STEP 4) Plug the cables onto the new thermostat’s connectors as noted in Step 2. The picture below shows a typical installation of a newly plugged in refrigerator thermostat.
The thermostat is basically a switch between the power outlet and the compressor. For this reason it does not matter if the ‘Active’ and ‘To Compressor’ wires are reversed, the thermostat will still work. It is important that the earth cable (typically yellow or green) is wired to the metal thermostat housing as shown.
Three key connectors found on regular fridge thermostats.
STEP 5) Re-install the new thermostat in the old housing and add the adjustment dial back on. Place the adjustment dial at its mid point for a temperature of about 4 degrees. If your freezer has a ‘Fast Freeze’ switch make sure you turn it off.
STEP 6) Turn the power back on - you now have a very energy efficient refrigerator!
Now it's time to check the performance of you refrigerator:
- Use a plug-in power meter to measure the fridges power usage.
- Use a thermometer to check the temperature.
Freezers Into Fridges - What Can They Be Used For?
Your converted freezer can be used as a regular refrigerator. It's not the same as one that you buy from the shop because it still has the freezer coils and other physical limitations inside.
Another limitation can be extra condensation compared to a regular refrigerator. For example, both the upright freezers I converted produced some condensation inside. This was 'okay' as they were only being used as drinks fridges.
Here are some typical uses of freezer to fridge conversions:
- Households for regular, wine or drinks fridges.
- Small business owners (eg. shops and restaurants) looking to slash costs. Probably best for non-customer-facing cold storage.
- Home brewers for beer fridges (aka a beer 'kegerator').
How to Check Your Energy Savings
Once done, you're probably going to want to check if it worked out. Or maybe you just want to check your current refrigerator's power usage to see if this idea is even worth pursuing.
For some 'before and after' testing I'd highly recommend the use of a simple plug-in power meter. I'd also use a thermometer to check your new set-point temperatures are working as expected.
Plug-in power meters to measure electricity usage.
Other Smart Ways to Save Energy
I hope you can make use of this free guide. But if it all looks a bit complicated, don't worry, there are far easier ways to save energy around your home! These include:
- Upgrade all your lighting to LED.
- Use quiet portable fans and DC ceiling fans to keep cool in summer.
- Install an electricity monitor to track your power usage.
- Switch to energy efficient cooking methods.
- Eliminate your standby power usage.
