Experts forecast very warm summer temperatures of nearly 40°C. But that doesn’t mean you have to give up the cold. With the right setup, you can enjoy a cold plunge at 1.6°C. How exactly? Inside a freezer!
Every ice swimmer knows this: you look forward to winter so that you can finally go ice swimming again. But with a little preparation, cold plunging also works in the warmer months! In this article, I’ll show you how you can enjoy the benefits of cold plunging to the full all year round.
Table of Contents
Why a Freezer Instead of a Cold Shower?
True cold plungers want water that’s really cold – not just a quick cold shower. If you don’t live by a mountain stream, your options include:
- Waiting for winter
- Taking cold showers
- Filling a tub or barrel with ice cubes
- Installing a professional cooling system
- Converting a chest freezer
Waiting until winter to take a cold shower is not a very good idea, making ice cubes for 200 liters of water isn’t practical, and professional systems can be expensive. That’s why preparing your own freezer is often the easiest and most cost-effective option.
How Does a Freezer Work?
Most households have one: either a freezer compartment is built into the fridge or, if you need more space, as a separate appliance, which is usually located in the cellar or garage. The functionality of chest freezers varies slightly depending on the manufacturer and model. Here’s the basic cycle:
- The gas cycles back to the compressor, and the process repeats.
- The compressor compresses refrigerant gas, raising its pressure.
- The gas moves into the condenser coils at the back, where heat is released and the gas condenses into liquid.
- The liquid enters the evaporator inside the freezer, absorbing heat and turning back into gas.
The gaseous refrigerant is then recirculated back into the compressor, and the process starts all over again.
This recurring cycle continuously removes heat from the interior of the freezer, and after a while, the freezer reaches icy conditions.
Which Sizes Are Most Suitable?
Select a freezer that’s compact but large enough for you to submerge comfortably. An oversized freezer takes significantly longer to cool, while an undersized one may not fit your body properly. A smaller chest freezer not only saves space but is also more energy-efficient and can cool down the amount of water more quickly. Of course, the most important thing is that you fit in well, but you don’t have to be able to stretch your legs out completely or lie down in it.
My freezer has the following dimensions:
Inner length: 92 cm
Inner depth: 65 cm
At 1.83 m tall, this is just enough for me, because the compressor also takes up space. That means I can’t sit on it, otherwise I’ll be too high up and my shoulders won’t be covered with water.
How Many Liters Do You Need?
I have invested in a second-hand Hanseatic freezer. It’s quite small, but at 1.83 meters tall, I fit in so that I’m completely covered in water. The freezer has a volume of 250 liters, but I only need about 150 liters because my body fills the rest.
The energy consumption was not really decisive for me, as the chest runs for a maximum of 2-3 hours a day and usually only when the sun is shining.
Bottom line: A smaller volume means faster cooling and lower energy use.
How to Prepare Your Freezer for Cold Plunging?
In principle, it’s super simple. Here’s what I did to make your freezer watertight:
You need commercially available sanitary silicone. I used transparent silicone so that you can’t see the joints clearly, and also paid attention to the quality (just bought the most expensive :-) ) as I didn’t want to risk water leaking out.
You also need a little soapy water to smooth out the silicone and a kitchen roll to wipe away the excess silicone.
If your chest has a drain, secure the plug with silicone tape and a seal. I didn’t do this the first time I tried it, and it leaked all the time.
And then it’s time to grout. Simply apply a good strip of silicone wherever you see a gap and then smooth it out with your finger. Then go over it with soapy water.
Wrap silicone tape around the (plastic) thread of the plug and put the seal on it. The whole thing is ready! Then leave to dry overnight and fill with water the next day.
Nothing should drip out through your joints. When the floor around the chest is dry and the water level remains the same, you can insert the plug and cool your chest.
Pro tip: If possible, leave plugs in, as it should be possible to drain the water from time to time. If this is not possible, you would have to pump it out or laboriously remove it with another container. I have already seen some prepared freezers where the stopper has been glued shut.
And this is what the freezer filled with water looks like – the water stays inside and just needs to be cooled.
What the Final Setup Looks Like
This is how ice bathing works in a small but sufficiently large freezer. And it gets really cold, too! You can make the freezer as cold as you like – if you leave the freezer running all the time, you’ll end up with a block of ice. In my case, the water cooled down to 1.6 °C.
Safety Precautions
- Always unplug the freezer completely before entering. Water and electricity don’t mix.
- Never touch the water while the freezer is still powered.
- Check seals regularly to prevent leaks.
Cooling Time
For my 150-liter setup, water reached 1.6 °C in about 12 hours. To hit a comfortable 4–5 °C, it takes far less time. On average, expect a drop of 1–2 °C per hour.
Costs and Energy Consumption
Here’s what I spent:
- Second-hand freezer: €80
- Transport: €30
- Silicone & seals: €10
- Total setup cost: ~€120
Power use is modest:
The freezer scores highly in terms of power consumption, as the system is designed to cool as efficiently as possible. The cooled water remains in an insulated container, which is why there is little loss of efficiency. A normal chest freezer consumes between 100 and 300 watts of electricity, depending on the size and model.
Due to its small dimensions, my chest freezer uses around 120 watts, which makes it perfect for use with my balcony power system.
As for energy consumption, the manufacturer’s specification is 0.53 kWh per 24h.
As the freezer has to run for a maximum of 12 hours to really cool down properly, the requirement would only be 50% of the specified 0.53 kWh, i.e., 0.26 kWh * 0.4 EUR = approx. 11 cents per cold plunge.
If powered by solar or balcony panels, the cost drops even further.
I also take the opportunity to draw water for the freezer from my rainwater barrel, which saves water. That’s my way of going green.
Alternatives to the Freezer?
Professional systems with flow-through coolers can chill water from 20 °C to 4 °C in just 3–4 hours. They’re faster, but:
- Require pumping systems that add complexity
- More expensive
- Less energy-efficient
Conclusion
A freezer is one of the simplest, most affordable ways to enjoy ice bathing at home year-round. Its advantages include:
- You can control the temperature of the water fairly precisely, and even as a beginner, you can easily get used to the cold and gradually increase the temperature.
- Low purchase costs (a new freezer starts at around 300 euros)
- Easy maintenance
- Dual use for cold storage when needed
The disadvantage of a freezer is that it is naturally designed for cooling drinks and food. If you prepare and use it for ice baths, you will probably lose the legal guarantee, which is quite annoying if the freezer gives up the ghost prematurely.
The main drawbacks are slower cooling times and loss of the manufacturer’s warranty. And remember – always unplug the freezer before use to avoid electrical hazards.
With the right precautions, a freezer cold plunge is a practical and powerful way to bring cold therapy into your daily routine.
