Quick answer: An ice bath chiller works like a small fridge for your water. A pump pulls water out of the tub, pushes it through a filter and past a cold coil, then sends it back in. A refrigerant inside the chiller carries the heat away and lets it out through a fan. A thermostat holds the temperature you set.
What does an ice bath chiller actually do?
A chiller keeps your ice bath at the temperature you choose. You set a number, and the chiller works to hold it there.
Without a chiller, you need to buy bags of ice every time you plunge. The water also warms up over time, so the next session is never quite the same.
A chiller does three jobs in one box:
- Cools the water (and on our models, it can warm it too).
- Moves the water around with a built-in pump.
- Cleans the water with a filter and an ozone system.
How does a chiller make water cold?
This is the fun part. A chiller does not "make cold". It moves heat out of your water and dumps it into the air.
It uses the same idea as your fridge or a heat pump at home. Inside the chiller is a special liquid called a refrigerant. It goes round and round in a closed loop. Here is the loop in simple steps:
- Soak up heat. At low pressure, the refrigerant is very cold. Your ice bath water flows past it. The refrigerant soaks up heat from the water and turns into a gas.
- Squeeze it. A compressor squeezes that gas. Squeezing a gas makes it hot.
- Let the heat go. The hot gas goes through a coil with a fan. The fan blows the heat out into the air. As it cools, the refrigerant turns back into a liquid.
- Start again. The liquid drops back to low pressure, gets cold again, and goes back to soak up more heat.
Energy Star describes heat pumps the same way: low pressure lets the refrigerant absorb heat, and high pressure lets it release heat. That is why the back of a chiller blows warm air. It is your water's heat leaving.
Many chillers can also run this loop in reverse. That lets them warm the water instead. Our Storm Plus Chiller and Blizzard Chiller can both be set anywhere from 3 to 40°C.
How does the water get from the tub to the chiller?
Two hoses join the chiller to the ice bath. One takes water out. One brings it back.
- Chiller outlet goes to the ice bath inlet.
- Ice bath outlet goes to the chiller inlet.
A pump inside the chiller keeps the water moving. Our chillers come with hoses of about 80 cm and quick connectors, so setup takes a few minutes and needs no tools.
Keep the hoses short. We recommend no more than 1.5 m between the chiller and the tub. Longer hoses slow the pump down and make the chiller work harder.
How does a chiller keep the water clean?
Cold water stays fresh longer than warm water, but it still needs looking after. A chiller helps in two ways.
1. A filter. All the water passes through a filter cartridge on its way round. This catches hair, leaves, skin flakes and other bits.
2. Ozone. Ozone is a form of oxygen. The US EPA explains that ozone cleans water by oxidation, which breaks down the outer wall of bacteria. Ozone is unstable, so it is made on the spot and soon turns back into normal oxygen.
A few simple rules for the ozone system on our chillers:
- Run it for about two hours a day, depending on how much you use the bath.
- By default it switches off after one hour. You can change this in the settings.
- Do not get in the ice bath while ozone is running.
With a filter and ozone working together, many people only change their water every few months.
What size chiller do I need, and what power does it use?
Size depends on how much water you have. Our Storm Plus and Blizzard chillers suit tubs from 300 to 1,000 litres. They change temperature fastest with 300 to 500 litres.
Both plug into a standard 10 amp household socket. No special wiring is needed for the chiller itself. Both can be left on 24/7, so the water is ready when you are.
Things that make a chiller work harder:
- A hot day or full sun on the tub.
- Leaving the lid off. A good insulated lid keeps the cold in.
- Very large tubs or very cold set temperatures.
- Long hoses.
Can a chiller go outside?
Yes. Our chillers have an IPX4 rating, which means they handle splashing water. They are fine indoors or outdoors.
For outdoor setups, we recommend adding the Outdoor Chiller Protective Case. It keeps the chiller looking good for years in Canterbury weather.
Two other tips:
- Give it space to breathe. The fan needs fresh air to push the heat out.
- Expect a small drip. A little condensation runs out the back. Connect the supplied hose so it drains to the drip tray.
Storm Plus or Blizzard: what is the difference?
Both chillers use the same cooling idea, filter and ozone system. The main differences are:
- Storm Plus: push-button controls. Measures 700L*450D*474H mm.
- Blizzard: smaller at 465L*472D*500H mm, with a touch screen, a self-check system, and WiFi app control. You can set the temperature and start times from your phone. It also has a little more cooling and heating power.
Is an ice bath safe for everyone?
Cold water is a big shock to the body. Researchers at the University of Portsmouth explain that the first moments in cold water can cause gasping and fast breathing. This "cold shock" is strongest in the first 30 seconds.
Their advice includes getting in slowly, not jumping or diving in, and having someone nearby. If you have a health condition, are pregnant, or take medication, check with your GP before you start using an ice bath.
Key takeaways
- A chiller moves heat out of your water using a refrigerant, a compressor and a fan, just like a fridge.
- A pump and two short hoses (1.5 m max) keep water flowing between the tub and chiller.
- A filter plus ozone keeps water clean, so changes are needed far less often. Never plunge while ozone runs.
- Our chillers suit 300 to 1,000 litre tubs, plug into a normal 10 amp socket, and can be set from 3 to 40°C.
- Get in slowly, and check with your GP first if you have a health condition.
Frequently asked questions
Do I still need ice if I have a chiller?
No. The chiller cools the water for you, so there is no need to buy bags of ice.
Can I leave my ice bath chiller on all the time?
Yes. Our Storm Plus and Blizzard chillers are designed to be left on 24/7 so your water is always ready.
Why does my chiller blow warm air?
That warm air is the heat taken out of your water. The fan pushes it out so the refrigerant can cool down and collect more heat.
How often should I change the water?
With the filter and ozone running, many people only change the water every few months. Change it sooner if it looks or smells off.
Can I use the ice bath while the ozone is on?
No. Wait until the ozone cycle has finished before you get in.
Does a chiller need an electrician?
No. Our chillers plug into a standard 10 amp household socket.
Ready to make cold plunging easy? Have a look at our ice bath and chiller bundles, or read our guide to the best temperature for ice bathing. Got a question? Call us on 03 662 9381 or email info@healthhq.co.nz. We are always happy to help.
Sources: Energy Star, "How Does a Heat Pump Work?"; US EPA, Wastewater Technology Fact Sheet: Ozone Disinfection (1999); Tipton M, Massey H, Mayhew A, Morgan P, "Cold water therapies: minimising risks", University of Portsmouth; HealthHQ Storm Plus Chiller specifications; HealthHQ Blizzard Chiller specifications.
