What a cold plunge actually costs to run
Less than you think — a chiller cycles rather than running flat out. But there's a catch worth stating up front: nobody publishes the number you'd need to be exact.
Last verified · Ice & Cedar editorial
A half-horsepower-class chiller cycling around six hours a day costs roughly $20.62 a monthat the US average rate. That is an illustration of the archetype, not a product claim — because not one of the five chillers we compare publishes a rated wattage.
Why this page is vaguer than our sauna cost page, on purpose. The sauna page can be exact because heaters publish kW. Chillers do not publish watts — they publish horsepower, which describes the compressor motor rather than the power draw. We could convert HP to watts with a textbook factor and print a confident-looking per-product table. It would be a guess in a suit, and this site does not ship those. The numbers below model the class; the nameplate on the actual unit is the real answer.
Illustrative cost by chiller class
Assumes the compressor runs 6 hours a day at 18.83 cents per kWh. The wattages are typical for the class, notmanufacturer figures — there are none to cite.
| Class | Typical use | Assumed draw | kWh / month | Per month |
|---|---|---|---|---|
| 1/3 HP class | Small tub, holding temperature | 400W | 73 | $13.75 |
| 1/2 HP class | Typical 100-gallon setup | 600W | 109 | $20.62 |
| 1 HP class | Large tub, or fast pulldown | 1100W | 201 | $37.80 |
Assumed draws are illustrative of each compressor class and are not taken from any manufacturer’s published specification, because none of the units we compare publish one.
The tub decides the bill, not the chiller
This is the useful insight, and it inverts how most people shop.
A chiller does not run continuously. It runs when heat gets into your water, and then it stops. So your monthly cost is not really a property of the chiller at all — it is a property of how fast your tub gains heat. Volume and insulation set that, and the chiller just pays the bill.
Which means the cost-saving decision is made when you buy the tub, not the chiller. An insulated 88-gallon tub indoors will cost a fraction of an uninsulated 216-gallon tub in an August garage — with the identical chiller attached. Buy the smallest tub that actually fits you, and pay for insulation if it is offered.
Against ice
The comparison that actually matters. Ice is free to start and expensive forever: a recurring cost every session, plus a trip to buy it. A chiller is expensive once and then costs something like $20.62 a month.
The money argument favours the chiller within months for anyone plunging several times a week. The better argument is adherence: the errand is what stops people, not the temperature. A chiller removes the errand.
What to ask before you buy
Ask the seller for the nameplate wattage and the BTU rating. Wattage lets you compute your actual running cost with the arithmetic on this page; BTU tells you whether it can actually cool your volume. Only one of the chillers we compare publishes BTU, and none publish watts — so this is a question you have to ask rather than look up, which is itself worth knowing before you spend $900.
Frequently asked questions
How much does a cold plunge chiller cost to run per month?
For a half-horsepower-class chiller cycling around six hours a day, roughly $20.62 a month at the US average rate of 18.83 cents per kWh. Treat that as an illustration of the archetype, not a product specification — because not one of the five chillers we compare publishes a rated wattage, so nobody, including us, can compute an exact figure from the listings.
Why can't you give exact running costs per chiller?
Because the manufacturers do not publish rated wattage. Not one of the five chillers we compare states it, and horsepower is a description of the compressor motor, not a power draw. We could convert HP to watts with a textbook factor and print an authoritative-looking table, but it would be a guess wearing a suit. The wattage is on the unit's nameplate — ask the seller before you buy.
Is a chiller cheaper than buying ice?
Almost certainly, and quickly. Bagged ice is a recurring cost every session, forever, plus the errand of fetching it. A chiller is one purchase plus a modest monthly electricity cost. If you plunge several times a week the chiller wins on money within months — and it wins on adherence immediately, because the friction of buying ice is what stops most people.
What actually drives a chiller's running cost?
Three things, in order: how much water you are cooling, how well the tub is insulated, and how warm the space is. The chiller only works when heat gets into the water — so an insulated 88-gallon tub indoors costs a fraction of an uninsulated 216-gallon tub in a hot garage. The chiller you pick matters less than the tub you pair it with.
Does the chiller run all the time?
No — it cycles. It works when the water drifts above your set point and idles otherwise, which is why the running cost is so much lower than the compressor rating suggests. In an insulated tub in a cool room it may run very little. In August in an uninsulated tub, it may run nearly continuously, which is the scenario where these numbers go badly wrong.
Does a colder set point cost more?
Yes, for a straightforward reason: the bigger the gap between your water and the room, the faster heat flows in, and the more the chiller works to remove it. Holding 38°F in a warm garage is materially more expensive than holding 55°F — which is one more argument for the published guidance, since 50-59°F is both the recommended beginner range and the cheaper one.
Related
Sources
- U.S. Energy Information Administration — Electric Power Monthly, Table 5.6.A — US average residential price, April 2026 (released 2026-06-25). Your utility rate is the number that matters — override the default. US average 18.83 cents/kWh. (accessed 2026-07-16)
- Manufacturer listings for all five chillers (Amazon detail pages) — Read 2026-07-16. Basis for the statement that none publish a rated wattage and only one publishes a BTU figure. (accessed 2026-07-16)