A chiller is a small refrigeration unit, so it hums, and unlike a dishwasher, it may run at any time of day to hold the water cold. Where it sits, and how loud it is, decides whether you notice it.
This article explains how to read chiller noise ratings. For the rest of the cold plunge decisions, start with the cold plunge buying guide.
Short answer: a published 58 dB rating at about 3 feet sounds like a running dishwasher up close. Put the chiller away from bedrooms and shared walls, and ask for a rating if the brand doesn’t publish one.
What the numbers mean
| Sound | Level |
|---|---|
| Normal conversation, dishwashers | 60 dB |
| Renu Cold Stoic 2.0 and Vero chillers (about 3 ft) | 58 dB |
| Moderate rainfall | 50 dB |
| Quiet library | 40 dB |
Everyday sound levels from the American Academy of Audiology; chiller ratings from Renu Therapy’s listings.
Decibels are logarithmic, so a few dB makes a noticeable difference. Distance helps too: the further you are from the chiller, the quieter it sounds.
Which tubs publish a rating
Renu publishes 58 dB at about 3 feet for the Cold Stoic 2.0 and the Vero. Many other listings we checked, including The Plunge Original and the Nordic Wave Viking Premier, don’t publish a noise rating.
Here’s what the spec sheet won’t tell you: a rating without a distance can’t be compared with one that has it. Ask for both.
Placement tips
- Keep the chiller away from bedroom windows and shared walls.
- Give it airflow; chillers shed heat and may run more if boxed in.
- Outdoors near a property line, check local noise rules for equipment that runs at night.
- Indoors, a garage or utility area is better than a living space.
My rule of thumb: if the tub will sit within a few feet of where people sleep, pick a model with a published rating.
What each chiller publishes
| Cold plunge | Chiller size | Noise rating |
|---|---|---|
| Renu Cold Stoic 2.0 | 0.25 HP | 58 dB at about 3 ft |
| Renu Vero | 0.8 HP | 58 dB at 3 ft |
| Renu Cold Stoic 3.0 | 0.5 HP | Not stated in our data |
| Renu Siberian Pro | 0.8 HP | Not stated in our data |
| Nurecover Plunge + Chiller | 0.3 HP | Not stated in our data |
| Plunge Original | Not stated | No figure; maker describes its Gen 2 chiller as quieter |
| Nordic Wave Viking Premier | Not stated | Not stated in our data |
From manufacturer listings, checked September 2026.
Run the numbers on the two that publish. The Vero’s chiller is rated at more than three times the horsepower of the Cold Stoic 2.0’s, and both list 58 dB. So a bigger chiller isn’t automatically a louder one. You can’t guess the noise from the size.
“Quieter” without a number, as on the Plunge listing, tells you the direction and nothing else. Ask what it was measured against.
How long it runs matters as much
A chiller only makes noise while the compressor is on. Two things shorten that time.
Insulation. Renu lists 4 inches of foam on the Cold Stoic tubs. A well-insulated tub gains heat slowly, so the chiller cycles on less often.
The lid. An open tub warms from the air and the sun. Keeping the cover on between sessions means fewer and shorter cycles, including at night.
A separate chiller gives you options
The Vero ships as two modules, a tub and a chiller. That may let you put the chiller a little further from where you sit or sleep. Ask Renu how long the connecting hoses are before you plan on it.
Ask before you buy
- The decibel figure, and the distance it was measured at.
- Whether that is with the compressor running.
- Whether the chiller can sit apart from the tub, and how far.
To compare chiller tubs side by side, see our cold plunge comparison.
Bottom line: a 58 dB chiller is about dishwasher-loud up close. Placement matters more than a few decibels either way.
Sources
- American Academy of Audiology, “Levels of Noise in Decibels (dB),” September 2023: audiology.org
- Chiller noise ratings: Renu Therapy listings for the Cold Stoic 2.0 and Vero, checked September 2026