Renu Cold Plunge Review: Renu Therapy Publishes Its Tank Dimensions, So We Checked Them

What Renu Therapy actually sells

Five models, not variations on one tub. Cold Stoic 3.0 is the flagship sit up plunge, 0.5 HP, 37 F to 104 F, so it heats as well as chills. Cold Stoic 2.0 is the same shell with a 0.25 HP chiller, cold only. Aurelius is the laydown. Vero is the upright for small spaces, 0.8 HP but the thinnest insulation here. Siberian Pro is the big one, 650 lbs dry, 120 gallons, 0.8 HP, wood body.

One correction first. Renu has a reputation for stainless and hardwood, and that is not the current range. Renu’s own warranty document splits the line into “plastic tubs” and “wood body tubs”. The redwood, cedar, composite and granite names are decking and finish choices on a plastic shell. Only the Siberian family is wood bodied.

The arithmetic, which is the point of this review

Most brands publish only the cabinet’s outside, so a capacity claim is uncheckable. Renu publishes the tank. Length times width times depth, divided by 231, gives brim gallons.

Cold Stoic 3.0 and 2.0. 40 by 25 by 31 inches is 31,000 cubic inches, or 134.2 gallons. Renu states 134 maximum. That is not a rounded guess, that is the measurement. The 95 gallon fill means about 21.9 inches of water in a 31 inch tank, leaving nine inches for your body to displace into.

Siberian Pro. 48 by 24 by 30 is 34,560 cubic inches, or 149.6 gallons. Renu’s specification sheet says 150 total. Again, the measurement.

Aurelius. 62.5 by 26.75 by 26 gives 188.2 brim gallons, filled to 95. That is about 13 inches of water in a 26 inch tank, which is what a laydown tub needs.

Vero is the exception, and it is a large one. The product page lists the interior at 30 by 18 by 20 inches. That is 10,800 cubic inches, or 46.8 gallons filled to the absolute brim. The same page says the tub holds 95 gallons. Those cannot both be right, and they are separated by about half the water. Either the interior dimensions describe something other than the tank, or the capacity was carried over from another model. We are not guessing which. We are saying that if you are comparing the Vero to a Cold Stoic because both read 95 gallons, confirm it first.

Two smaller wobbles. The Siberian Pro lists 650 lbs dry and 120 gallons, which at 8.34 lbs per gallon is about 1,651 lbs filled. The page says approximately 1,500, matching roughly 102 gallons rather than 120. If you are loading a deck, plan for the larger number. And the Aurelius filled weight implies water at about 8.09 lbs per gallon, which is light. The Cold Stoic pages use a correct figure.

The chiller is small, and Renu says so

Divide gallons by horsepower. Cold Stoic 2.0: 380 gallons per HP. Cold Stoic 3.0 and Aurelius: 190. Siberian Pro: 150. Vero: 119 on its stated capacity. So the least expensive tub has the most chiller per gallon, and the flagship has half a horsepower moving 95 gallons.

The consequence is in Renu’s own FAQ: around 1 to 2 degrees per hour of cooling, and 12 to 24 hours to reach a target from ambient. One published hands on review reported about an hour to shift a single degree. Credit where it is due, a brand that prints the unflattering number is one you can trust on the flattering ones. Several competitors here claim ten degrees an hour on similar horsepower.

So a Renu is not a tub you cool down before a session. It runs at temperature continuously, and our chiller sizing guide explains why insulation matters more than horsepower once you work that way. Four inches of foam is doing real work.

What it costs to run

Renu publishes watts and amps, which puts it ahead of most of this price band. Cold Stoic 3.0: 518 watts cooling, 1,013 watts heating. Cold Stoic 2.0: 450 watts. Siberian Pro: 350 to 500.

At 518 watts, an hour of compressor time is about 0.52 kWh. Six hours of run a day is roughly 3.1 kWh, so about 93 kWh a month. That is a calculation from Renu’s figure and an assumed duty cycle, not a measurement, and the duty cycle is set by ambient temperature. Our running cost breakdown covers why a garage in August behaves nothing like a basement in October.

One conflict worth flagging: the Vero product page says 1,080 watts cooling, the specification sheet says 580. That is also the Vero’s filled weight on the same page, so it looks like a copy error.

The warranty headline and the warranty document

“5-Year Limited Warranty” sits on the product pages. The home use warranty document says five years covers the plastic tub body on the Cold Stoic 2.0 and 3.0, Vero and Aurelius, while the chiller is covered for one year from delivery. The wood bodied Siberian and Siberian Pro get one year on the body too, so the most expensive tub has the shortest coverage.

The chiller extension adds four years but must be purchased within 364 days of shipment. Write that deadline down, because it falls inside the period when nothing has gone wrong yet.

Three more terms. Warranty labour is reimbursed at a set hourly rate for a maximum of two hours, below what a refrigeration technician charges, so a service call is likely to cost you something. The buyer pays shipping on parts and travel fees in rural areas. Cover applies only to the original purchaser, so a second hand Renu carries nothing.

Exclusions include water leaks, poor water chemistry, neglected filter maintenance, freezing, power outages and low water flow. Filters need changing every two to six weeks per the FAQ. Read that list next to the maintenance schedule and you can see how a claim gets declined.

Commercial use voids the warranty entirely, while Renu’s shipping copy offers delivery to your home or business. If this is for a gym, ask which document applies before you pay.

Getting it to your house

Lead time is four to six weeks on the Cold Stoic 2.0, 3.0 and Siberian Pro, six to eight on the Vero and Aurelius. Delivery is free curbside inside the contiguous 48, which means a crate on your kerb, and the Siberian Pro is 650 lbs dry.

Returns run 45 days with a 5 percent restocking fee, better than several rivals. But you pay return freight, carry the transit risk, and Renu does not publish that cost. Sale items are final.

Renu also specifies 27 inches of clearance at the large vent and 15 at the small one. On a 70 inch tub the space you need runs over eight feet. Measure first.

Cheaper ways to the same water

If the wood is what you want, a two person red cedar tub with a 1 HP chiller included sits two price bands below the Cold Stoic 3.0 and puts twice the horsepower on more water. You give up the cabinet, the app and the finish.

If you liked the Vero for floor space, an upright resin tub around 100 gallons with a built in seat and step costs a fraction of it, and you add a chiller separately.

If you want to match the flagship’s refrigeration, a half horsepower drop in chiller rated to 150 gallons is the same class of hardware as the one inside the Cold Stoic 3.0. Our chiller comparison covers what to check.

Our verdict

Renu Therapy is one of the few brands here that lets you audit it, and on the Cold Stoic and Siberian Pro tanks it passes cleanly. It publishes wattage and a slow cooling rate when it could have published neither. That is rare in a category built on invented gallons.

The gaps are on paper. A five year headline over a one year compressor. A wood bodied flagship with one year on everything. A commercial exclusion that contradicts the delivery copy. A Vero capacity figure that cannot be true.

Buy one if the tub is going in a home, if you treat year one as the window for any fault to appear, and if you buy the chiller extension well before the 364 day deadline. If you are still weighing options, the tub comparison has choices where the warranty and the horsepower line up more easily.