A cold plunge may look straightforward: a tub, cold water and a place to sit or recline. The installation also has to account for filling, drainage, cooling equipment, power and service access.
Cold plunge plumbing requirements vary by system. Some residential cold plunges are designed to be filled and drained without permanent household plumbing. Others use dedicated drain fittings and separate connections between the tub and chiller.14
At My Sauna Plus, we recommend planning the cold plunge as part of the overall sauna environment before the space is finished. The tub itself is only one piece of the installation.
Does a Cold Plunge Need Permanent Plumbing?
Not necessarily.
For example, Icetubs describes its IceBath as a system that can be filled with fresh water and connected to its cooling engine using the supplied connectors. This type of installation does not depend on a permanent household water-supply connection.4
Other systems are configured differently. The SaunaLife Model S2 has a dedicated 1-inch drainage connection and 3/4-inch NPT chiller connections. Its installation instructions direct the installer to connect the pipes before filling the tub.12
That distinction matters.
The plumbing that moves water between a tub and its chiller is not necessarily the same thing as permanently plumbing the cold plunge into the building's water supply.
Before construction is finalized, establish three separate things:
- How will the plunge be filled?
- How will the plunge be completely drained?
- How will water circulate between the tub and its cooling or filtration equipment?
Those answers should come from the installation requirements of the cold plunge you are actually considering.
Plan the Tub Drain-Down Before You Choose the Final Location
A floor drain should not automatically be added to a cold plunge plan simply because the room contains a plunge.
Some systems can be drained through a hose. Others provide a dedicated drain connection.14
Where will the water go when you need to empty the tub?
Think through a complete drain-down, not just everyday splash.
If draining the plunge would require running a hose through a finished living area, moving equipment each time or discharging water somewhere unsuitable, the location may be less practical than it first appears.
Leave Space for the Chiller, Pump and Service Access
Planning around the tub dimensions alone can leave too little room for the equipment that circulates and cools the water.
An externally chilled plunge also needs room for the equipment that moves, filters and cools the water.
That equipment may need:
- clear space for airflow
- access for filter service
- room to reach valves and fittings
- suitable hose routing
- a level and stable surface
- access if the equipment later needs repair or replacement
Those requirements are model-specific.
The IceBath installation guide treats the cooling unit as a planned part of the layout. It calls for a well-ventilated environment and requires the cooling-unit connections to align correctly with the tub.3 The guide does not establish a universal clearance dimension, so the space around another chiller should come from that unit's own installation instructions.
Connection alignment can matter as well. For the IceBath, the installation guide directs the installer to align the cooling unit's inlet and outlet with the tub connections and adjust the tub's leveling feet until the installation is stable.3
Follow the selected system's connection layout rather than assuming the cooling unit can be placed wherever it is most convenient.
Plan Electrical Service Before the Space Is Finished
Electrical requirements should be treated the same way as plumbing requirements: verify the actual equipment rather than assuming that all cold plunges use the same setup.
For example, the current IceBath installation guide requires its cooling unit to be connected to a grounded outlet.3 The exact voltage, current, receptacle and protection requirements still need to come from the documentation for the product supplied in that market.
That includes the required voltage, current, receptacle arrangement, grounding and electrical protection specified by the equipment manufacturer and applicable local electrical rules.
For U.S. projects, Consumer Product Safety Commission guidance for pools, hot tubs and spas calls for qualified electrical work in accordance with applicable codes and GFCI protection for electrical equipment used with those installations.6 A cold plunge may be classified or connected differently, so follow the requirements for the actual equipment and local jurisdiction rather than transferring pool or spa rules automatically.
Check the Filled Weight Before Choosing the Floor or Deck
The empty weight shown on a product page is not the weight the supporting surface will carry during use.
Water changes the calculation substantially.
The Model S2 cited above is listed at 1,665 pounds when filled.2
The IceBath is listed at 555 kg when filled, including its engine and cooling protector, and the larger IceBath XL is listed at 680 kg. Those figures are approximately 1,224 and 1,499 pounds respectively.4
These examples do not establish a universal structural requirement, but they show why the filled operating weight matters when a cold plunge is planned for a deck, terrace or elevated floor.
Manufacturer foundation requirements also vary. The Model S2 installation manual, for example, specifies a level, stable base and gives additional requirements for that particular installation.1
Use the actual filled weight and installation instructions for the selected plunge when evaluating the supporting structure. Do not rely on the appearance of the tub or its empty shipping weight.
Plan for Splash and Wet Feet
Cold plunge placement is also a room-planning decision.
Water does not remain perfectly inside the tub. People step out wet. Water can collect around entry points. Maintenance and draining introduce additional water.
For an indoor installation, consider the path water is likely to take:
- Where will someone step when leaving the plunge?
- Is the walking route between the plunge and sauna easy to keep clear?
- Are the surrounding finishes appropriate for the water exposure expected in that location?
- Can you reach the equipment without climbing over or moving the tub?
- Is there a practical route for draining and servicing the system?
These are planning questions rather than universal construction specifications.
The correct waterproofing assembly, floor construction and drainage details depend on the building, materials, installation and applicable local requirements. We would not recommend copying a generic detail from another cold plunge installation and treating it as a construction specification for your project.
Indoor and Outdoor Cold Plunge Placement Are Different
Do not assume that a plunge designed for outdoor use is automatically appropriate indoors, or that equipment approved for indoor installation can be placed anywhere inside a sauna environment.
The Model S2 is specifically described as an outdoor cold and hot immersion tub.2
The IceBath and IceBath XL are listed for both indoor and outdoor placement and have specified ambient-temperature limits.4
For an Indoor Cold Plunge
For an indoor installation, apply the water, equipment-access and electrical planning already discussed above, then verify that every component is approved for the environment where it will operate.
Approval for indoor use does not automatically mean the plunge or chiller is suitable inside the heated sauna enclosure.
Equipment has its own permitted operating environment. A high-temperature sauna cabin is very different from an adjacent wellness room. Unless the manufacturer specifically approves that environment, keep the equipment within the ambient conditions stated in its documentation.
For an Outdoor Cold Plunge
Check:
- whether the tub and chiller are approved for outdoor use
- the permitted operating temperatures
- protection required for the equipment
- cold-weather operating instructions
- winterization requirements
Winter instructions vary significantly between systems.
The Model S2 installation manual instructs owners to drain the tub and connected equipment in winter to prevent freezing and to follow the chiller manufacturer's storage instructions.1
Other systems use different operating and frost procedures.5 A winterization method from one cold plunge should not be transferred to another unless the manufacturer supports it.
How Close Should a Cold Plunge Be to the Sauna?
There is no useful universal distance that we can recommend between the sauna and cold plunge.
Instead, plan the relationship between them around how the space will actually work.
Check:
- sauna door swing
- plunge entry and exit
- the wet walking route between them
- clear circulation space
- access to the chiller and plumbing connections
- space needed to remove or service equipment
- manufacturer-required equipment clearances
Placing the plunge close to the sauna can make the pairing convenient, but proximity alone does not create a good layout.
A cold plunge tucked tightly into a corner may look efficient on a floor plan and still create problems if the filter cannot be reached, the chiller cannot get the airflow it requires or the tub cannot be drained without moving equipment.
Plan the Sauna and Cold Plunge as One Space
Address these issues before construction and finishing decisions restrict your options.
We recommend working through the installation in this order:
- Choose the intended environment. Decide whether the plunge will be indoors or outdoors.
- Identify the plunge configuration. Establish whether it is self-contained, externally chilled or uses another equipment arrangement.
- Check the filled weight and base requirements.
- Decide how the tub will be filled.
- Plan where a full drain-down will discharge.
- Identify every tub-to-chiller or circulation connection.
- Allocate the manufacturer's required chiller and service space.
- Confirm the electrical requirements for the actual equipment.
- Plan for splash and wet-foot traffic.
- Check the walking route between the sauna and plunge.
- Verify the final layout against the current installation documents before construction is finalized.
This sequence matters because a cold plunge is not only a tub.
Treat the plunge as a set of interfaces, not just a tub: water in, water out, circulation, cooling equipment, power, structural support, service access and environmental limits. That is why two tubs with similar outside dimensions can require very different installation plans.
Compare Installation Requirements Before You Buy
If you are still choosing the plunge itself, review installation requirements alongside dimensions, appearance and temperature capability.
Start with our Cold Plunge Tubs collection to compare dedicated cold-plunge options.
We also carry cold and hot immersion tubs for installations where both heating and cooling capability are part of the plan.
Before ordering, review the current installation documentation for the exact model and make sure it fits the planned space. Doing so can prevent later changes to drainage, power, equipment space or structural planning.
Sources
- SaunaLife, Soak Series Model S2 Installation Manual (Rev. 1.0, 01/2025), saunalife.com
- SaunaLife, Model S2 product specifications, saunalife.com
- Icetubs, Installation Steps / Quickstart Guide, icetubs.com
- Icetubs, IceBath product specifications, icetubs.com
- Icetubs B.V., Warranty & Service Terms (updated June 17, 2026), icetubs.com
- U.S. Consumer Product Safety Commission, "Ways to Protect Yourself and Others from Shock or Electrocution" (updated July 31, 2019), cpsc.gov
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