Steam Shower Buying Guide: Units, Generators, Controls

What is a steam shower and how does it differ from a regular shower?

Steam showers have moved steadily into mainstream bathroom remodels over the past decade. Once confined to spas and luxury resorts, prefabricated steam enclosures and modular generator kits are now sold at home improvement retailers and widely installed by licensed electricians and plumbers. The appeal is straightforward: consistent moist heat at home without the recurring cost of a spa membership.

Understanding the core components before you buy saves you from mismatches that are expensive to fix after installation. The four pillars of any steam shower system are the generator, the control panel, the enclosure (tile, glass, and structural features), and the ventilation strategy. Each feeds into the others, so sizing one incorrectly throws off the rest.

How do you calculate the right generator size for a steam shower?

The standard sizing formula used by MrSteam, Kohler, Steamist, and other leading manufacturers runs as follows:

1. Measure the interior dimensions of the enclosure in feet. Multiply length x width x height to get cubic footage.
2. If walls are ceramic or porcelain tile, use the raw cubic footage as your baseline.
3. If walls include natural stone (marble, travertine, granite, slate), multiply baseline by 1.25--2.0 depending on thickness and density. Marble is less porous than travertine, so travertine demands the larger multiplier.
4. For each glass wall or glass ceiling panel, add 15 percent to the adjusted cubic footage.
5. For each exterior wall that faces outdoor conditions, add 25 percent.
6. Match the adjusted cubic footage to the generator's rated capacity. Stay at or below 80 percent of the generator's maximum rated cubic footage to allow headroom.

Example: a 48-inch x 36-inch x 84-inch shower (about 84 cubic feet) with one glass door and marble walls. Baseline = 84 cubic feet. Marble multiplier x 1.5 = 126 cubic feet. Glass door adds 15 percent = approximately 145 cubic feet adjusted. You would need a generator rated for at least 145--180 cubic feet, which typically falls in the 9--10 kW range.

Row marked Best for most homeowners reflects the 80--150 cu ft range that covers the majority of master bathroom steam shower builds.

What types of steam shower controls are available and which is best?

Here is a practical breakdown of the three control tiers:

Analog Controls

Analog dial-and-switch controls are the most affordable option and are often included with entry-level generator packages. They work reliably but offer limited precision -- temperature is set by feel and a simple range dial, and there is no delay-start or remote preheat function. For a secondary bathroom steam shower used occasionally, analog controls are a serviceable choice.

Digital In-Shower Touchpads

Digital touchpad panels are the current standard in mid-range and premium installations. They display the actual enclosure temperature in real time, allow you to set a specific target temperature (typically in 1-degree increments), set a session timer, and trigger the generator to pre-steam the enclosure before you step in. Most panels are rated for wet environments (IP65 or higher). Leading examples include the MrSteam AirTempo, Steamist SM Series, and Kohler's DTV+ interface.

Smart App-Connected Controls

App-connected systems add remote scheduling, usage logging, and sometimes integration with Google Home or Amazon Alexa. MrSteam's iSteam 3.0 and Steamist's SteamLinx module are the most widely installed options. The practical benefit is being able to preheat the enclosure from bed, so it reaches your preferred temperature by the time you get in. Installation requires the generator to be within Wi-Fi range or connected via a smart home hub.

What enclosure materials work best for a steam shower?

The enclosure decision affects not just aesthetics but structural performance:

• Porcelain tile (large format): Large-format porcelain (24x24 or larger) reduces grout joints, which reduces moisture infiltration and cleaning effort. It handles heat well and is available in stone-look finishes that approximate marble without the maintenance or generator-sizing penalty.
• Ceramic tile: Classic choice. Lower cost than porcelain, appropriate for walls and bench surfaces. Use a minimum Class 3 abrasion rating for any floor tile in a steam shower setting.
• Marble: Dense white marbles like Carrara perform better in steam environments than more porous options. Still requires periodic sealing and bumps up generator requirements.
• Travertine and limestone: Porous stones that demand aggressive sealing schedules. Visually distinctive but higher maintenance and higher generator demand than tile alternatives.
• Glass walls and partitions: Frameless glass panels are popular for visual openness. Tempered glass (minimum 3/8-inch thickness) is mandatory. Each glass surface adds to heat loss, so factor this into generator sizing.
• Acrylic prefab units: Purpose-built steam shower kits from manufacturers like Steam Planet or Maya Bath combine the enclosure, generator, and controls in one package. Easier to install and lower upfront cost, but the enclosed footprint is fixed and the steam experience is generally less immersive than a custom tile build.

Ceiling Slope: Why It Matters

Any steam shower ceiling must be sloped -- a minimum pitch of 2 inches per foot is the widely cited standard -- so that condensation runs toward the walls rather than dripping on occupants. A flat ceiling in a steam enclosure creates a steady drip that disrupts the experience and can be dangerous if steam condenses and drips onto electrical fixtures. Custom tile builds allow you to control this precisely; prefab units build the slope in from the factory.

How much water and electricity does a steam shower actually use?

The water efficiency of steam showers is one of their most underappreciated qualities. While the EPA WaterSense program does not currently certify steam shower generators specifically (its certification focus is on showerheads, faucets, and toilets), the water consumption profile of steam showers aligns well with water conservation goals. Steam is produced from a very small reservoir of water that is continually heated; no water is flowing continuously down a drain during steaming.

For comparison, an EPA WaterSense-certified showerhead flows at a maximum of 2.0 gallons per minute. A 20-minute shower with a WaterSense head uses 40 gallons. A 20-minute steam session uses roughly 2 gallons. The electricity cost is the primary operating expense to budget for, not the water bill.

What are the top steam shower generator brands and how do they compare?

Here is a closer look at the leading brands:

MrSteam

MrSteam (a division of Feel Good Inc.) is the most widely specified residential steam generator brand among plumbing and tile contractors in the United States. Their product line covers 3 kW through 30 kW, with residential-focused models ranging from the eSeries (budget) through the iSeries (premium) with the iSteam 3.0 control module. Auto-drain, self-cleaning flush cycles, and stainless steel tanks with polished interiors are standard across the residential line. MrSteam generators are manufactured with a focus on quiet operation -- most are rated below 45 decibels at 1 meter.

Kohler

Kohler's steam generators are available in 6, 9, 11, 13, and 15 kW configurations and pair with the DTV+ digital interface, one of the most polished control systems in the residential market. Kohler's broad dealer network is a practical advantage -- service and replacement parts are more readily accessible than some specialty brands. Their generators use self-draining technology and carry a 3-year limited warranty on most models.

Steamist

Steamist positions itself as a value-focused alternative to MrSteam. Their SM and SMX series generators cover 6--18 kW and are compatible with the SteamLinx Wi-Fi module for smart control. Contractor feedback on Steamist is generally positive for straightforward residential installs, though the control panel ecosystem is slightly less refined than MrSteam's iSteam. Warranty terms are competitive at 3 years on the generator tank.

ThermaSol

ThermaSol specializes in high-end steam and has produced generators for luxury hotel and spa projects as well as residential installations. Their Signature series includes advanced features like multiple steam outlets for larger enclosures, aromatherapy ports integrated into the generator, and chromatherapy lighting coordination. Price points are correspondingly higher, but the build quality and feature set appeal to buyers targeting a true spa experience at home.

Amerec

Amerec (owned by Thermasol parent Sussman Automatic Corporation) manufactures generators for both residential and commercial applications. Their AX and AI series are frequently specified for hotel fitness centers and larger residential installations. For home use, Amerec is a reliable choice if you are sizing above 12 kW or planning a multi-person enclosure.

Steamcore / Ess Series (Budget Tier)

The budget segment includes Steamcore and similar brands available through online retailers. These generators are functional for smaller enclosures and tight budgets but typically carry shorter warranties (1 year), limited service networks, and fewer control options. For a primary master bathroom steam shower, most contractors advise against budget-tier generators given the cost of re-installation if the unit fails within a few years.

What installation requirements should I know before buying a steam shower?

Before you purchase a generator, confirm the following with a licensed electrician and plumber:

Electrical Requirements

• Most residential generators operate on 240V single-phase power. The generator's data plate shows the amperage draw. Add 25 percent to the running amperage to determine the minimum circuit breaker size (e.g., a 9 kW / 37.5A unit needs a 50A dedicated breaker).
• The generator must not share a circuit with any other appliance.
• A ground fault circuit interrupter (GFCI) is required in bathroom circuits per the National Electrical Code. Verify whether the generator manufacturer requires or prohibits GFCI protection (some generators have internal protection that can conflict with external GFCI breakers).
• Run time the wire from the panel to the generator location before tiling the shower, as routing electrical wire through a finished tile shower is extremely costly.

Plumbing Requirements

• Cold water supply only is needed for the generator. Do not connect to hot water -- feeding hot water into the generator affects pressure and performance, and can damage the heating element.
• The water supply line should be shut-off valve accessible for maintenance and winterization.
• Auto-drain systems (standard on most quality generators) drain residual water after each session, which prevents mineral buildup and extends tank life. Verify the drain outlet has a clear gravity-drain path.
• If your area has hard water (above 7 grains per gallon hardness), consider installing a scale inhibitor or softener upstream of the generator. Mineral scale is the primary cause of generator element failure over time.

Generator Placement

The generator is installed outside the enclosure -- in a nearby closet, under a vanity, in a mechanical room, or in a crawl space. Manufacturer specs typically allow the generator to be up to 25--60 feet from the steam head (varies by brand). The generator must be in a space that does not freeze, has adequate ventilation, and allows access for annual maintenance (flushing the tank and inspecting the heating element).

Ventilation and Moisture Management

Ventilation in a steam shower operates differently than in a standard bathroom. You do not want to exhaust steam during the session -- that defeats the purpose. Instead, the steam shower enclosure should be tightly sealed during use, with ventilation activated after the session to purge residual moisture. A dedicated exhaust fan with a humidity sensor (set to activate when RH drops below a threshold) or a manually operated timer fan connected to the enclosure is the standard approach. The bathroom itself needs adequate ventilation to handle the moisture that exits the enclosure when the door is opened after a session. Kohler, Broan, and Panasonic all make exhaust fans rated for high-humidity bathrooms adjacent to steam showers. You can also review our bathroom exhaust fan guide for selection criteria and sizing.

For a complete overview of how steam showers fit within a broader bathroom renovation, see our bathroom remodel buying guide.

What maintenance does a steam shower generator require?

Here is a maintenance schedule most manufacturers recommend:

• After every session: The auto-drain cycle (if equipped) handles residual water removal automatically. No user action needed beyond activating the auto-drain via the control panel if not set to automatic mode.
• Monthly: Wipe the steam head nozzle with a damp cloth and check for visible mineral deposits. If the steam flow seems reduced, the nozzle orifice may be partially blocked.
• Every 6--12 months (depending on water hardness): Flush the generator tank per the manufacturer's procedure. Most generators have a drain valve at the bottom of the tank. Open the valve, allow the tank to drain fully, then run a brief fill-and-drain cycle to remove loosened scale. Some manufacturers offer a descaling solution added to the water supply line during the flush cycle for areas with very hard water.
• Annually: Inspect the heating element visually during the flush cycle if accessible. Heavy scale on the element looks like white or off-white calcium crust. If scale is significant, a professional descaling service or element replacement may be needed.
• Every 2--3 years (stone surfaces): Re-seal natural stone walls, bench, and floor surfaces with a penetrating stone sealer rated for wet environments.

For homeowners in hard water areas (common across the Southwest, Midwest, and Mountain West), a scale inhibitor cartridge installed on the cold water supply line before the generator is one of the most cost-effective upgrades available. These cartridges (available from most generator brands and third-party suppliers) condition the water to reduce calcium and magnesium precipitation inside the tank, extending element life substantially.

How do steam showers compare to saunas and infrared saunas?

The choice between a steam shower, a traditional sauna, and an infrared sauna often comes down to space, budget, and personal preference for the type of heat:

• Steam showers occupy existing shower footprint and add roughly $2,000--$8,000 for a custom tile build with a mid-range generator and controls (excluding any structural modifications).
• Traditional Finnish saunas require a dedicated room, wood construction (cedar or Nordic spruce), a kiuas (sauna stove), and proper ventilation. Costs for a home sauna room typically run $5,000--$20,000 depending on size.
• Infrared sauna cabinets are available as prefabricated plug-in units for $1,500--$8,000. They require only a standard 20-amp circuit and minimal installation but are not integrated into the bathroom.

For bathroom renovation purposes, the steam shower wins on integration -- it replaces or upgrades an existing shower with no additional floor space required, making it the most practical addition for most home bathrooms.

• EPA WaterSense, epa.gov/watersense
• MaP flush testing, map-testing.com
• Manufacturer published specifications
• MrSteam generator sizing guide, mrsteam.com
• Steamist installation and owner manuals, steamist.com
• Kohler steam generator product documentation, kohler.com
• ThermaSol Signature Series product documentation, thermasol.com
• National Electrical Code (NEC) Article 422 and 680 requirements
• Schluter Systems Kerdi waterproofing system documentation