Steam Shower Cutaway

Steam Showers: How Steam Shower Generators Work

Steam Shower Introduction

There are many details that go into the creation of a residential steam shower, from selecting the tile to choosing the right control. However, the heart of every steam room is the generator (read our guide on how to build a steam shower). Without this component, there would be no steam. Therefore, it is important to know exactly how this unit works and what to look for when comparing models. Make a selection so you can reliably enjoy the relaxation and health benefits of your steam shower for many years to come.

Producing Steam

As we all learned in science class, water (a liquid) turns to steam (a gas) when it is heated to boiling. This occurs at the temperature of 212°F at sea level. In a steam bath it is the generator’s job to heat water to this temperature. Water passes from a water line into the steam generator. An electric heating element raises the temperature of the water to the boiling point. A pipe moves the steam from the generator to the shower enclosure. The steam is released from an outlet called the steam head.

Here’s another science class fact. In the United States it’s important to select a steam generator that operates on 240 volts. Many inferior imported generators on the market are designed for 220 volts. While one of these generators will function, the lifetime of the unit will be shortened.

Different Methods of Producing Steam

While the scientific process of turning water into steam is generally the same in every generator, there are some differences between steam shower manufacturers that can change your experience. For example, some generators use one large heating element.  Others use two or more smaller heating elements, offering increased control over the exact temperature of the steam. Whereas a single heating element can be either on or off, having two or more elements allows the option of having only one on at a time. This means that steam is always being produced by one element or the other, sometimes referred to as “soft steam.”

A method called “proportional steam” uses multiple heating elements.  It also usually takes into account the temperature of the room and other factors to further control heating cycles. This prevents uncomfortable temperature fluctuations inside the shower.

Steam Speed

Some generator manufacturers tout the speed with which their units produce steam. These generators utilize one of two basic methods. The first is similar to the way the boiler in your home operates. A water tank keeps warm water at the ready at all times. The other method is to run electricity directly through the water, which can create steam within a minute or so.

Most manufacturers offer speedy options, such as InstaMist by Steamist, which promises “a generous volume of steam in under a minute.” However, these models may not be as economical or energy efficient due to increased power usage and even additional charges by the manufacturer In this case, you’ll have to decide how important the speed of steam production is to you. Many users find it just fine to turn on the steam and come back in ten minutes or so.

Size, Appearance, and Materials

The size of your steam generator will ultimately be determined by the size and construction details of your shower enclosure. Check out our Steam Shower Sizing Guide if you need help determining the right size steam generator for your space. If your generator is too small for the space, it will not create a fully immersive steam experience. If it’s too large, it can be wasteful. Size also comes into play when deciding where to locate the generator.

Most manufacturers offer “compact” models—generally about the size of a briefcase—that can be tucked away in a closet, attic, or other nearby space. If you don’t have a closet or attic space you can use, you might consider hiding the generator under bench seating. (This will also give you a place to towel off after your steam shower.) Because it will be hidden, the appearance of the unit is not of particular concern, but the materials should be. For example, a stainless steel tank is best for durability.

The Question of Noise

A quietly operating unit is ideal for a satisfying steam shower. However, be aware that most steam generators will make some kind of noise. The release of steam from the unit may be audible. The real concern is the sound of any mechanical components inside the generator. Common noise culprits include the valves that are responsible for bringing water into the generator or moving it between chambers. There are quieter alternatives, such as old-fashioned mechanical floats, but these can be less reliable than their more modern counterparts. The decision to include an audio system in your steam shower may also influence your selection on this point.

(See our guide on how to build a steam shower for more on installing an audio system.) Another way to keep your steam generator quiet is to install an in-line water pressure regulator. You could also choose to insulate the steam line itself for further noise reduction.

While some noise is normal for a steam shower, keep in mind that certain sounds could indicate a problem with your generator. For example, if you hear a high-pitched buzzing sound, this could signal a problem with the contactor or transformer. A loud buzzing from the solenoid valve that brings water into the generator could mean that the strainer built into the valve is clogged or that the water to the generator has been turned off. If you hear a noise that seems unrelated to the normal functioning of the unit, contact the manufacturer right away.

Don’t Forget the Controls

Since your generator will be hidden away, you’ll need a way to operate it from the shower area. This user interface is generally called “the controls,” and it is also responsible for monitoring the environment inside the steam shower. There are many designs and options to choose from. First, you must decide whether to install the controls internally—inside the shower enclosure—or externally—outside the shower enclosure. Internal controls are generally preferable, as you don’t have to leave the shower enclosure to make adjustments. See our guide on how to build a steam shower for tips on internal control placement.

Basic operations for the controls include turning the generator on and off and regulating the temperature, but there are other features available as well. These include timers and wireless remotes. Design-wise you can choose between options with touch screens, digital temperature and clock displays, and indicator lights, among other features.