How Air Tubs Work

Hydrotherapy makes it possible to recreate the experience of the hot bubbling waters of natural springs at home.
Hydrotherapy makes it possible to recreate the experience of the hot bubbling waters of natural springs at home.

From the bathhouses of Ancient Rome to the most luxurious spa resorts today, people have been captivated by the relaxing and therapeutic effects of hot bubbling waters. Hot tubs are found in homes and spas around the world, offering mineral water deep and warm enough to relax your tired muscles and calm your running mind.

But not everyone relaxes the same way. Some prefer a firmer massage, while others like a softer touch. That's where air tubs come in. Air tubs are water-jetted tubs, similar to whirlpool baths, that offer a gentler massage than their counterparts. Creating bubbles that some describe as a thousand tiny massaging fingers, air tubs have found a niche with bathers who prefer a gentler experience. From home enthusiasts to spa vacationers, people around the world are becoming more familiar with the air tub.


As you might expect, the technology that underlies whirlpool baths and air tubs is very similar. On the next page, we'll take a look at the two and what makes them different.

Whirlpool Baths vs. Air Tubs

Whirlpool baths use fewer, more powerful jets that pump both air and water. Air baths' jets only pump air.
Whirlpool baths use fewer, more powerful jets that pump both air and water. Air baths' jets only pump air.

Why use a whirlpool or air tub at all? Other than the fact that it feels good, it just may be good for you, too. You can get fancy, if you want, by calling it hydrotherapy. Hot water relaxes your muscles and jets massage and soothe your body. Proponents of hydrotherapy believe that it eases joint pain, improves circulation and is beneficial to the body's overall healing process [source: American Cancer Society]. In fact, it was hydrotherapy that launched the hot tub business. After engineering a submersible pump that could be used in a bathtub for a family member's hydrotherapy needs, the Jacuzzis built the first integrated whirlpool tub in the 1960s [source: Jacuzzi].

Whirlpool tubs mix air and water and force the mixture through outlets toward the person sitting in the tub. Manufacturers build outlets for the jets into the seating areas of the tub to massage and soothe tired bodies.


Air tubs create a much gentler massage by compressing air and jetting it out through the bottom of the tub via many smaller outlets. Millions of small bubbles rise through the water and surround the body, creating a less intense, effervescent massaging sensation. Tubs that combine air and water jets are also available and allow users to vary their massage depending on preferred pressure.

Air tubs are slightly easier to maintain and keep clean than whirlpool tubs. The fact that air tubs jet air means that they rarely allow excess water to build up internally, preventing mold and mildew from growing in and around the piping and pump. Whirlpool tubs that use water in their jets should be cleaned periodically according to the manufacturer's directions, usually with a disinfectant and possibly bleach [source: Heloise]. You can also buy purpose-made whirlpool cleaning solutions.

Air tubs are a little more expensive than water-jetted tubs at an entry-level price point. You can find water-jetted tubs starting around $500 and air tubs at about $1,200. Higher-end tubs of both types can be found between $3,000 and $4,000. Combo tubs are the most expensive with prices running from about $1,000 to over $5,000 [source: Consumer Reports].

Engineering of an Air Tub

Air tubs have four main parts -- the air pump, the air manifold, the tub and the controls.

Air Pump -- While the air pump is the heart of this operation, the machine and its function are quite simple. When the pump is turned on, a fan sucks air into a housing unit and pushes the air into the air manifold.


Air Manifold -- The manifold is the piping that surrounds the tub on the bottom, the sides or both and is usually hidden by a decorative frame. When air from the pump enters the manifold, it fills the entire space, which could have single or multiple channels, and is forced through very small holes and into the body of the tub.

Tub -- The tub has corresponding holes that quickly emit the air from within the manifold in the form of bubbles. The bubbles then rise to the surface of the water, creating a light massaging effect for anyone sitting in the tub.

Controls -- The person enjoying the air tub can use its controls to modify air pressure, water temperature and, depending on the air tub, scent (aromatherapy) and lighting (chromatherapy).

Installing an Air Tub

Once you purchase a new air tub, you'll have to get it installed, which can be a tricky process and will probably require the assistance of another person. Air tubs come in all kinds of configurations, whether you're thinking of putting yours in the backyard or replacing an existing bathtub. There are several tried-and-true installation methods that should help with most situations:

Drop-in Method -- If you've got an outdoor air tub, give this method a try. Drop the tub into a pre-built frame where it will rest on a subfloor, while the lip of the tub creates a frame around the pre-built deck. This lip should never bear weight and should have a very thin space between itself and the deck that you should seal with silicone.


Alcove Method -- Just like your everyday bath/shower combo, an alcove air tub has walls on three sides. These tubs don't need a pre-built deck, but you should always measure before installation to ensure your tub has a nice snug fit.

Undermount Method -- The lip of an undermounted tub is hidden completely beneath a covering layer creating a seamless edge from the surface of the cover into the tub. Install the tub first, followed by its decorative casing. Then the top, often made of stone or marble, is cut and fitted over the tub to serve as a kind of lid for the casing. This method requires a bit more planning, and possibly professional installation, due to the relocation of the tub's controls to the top of the cover.

Make sure to install an access panel near the air pump. The panel should be big enough to remove all of the tub's interior parts if necessary. And while it is possible to build your own air tub or retrofit your current tub with air jets, it's a huge endeavor [source: Leisure Concepts, Spa Depot, Quality Bath].

Now that you know what an air tub is, let's see what it's like to own one.

Owning an Air Tub

While eccentric millionaires may very well have pools in their living rooms and air tubs in their kitchens, chances are that you'll have an air tub in one of two places: in your backyard or in a bathroom.

Installation and maintenance of an air tub in your back yard is expensive, but when compared to a pool, the money, time and effort are significantly less. Installation of an in-ground pool will start at about $20,000, and upkeep on some pools can bring the investment even higher. Basic air tub installation usually requires just a few thousand dollars, and as we previously discussed, maintenance of an air tub is extremely low since the pumping system stays dry.


An outdoor air tub may require building a privacy structure and additional accessories like a tub cover, access steps and possibly a surrounding deck. Outdoor air tubs tend to be used with friends and family, so they will be a little larger on average than indoor tubs [source: Consumer Reports, Be Jane].

Indoor air tubs are usually designed for personal use and may need to fit the size of an already existing space. They can be stand-alone units or part of a bath/shower combo. Privacy and access are usually taken care of indoors and accessories are at a minimum

Safety is always a big issue with any water-based recreational equipment. Children should always be supervised and taught the proper way to enjoy pools and tubs. The biggest danger to children is accidental drowning in tubs that have been left uncovered. Users with heart conditions or seizure disorders should also be aware of the risks of bathing in hot waters for extended periods of time. And according to the American Journal of Public Health, alcohol is the most dangerous factor in tub-related deaths with intoxication and drowning as the cause of 38 percent of all hot tub related fatalities [source: Press].

Going back to their origins, hot bathing tubs and hydrotherapy have been regarded as having substantial health and hygiene benefits. In the next section we will explore some alternative health aspects relating to air tubs.

Holistic Practices for Air Tubs

It's easy for those interested in aromatherapy to add scent to their bathing experience by adding essential oils in a hidden compartment within an air tub's cabinet.
It's easy for those interested in aromatherapy to add scent to their bathing experience by adding essential oils in a hidden compartment within an air tub's cabinet.

While air tubs are widely used for relaxing and reviving muscles, many people use them for their holistic benefits in the form of aromatherapy and chromatherapy. Holistic medicine is described by the American Cancer Society as focusing on "how the physical, mental, emotional and spiritual elements of the body are interconnected to maintain wellness or holistic health." Many air-tub manufacturers have combined holistic practices of aromatherapy and chromatherapy with the medically accepted benefits of hydrotherapy [source: American Cancer Society].

The practice of aromatherapy, using naturally occurring scents to promote the health of the body, mind and spirit, has become a large part of the air tub experience. Users drop oils onto a pad inside a hidden canister near the rim of the air tub. This canister is situated in the path of the compressed air that comes from the air pump. So when the tub is turned on millions of bubbles carry the scent through the water and back into the air [source: National Associating for Holistic Aromatherapy, MTI Baths].


Aromatherapy and air tubs are a perfect fit. With an air tub, you also have the ability to mix bath oils and salts directly into the water. Introducing these extras to a whirlpool can cause their pumping systems to clog. This doesn't happen in air tubs because they don't pump water.

Recently, tub manufacturers have also added lighting options to their tubs. This practice is known as chromatherapy or color therapy and allows the user to add color to the water in the tub using underwater lighting. Chromatherapy is known for giving practitioners a sense of calm and balance [source: The Body Healer].

Lots More Information

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More Great Links

  • American Cancer Society. "Hydrotherapy." March 7, 2011. (Jan. 8, 2012)
  • Be Jane. "Backyard Swimming Pools." (Jan. 8, 2012)
  • The Body Healer. "What is Chromatherapy?" (Jan. 8, 2012)
  • Consumer Reports. "Types: Weigh the type of massage you want against noise and cost." January 2008. (Jan. 8, 2012)
  • Heloise. "Cleaning a Whirlpool Tub." Good Housekeeping. (Jan. 4, 2012)
  • Home and Stone. "Whirlpool Baths." (Jan. 8, 2012)
  • Leisure Concepts. "Installation/Technical Information." 2010. (Jan. 8, 2012)
  • MTI Baths. "Aromatherapy." (Jan. 8, 2012)
  • National Association for Holistic Aromatherapy. "What is Aromatherapy?" (Jan. 8, 2012)
  • Press, Edward. "The health hazards of saunas and spas and how to minimize them" American Journal of Public Health. August 1991. (Jan. 8, 2012)
  • Quality Bath. "How to Install a Jacuzzi or Hot Tub." (Jan. 8, 2012)
  • The Spa Depot. "SpaClopedia." 2012. (Jan. 8, 2012)
  • Swart, Peter, et al. "United States Patent Application Publication -- Air Bath." Feb. 6, 2004. (Jan. 8, 2012)