Let's face it: hot-tub jets can hurt. “People get in the tub to relax, but then spend their time constantly moving a part of their body either in front of the jets or away from them,” says Scott Tennant, chief operating officer for Acryline. Knowing this, Tennant and other “system bath” manufacturers emphasize education when homeowners request such tubs, because many consumers, and some professionals, don't know the differences between whirlpools and new air baths on the market. Identifying user preferences helps determine which bathing option is best.

FUNCTIONAL PHYSIOLOGY Whirlpools and air baths are built similarly, with plumbing consisting of a pump, water lines, and jet apertures for whirlpools, or an air injector, pipes, and air apertures for air baths. The major difference is that whirlpools move water through their plumbing, while air baths move air.

Aquatic Industries marketing director Tawnya Quiet says each technology creates a specific bathing experience. “Whirlpools provide a more vigorous, deliberate massage that delivers focused attention to your back, neck, or other areas that need stress relief,” she says. “An air bath is really an all-over body massage created as effervescent bubbles surround the body.”

Whirlpools can be great for athletes who need more intense massage. But Tennant says air apertures on air baths, such as Acryline's, are laid out to offer a “tactile” massage that stimulates the natural meridians along the neck, spine, and legs. These areas, studied by massage therapists, influence blood flow, heart rate, and breathing, he says. As a result, tired or tense bathers experience relaxation in an air bath. Alternatively, someone who wakes up groggy can get the blood flowing with a morning air-bath massage.

In light of these differences, buyers must consider how the tubs will be used, and by whom. Quiet developed a 10-point questionnaire to help users choose between whirlpools and air baths. Jacuzzi, which first introduced its eponymous jetted hydrotherapy tub 30 years ago, has a similar interactive Q and A on its Web site. Look for both questionnaires at www.remodelingmagazine.com/webxtras.

Mark Nover, general manager of Villeroy & Boch USA, says whirlpools remain more in-demand than air baths, though interest in the latter is growing. Many companies also offer combination units with both technologies to accommodate multiple users' preferences.

“We encourage people to see working tubs in the showrooms,” adds Jim Rennolds, national sales director for Neptune. “That's where you realize what the systems can offer you.”

COMPONENT CONSIDERATION System bath components have improved over the years, lessening callbacks. “Manufacturers have made inroads with better blowers and other parts, so the tubs operate more quietly and maintenance problems are rare,” Rennolds says. Still, he recommends adding an access panel to the tub surround, if the unit doesn't incorporate one. Quiet also recommends water-testing tubs before installation, which should be handled by a certified plumber.

With the right tub correctly installed, manufacturers say baths in both categories get rave reviews. “When homeowners discover the right system, we find we have a lot of repeat customers who buy the products for other baths in their home, or for their second homes,” Quiet says. “There's a large segment of consumers that research the product category and know there's a product out there that will make them feel better. Once they discover it, they use it consistently.”

Keep It Clean Contrary to some myths, whirlpool and air bath manufacturers confirm that all system baths can and should be cleaned regularly. For sanitation, manufacturers often use super-smooth or antibacterial air channels and plumbing, as well as “purge cycles” to evacuate as much water as possible. Still, residual moisture can cause bacterial growth, which can be pushed back into the water during a soak, and can interfere with the systems' efficiency.

To clean tubs, most manufacturers recommend running the system with a few inches of water and a small amount of emulsifying dishwashing liquid. Some whirlpool jets can be removed and sanitized in the dishwasher. Check operators' manuals for instructions specific to each tub model.