Soaking, Whirlpool and Air Tubs Compared

Soaking, whirlpool and air tubs answer the same wish, a better bath, in three different ways. A soaking tub gives you depth. A whirlpool tub adds a pump that drives water through jets. An air tub adds a blower that pushes air through small holes in the floor or walls. Each step up adds comfort, cost and upkeep, and each changes what has to be built around the tub.

The three compared

Some tubs combine both systems. They give the widest choice of feel and carry the costs and maintenance of both.

Soaking tubs

A soaking tub is deeper than a standard tub so the water covers your shoulders. What matters is water depth, which is set by the overflow. Two tubs with the same outside height can hold very different depths of water. Look at the depth to the overflow on the spec sheet, then sit in a display model if you can.

• Long and reclined soakers suit lying back. Measure the flat interior length at the bottom, not the rim length.
• Short and upright soakers, sometimes called Japanese-style, are deep and compact, with a seat. They fit small rooms and make bathing upright and immersed possible in a short footprint.
• Freestanding soakers are the usual primary-bath centerpiece; see freestanding tubs.

Deep tubs are also harder to step into and out of. If anyone in the house has limited mobility, a standard depth with a grab bar may serve better. See aging-in-place bathrooms.

Whirlpool tubs

A whirlpool tub draws bath water through a suction fitting, pumps it and pushes it back out through jets that can usually be aimed and adjusted. The massage is firm and targeted, which is why people with sore backs and legs choose them. Whirlpool and air-jetted tubs with a circulation pump are covered by ASME A112.19.7/CSA B45.10, which includes the suction fittings. Check that the spec sheet lists it.

The ownership question is cleaning. After draining, some water stays in the pipes and the pump. The fix is routine: fill above the jets, add a cleaner the maker approves, run the jets, drain and rinse. Tubs that sit unused for months need it most. Older jetted tubs are often removed in remodels because they have not been maintained and the owners no longer use them. Our blog post on jetted bath remodels covers that situation.

Air tubs

An air tub has a blower, usually under the tub, that forces air through a network of small holes. The result is a gentle, bubbly feel over a wide area rather than a few strong streams. Because only air moves through the channels, many models run a purge or drying cycle after the tub drains, which makes them easier to keep clean than a whirlpool. Warm air is usually part of the design so the bubbles do not cool the water.

What jetted tubs need from the house

Power

Pumps, blowers and heaters need electrical circuits planned with the electrician before walls close. The tub's installation manual states what each motor needs, and Washington's electrical rules for bathrooms apply on top. We do not restate those rules here; they are on our bathroom electrical code page, and permit questions are on electrical permits for a bathroom remodel.

Service access

The pump or blower will need service someday. Plan an access panel in the tub apron, the deck or an adjoining closet wall, sized to the maker's instructions. A jetted tub tiled in with no way to reach the motor turns a simple repair into demolition.

Ventilation

A long, hot soak puts a lot of moisture into the room. For bathrooms larger than 100 square feet, the Home Ventilating Institute sizes fans by fixture and recommends 100 cfm for a jetted tub, against 50 cfm for a standard tub. For bathrooms up to 100 square feet, HVI recommends 1 cfm per square foot. Those are HVI recommendations; what the code requires is on our bathroom ventilation code page.

Hot water

A deep soaker or a large jetted tub can hold more water than a tank water heater delivers hot. Compare the tub's capacity to the overflow with the heater's size and recovery. If the numbers are close, the last part of the fill runs lukewarm. The answer may be a larger or different water heater, which is its own plumbing and permit item, or a smaller tub.

Floor

Big tubs hold a lot of water. Filled weight on the floor is covered on our freestanding tubs page and applies to any large tub.

What to check before you buy

1. Water depth to the overflow and interior length at the bottom.
2. For jetted tubs: the standard (ASME A112.19.7/CSA B45.10) on the spec sheet.
3. Electrical needs from the installation manual: number of circuits and protection.
4. Where the access panel will go, and its size.
5. Capacity in gallons against your water heater.
6. The cleaning routine and which products are allowed.
7. Noise: listen to a running display model if you can.
8. Warranty terms for the shell and, separately, for the pump, blower and controls.

Who should choose which

• You want a better bath and no maintenance: a soaking tub.
• You want a firm massage for sore muscles and will use it often: a whirlpool, with a commitment to flushing it.
• You want a gentle, relaxing feel and easier cleaning: an air tub.
• You take a bath a few times a year: a soaking tub, or reconsider the tub altogether on our page about keeping a bathtub.

JDI Construction plans the circuits, the access panel and the fan with the tub in the design, so nothing is discovered after tile. To plan a soaking or jetted tub in your bathroom, start with bathroom remodeling in Vancouver, WA.