The Complete Handbook of Bathtub & Shower Jets

Chapter 1: Understanding Bathtub & Shower Jets

A bathtub or shower jet system is a simple concept with a surprisingly deep set of engineering decisions behind it. At its core, the system is about moving a controlled volume of water (and sometimes air) through nozzles built into the tub wall or shower enclosure to create a specific physical effect on the bather. That effect might be a gentle, aerated soak; a deep, directed massage for a sore back; or a full-body water pressure wash for an athlete's recovery. Understanding what these systems actually are requires moving past the marketing language of "spa experience" and looking at them as a specific type of plumbing appliance: one that uses a pump, a set of conduits, and engineered orifices to do work.

Consider the most common scenario: a homeowner is renovating a master bathroom and wants a jet tub. The contractor, asked for a recommendation, has to choose between a "whirlpool" system and an "air bath" system. This is the first critical distinction, and it's purely mechanical. A whirlpool system (also called a hydromassage or water jet system) draws water from the tub itself through a suction fitting, passes it through a pump, and pushes it back into the tub through a series of small, adjustable nozzles. The action is hydraulic; you feel the physical pressure of the water stream. In contrast, an air bath system does not recirculate water. Instead, a blower forces air through a manifold and out through holes in