Apart from brand name, there is no substantive difference between a Jacuzzi and a whirlpool bath. Although Jacuzzi invented the whirlpool bath, today it is simply one of many brands of whirlpool tubs, also known as spas or hot tubs. Whirlpool bath brands differ in the systems that circulate, filter and aerate the water, but all work in the same basic fashion.
The family-owned Jacuzzi firm, which originally made agricultural pumps, invented the Model J-300 portable submersible whirlpool hot-bath pump in the late 1950s. The company marketed it to hospitals and health clubs as a device that turned an ordinary bathtub into a therapeutic tool to ease the pain of sore joints and muscles. Jacuzzi introduced the first integrated whirlpool hot tub for consumer use in 1968. This product, dubbed the "Roman" bath, started the whirlpool bath industry. By the 1980s, numerous competitors had entered the market with similar products, but consumers had taken to using the Jacuzzi brand name as a generic term for all whirlpool tubs.
The Jacuzzi and other brands of whirlpool hot tub have a pump that draws water from the tub and circulates it through heating, filtration and aeration systems. The pump then sends the hot, filtered, bubbly water back into the tub through pulsating water jets to create the whirlpool effect that promotes physical relaxation and eases muscle and joint pain. A low-voltage electronic control system regulates water heat, flow rate and amount of aeration.
Pump and Heater
The electric pump draws water from the pool surface, from suction intakes in the foot well or both. Some models have multiple pumps, while others use a single multispeed pump. Water circulates through an electric heater that warms the water to the desired temperature. The heating system includes a water pressure or flow switch to cut off the heater if water flow is interrupted or restricted. There's also a high-limit overheat switch to disconnect the heater if water temperature exceeds 104 degrees, the legal limit.
Whirlpool tubs use either a suction filter or pressure filter to clean the water as it recirculates. With a suction filter, the pump pulls the water through a strainer and a filter attached behind the strainer. With a pressure filter, the pump pushes the water through the filter under high pressure. In this system, the strainer and pressure filter are in different locations.
Whirlpool tubs use either air induction or an air pump to aerate the water. In air-induction systems, the water jets are connected to the water pump and to atmospheric air lines. As water jets into the pool, the water flow sucks in air using the Venturi effect and mixes the air into the water. In air-pumped systems, a separate pump sucks in air and pumps it into the pool through pressure lines separate from the water lines.