How Do Hot Tubs Work?

Hot tubs as you may well know come in a variety of sizes, shapes, colors and vary in the many features. The earliest form of a hot tub was simply a pump you place in your bath tub for hydrotherapy. As hot tubs have change into what you see today it’s taken less than sixty years. Basic hot tub designs as we know them today run on centrifugal pumps which are usually used for moving liquids through a system of pipes. The pump is a motor anywhere between .5 horsepower to 2 or more. The motor spins the drive shaft which is attached to turbine impeller that is inside a water tight chamber. Basic Hot Tub Schematic As the impeller spins it pulls water from the hot tub, in some designs through a filter first to keep any compounds from clogging the other internal working parts. After passing through the suction filter which two ways as a water skimmer, it is sucked into the pump as kinetic energy when it hits the turbine it is shot out of the pump as potential energy at a higher pressure. After exiting the pump it heads to the heating element that is usually designed with some wound metal inside a container known all together as an electrical resistance heater. The metal inside is heated according to the thermostat and as water passes through and is pushed against the metal is heated and pushed back out the other side. On most Dreammaker hot tubs the heating element has two settings high, and low which allow for them to save power, they call this a “hybrid hot tub”. After exiting the heating element the water is pushed on to a division of tubes where it is distributed to any number of jets, however before entering back into the tub the water will enter a Venturi air injector which is a small piece of plastic tubing that looks like a T.

The water will pass straight through a narrowing in the tubing that will increase the water pressure, as it passes over the other tube, the air inlet which draws air from the motor and heating compartment, it creates a vacuum, sucking the warm air into the water with it. Usually users can control the air water mixture with a lever on the top level. The reason the air is taken from within the hot tub enclosure is to try and use the heat, if the air intake was coming from outside then the cooler air would then cool the water, not making for a very efficient effect. The air water mixture creates for a more robust experience with the hot tub jets. Different designs as far as the order and number of things may vary. For instance the filter may not be located till after the water pump, known as a pressure filter, then the water skimmer will be located separately on the top. Many larger models of hot tubs have multiple pumps to help send water to and increased number of jets.