Hot tubs work by drawing water through a system of pipes into a heating element and then dispensing the water into the tub itself.
Setting the Temperature
Modern hot tubs have digital keypads that allow you to select the water temperature. Regulations are in place to prevent modern hot tubs from heating the water past 104 degrees F.
Once the temperature has been selected, the data goes to the hot tub's control box , which will then regulate the various parts of the hot tub.
The water that fills the hot tub must be drawn from the surface and then filtered, which is done either with a suction filtration system or a pressure filtration system. Suction filters skim the water for impurities as it is being drawn through the pump, while pressure filters use cartridges to filter the water.
Once the water is filtered, it is pumped through the heating element. Inside of the heater housing, the water is warmed to the desired temperature.
The heater is outfitted with flow switches and an overheat high-limit switch. These are to prevent damage in the event that the water flow becomes restricted or that the water is heated too much.
After the water passes through the heater, it goes through a series of PVC pipes until it reaches the jets. Hot tubs have several jets that shoot the water into the tub itself.
Modern hot tubs have better, more adjustable jets that use air induction, a technique that allows warm water to mix with air. This makes the stream from the jets more robust.
Most hot tubs allow you to control the proportion of air to water to fine-tune the setting.
The final important device is the drain, which obviously comes into use when you are finished using the hot tub. Drains on hot tubs work very similarly to drains on sinks of showers.
Hot tubs could also be outfitted with several other options. Ozonators filter the water, resulting in less chemical.
Hot tub lights allow the tub to be used in the dark.