Hot tubs can be classified on the basis of their location – that is, where they are designed to be placed, so that people can subsequently submerge themselves in the tubs, and hence obtain the relaxation and therapeutic benefits associated with them.
With location as basis for classification, we end up with two major types of hot tubs, namely:
1. Outdoors hot tubs: traditionally, hot tubs were meant to be outdoors amenities. The outdoors environment was deemed to enhance the relaxation people submerged themselves into the tubs in pursuit of. Outdoors tubs are still popular today. Take note though, that although these tubs are placed outdoors, they are by no means placed ‘in the open.’ They are typically placed outdoors, but in sheltered conditions, thus protecting the privacy of the people making use of them (because, naturally, one has to undress before submerging into a hot tub).
Some outdoor hot tubs are to be found above ground, even as others are found below ground level. Those found below ground level can be easily mistaken for mini-swimming pools. But they are differentiable by their typically small size (compared to even the smallest swimming pools): seeing that the swimming pools are meant for use by people in motion, whereas the tubs are meant for more or less stationary relaxation by seated people.
The outdoors hot tubs, as mentioned earlier, provide for optimal relaxation, beneath the open sky. But they are also less energy-efficient, seeing that the warmth in the water dissipates fast outdoors. Thus, the interchange of water (where new warm water is pumped into the tubs even as ‘used’ water is sucked out) has to be fast. This means extra expenditure on both heating energy and pumping energy.
2. Indoors hot tubs: these are very popular nowadays, as more and more people seek to have their own individual tubs in their homes, where they can relax by submerging themselves in water when occasion demands.
Some of the indoors hot tubs are also portable, and made from materials such as plastic. We also have semi-portable indoors hot tubs made from materials such as acrylic, with or without claw-feet pedestals. It is, however, hard to come across underground (excavated) swimming pool-like hot tubs which are indoor-based.
Indoor hot tubs provide optimum privacy, which is important to many people who are too shy to undress outdoors. They are also very energy efficient, as the warmth in the water with which they are fed doesn’t end up being ‘carried away’ by the wind. On the downside, one may argue that the indoors environment is not perfect for optimal relaxation expected through hot water submersion. But it can also be counter-argued that the relaxation is supposed to come from the warm water, and not the outdoors environment. That would mean that whether the setting is indoors or outdoors, as long as the water is warm enough, and the submersion long enough, optimum relaxation would still tend to take place.