History of hot tubes
The earliest hot tubs were in which hot stones were placed to heat the water. It has been a very popular place particularly for hydrotherapy ever since the 4th century. The remains of wrecked marble bathtubs along with a pre-historic aqueduct that have been unearthed from this area bear ample testimony of the place’s popularity in the ancient times.
In ancient Rome there were three types of baths: baths at home (balnea), private baths (balnea privata), and public baths (balnea publica). The practice of bathing was so engrained that the Roman legions, during their long occupations in foreign lands, built their own baths at mineral and thermal springs in the newly conquered lands. Examples are found all over Europe.
After the fall of the Roman Empire in 476 and the rise of Christianity, cleanliness was abandoned since the Church considered that the practice of bathing a prelude to forbidden behaviour. At Cluny custom required monks to take a full bath at Christmas and Easter. Private bath-rooms in castles, such as the one at Leeds, could often accommodate multiple bathers. From the 13th century onwards, baths gradually came into re-use, particularly in southern Europe under the influence of the Moors.
In the 1940s hot tubs began to appear in the US, inspired by the Japanese ofuro. Hydrotherapy pumps were introduced by Jacuzzi. Fiberglass shell hot tubs appeared around 1970 and were soon superseded by cast acrylic shells.
Fiberglass and Acrylic Spas – 1960 through 1970
Fiberglass spa shells debuted in the late 60’s. They simultaneously dealt with the health issues of wooden tubs and the install issues of gunite spas. While these shells could be quickly made, they were prone to blistering and staining, and were soon replaced by acrylic.
In the mid 70’s, spa shell manufacturers created the first portable spa by installing a cabinet around the shell. Adding framework and hiding the equipment under wood skirting made it a self-contained unit.
As the decade progressed, more features were added, including more advanced filtration systems, jets, and the first spa pack in 1976. The combination of lower cost materials and ease of install made portable spas attractive to many more home-owners.
Plumbing
The plumbing of the hot tub consists of:
• A pressure system delivering water to the jets
• Induced air: The jets may use a to incorporate air into the water stream for a lighter massage effect; this requires another set of hoses.
• Our models use an air blower to force air through a separate set of jets for a different “bubbly” massage effect; this is a separate system from the induced air.
Heating
Our Hot tubs are usually heated using an wood heater, Hot tubs are also found at natural hot springs; in this case, the water may be dangerously hot and must be combined with cool water for a safe soaking temperature. The hot tubes cannot be overheated 50 C˚. The perfect temperature is 37 – 38 degrees by Celsius.
Effective insulation greatly improves the energy efficiency of a hot tub. There are several different styles of hot tub insulation: some manufacturers fill the entire cabinet with foam, while others insulate the underside of the shell, the inside of the cabinet, or both. Many manufacturers advertise the superiority of their approach to insulation, but few independent side-by-side comparisons are available.
Hot tub covers have been shown to reduce most of the evaporative losses from the pool when not in use. With this component of heat loss being 70% a cover with even a small R-value is able to achieve as much as a 75% reduction in heating costs when used as opposed to leaving the water surface exposed.