Hot Tubs Explained

There are many issues to think about when deciding on purchasing your hot tub.  Below are an explanation of some of the things which should be considered.

Hot Tub Heating Explained

Heating energy accounts for over half the energy consumed by a typical hot tub. Heating requirements are in large part determined by standby losses through the cover and shell, and heat loss and water evaporation during use. Most portable electric spas rely on resistance heaters to maintain their temperature, though some inexpensive ones use just pump friction. Most resistance heated hot tubs use direct-contact heaters, which can boast efficiencies of 98% or higher. The element and other heater components must be of high quality to resist corrosion and decay from constant contact with the spa’s chemical charged water. Some firms tout the maintenance benefits from heaters that separate the spas water from the heating element itself. Up to 96% efficiency claims are made for these systems. Thus heater efficiency is generally quite high, with little difference between different design approaches.

Hot Tub Pumps Explained

Pumping is the second major component of hot tub energy use, accounting for around 25-50% of the energy used in a portable spa. Portable hot tubs have at least one pump to provide filtering and circulation and to run the jets when the user turns them on. Several
configurations are possible, resulting in widely variable pumping energy use; some models include a separate, small pump for filtration and circulation duties, which can reduce energy requirements. Smaller spas, and less expensive spas generally, tend to have one multi-speed pump that both runs the circulation and filtration system, and powers the jets.  Pumping energy use is further complicated by the fact that a significant portion of heat generated by the motors and pumps effectively contributes to heating the spa. Therefore a fraction of the energy savings from pump and motor improvements will have to be replaced by resistance heat. How much waste heat is lost depends on the location of the pump and the insulation configuration of the hot tub. The heat from filter pump operation may also overheat a well insulated spa during warm summer months.  Related to pumping is the presence of increasing numbers of jets and hoses in new spas.  Ever more powerful jets are incorporated to provide health and relaxation benefits to the
user. In essence the hoses can act as heat exchangers with the surrounding air, losing heat and increasing heating energy requirements. Additionally, air is often introduced to the water being pumped to the jets. Ambient air used for this purpose can accelerate the spa’s cool-down. Some spas use air from the pump cabinet for this purpose and so take
advantage of the pump’s waste heat, thus saving some energy.

Hot Tub Controls Explained

Controls for hot tubs in all sectors of the market focus on keeping the water adequately filtered and heated to the temperature programmed by the user. Most new controls are equipped with many of the advantages enabled by simple electronic circuitry: digital temperature controls, password-protection prohibiting unauthorized use, timed automatic jet shut-off, etc. Some models already include energy-saving set-backs that lower the temperature when indicated by the user, or by a programmable time clock. As a rule, however, control panels do not include these and other so-called “smart” features. Smart
controls could save significant amounts of energy—perhaps 5-10% of a spa’s heating energy requirement—and could provide important reductions in peak load per unit, although the coincidence between peak spa heating demand and utility summer on-peak periods is low.

Hot tub spa covers explained

The construction of hot tub cover and spa covers are to maximise the insulation properties of the hot tub.  Covering the spa with a solid spa cover will also minimize condensation. Hot tub covers reduce most if not all of the evaporative losses from the pool when in use. With this component of heat loss being 70% a cover with a small R value can achieve as much as a 75% reduction in heating costs when used. (see heat losses from spas and pools)

If wrapping your water heater can make a difference in your energy bill, imagine what "wrapping" your other water heater (your spa) would do. Your hot tub uses the same type of heater your household water heater does only your household water heater may have twice as many elements to heat up about forty gallons of water while your spa is trying to heat four hundred gallons. Good insulation around the sides and bottom of your spa play a vital role in helping keep that spa water warm.

However that insulation is done when the spa is constructed. Any good hot tub manufacturer is going to put a good amount of insulation around the spa shell. Insulating the pipes the jets are fed from is important too and should be done by the manufacturer. Once you have purchased your spa insulating it after the construction can be done however it may be difficult and expensive. The last place most spa owners look for insulation is in the cover.

To begin with that spa dealer is going to send some sort of cover home with your new spa. The spa dealer may spend some time talking to you about the benefits of a cover but lets be honest you didn't go there to buy a spa cover and as an after thought decided to get a spa to go under it. No, you wanted a spa. One with lots of features. Jets where you wanted them to ease your pain and tension. If the spa dealer talked to you about the cover you might have seen his lips moving but you were still concentrating on how good those jets of water were going to feel as they pummelled your aching body with soothing pulsing action of warm water. You may have not even thought of the cover when you got your first utility bill.

But you should think about the cover since heat rises. Most of the heat lost from your spa water is going straight up. Insulating the water from the water then makes the most sense. But rigid foam covers are trying to insulate your spa water from way up on top of the spa acrylic. In most cases this can be several inches off the water surface, ten or more is not uncommon. If you have a rigid foam cover twelve inches thick it still doesn't insulate the water since it isn't in contact with the water. you loose heat under the rigid cover because warm water is evaporating, turning into steam. The steam rises and either escapes from the crack between the halves of the cover or hits the bottom of the spa cover, cools and condenses back into liquid and falls (cooled) back into the spa water below. In your car you would call this a radiator and consider it good because it keeps your engine cool. In your spa this is bad because it causes your spa to work harder to keep your spa water up to temperature. This is despite the fact that the outside of the rigid foam cover can be the same temperature as the ambient air outside, giving the impression that it must be insulating. The simple explanation for this is that the rigid foam spa cover is in contact with the ambient air outside the spa and NOT the water it is supposed to keep warm.

Hot tub rehabilitation

Learn how our hot tubs provide alternative approaches to the treatment and rehabilitation of Rheumatoid Arthritis and other circulation problems that improve with regular use of heated swirling water. Although there are several mechanisms available to deliver symptomatic treatment using local heat to a give relief to a patient, including packs, paraffin wax, and heating pads, whirlpool type baths and spas are often the most convenient and effective. Prescriptions from Doctors can be obtained for serious medical conditions and most times your spa purchase can be used as a medical write off.

Indoor hot tubs

Controlling hot tub condensation: Efficient ventilation and a dehumidifier are your best means of controlling the condensation that can collect on walls, windows, and ceiling, even when the spa is not in use. Covering the spa with a thermal blanket or a solid spa cover will also minimize condensation.

To have the maximum control over your indoor climate, it may be necessary to back up the natural cross ventilation with a forced air system or a closed-loop energy recovery system.

In addition to ventilation, plan on double-glazed windows and skylights that improve insulation and inhibit condensation. Walls panelled with unfinished wood and moisture loving plants are useful because they absorb excess moisture

How to improve efficiency

Measure 1: Improved cover and increased spa insulation levels.

Plentiful insulation in the spa cover and body, properly installed, is the main route to decreasing spa energy consumption, and would decrease energy use by up to 30% for a spa of average-to-low efficiency—more for the least efficient spas. It is likely that these measures would be the first ones deployed, since they require little additional engineering
and design work.

Measure 2: Circulation/filtering pump Improvements.

In general this change would be understood as the addition of a low-wattage circulation pump, but other equivalent options could be imagined to achieve the same effect, such as
improved pump efficiency, innovative multi-speed motor designs, variable speed control and the like. This option could save roughly 15% of the energy consumption of the average-efficiency spa and up to half of the pumping energy used for circulation and filtering. This measure would require some manufacturers to invest in product development and design work, and would likely be deployed after insulation improvements.

Measure 3: Automated programmable controls.

Controls could save about 5% of a spa’s energy consumption by permitting the user to customize settings based on anticipated usage patterns. Another potentially important

For ease of muscles use Golf Trolleys available here

Hot tubs Benefits Explained

Interested in the health benefits of Spas, Hot Tubs and Swimming Pools? Click here for research on hot tubs and spas

University research shows how hot tubs can have health benefits
Click here for research on hot tubs

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Story about hot tub monkeys

Why do the Monkeys know?
Another story about hot tub monkeys.

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Interested in the history of Spas, Hot Tubs.
History about hot tubs from the Roman times