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Modern hot tubs: Efficiency redefined

Green manufacturing processes

In today’s hot tub manufacturing environment, many improvements have come through the experience of other industries. For instance, the automobile manufacturing industry has proven the effectiveness of programs such as Lean, Just In Time (JIT), Kaizen (Japanese for ‘improvement’ or ‘change for the better’), and the International Organization for Standardization (ISO).

Many hot tub manufacturers are adopting these new techniques as ways to improve product work flow, manage inventory, and improve product quality. These programs are also important in reducing manufacturing waste.

Continuous improvement programs can deliver green manufacturing results through the very essence of Lean, which is waste reduction. In a quest to reduce operational waste on all fronts, the byproduct has always been reduced environmental waste. In fact, in the last few years, many companies have reduced manufacturing cycle times, process variability, and inefficiencies in all areas.

To achieve these lean results, manufacturers have had to reduce non-value added process steps diligently, and as a consequence, non-value added parts and raw materials, all of which have a direct impact on the environment, have also been decreased. For example, most companies have reduced epoxy usage by 70 per cent, chemical VOCs by 40 per cent and parts usage (e.g. fittings and hoses) by 25 per cent. Further, the energy required during the manufacturing process has also decreased via the efficiencies gained.

Recycled materials

This area is quite new to the hot tub industry as there are not many components that can use recycled material. However, some manufacturers are exploring the use of recycled denim (cotton) as an insulation material, as well as some new engineered cellulose materials made from recycled paper. New fibreglass material designs are now also using post-consumer content, which further helps with the green footprint.

Further, materials like polystyrene used in hot tub cover construction, can also be recycled and is growing in popularity. The movement towards more sustainable materials will continue to grow and give manufacturers more options when designing energy-efficient hot tubs to reduce operating expenses.

To raise the temperature in a hot tub containing 1,552 L (410 gal) of water by one degree it takes 1 kilowatt hour (kWh) of electricity.
Therefore, a 1-kW heater will take one hour to raise the temperature, while a 4-kW heater will accomplish this task in 15 minutes. A larger heater does not use more energy to heat the water, it just heats it faster.
Higher voltage does not mean more energy use, either. Watts (W) or kilowatts (kW) equals voltage times amperage. For example, a 1-kW heater at 110 V uses 9 amps, whereas a 1-kW heater at 220 V uses 4.5 amps. Therefore, both 110- and 220-V heaters use the same amount of electricity to heat the water.


Hot tubs have changed considerably over the years and are not the ‘energy hogs’ everyone thinks they are. The benefits of hot tub ownership, which provide wellness for the body, mind, and spirit, are well worth the cost of a modern hot tub.

The more the consumer knows about the product they are buying, the better they will understand the impact it will have on their household energy bill.



Walker_HeadshotVic Walker is the product design and marketing manager for Custom Molded Products Inc., a manufacturer of components for the swimming pool, hot tub, and aquatics industries in Newnan, Ga. He has almost 20 years experience as an industrial designer and more than 13 years experience in the pool and hot tub industry where he has been awarded more than 15 patents for his contributions. He can be reached via e-mail at

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