Little and Often

Collectively, the human race uses huge amounts of energy every day, which is taking a toll on the planet. Cutting down on this consumption has become a priority and 'little and often' is proving to be a very effective strategy. Hand drying uses a small amount of energy but billions of people do it multiple times a day.

It is a simple truth that we all must wash our hands several times a day. If we didn't, bacteria would start multiplying and then quickly begin transferring from person to person. Public health would suffer fairly rapidly and if the spread of illness wasn't checked, epidemics would break out.

However, each hand-washing session has an effect on the environment and these add up fairly quickly. But if each washing could be made a bit more eco-friendly, those gains would also add up at the same rate. Let's look at the possibilities.

Effective washing needs a certain minimum amount of soap and water. Taps and dispensers can be designed to encourage prudent consumption of these resources while the heat of the water can be optimised to balance effectiveness, comfort and energy efficiency.

Hand drying has the potential for massive energy saving, thanks in part to the emergence of a new generation of hand dryers.

Today, few public washrooms use linen towels because of the cost of laundering them. People do not like to use a towel that is not absolutely fresh, with the result that linen towels tend to be used once then sent to the laundry. Paper towels are intended to be single-use but this means there is constant consumption - which means constant manufacture (paper-making is an energy-intensive process), constant vehicle movements for delivery of new towels and the effects of the disposal procedures.

Consider, as an example, a company located in a 10-storey office building and using 320,000 paper towels per month. This would generate 770 kilograms of waste paper, equivalent to16 trees per month or 192 per year. (This assumes a tree to be eight metres in height and 14cm in diameter and that it could be processed into 20,000 towels with a thickness of 0.088mm.) If the waste paper were piled up, it would reach 28 metres per month or 336 metres per year, roughly the height of an 80-storey building.

We are left therefore with the realisation that the greenest option is electric hand dryers. Conventional dryers work by using hot air to evaporate moisture from the hands. This uses a lot of energy because you need to heat the air to a high temperature and then get it moving quickly to deliver the heat before it all disperses.

Back in the early 1990s, long before eco-considerations were mainstream, far-sighted design engineers at Mitsubishi Electric began to wonder about improving on this concept. The idea they developed is today embodied in the Mitsubishi Electric Jet Towel hand dryer. This does not work in the same way as conventional units; instead, it creates a high-speed sheet of air that shears water off the hands.

While testing the concept, Mitsubishi Electric saw its remarkable energy efficiency and set about optimising the product design to ensure maximum efficiency. The main power consumer within the Jet Towel is the fan motor and Mitsubishi Electric realised that it had the opportunity to completely redesign this.

Most motors are intended to be adaptable to as many different duties as possible, so end up as a compromise design. However, the expected production levels of Mitsubishi Electric's Jet Towel were such that it was viable to design a unique motor, tailored exactly to the needs of the application. It had to be small and very quiet, whilst being able to accelerate up to a set running speed in an instant. The engineering team set about developing a design and realised that energy efficiency could be improved massively over a general purpose motor.

With such a success on the motor, the team was spurred on to examine other aspects of the Mitsubishi Electric Jet Towel for energy optimisation too.

For instance, one radical decision was to create a 'drying chamber' into which users would insert their hands. This would concentrate all the power of the air flow and almost completely eradicate the sort of dispersal losses that plague traditional hot air dryers where much of the power is lost to the surroundings. Fearful that users would not like to put their hands anywhere they could not clearly see, ergonomists were brought in and the chamber was developed as a slot, open to the top and both sides of the Mitsubishi Electric Jet Towel body.

Detailed design went into developing optimised nozzle shapes and air flow paths so that energy efficiency was never compromised. A very attractive by-product of all this focus on efficiency emerged in that very little of the energy is wastefully converted economy into noise. As a result, the Mitsubishi Electric Jet Towel is whisper quiet in operation (58-61dB) and has even been awarded a coveted Quiet Mark Award from the Noise Abatement Society.

Mitsubishi Electric's Jet Towel is fitted with a highly efficient 550W motor compared to an averagely efficient 2500W motor in a dryer. Because of the optimised design, drying times are from only 9 seconds compared to 30 seconds for an old-style unit. The combined result is a reduction in energy consumption of about 90%.

This economy can be illustrated by looking at the amount of the greenhouse gas carbon dioxide involved. A rough calculation shows that the power savings achieved by a Mitsubishi Electric Jet Towel compared to a conventional dryer would result in savings of about 1300kg of CO2 per year, which is equal to boiling a kettle for 18 years or running a tumble dryer for eight years.

The Mitsubishi Electric Jet Towel's energy-efficiency is reflected in its running costs and has been recognised by the Enhanced Capital Allowances Scheme (ECA) - a key part of the Government's programme to manage climate change. The scheme provides businesses with enhanced tax relief for investments in equipment that meets published energy-saving criteria.

In conclusion, we can say that Mitsubishi Electric's Jet Towel is probably the world's most eco-friendly way to dry hands. A by-product of this is that they are also a very cost-effective option for washrooms of all sizes in every sort of public building.

About Mitsubishi Jet Towel

Mitsubishi Electric's first Jet Towel was launched in 1993 and the version now available in Europe is in the eighth generation of its development. It has proved a winner with installers for its high tech elegance, with operators for its low running cost and reliability, and with users for its convenience, speed, hygiene and innovative design. The Jet Towel has high environmental credentials, avoiding the use of paper towels or rolled cloth and lowering power consumption and noise levels to a fraction of alternative hot air dryers.

Further Information

Website: www.jettowel.co.uk
Email: [email protected]