Independent Testing On High Speed Hand Dryers

This article looks at the comparative dry speed and energy consumption of some of the best known hands under, high speed hand dryers. The majority of information on the internet is based on manufacturer’s specifications which follow no common criteria for testing and are largely subjective judgements. Our studies have shown that virtually all information on the net is misleading. It is so common to see hand drying time as 10 seconds, when in fact there is probably no dryer that currently achieves complete drying in this time period

As such, over a period of time, Intelligent Hand Dryers are conducting the most comprehensive comparative hand drying testing ever to take place.

This article looks at testing on the The Airforce, The Stealthforce, The Vortex, The G-Force, The C-Force and the TurboForce. We also included one of the best performing traditional hand dryers the UltraDry Pro hand dryer as a point of comparison

The Testing was carried out by Int according to the principles outlined in the P335 hand drying protocol. The conditions of which are shown at the end of the article. It looks at the residual moisture left on the hands after a defined time period and then looks at the energy consumption while the hand dryer was in use. All testing is available in video format on request and will shortly be posted on your youtube channel. The starting level of moisture was 2.957 grams before using the hand dryer.

For the hands to be completely dry we believe the hand dryer should achieve a 95% reduction allowing for 5% natural moisture on the hands.

The UltraDry Pro 1 hand dryer – Well know for being one of the better traditional hand dryers and chosen for this very reason. Rather than looking at the very worst conventional hand dryer we thought we should compare with one of the best, this gives a more realistic idea of the minimum cost and energy savings, high speed hand dryers can provide over the very best conventional hand dryers.

Typical purchase price £99 to £129 with a 3 year guarantee

UltraDry Hand dryer a high performance conventional hand dryer

After 15 seconds the UltraDry Pro 1 had achieved a moisture reduction of 74.6%. After 30 seconds the Ultradry pro 1 had achieved a 93.6% reduction. So total hand drying would be achieved between 30 and 35 seconds. The UltraDry Pro 1 is rated at 2.5kw however testing showed it came in under this level at 2.25kw. Therefore the Ultradry pro 1 uses a minimum of 20 watts per dry. We can assume  that 95% of conventional hand dryers will use considerably more than this as most are less effective than the UltraDry Pro 1.

The Vortex – Promoted as a The ‘Guiness book of records holder for the most dries using 30kj of energy’. The mark II version is currently sold at around the £500 mark. The Vortex hand dryer is rated at 0.55kw and measured in our test at just 0.475kw. After 15 seconds the Vortex had achieved a average mositure reduction of 71.5%. Further testing is needed to find out how long it would take to achieve 95% reduction, however this reduction was lower than the conventional hand dryer sample and far less effective than the other high speed hand dryers tested as the following results show.

Vortex hand dryer was the worst performing high speed hand dryer tested

The G-Force hand dryer – Typical purchase price between £155 and £229. The G-force Turbo is a 1.1kw rated appliance and measured at 1.12kw. It is EU manufactured with a 5 year guarantee. There is also a G-Force eco 0.55kw version available that we will publish results for shortly.

After 15 seconds the G-Force achieved an average moisture reduction of 85.2%. The amount of moisture left on the hands was 0.44 grams. The range recorded was between 0.3 and 0.54 grams over the 10 dries. The G-force was tested after 20 seconds and achieved 95% moisture reduction. Therefore The G-Force used 4.66 watts in 15 seconds and achieved a Total dry using 6.22 watts or less.

Out performed the better known Airforce in independent testing 

The Airforce hand dryer – Typical purchase price between £250 and £390 promoted mainly by PHS on rental agreements and one of the most widely seen hand dryers. The Airforce is provided with a 3 year guarantee and is rated at 1.1kw. The test measured energy consumption at 1.136kw.

After 15 seconds the Airforce hand dryer achieved an average moisture reduction of 83.7%. The amount of moisture left on the hands was 0.484 grams. The Airforce took between 21 and 25 seconds to achieve 95% mositure reduction therefore the Airforce is achieving complete drying using between 6.62 and 7.88 watts.

The Stealthforce – Typical purchase price £309 to £399, covered by a 5 year guarantee. The Stealthforce is rated at between 0.275 and 0.7kw, it was tested at 0.36 to 0.713kw on eco and turbo setting.

After 15 seconds on the Turbo 0.7kw setting the Stealthforce had achieved an average mositure reduction of 85.4% with 0.432 grams remaining. By 25 seconds the Stealthforce had achieved a 95% reduction in moisture. The total consumption was therefore 4.86 watts to achieve a complete dry. On the Eco setting the stealthforce has achieved 94.5% mositure reduction. Therefore the total energy consumption was achieved using between 3.3 and 4.8 watts.

One of the World’s lowest Energy consumption hand dryers

The TurboForce – Typical purchase price £195 to £245 with a 5 year guarantee. The TurboForce is rated between 0.35kw and 1.6kw. The test is based on the 1.6kw setting, however the performance is not thought to be effected by operating the hand dryer without heat on the 0.7kw setting. We will update this article shortly with the results of the non heated version.

The TurboForce achieved a 92% reduction in moisture within 15 seconds and had achieved a 96% reduction after 20 seconds. Therefore the Turboforce can claim to have achieved complete hand drying between 16 and 20 seconds using approximately 7.7 watts per dry. The 0.7kw version would be expected to consume just 3.4 watts to achieve complete hand drying

The TurboForce high speed hand dryer. Produced the quickest total Hand Dry

Conclusion

It is important to consider hand dryers against a number of criteria, however in terms of the Hand Drying Speed of the dryers tested (listed from fastest to slowest):

1. TurboForce price range £195 to £240

2. G-Force price range £155 to £220

3. Stealthforce £319 to £399

4. Airforce £259 to £399

5. UltraDry Pro 1 £99 to £129

6. Vortex £500

In terms of Energy Efficiency. The Vortex needs further testing to see how long complete drying takes before it can be included

1. Stealthforce

2. TurboForce (requires confirmation on unheated mode)

3. G-Force

4. Airforce

5. UltraDry Pro

We will be following this up with a look at blade hand dryers which on the whole proved to be more effective than hands under hand dryers, however there is of course a obvious price jump. What this study showed is that high speed hand dryers will generally generate an absolute minimum 65% energy consumption saving (13 watts per dry) against the very best conventional hand dryers and the gap in consumption widens between the very best high speed hand dryers and the very worst conventional hand dryers.

When we conduct site surveys to identify your current models we will apply more fact than general assumption to show what the realistic energy savings are that your business can achieve from changing to energy efficient, high speed hand dryers and make sure that the hand dryer we recommend to you makes genuine financial sense.

Testing Conditions

  • Each hand dryers needs to be pre-tested on hands measured form the tip of the little finger to the outer tip of the thumb. Mean max size for male is 219.9mm +/- 5%. This test was carried out using only one persons hands throughout.
  • Test was repeated 10 times to provide a conclusive average performance and demonstrate levels of consistent hand drying
  • Room Temperature was controlled to 23 0C +/- 5%
  • All jewellery and watches were removed
  • Weigh a folded paper towel on a digital scale and then zero weight
  • place the hands up to wrist level at a controlled temperature of 37 oC for 5 seconds
  • drip without shaking for 5 seconds
  • Place hands under hand dryer for 15 seconds
  • Dry excess water from hands using pre-weighed paper towel then measure the new weight

* Source results from Int testing conducted for Intelligent Sourcing Systems Ltd in July 2013.

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