High speed hand air dryers are products that are specifically designed to dry hands by moving air in such a manner that the water is physically removed or evaporated. The ETL aims to encourage the purchase of high speed hand air dryer products with the highest efficiency.
There are three main types of electric hand dryers:
- Conventional warm air dryers use a wide jet of warmed air to dry hands by evaporation. Hands are held beneath the dryer outlet in the airflow and typical drying times are 20-30 seconds. The ETL does not cover this type of electrical hand dryer.
- High speed warm air dryers use jets of warmed air driven at higher speeds than the conventional dryers. A more powerful motor is used to increase air speeds to around 50-80m/s, which allows drying times to be reduced to around 10-15 seconds. Energy is thus saved through reduced drying times and heating requirements.
- High speed ambient air dryers use ambient air at high speeds so that water is removed from the hands. The motor used to drive the air is more powerful than for the warm air dryers so air speeds are greater, and no heater is required. Typical drying times are around 10-15 seconds.
Full lifecycle analysis shows that high speed hand air dryers can save significant amounts of money and CO2 compared to using paper towels.
ETL listed high speed hand air dryers can use up to 70% less energy than standard warm hand air dryers.
ETL listed high speed hand air dryers must:
- Incorporate an electrically driven blower that produces one or more jets of high speed air that can be used to dry hands that are placed beneath, or into, the product.
- Automatically switch off power to the blower and air heater (where fitted) when hands are removed from the product’s drying zone.
- Eligible products must use less than 5.5 kWh of electricity per 1,000 standard drying cycles in its normal mode of operation.
- Have a standard drying time that is less than, or equal to, 15 (+/-0.5) seconds.
Example: installing a single ETL listed high speed hand air dryer rather than a non-listed product, will result in potential annual savings of:
- 972 kWh
- 0.3 tonnes CO2
ETL listed high speed hand air dryers must undergo rigorous testing before they can be listed in order to ensure that they meet both the necessary energy usage requirements, and the expected hygiene, sanitary, drying and time requirements of the user.
Testing procedures are clearly outlined within the ‘ETL Method for the Testing of High Speed Hand Air Dryers’, which can be found online here.
Testing requires standardised procedures for setting and drying of hands, volunteers, setup, and calibration of equipment. These requirements are in line with the NSF protocol P335, which establishes minimum requirements for health and sanitation characteristics of hygienic commercial hand dryers.
The protocol incorporates requirements for the following: air filtration, air temperature, drying time, water disinfection, and automated operation.