When specifying the hardware for bathrooms, most facilities managers will choose between paper towels, or hand dryers.  Reducing waste, environmental impact and costs will often rule out paper towels due to the high CO2 emissions from their manufacture and high stocking costs, not to mention disposal.  This leaves electric hand dryers.

There are two main types of hand dryer on the market.  Warm air or evaporative hand dryers, and jet hand dryers. While both types look similar, they work in very different ways.

Evaporative hand dryers rely on heating the air that passes through them to dry the hands.  As moisture is spread over the skin in the airflow, it effectively boils away.  Jet hand dryers use fast moving air to blow the droplets of water straight off the skin.  In the case of a hands-in hand dryer like the Mitsubishi Electric Wave i01, this moisture is collected in a reservoir for later disposal.

The advantage of a jet hand dryer such as the Mitsubishi Electric Wave u02 in terms of hygiene is that nothing is left on the skin after use.  With a warm air design, as the water evaporates from the skin it leaves behind any traces of soap and bacteria that were suspended in the water.  This can leave a thin layer of residue on the skin after use.

Choosing a no-touch design

No-touch, or automatic hand dryers start to operate when a user puts their hands into the drying area.  A proximity sensor is activated, and the fan begins to work.  This means that unlike in older dryers which were manually operated, there is no need to push a button and risk spreading germs from one person to another.

A further advantage of an automatic design is that the hand dryer only operates for as long as the user has their hands in place.  This can save a substantial amount of electricity when compared to a design which runs on a timer and may continue to operate for some time after the user has left.