With energy-consuming equipment, such as water heaters and refrigerators, we have good data on energy consumption and can set clear standards accordingly. In some product categories—clothes washers, for example—Energy Star standards were adopted because those standards provide a high enough threshold to represent just the very top segment of the product market (less than 10%). In other product categories—e.g., refrigerators and dishwashers—we set a higher threshold than ENERGY STAR: for example, exceeding those standards by 10% or 20%. With lighting and lighting control equipment, certain generic products qualify, such as compact fluorescent lamps and occupancy/daylighting controls, while in other categories only a subset of products qualify. In some cases, products that meet the energy efficiency requirements are excluded, because of evidence of poor performance or durability. Microturbines are included here because of the potential for cogeneration (combined heat and power) that they offer.
Alternative wastewater disposal systems reduce groundwater pollution by decomposing organic wastes or removing nutrients more effectively. Hand dryers reduce water and paper towel use, alternative treatments for cooling tower water reduce chemical use, and carpet tile allows modular replacement of worn areas. In screening products for this area, we focus on quantifiable environmental benefits and strong performance records.
Airforce is a touch-free, high-speed hand dryer that uses multiple air nozzles to blow and evaporate water off hands in about 12 seconds. An infrared sensor triggers the unit and there is a 30-second vandal-resistant shut off. These units use 1,100 watts to power a 34,000 RPM motor that pushes air through eleven small openings, converting a low 53 cfm into 10,500 lfm of air flow at a sound level of 83 dB. The compact Airforce is 10.7" H x 8.9" W x 6.5" D and weighs seven pounds. Available with a chrome finish or a white paint that incorporates SteriTouch, a silver antimicrobial treatment. World Dryer also makes the Air Max, a heavier duty machine for high-use or vandal-prone settings, such as schools or rest areas.
Use of electric hand dryers generally carries significantly lower environmental burdens than use of paper towels. Electric hand drying also significantly reduces custodial labor requirements.
GreenSpec lists high-performance electric hand dryers that are energy-efficient, fast, and convenient—maximum 1,600 watts, less than 15 seconds drying time—resulting in significantly lower energy use than conventional electric hand dryers.
One weak point of hand dryers in general, including high-performance hand dryers, is their noise. Although not widely used, the NSF Protocol P335 certification establishes a 15-second drying time and a 90 dBA limit on continuous noise, which GreenSpec has also adopted.
Ratings and Commentary