The High Efficiency Urinal (HEU) has been a part of the North American plumbing fixture marketplace for close to 20 years. This long history includes both flushing and non-water urinals. The HEU is defined as a fixture that flushes at 0.5 gallons per flush or less, a threshold that is 50 percent of the current U.S. national standard (maximum) of 1.0-gpf mandated by the U.S. Energy Policy Act in 1992. Although fixtures currently considered as qualifying for the HEU designation fall into several different design and flush volume categories, the Town of Windsor provides rebate incentives only for pint flush and waterless varieties. These urinals save the greatest amount of water and reduce wastewater without sacrificing performance.
Pint flush urinals (0.125 gpf) can be configured with manual or automatic sensor style flush-o-meter valves and typically requires matching vitreous china that comes in a range of styles and mounting options.
Waterless urinals all use basically the same science. Urine flows down the bowl of the urinal past a debris-catching strainer. The urine then passes through a sealing liquid, usually a specially designed vegetable oil based fluid, and collects in the waste pipe below. The different densities of urine and oil (urine is denser than oil – oil floats!) mean that the urine sinks through the sealing liquid and the oil floats on top of the layer of urine below. Any air bubbles rise to the top and escape, leaving the urine in a relatively low oxygen environment. Odor is therefore trapped below the oil layer and cannot find the nose of bathroom occupants.
There are two varieties of waterless urinal: cartridge based and non-cartridge based units. Cartridge based units use a replaceable cartridge that is pre-filled with sealing liquid. Cartridges are periodically replaced as the sealing liquid is slowly eroded or degraded. Non-cartridge based systems work by simply introducing the sealing liquid into the drain hole and allowing it to naturally settle into the correct position.
What about performance?
All flushing HEUs must meet the very same waste removal performance requirements as all other flushing urinals sold in North America. All urinals, regardless of flush volume, may experience problems when installed in commercial building locations with degraded, aging, or poorly installed systems, e.g., insufficient drain-line slope, pre-existing buildup of solids, etc. In most cases, additional sources of wastewater upstream of the urinal fixture may help to reduce or prevent solids build-up in the drain line.
Performance testing protocols (such as MaP testing for toilets) have not yet been developed for urinal fixtures and, as such, readers are urged to seek out performance and maintenance information from other sources. In addition, readers are strongly urged to perform a full life cycle cost analysis of purchase, installation, and maintenance before making a purchase decision. When authoritative performance testing protocols are developed and fixtures are tested, the results will be made available.drain-line