Builder - January 2009 - (Page 50) HOUSECALL GREYWATER CULVERT DETAIL GREYWATER SYSTEMS detailed of these studies concluded that the delivery time of hot water to the farthest fi xture was cut in half for a PEX home-run system compared to copper trunk-and-branch, and that in most cases, PEX home-run systems maintained a steadier pressure during simultaneous flow events. SYSTEM LAYOUT A consolidated plumbing and mechanical system offers both cost efficiencies and homeowner benefits. For the builder, the shorter and more direct systems are more efficient and more affordable to install. For a homeowner, the concentrated pipes free up the floor plan so that it can be configured however the buyer wants without moving ducts or pipes. Shorter runs also mean quicker hot water at the fi xture and less heat loss along the way. A good layout is shown in the Concept Home, a national, LEED-Silver demonstration house recently constructed in Omaha, Neb. Here, all of the wet areas in the house are stacked vertically and adjacent to the home’s mechanical core, which holds the bulk of the plumbing and ducts for the entire house in a consolidated area. This layout has the least amount of PEX tubing (saving material and labor cost) and the water travels the shortest distance possible—so the homeowner gets hot water fast and wastes less water waiting for it. Common sense approaches such as a stacked plumbing layout have been around for decades and are especially efficient to use today in combination with modern plumbing materials such as PEX. The plumbing industry has other innovative technologies that may be of interest to builders. Residential greywater systems, which allow homeowners to use water twice before it leaves the home, are now breaking into the U.S. market. Greywater is any water that has been used in the home and is free from waste. Grey-water can be used as supply water for toilets and landscaping; this is particularly useful in arid areas of the country. Greywater systems are considered environmentally preferable because they reduce the amount of water supplied to a building and also reduce flows into treatment plants or septic systems. Greywater represents 50 percent to 80 percent of the waste water volume from a typical home, so the water-saving benefits are significant. One such unit, the Hansgrohe Pontos greywater system, allows water from lavatory sinks and showers to be cleaned and recycled. Following fi ltration and sterilization, the recycled water is used for clothes washing, irrigation, and supply water for toilets. In addition to saving water, the Pontos unit uses no chemicals in the cleaning of the water. Michael Chapman of Chapman Homes used a combination of systems in Santa Fe, N.M., in 2000. Because the area has inadequate water resources, both a greywater reuse system and rainwater collection system were installed in an effort to conserve water. The two systems were able to provide irrigation to the homes’ landscaped areas (local government water-use restrictions typically prevent homeowners from planting shrubs and trees). The greywater system filters used water from bathroom sinks, showers, and bathtubs and pumps it to a mulched garden area. On a much smaller scale, the AQUS is a greywater recycling system that captures drain water from the bathroom sink and recycles it for toilet supply water. The system can reduce water usage in a twoperson household by 10 to 20 gallons per day, or approximately 5,000 gallons per year. System costs are typically $200 to $300, though with reduced water usage, this cost would pay for itself within about five years—AQUS systems typically last about 10 to 12 years. TOILETS AND LAVATORIES Wall-mounted toilets are another innovation in the plumbing industry. Because the toilets are fastened to the wall instead of the floor, they can be set at almost any height. This allows for easier bathroom cleaning and saves valuable square footage since the water tank is held inside the wall cavity. Wall-mounted toilets flush quieter than the traditional toilet and can save water as the toilets provide effective waste removal, which does away with double flushing and clogs. And, when you are looking to set your project off from the competition, these units add a bit of design and style. HANGING OUT: Wall-mounted toilets create extra space. GREEN BUILDING CREDITS rendering: Courtesy NAHB Research Center and HUD; photo: courtesy Dur avit Taking all of the above together, how many green building credits can you get with your plumbing system? As it turns out, you can get about 20 percent of all the points you need for certification either with LEED or the National Green Building Standard with a sensible, welldesigned plumbing system. The greywater system is probably most appropriate in water restricted areas; however, homerun PEX systems and consolidated plumbing layouts are good bets all over the country.—James Lyons HAVE A CONSTRUCTION QUESTION? E-MAIL DENISE DERSIN AT: ddersin@hanley wood.com 50 ■ B U I LD E R ja n ua ry 2 0 0 9 W W W.BUILDERONLINE.COM http://WWW.BUILDERONLINE.COM
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