« Return to BuildingGreen.com
  • Remove facet 22 00 00: Plumbing
View: GridList

Access to fresh water is one of the world’s major geopolitical issues, yet in most of the U.S. we still use drinking-quality water as if it were free and unlimited. A substantial portion of this usage happens in buildings where leaky plumbing drips it away and fixtures designed decades ago use exorbitant quantities.

In some areas of North America, water is drawn from ground and surface sources at unsustainable rates—in other words, withdrawals from aquifers exceeding annual recharge rates. For much of the year, for example, the Colorado River no longer reaches the Gulf of California. In the U.S., we currently withdraw more than 300 billion gallons of fresh water per day from streams, reservoirs, and wells. Even in places where the water supply has traditionally not been a concern, problems are appearing as populations grow or precipitation patterns change (perhaps due to global climate change).

Water-saving designs

Toilet flushing uses over 4 billion gallons of water per day in the U.S. alone. While older toilets use about 4 gallons per flush, modern toilets conform to the requirements of the Energy Policy Act of 1992 and use no more than 1.6 gallons per flush (gpf). The Energy Policy Act of 1992 also mandates that showerheads and faucets can use no more than 2.5 gallons per minute (gpm); some models use substantially less. Retrofitting these devices in older buildings is usually a very easy and extremely cost-effective investment.

GreenSpec lists plumbing fixtures, such as low-flow toilets, showerheads, faucets, and waterless urinals, that significantly outperform federal water efficiency standards and meet or exceed EPA’s WaterSense standards. Equipment that can be combined with low-flow fixtures to further save water through refining on off controls is also included.

Energy use of water systems

Constant access to clean hot and cold water is a great creature comfort, but comes at a high cost. Treating and transporting potable water and wastewater is energy and chemically intensive. Heating and cooling water also uses a great deal of energy. Wasting water also wastes energy.  Attention to increasing the efficiency and performance on plumbing fixtures, water heaters and coolers, and wastewater options are important elements of green building.

Heat-pump water heaters can be very efficient, but are not a good fit for all environments. On-demand gas water heaters are more efficient than storage-tank type systems. If storage tank-type water heaters are used, consider adding an insulating blanket, which can reduce standby heat loss by 25% to 45% according to the U.S. Department of Energy.

Heat exchangers and heat recovery systems can help optimize the performance of residential and commercial hot water heaters.

Many types of solar thermal systems are available and increasingly used for both water heating and pool heating. These systems are covered in Heating, Ventilating, and Air-Conditioning (HVAC).

Rainwater harvest and graywater recycling

The drain on limited water supplies can also be reduced by harvesting rainwater. On some of the Virgin Islands, rainwater-storing cisterns provide the primary water supply to most homes. In parts of the U.S., it is not uncommon for collected rainwater to be used for landscape irrigation, toilet flushing, laundry and other nonpotable uses in both residential and commercial buildings. For use as potable water, collected rainwater should be filtered and disinfected. Rainwater collection systems are listed in the Utilities category.

Consumption of potable water can also be reduced by recycling graywater for nonpotable uses, such as irrigation and toilet flushing, although these systems may be prohibited by local health codes. In most of California it is legal to use graywater for landscape irrigation, provided the system meets certain conditions.

Wastewater treatment

The other end of the plumbing system is wastewater disposal. Many conventional wastewater treatment systems, including both large municipal systems and private on-site septic systems, are inefficient and/or expensive. Alternative technologies—from composting toilets and recirculating sand filters to ecological wastewater treatment systems that rely on enhanced biological treatment processes—are available for systems of all sizes.

graywater systems and composting toilets can significantly reduce wastewater discharge from buildings, offset irrigation demand (graywater), and treat waste and recover nutrients onsite.

Piping options

The three major materials currently used in supply piping in North America are copper, chlorinated polyvinyl chloride (CPVC), and cross-linked polyethylene (XLPE or, more commonly, PEX). Polypropylene (PP) piping is also available, though far less common.

Most sanitary drain waste and vent (DWV) piping used today is made from PVC or ABS plastic, replacing cast iron, the traditional DWV pipe material. Vitrified clay pipe can be used in buildings as drain pipe but is more commonly used for larger-diameter sewage applications (where it competes with concrete and PVC); although heavy and labor-intensive, vitrified clay is the most durable waste and sewage piping material. Finally, there are some polyolefin (polyethylene and polypropylene) plastic pipes that can be used for drainage and venting.

All of these materials present their own environmental challenges, and while there are life cycle analysis studies that compare some of these options, there is to date no exhaustive study that addresses the range of relevant issues including manufacturing impacts; potential corrosion and leaching concerns; energy impacts of plumbing design and layout; and end-of-life considerations.

Access to fresh water is one of the world’s major geopolitical issues, yet in most of the U.S. we still use drinking-quality water as if it were free and unlimited. A substantial portion of this usage happens in buildings where leaky plumbing drips it away and fixtures designed decades ago use exorbitant quantities.

In some areas of North America, water is drawn from ground and surface sources at unsustainable rates—in other words, withdrawals from aquifers exceeding annual recharge rates. For much of the year, for example, the Colorado River no longer reaches the Gulf of California. In the U.S., we currently withdraw more than 300 billion gallons of fresh water per day from streams, reservoirs, and wells. Even in places where the water supply has traditionally not been a concern, problems are appearing as populations grow or precipitation patterns change (perhaps due to global climate change).

  • Rada Digital Thermostatic Faucet
  • Rada Digital Thermostatic Faucet
  • Rada Controls
  • Rada Digital Thermostatic Faucet
    Rada Controls
    Customized for hospitals and other healthcare settings, digital thermostatic faucets from Rada are touchless, low-flow fixtures designed to automate pathogen management activities that are important for flushing biofilms from plumbing pipes and fixtures in healthcare settings. (Such biofilms, once they take hold, can distribute Legionella and other disease-causing pathogens to patients and others in aerosolized water.) Automation takes a major burden off facilities personnel while also using less water and energy than manual maintenance procedures. The fixtures also support high water-heater setpoints because they mix very hot water with cold water safely right at the tap, and they feature digitally controlled low flow rates. The digital controls eliminate the need for a flow regulator on the faucet itself, at the same time making it possible to perform automatic flushing at very high flow rates. They also have a simplified interior design that minimizes the use of elastomers, which can encourage biofilm growth. The faucets are distributed by Kohler in the U.S.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Rada Digital Thermostatic Shower
  • Rada Digital Thermostatic Shower
  • Rada Controls
  • Rada Digital Thermostatic Shower
    Rada Controls
    Customized for hospitals and other healthcare settings, digital thermostatic showers from Rada are low-flow fixtures designed to automate pathogen management activities that are important for flushing biofilms from plumbing pipes and fixtures in healthcare settings. (Such biofilms, once they take hold, can distribute Legionella and other disease-causing pathogens to patients and others in aerosolized water.) Automation takes a major burden off facilities personnel while also using less water and energy than manual maintenance procedures. The fixtures also support high water-heater setpoints because they mix very hot water with cold water safely right at the tap, and they feature digitally controlled low flow rates. The digital controls eliminate the need for a flow regulator on the shower itself, at the same time making it possible to perform automatic flushing at very high flow rates. They also have a simplified interior design that minimizes the use of elastomers, which can encourage biofilm growth. The showers are distributed by Kohler in the U.S.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Niagara Low-Flow Faucet Aerators
  • Niagara Low-Flow Faucet Aerators
  • Niagara Conservation Corp.
  • Niagara Low-Flow Faucet Aerators
    Niagara Conservation Corp.
    Niagara Conservation, an AM Conservation division, offers a diverse line of low-flow bathroom and kitchen aerators to help lower water and energy use. Bathroom aerators are available in dual-thread, male/female thread, and tamperproof versions with flow rates of 0.5 and 1.0 gallons per minute (gpm); the Tri-Max units have adjustable flow rates from 0.5 to 1.5 gpm. Niagara’s kitchen aerators are available in 1.0 and 1.5 gpm models, with some that have a swiveling head and a pause feature that reduces flow to a trickle when activated.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Wahaso Graywater Harvesting
  • Wahaso Graywater Harvesting
  • Wahaso
  • Wahaso Graywater Harvesting
    Wahaso
    Wahaso offers a commercial-grade graywater harvesting system, which includes pumps, storage, filtration, and controls that are custom-designed by the company. The systems consists of a two-stage filtration for particulates, sanitation with chlorine or UV light, a repressurization system of two commercial-grade pumps, and automated controls and reporting that are compatible with building automation systems running BACnet. Wahaso's systems are pre-built on skids and delivered ready for installation. Four models are available for capacities from 7,200 gallons per day to 36,000 gallons per day. The system is pending NSF-350 certification.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Aquatron and Dubbletten Toilet Systems
  • Aquatron and Dubbletten Toilet Systems
  • Rosie's Natural Way
  • Aquatron and Dubbletten Toilet Systems
    Rosie's Natural Way
    Rosie’s Natural Way distributes a urine diverting system, called the Dubbletten, and a composting system, called the Aquatron. The Dubbletten is a low-flow toilet with a split bowl that keeps urine separate from fecal waste from the outset; solids go in the back and liquids in the front. A 1.0 gallon flush is used for the back, and an optional “spritz” (0.01 gallons) is provided for the urinal. The urinal has an elastomeric membrane without a trap, but urine goes directly to a storage tank, where it is sealed by an oil solution. Buildings can then use the urine as a nitrogen-rich fertilizer.

    The Aquatron attaches to the back bowl of the Dubbletten or to a conventional toilet to retrofit it into a composting toilet. The system can be installed up to 196 ft (60m) away because a non-mechanical separator installed an angle below the toilet uses centrifugal force to separate 98% of liquids and flush water from solid waste. Solid waste is diverted to a biological chamber where it decomposes into compost. Liquid waste can then be directed through a UV-filter and phosphorous trap, producing water suitable for irrigation. Aquatron systems range in size from 13 gallons (50 liters) for second homes to 3,170 gallons (12,000 liters), designed for use with 10–12 toilets.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Nexus eWater System
  • Nexus eWater System
  • Nexus eWater
  • Nexus eWater System
    Nexus eWater
    The Nexus eWater system converts a home’s graywater into near-potable water and utilizes waste heat in the water for more hot water heating. The system directs graywater to a collector that has an embedded heat exchanger, which uses refrigeration coils to transfer the heat to the Nexus reHeater. The 70-gallon hot water heater uses 15 kWh per day to heat water to 120°F and has a COP of 4.0. Once the heat is extracted, graywater is pumped through the Nexus reCycler, filtering the water to standards required by NSF-350 at a capacity of 200 gallons of per day. Bubbles are circulated to adhere to soap, dirt, and oils, eventually hardening into a foam that is returned to the sewer. After passing through a UV and carbon filter, the water is near potable and can be used for irrigation or for toilets (code allowing). The system recovers more than 90% of graywater for reuse but requires separate black and graywater plumbing.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Zurn Omni-Flow Urinal
  • Zurn Omni-Flow Urinal
  • Zurn Plumbing Products Group
  • Zurn Omni-Flow Urinal
    Zurn Plumbing Products Group
    The Zurn’s Z5755 Omni Flow Urinal provides the unique feature of accommodating multiple flow rates from 0.125 gpf to 1.0 gpf. This allows plumbers to install multiple low-flow urinals and set one or two to high flow to help move water down the line, preventing uric salt build-up and pipe corrosion. The urinal comes in a standard size for retrofitting and the flush valve has a 10-year life on the battery. Its asymmetric back wall minimizes splash-back.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Steward Hybrid High-Efficiency Urinal
  • Steward Hybrid High-Efficiency Urinal
  • Kohler Co.
  • Steward Hybrid High-Efficiency Urinal
    Kohler Co.
    The Steward Hybrid urinal has the same appearance as Kohler's Steward Waterless model, but flushes with 0.125 gpf. This makes it ideal for installing along with the waterless models in order to provide a flush that will help clear the pipes down the entire line. This wall-hung, vitreous china urinal has a large footprint that can cover an old urinal wall print, making it an easy retrofit. A 15 5/8" extended rim and 3/4" top spud allows for ADA installation. The funnel bowl shape minimizes splash-back and a "flushing spreader," located on the back wall is designed to clean the entire bowl. The urinal is WaterSense compliant when used with WaterSense flushometer.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • DRAIN-FX
  • DRAIN-FX
  • Boemar Products Inc.
  • DRAIN-FX
    Boemar Products Inc.
    The Drain-FX system attaches to any faucet with a removable aerator and by narrowing the flow, creates a pressure washer that can be used to clear clogged drains without chemicals. Reaching a pressure level of 250 psi, the manufacturer claims that the system can break down clogs within one minute. Parts consist of a tool to remove the faucet aerator, a pressure adapter, and a drain clearing hose. The company offers models with varying hose lengths according to the use: the Drain-FX mini for bathrooms, Drain-FX sinks for the bathroom and kitchen, and Drain-FX plus and ultra for the bathroom, kitchen, and laundry.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Polystar Polypropylene Pipe
  • Polystar Polypropylene Pipe
  • ISCO Industries
  • Polystar Polypropylene Pipe
    ISCO Industries
    Polytherm PP-RCT polypropylene pipe is a non-PVC piping that can be used for a variety of applications, including hydronic heating, ground-source systems, potable water, and graywater distribution. The polypropylene pieces are heat-joined in the field with an electric fusing tool to create truly monolithic plumbing systems without the use of solvents or glues. Polystar PP-RCT can function at higher temperatures and pressures than standard PP-R piping, according to the company. The company offers three pipe lines: CT-Red is for high temperature/pressure applications; CT-White is for non-potable applications; and CT-Blue for ambient temperature applications. Polystar is available in diameters from ½" to 24" and in lengths to 20'.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Resno Waterless Urinal
  • Resno Waterless Urinal
  • Enman Corporation
  • Resno Waterless Urinal
    Enman Corporation
    The Resno is a waterless urinal for residential applications that is concealed in a wall and has a tip-out door that can close when not in use. A "biological puck" sold by the manufacturer is placed in the retainer to remove odors and prevent build-up in the sewer pipes, using bacteria to dissolve naturally occurring salts. The puck lasts 1 to 2 months and may have to be periodically rotated to ensure it evenly dissolves. Made of ABS plastic, the urinal is designed for installation into any 2x4 wall.
  • (2 User Ratings)
    Add comment
  • Save to your portfolio 
  • Bison Well Hand Pumps
  • Bison Well Hand Pumps
  • Bison Pumps
  • Bison Well Hand Pumps
    Bison Pumps
    Bison Pumps are manual-operated water well pumps welded from mostly stainless steel components. Bison sells a variety of pumps, including a shallow-well pump for 25-foot depths, pumps for 200-foot depths, and pumps designed for continual use in agricultural, recreational, or commercial settings. Standard models can be installed alongside conventional submersible pumps, while additional models are available for other well types or needs.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • The Chilipepper Appliance
  • The Chilipepper Appliance
  • Chilipepper Systems
  • The Chilipepper Appliance
    Chilipepper Systems
    The Chilipepper Appliance is an on-demand water circulation device that speeds the availability of hot water at the tap. This energy- and money-saving appliance is easily mounted at the most remote tap. The 115-volt pump moves cold water out of the hot-water line and back to the water heater via the cold-water line. The Chilipepper is activated by either a wireless remote or a wired controller.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Simple Pumps
  • Simple Pumps
  • Simple Pump Company
  • Simple Pumps
    Simple Pump Company
    The Simple Pump Company offers a variety of manual and motorized well-head pumps that can operate either as a primary well pump or alongside an existing pump as a secondary option for power outages. Motorized pumps use 12V or 24V DC current and are designed to be powered by a small solar or wind array. Hand pumps are available, and can be switched easily with motorized pumps. Simple pumps can draw from as deep as 350 feet.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio 
  • Full Circle Composting Toilets
  • Full Circle Composting Toilets
  • Full Circle Composting Toilets
  • Full Circle Composting Toilets
    Full Circle Composting Toilets
    Full Circle offers a waterless composting toilet with modular, interchangeable composting containers. The bathroom commode, available in wood, porcelain, or plastic, uses wood shavings for a "dry flush" and a 4-watt ventilation fan to manage odor. A single commode connects via a sealed plastic chute to a roll-off container the size of a garbage pail stored below in a basement or crawl space. When a container is filled, it is disconnected, capped, and set aside to compost. A new container is wheeled into place and connected to the chute. Both active and resting containers are sealed and connected with the exhaust, and the air-handling system draws air through up through the entire compost bin, supplying oxygen to all corners of the container for complete composting. Containers with completed compost can be wheeled outside and emptied onto landscaping. Maintenance takes 15–30 minutes and happens every six months to a year, according to the company. An electronic light indicates when it is time to swap compost bins. A divided, urine diverting bowl is available, to direct urine into a dedicated drain for storage, treatment, and reuse as fertilizer.
  • (0 User Ratings)
    Add comment
  • Save to your portfolio