Green codes and water conservation
By Ron George,CPD,
President, Ron George Design & Consulting Svcs.
International Green Construction Code is finalized
The International Code Council (ICC) has finalized its International Green Construction Code and is readying it for publication by the spring of 2012. The code is being coordinated with other international codes already in place and includes many water and energy saving features that will be familiar to anyone who has followed other green codes, standards and programs. It also has provisions intended to make the code simple to follow without performing a lot of calculations.
The ICC green code will cover water conservation issues such as:
• Fixtures, fittings and appliances, including faucets, toilets, urinals, dishwashers, washing machines, pre-rinse spray valves, showers and drinking fountains.
• Hot water delivery system design, including pipe sizing and insulation.
• Reclaimed water use and systems, including municipally reclaimed water, onsite water recycling systems, rainwater catchment systems, condensate capture systems, foundation drain-water reclamation systems and dual plumbing considerations and requirements.
• Landscape and site water use, including xeriscaping, turf, landscaping and storm water management.
• Recreational water such as pools, spas, ornamental water features and water parks.
The proliferation of codes, specifications, standards, guidelines, regulatory mandates and similar initiatives throughout North America is largely unnecessary. Multiple editions of green codes and standards are being simultaneously developed in a flurry that reminds me of the space race. Everyone is trying to have the first green code, standard or supplement available on the market so it will be adopted by the various authorities having jurisdiction. The number of green codes and standards that are being developed can be confusing. ICC and IAPMO, LEED and Green Globes, ASHRAE 189 Standard for the Design of High-Performance Green Buildings and several others are all green codes, standards and guidelines, and they do not all agree. In some rare cases, these actually encourage wasteful designs and practices.
This is not a condemnation of the green codes, which are very important contributions to improving the built environment. Because multiple competing documents are being developed simultaneously, it is nearly impossible for someone to attend all of the hearings, review the drafts and provide comments to nearly a dozen different green codes and standards. This renews the debate for one code. The plumbing industry has been dealing with multiple plumbing codes and politics for years, but the electrical industry has one code.
Recently, numerous proposals and changes were made to the initial draft of the International Green Construction Code. With a few exceptions, there was not much testimony on code change proposals from plumbing industry people. Most of the input seemed to be from individuals or groups interested in conservation. Many of them did not seem to be aware of the language in the current plumbing codes and standards, the laws of physics, plumbing installation practices or engineered plumbing systems.
Compared to other codes and standards, such as ASHRAE’s Standard 90.1, Requirements for Pipe Insulation, which requires calculations, Section 607.5 of the International Green Construction Code tried to keep it simple. Insulation thickness is equal to the pipe diameter, up to two inches; ½-inch pipe, for example, requires ½-inch insulation and so on up to 2-inch pipe diameter. Pipe 21/2 inches in diameter and larger would also get a minimum of two inches of insulation. If larger pipe is installed in a commercial building, it is usually specified as part of an engineered system; the engineer understands the resistance value (R-value) of various insulation materials and, typically. specifies the insulation material, R-value, jacket type and insulation thickness, based on the system temperatures and the design requirements.
Another simplification involves the length of pipe from the source to the fixture for hot water systems. A lot of water is wasted waiting for hot water to flow from the water heater to the fixture. To reduce this waste of water and energy, most green codes, including the International Green Construction Code, require either an on-demand hot water recirculation loop or heat tracing on the pipe. Some design professionals have expressed the concern that the use of heat tracing cables on domestic hot water pipes could allow hot stagnant water to sit in the pipes at a temperature that is ideal for amplification of any bacteria and pathogens that may be in the water supply. Provisions should be made to periodically raise the hot water temperature to a disinfecting temperature of about 160 F or higher. Precautions should be taken to prevent scalding by scheduling down time for the hot water system. During this disinfection, which should be done during an off-peak period, the hot water main valve should be closed to prevent usage that could scald someone.
Previous attempts to limit the amount of wasted ambient temperature water in the hot water pipe mandated how far the fixture could be from the hot water source using the developed length of the pipe. The plumbing code called for the hot water to be within 100 feet of the fixtures served or within 100 feet of a circulated hot water line; otherwise a temperature maintenance system would be required. Previous attempts to limit wasted water also addressed lowering the distance and limiting the volume of water in the pipe between the source of hot water and the fixture. The problem with calculating the volume of water was that each type of pipe material — copper, PEX, or CPVC — has a different interior volume.
The International Green Construction Code abandoned that approach and now considers all pipes to be the same. Table 702.8 gives the maximum number of linear feet of pipe allowed for 11 sizes of pipe from ¼-inch to 2-inch. The table says, for example, that for ½-inch pipe, you can run 43 feet of pipe on systems that do not have a hot water return circulating loop or heat tracing. For systems that have a hot water circulating loop or heat tracing line, the maximum length of ½-inch pipe from the loop to the fitting is 16 ft.
The maximum distance for public lavatory faucets is two feet. This will require most systems to circulate domestic hot water through the plumbing chase behind public restroom lavatories. In a public restroom, the flow rate for metering faucets is mandated as ½ gpm per minute, in accordance with the Energy Policy Act of 1992. People using public washrooms tend not to wait for hot water and to wash their hands in cold or ambient temperature water
The International Green Construction Code prohibits continuous running of circulating pumps on domestic hot water systems, timer operation or water temperature-initiated or aqua-stat operation of a circulating pump. Gravity or thermo-siphon circulation loops are also prohibited. Many of these are viable options for larger institutional, commercial or industrial facilities with continuous or 24-hour demands.
Domestic hot water circulating systems must now be controlled with either hard-wired or wireless controls activated by one of the following:
• A normally open, momentary contact switch.
• Motion sensors that make momentary contact when motion is sensed. After the signal is sent, the sensor must lock out for at least five minutes to prevent restarting the pump while the circulation loop is still hot.
• A flow switch. This will not be practical in large buildings, where it could take in excess of 10 minutes to get hot water to the farthest fixture from the hot water source. This option can also contribute to hot water temperature fluctuations and sudden temperature changes during showering in larger buildings.
• A door switch. This has the same drawbacks as the flow switch.
The controls have to keep the pump off if the temperature is above 105 F, in case the device that senses temperature rise fails. Controls must also have a lockout that prevents extended operation of the pump if the sensor fails or is damaged.
Plumbing fixture flow rates were simplified to single numbers on a table. The International Green Construction Code originally had two numbers built around a base case and a better case. California’s CalGreen code has three possible flow rates. Again, water conservation was the main focus during the hearings, and there was no supporting data addressing scalding with low flow showers, thermal shock or drainline carry at these lower flows.
Showerheads would be limited to a maximum of 2.0 gpm, private lavatory and bar sink faucets to 1.5 gpm, kitchen faucets to 2.2 gpm, urinals to 0.5 gallons per flush (gpf) or non-water and toilets to 1.28 gpf. No comprehensive drainline flow studies were done to support drainline transport of solids at these rates. Because of the proliferation of drain blockages in large horizontal buildings with 1.6 gpf fixtures, an amendment was accepted to allow higher flowing fixtures for these buildings. More research is needed in this area. The table also has flow rates for public lavatory faucets, pre-rinse spray valves and drinking fountains.
Because of the possibility of drainline blockages with current 1.6 gpf fixtures, there was one proposal for remote water closets on the end of drainlines in large industrial or commercial buildings. These can be 1.6 gpf water closets if they are located not less than 30 feet upstream of other drainline connections or fixtures and where less than 1.5 drainage fixture units are upstream of the drainline connection. This still will not solve the problem if current 1.6 fixtures are not getting the job done.
Green legislation: California law requires water conserving fixture disclosure
A new California real estate transfer law will likely drive the demand for more water efficient fixtures in 2012 and beyond. The new law, effective January 1, 2012, revises the California real estate transfer disclosure statement (TDS) to include a checkbox for the seller to disclose whether a property has water-conserving plumbing fixtures.
By January 1, 2017, a single-family residence built on or before January 1, 1994 must be equipped with water-conserving plumbing fixtures, which include low-flow toilets, showerheads and faucets under section 1101.3 of the California Civil Code. There is a danger associated with mandating low flow fixtures on older homes without verifying the existing plumbing systems that the fixtures will be connected to. For example: if an older home has a two-handle shower valve of the non-temperature compensating type or non-pressure compensating type, installing a low flow shower valve can significantly increase the potential for scalding incidents because of the potential for crossover flow. No amount of water savings is worth having hundreds of people scalded and severely burned.
The public and the plumbing industry must be warned of the dangers of mandating ultra-low-flow (ULF) showerheads on older non-code compliant shower valves. I worked on a scald awareness task group with the American Society of Sanitary Engineering (ASSE) to develop a white paper warning of the dangers of scald hazards associated with low-flow showerheads. The paper can be can be downloaded at www.asse-plumbing.org/ScaldHazards.pdf.
Some types of code compliant shower control valves will not perform well with ULF showerheads. Any legislation calling for installation of low-flow or water conserving fixtures should require that the shower valve and showerhead be purchased as a matched set from the manufacturer, in order to assure that scalding will not occur in ULF showers.
As for drainline carry, many older homes have 4-inch or 6-inch building drains and building sewers leading to the public sewer. If low-flow fixtures are mandated for these older buildings, there will likely be an exponential increase in drainline blockages, because the hydraulic depth of flow will not be sufficient in large drainlines with ULF water closets. California and Texas have legislation requiring 1.28 gpf ULF water on all new construction in 2014.
In new construction, drain sizes can be reduced to accommodate the lower flow rates and maintain a hydraulic depth of flow in the drains.
If this ULF fixture requirement is applied to existing construction, it could be devastating for drainline carry of solids. It will be great news for drainline cleaning businesses. The larger pipe sizes, coupled with lower flows from ULF fixtures, will likely result in insufficient flows for drainline transport. I have always said, “There has to be enough water in the river to float the boats.” If this legislation goes through, I would advise you to consider buying stock in a sewer cleaning business.
Drainline carry study needs funding to proceed
Water-efficient fixtures lead to reduced water consumption and result in lower drainline and sewer line wastewater flows. Lower mandated flow rates for fixtures provoke important drainage questions: Do these reduced flow rates lead to stoppages of waste in building drains? How low can flows be reduced without causing solids to clog the drainline? What is the minimum drainline flow rate for each pipe size? Does the installation of certain high-efficiency plumbing fixtures or systems contribute to drainline stoppages? If so, are remedies available that can mitigate or prevent drainline stoppages?
The Plumbing Efficiency Research Coalition (PERC) is undertaking an important study on the potential for building drainline blockages with low-flow plumbing fixtures. Work on this important research can begin in early 2012, thanks to generous contributions from water utilities and others and a kind offer from American Standard Brands to allow the use of its test apparatus. However, an additional $50,000.00 of funding is necessary to get this study started. If you would like to support this research, please contact Mary Ann Dickinson at the Alliance for Water Efficiency. Contributions are tax deductible. You can send a tax deductible check in any amount to:
The Plumbing Efficiency Research Coalition
Care of The Alliance for Water Efficiency
300 W. Adams Street, Suite 601
Chicago, IL 60606
More green legislation: Mortgage underwriting could take energy efficiency into consideration
An energy efficient home could mean a better mortgage for the borrower. Legislation titled “The Sensible Accounting to Value Energy” (SAVE) Act of 2011 (S.1737), introduced on October 19 by Senator Michael Bennet, (D-Colo.) and Senator Johnny Isakson, (R-Ga.) would require that home energy costs be factored into the formula for determining a home’s overall value and the prospective homebuyer’s eligibility for a loan.
The SAVE Act seeks to incorporate energy efficiency into appraisal and mortgage guidelines so as to ensure appropriate valuation of energy costs and energy efficiency improvements in the mortgage process. This legislation deals directly with federal agencies involved in mortgages (e.g., Fannie Mae and Freddie Mac). Because these agencies guarantee around 90% of the home mortgages in the United States, changes to their standards would likely affect the vast majority of new home mortgages in the United States, including home re-financings.
These guidelines would require that an energy efficiency report provided to the mortgagee be used to determine energy savings. The present value of the estimated energy savings would be added to the appraised value of the property when determining loan-to-value ratios of the property if the value of the energy efficiency is not included in the appraisal. Energy savings would be calculated relative to an average comparable house, according to rules set by HUD. They would account for the estimated life of the applicable equipment, and they would be discounted annually, using the average interest rate for 30-year mortgages.
Several adjustments would be made to the Financial Institutions Reform, Recovery, and Enforcement Act of 1989 to better enable appraisers to consider the energy efficiency of a home. Appraisals that use an energy efficiency report would need to be done by state certified appraisers, who meet higher qualification requirements. Lenders would be required to grant state certified appraisers timely access to information about a property’s energy and water conservation features, including ratings.
Regulations would include any necessary limitations to protect against double counting and under- or over-valuation of efficiency improvements. After seven years, HUD could alter regulations or add additional exceptions to better reflect actual market values for properties’ energy efficiency.
Within 18 months of enactment, HUD would establish an advisory group to report and comment on implementation of these underwriting criteria. They could suggest revisions or additions, which can include the addition of location-based transportation costs and water costs as factors in the underwriting.
Although the law would allow other suitable third-party methods to be used, the preferred tool for estimating energy costs is The Home Energy Rating System (HERS) index, which was established in 2006 by the Residential Energy Services Network (RESNET), a California-based national association of home energy raters and energy-efficiency mortgage lenders. The lower a home’s HERS Index, the more efficient the home.
To calculate a home’s HERS index, a rater uses a computer program — most commonly, REM/Rate. (RESNET has also approved three other software programs.) REM/Rate compares the home being rated to a “reference home,” which is an imaginary home of the same size and shape as the home being rated. The reference home is assumed to barely meet the 2006 International Energy Conservation Code. If the home being rated has thicker insulation or better window glazing than the reference home, those improved specifications will result in a lower (better) HERS Index.
The HERS Index is a useful metric; it doesn’t indicate, however, how much energy a home will use. Although it’s a good sign if a home has a low HERS Index, that doesn’t mean that energy bills will be low. For example, if you have a large house with a low HERS Index, all you know is that your house will use less energy than a typical large house. But a large HERS 70 house can still use more energy than a small HERS 100 house.
The HERS Index doesn’t take occupant behavior into account. Researchers who study residential energy use have long known that occupant behavior explains much of the variation from one house to another. When all other things are equal, occupants who use higher thermostat settings and take longer showers can affect the overall energy usage.
Green legislation: California rainwater capture bill vetoed
California Gov. Jerry Brown recently vetoed California Assembly Bill AB 275, the proposed Rainwater Capture Act of 2011, which would have authorized a landowner to install and operate a rainwater capture system for two purposes: (1) outdoor non-potable use or infiltration into groundwater or (2) subsequent indoor non-potable use.
In his veto message, Gov. Brown stated his preference for adopting a rainwater capture standard through the state’s Building Standards Commission process. This bill would apparently have created a conflict with the commission’s existing process for adopting codes.
Although rainwater catchment systems are growing in demand and popularity, this is the second year in a row that a California governor has vetoed a rainwater capture bill. Governor Arnold Schwarzenegger vetoed a similar bill last year but for different reasons.
Ron George is president of Plumb-Tech Design and Consulting Services LLC. He has served as chairman of the International Residential Plumbing & Mechanical Code Committee. Visit www.Plumb-TechLLC.com, email Ron@Plumb-TechLLC.com or phone 734/755-1908.