IAPMO is tackling water waste, one over-sized pipe at a time.
The mission of IAPMO is to develop and enforce safe and efficient codes and standards, along with identifying best practices for the installation of certified products, systems and materials. While providing value to members and the plumbing industry is vital, the organization is also committed to supporting sustainability for water resources. Fortunately, those simultaneous commitments don’t contradict each other.
IAPMO’s Water Demand Calculator tool was developed in recognition that outdated modes of evaluating how much water residences would need results in the installation of oversized plumbing systems. Not only does this lead to higher construction costs, but the wrong size pipes also contribute to water waste. In addition, the lack of water flow in some of these larger pipes makes it easier for harmful bacteria to grow.
The issue of the mismatch between pipe sizes and actual water use became even more apparent once more efficient appliances and plumbing fixtures were introduced to the residential market for both multifamily buildings and single-family homes.
“The way that water systems in the U.S. have been designed is that they assume that every building - whether it’s a home, an office, a school or a hospital - operates like a sports stadium at halftime with a line of people queued up at every plumbing fixture,” says Christoph Lohr, PE, vice president of technical services and research for IAPMO.
“They estimate your peak flow rate around that kind of a condition, but we know it doesn’t work that way. Even when you host a Super Bowl party, you don’t have that kind of a queuing line outside your bathroom door – and not at the shower and the kitchen sink, either.”
Lohr says the plumbing industry has known for decades that basing their water demand and piping estimates on every fixture and faucet being in use simultaneously is inefficient, but it took until about 2017 for IAPMO, ASPE, and University of Cincinnati to incorporate their findings into IAPMO codes and standards.
While many builders, engineers and plumbing contractors have adopted the calculations in their plumbing system designs, others continue to use the methods with which they are more familiar even if it’s less accurate.
Before the 1920s there was no uniformity on how to estimate the water supply demand needed for a building or how to know the minimum supply pipe size. Generally, it was a guess, and the pipe was generously sized to meet any demand. Then in the 192os,
Roy B. Hunter, known as the father of modern plumbing engineering, developed the method still used by many building codes, builders and engineers today that base pipe sizes on probabilities of peak demand. Hunter was trying to eliminate the tendency for oversizing the water distribution system in cases where there were many fixtures in larger buildings, which was more of an overestimate resulting in a too-large plumbing system.
Plumbing fixtures and appliances that use water have become more efficient and less wasteful over the decades since Hunter first developed his method. At the same time, water demand analysis has changed in recognition that not every fixture and appliance is used simultaneously or in quick succession.
Researchers at IAPMO, University of Cincinnati, and the American Society of Plumbing Engineers (ASPE) recognized that the frequency of use for the same kind of fixture varied as modern building design and occupancy became more diversified.
The preference for low-flow fixtures is evident from Green Builder Media’s COGNITION Smart Data, which found that more than 80% of consumers and more than 75% of building professionals are willing to pay more for low-flow fixtures.
Why Accurately Measuring Water Demand Matters
IAPMO is tackling water waste, one over-sized pipe at a time.
The mission of IAPMO is to develop and enforce safe and efficient codes and standards, along with identifying best practices for the installation of certified products, systems and materials. While providing value to members and the plumbing industry is vital, the organization is also committed to supporting sustainability for water resources. Fortunately, those simultaneous commitments don’t contradict each other.
IAPMO’s Water Demand Calculator tool was developed in recognition that outdated modes of evaluating how much water residences would need results in the installation of oversized plumbing systems. Not only does this lead to higher construction costs, but the wrong size pipes also contribute to water waste. In addition, the lack of water flow in some of these larger pipes makes it easier for harmful bacteria to grow.
The issue of the mismatch between pipe sizes and actual water use became even more apparent once more efficient appliances and plumbing fixtures were introduced to the residential market for both multifamily buildings and single-family homes.
“The way that water systems in the U.S. have been designed is that they assume that every building - whether it’s a home, an office, a school or a hospital - operates like a sports stadium at halftime with a line of people queued up at every plumbing fixture,” says Christoph Lohr, PE, vice president of technical services and research for IAPMO.
“They estimate your peak flow rate around that kind of a condition, but we know it doesn’t work that way. Even when you host a Super Bowl party, you don’t have that kind of a queuing line outside your bathroom door – and not at the shower and the kitchen sink, either.”
Lohr says the plumbing industry has known for decades that basing their water demand and piping estimates on every fixture and faucet being in use simultaneously is inefficient, but it took until about 2017 for IAPMO, ASPE, and University of Cincinnati to incorporate their findings into IAPMO codes and standards.
While many builders, engineers and plumbing contractors have adopted the calculations in their plumbing system designs, others continue to use the methods with which they are more familiar even if it’s less accurate.
Roy B. Hunter, known as the father of modern plumbing engineering, developed the method still used by many building codes, builders and engineers today that base pipe sizes on probabilities of peak demand. Hunter was trying to eliminate the tendency for oversizing the water distribution system in cases where there were many fixtures in larger buildings, which was more of an overestimate resulting in a too-large plumbing system.
Plumbing fixtures and appliances that use water have become more efficient and less wasteful over the decades since Hunter first developed his method. At the same time, water demand analysis has changed in recognition that not every fixture and appliance is used simultaneously or in quick succession.
Researchers at IAPMO, University of Cincinnati, and the American Society of Plumbing Engineers (ASPE) recognized that the frequency of use for the same kind of fixture varied as modern building design and occupancy became more diversified.
The preference for low-flow fixtures is evident from Green Builder Media’s COGNITION Smart Data, which found that more than 80% of consumers and more than 75% of building professionals are willing to pay more for low-flow fixtures.
Size Plumbing Smarter Today: Click here to get the free IAPMO eBook with water demand calculator information.
By Michele Lerner, Associate Editor
Michele Lerner is an award-winning freelance writer, editor, and author who writes about real estate, personal finance, and business.Also Read