As hydronic and domestic water systems age, or come on line for a tune-up, piping and pumping strategies and the condition of infrastructure are scrutinized by experts. Though the close inspection of operation and efficiency likely won’t inspire a “Mechanical Systems CSI” television series, there’s certainly no lack of interest by commercial system pros. It’s Read more
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As hydronic and domestic water systems age, or come on line for a tune-up, piping and pumping strategies and the condition of infrastructure are scrutinized by experts. Though the close inspection of operation and efficiency likely won’t inspire a “Mechanical Systems CSI” television series, there’s certainly no lack of interest by commercial system pros.
It’s the sort of shake-up that’s sure to happen as pipes approach their second or third decade, when building are renovated, and when new technology avails a better way of doing things. Within the commercial, piped world, new technology has emerged and now takes center stage: smart, variable speed pumping.
Why all the attention? Because the benefits are so numerous, impacting overall systems, key components, operational efficiency and performance. Some experts believe that what we’re seeing now is the broad application of technology whose time has finally come. And, best: it’s all about flow. Not ECM motors, a new pump impeller design, or high-tech pipe lining, or pipe-joining technique. There’s no more important, all-encompassing facet to the design, installation or retrofit of large, pumped water systems than to reduce flow to its essential need.
Two experts, both well recognized in their fields, share their insights about this newly-piped world: Watts Radiant’s John Sweaney, hydronic product manager, and Taco’s Bryan Payne, Southeast commercial regional manager.
Hydronically speaking
Sweaney, who’s studied large system flow for nearly two decades, says that, whether it’s flow on the heat-source side, or flow on the load side, there’s a huge focus on energy efficiency, and fluid flow is at the center of the movement. “Many things can be done to minimize flow, yet maintain or optimize comfort or performance – that’s the key,” said Sweaney.
“We often look at Delta-Ts [or “ΔT:” the temperature difference between supply and return water temperatures] from a design standpoint, especially if it’s a commercial system like a shop, warehouse, or snowmelt system. Installations like these call for larger Delta Ts – 30 degrees or more – which reduce system pumping requirements.”
Cooler return water temperatures also play nicely into the use of efficient heating systems, like modulating-condensing boilers which purposefully harvest BTUs from condensation that forms within the system, geothermal heat pumps, and water-sourced heat pumps.
Though ideal Delta Ts for most hydronic systems is a comfort/consistency issue, targeting 10, 15 or 20-degree ΔTs, many larger systems can be designed to meet the very most basic comfort or performance requirement while conserving energy across the board. “With many properly-designed commercial systems we can ease-up on flow requirements to the point where fuel use, and pump size and type are substantially influenced . . . all leading toward enhanced system efficiency.
“The key exception is with snow melt systems where performance can’t be compromised,” added Sweaney. “I’m referring to systems that are installed to remove ice and snow in critical ASHRAE ”Class III” areas like emergency room entries, hospital steps and helicopter landing pads. Typically, we do not recommend a design calling for a Delta T greater than 30 degrees, though for critical areas, the required Delta T should be 20 degrees.”
When designing hydronic systems – whether radiant, snow melt, or for high-temperature fan coils or baseboards – there’s a direct relationship between the ΔT and flow. “Double the Delta T and cut the flow in half,” explained Sweaney. The benefits of a reduced Delta T stretch beyond a reduced need to burn fuel at the heat source. “It extends to pumps of lesser size meeting the need and the down-sizing of piping, fittings, valves and other components,” added Sweaney.
“A change in Delta T for a snow melt system could mean the ability to cut the flow rate from 40 gallons a minute to 20 so that instead of two-inch distribution copper, it could be reduced to 1.5,” he continued. “This could also mean a reduction in the size of the distribution manifold and smaller radiant tubing or, perhaps, a more frugal layout.”
Sweaney referred to two key trends:
1. District heating and cooling with insulated PEX. “This is one we’re seeing more of as the green revolution has taken off,” began Sweaney. “Central, district heating applications have grown substantially over the past couple of years with the use of super-insulated PEX distribution lines to carry the BTUs between a central plant and, say, living units. New military housing developments are using this approach.”
The use of insulated lines often accompanies the application of alternative energy sources such as biofuel, biogas, geothermal and solar at prisons, universities and apartment complexes. In Alaska, a military installation heats all housing units hydronically with waste heat recovered from the on-base electric power plant. Smart! Another similar application is the use of insulated PEX, trenched underground, to carry injection loop BTUs to remote locations.
2. Variable-speed pumping to enable variable flow. John Sweaney led us directly into this one, though we’ll turn to Taco’s Bryan Payne for insights into a burgeoning trend: the application of variable drives to all pumps, both constant and variable flow.
According to Payne, the application of variable frequency drives (VFDs) to constant speed pumps is now the fastest growing segment of the commercial pumping industry, a trend that improves the performance and efficiency of both large domestic water and hydronic heating and cooling systems.
Since ASHRAE 90.1 was adopted by many states as their energy code (early to mid 90s), the shift in the HVAC industry of applying drives to system distribution pumps has been substantial. “The pumps most commonly retrofitted by upgrading the electrical starters to VFDs for quick payback are of larger horsepower, serving loads that vary,” said Payne. “The benefits are dramatic, so we’re now seeing quick response in the industry to make the improvements; it’s the low-hanging fruit.”
According to Payne, in the last eight years, two trends have greatly impacted the adoption of VFDs into more applications. The first is that the cost of drives is decreasing. Second: manufacturers have rushed to add features and functionality.
The advantages to retrofitting constant-speed pumps with VFDs include:
- greater energy efficiency,
- more precise flow control,
- soft-starting and stopping of motors to prolong pump life,
- the integration of BMS communication,
- better balancing with speed control versus imparting ‘false’ head, and
- installing the ability to easily adjust flow to rerate energy plants when system flow gets out of balance or experiences reduced Delta T.
“Most people tend to relate the energy savings of drives and pumps with variable speed system pumps,” added Payne. “But there’s a key opportunity not as readily seen. It’s the savings that can be found by balancing constant speed pumps with a drive as opposed to balancing by controlling flow with a discharge balancing valve.
“In very general terms, most pumps are designed with a safety factor of 10 to 20 percent. This is a legitimate, useful practice that allows for flexibility to accommodate a different mix of equipment to be installed other than what was specified, or future expansion,” continued Payne.
“For instance, this might mean that a pump selected at 1,750 rpm with a safety factor on the design head was installed, started up and over-pumped the system because it was designed with a ‘little extra’ capacity. At this point the test and balance contractor would take the discharge balancing valve and throttle it back – imposing “false head” – to move the pump back to design flow.
Pump affinity law
According to Payne the newer, best industry practice being adopted is to use a drive to balance the pump while using the discharge valve as a flow measuring point, not a throttling point. Pump affinity laws help us to evaluate what the savings are for most jobs. The laws say that the change in horsepower consumed is proportional to the cube of the change in speed. To illustrate, Payne adds, “Let’s say that we can reduce the speed of most pumps by 10 to 20 percent based on safety factor. That means most pumps after start-up would only need to run at 80 to 90 percent of their rated top speed.
“Doing the math shows us that 80 percent (0.80) cubed is .512 and 90 percent (.90) cubed is .729,” explained Payne. “This means that a constant speed pump set up and balanced with a drive consumes only 73 percent of design horsepower if it has a 10 percent safety factor; a pump with a safety factor of 20 percent consumes only 51.2 percent.”
“These are significant energy savings,” continued Payne. “Other benefits for constant speed pumps installed with drives is that they’re now running at reduced speed which extends their life, and they’re also soft-started as a function of the drive. This puts less wear on pump and system components. These become an advantage for the equipment and the building owner.”
“With the focus on first cost, green construction and energy optimization, our industry needs advantages like these,” said Payne. “The decisions we make about design Delta T and flow balancing can have a significant positive impact on system performance.”
By Amanda Hill PVC is an exceptionally durable material that has a low rate of failure. In fact, the failure rate of this material is so low that, when failures occur, it is almost always the result of poor installation or usage practices. To ensure that your crew is not contributing to failure of the PVC Read more
By Amanda Hill
PVC is an exceptionally durable material that has a low rate of failure. In fact, the failure rate of this material is so low that, when failures occur, it is almost always the result of poor installation or usage practices. To ensure that your crew is not contributing to failure of the PVC and CPVC pipes you work with, make sure you are aware of these potential problems.
Improper Installation or Engineering
If the system is not properly planned or installed, the pipe could fail. One common problem is the use of too much cement to bond a pipe to a fitting. The porous PVC will absorb the cement, and an excessive amount breaks down the integrity of the pipe. The cement also allows more water to be absorbed, which can hurt the integrity of the pipe. Insufficient cement use will also be problematic, as it makes the bond too weak. Use enough cement to create a complete bond on the inside of the fitting and the outside of the pipe, but not enough that it pools in large amounts.
If the installation requires you to cut the pipe, make sure that you do not create any residue on the end of the pipe. If you see any burrs or other problems, remove them. Also, smooth the sharp outer edge of the pipe. These faults can make it difficult for the cement to bond with the pipe, leading to pipe failure. Short insertion is another type of installation error. When installing a pipe into a fitting, make sure you push it all the way to the stop. If you don’t, the gap will allow contaminants to accumulate and the pipe system will fail.
Engineering of the system can also be at fault. For example, PVC has a high coefficient of linear thermal expansion and needs room to expand when temperatures fluctuate. Expansion loops or roller hangers can help eliminate this problem. Using a qualified system engineer will also ensure that the system is designed to account for expansion. Similarly, the pipe must be installed so that it does not have excessive bending deflection. This will lead to both pipe and fitting failure, as it places too much stress on the plastic. Pipes need to be installed into fittings in the proper alignment to avoid this problem.
Improper Use of System
PVC is incredibly strong when used properly. However, improper operation of the system will lead to failure. For example, exposing the system to freezing temperatures without proper freeze protection is a recipe for failure. Filling the pipes with glycerin solution can help. Over-pressurization of the system is another problem. Be certain the system uses the proper schedule of PVC for the amount of pressure you will be placing on it.
Sometimes the system will be set up so that conduit bends around the PVC pipe. This places stress on the PVC at the point of contact with the conduit. This can also cause the conduit to fail and should be completely avoided.
Contamination of the System
For external contamination, watch for exposure to elements used in other systems that are not compatible with PVC use. For instance, PVC should never be in contact with aromatic ester plasticizers or flame retardants. These components are commonly found in fire caulk, and even a drop of the caulk that falls onto the PVC can damage the plastic and lead to failure. Similarly, black grommets, which are incompatible with PVC use, should never be used to seal any part of a PVC system. The phthalate ester plasticizers in a black grommet will damage PVC. Solder flux, polyurethane spray foam and antimicrobial linings found in steel pipes can also contaminate PVC.
PVC’s durability means it can handle many corrosive chemicals once the system is installed. Interior contamination typically happens during installation when non-approved materials are used in the PVC system. That being said, some products, like fire protection foam, should not be delivered via PVC systems, as they will cause internal contamination.
To avoid internal contamination, discuss the system with the PVC manufacturer, and only use PVC for transporting fluids it is designed to carry. If you are concerned about the product it will be carrying, ask before installing.
Manufacturing Defects
Manufacturing defects in PVC are quite rare, but they can happen. If the extrusion and cooling process is not carefully monitored and performed, defects in the pipe can lead to failure. These defects can occur because of a dirty die, which causes extrusion lines or improper cooling, which cause stresses throughout the pipe. When pipes are frozen with stresses from the manufacturing process, they react like coiled springs seeking a way to relieve that stress. While you can’t avoid this problem entirely, working with a trusted manufacturer can help.
Defects in the Resin
The resin used to create PVC and CPVC pipes must be carefully mixed to avoid defects. If the filler content is wrong, the pipe will not be as strong as it should be. Similarly, if the chlorine content is wrong in a CPVC pipe, it will not be able to withstand normal operating pressures. Additives or pigments that are added in the wrong way can also cause problems. Again, using a quality distributor and manufacturer you trust can help limit these issues.
Distributor Abuse
PVC should not be stored in direct sunlight for extended periods of time. While the material should be strong enough to withstand repeated exposure to the elements, lengthy storage in this way could damage its integrity. Also, if the PVC is damaged in transport, it can lead to pipe failure. Buy your PVC from a supplier you trust, and inspect every pipe thoroughly before putting it into the system to avoid this problem.
Careful installation, using the right distributor and manufacturer, and avoiding contamination issues are the keys to preventing pipe failure in your PVC systems. Pay careful attention to these areas, and your systems should remain strong for years.
Author Bio:
Amanda Hill is the Content Manager for CIS (Commerical Industrial Supply), a supplier of PVC pipes, fittings, and other accessories for plumbing professionals all across the country.
By Patricia Bonacorda Regardless of where your plumbing company is located, it’s probably not the only game in town. Just because a customer hires you to perform repairs once is no guarantee that he or she will hire you again in the future. That’s true even if you deliver service of the utmost quality. When the Read more
By Patricia Bonacorda
Regardless of where your plumbing company is located, it’s probably not the only game in town. Just because a customer hires you to perform repairs once is no guarantee that he or she will hire you again in the future. That’s true even if you deliver service of the utmost quality. When the need for a plumber arises again, it’s all too easy for customers to forget the name of your business and to choose a different company at random.
Some plumbing business owners worry more about attracting new customers than about retaining existing ones, but that’s a big mistake. The fact is that it costs a lot less to keep current customers than it does to earn new ones. By ensuring that customers remember your company in the future, you’ll continue to earn their business. What’s even better is that when customers are able to easily recall the name of your company and are happy with the service you provide, they are more likely to refer people to you as well.
With so much competition out there, how can you make customers remember your plumbing company in the future? A few prime examples include the following:
Make Customers Feel Important
Building and nurturing relationships with existing customers increases the odds that they’ll hire your company again in the future. A great way to do this is by making customers feel special and important. A simple thank-you card can go a long way. Another option is to occasionally send special offers via regular mail or email. When customers know they’ll get a special discount by hiring you again, they’re a lot likelier to do so.
Use Promotional Items
People love getting stuff for free, so why not hand out promotional pens, notepads, magnets or other items after completing service calls? Promotional items can be ordered in bulk, which usually makes them affordable. With your company’s name, number and other contact information emblazoned on each item, people will be reminded of your plumbing business and know precisely who to call the next time they need help with a clog or other plumbing problem.
Follow Up after Completing a Job
Very few plumbing companies take the time to follow up with their customers to ensure that the work was done to their satisfaction, so this is a great way to stand apart from the crowd. By contacting your customers within a day or two of completing the work, you’ll show them that you really care. Most people are pleasantly surprised by such efforts, so the name of your business is much more likely to stay in their minds in the future.
Develop Strong Relationships
Rather than treating customers as a once-off proposition, make a point to get to know them to establish long-term relationships. Customer management software can really come in handy by allowing you to keep notes about each customer’s previous jobs and details about their homes. Simply making a point of referring to your customers by name as often as possible can have an enormous beneficial impact.
Send Helpful Newsletters
As the owner of a plumbing company, you undoubtedly know all kinds of tricks and tips that your existing customers will find useful. Why not share them by sending out newsletters on occasion? Whether you send the newsletters on a monthly or quarterly basis, they will help to keep your business in customers’ minds. They can be sent via direct mail or email. In the case of the email, be sure your customers opt in first.
Send Holiday Greetings
Very few plumbing companies bother to send greetings around the holidays. Other times, they only send cards to their biggest customers. Stand out among the competition by sending holiday greetings to as many existing customers as possible. Just remember that not everyone celebrates the same holidays, so keep the greetings somewhat generic in nature.
Make Effective Use of Social Media
You may have written off using social media because you don’t think anyone would follow a plumbing company on a site like Facebook. But if you give people a reason to do so, many of them will. Offer incentives to customers who follow your business on Facebook, and periodically post friendly updates to remind people that you’re available to help. The return on the minimal amount of time and effort needed to be active on social media can be considerable.
Conclusion
Don’t fall into the trap of exclusively focusing your marketing efforts on new customers. Your current customers are very valuable to you, so take steps to remind them of your plumbing business. You’re sure to be pleasantly surprised by the payoff.
Author Bio:
Patricia Bonacorda is the President of Spartan Plumbing a plumbing and HVAC Company that has been in business since 1964. Spartan Plumbing assists both residential and commercial customers all throughout the Washington DC Region.
By Jim Hinshaw I just had a great conversation with Allen eaker (his company earned an award for selling high-end systems, in the 20 seer territory, in his market). He asked me if there was a great restaurant in Fort collins, colo.—someplace where i would like to take my wife for a special dinner. i Read more
By Jim Hinshaw
I just had a great conversation with Allen eaker (his company earned an award for selling high-end systems, in the 20 seer territory, in his market). He asked me if there was a great restaurant in Fort collins, colo.—someplace where i would like to take my wife for a special dinner. i said we liked steak, so we went to Sonny lubicks, a great steak house. But what was the special occasion? He said he wanted to buy us a nice meal; he had just closed a couple of large sales and had used some concepts from my training he attended years ago. He had my full attention.
He had a job for an older building in the center of town, a unit on the second floor was out, and the owner wanted to look at a replacement 4-ton unit because the second-floor occupants were roasting. Allen had not done work for this customer for over 20 years. He listened to their concerns, asked some ques- tions, and installed a used condensing unit to give himself some time to do a complete analysis of the entire building. this is a public building; he was one of several bidders on the proj- ect. the end result was he got a contract for hundreds of thou- sands of dollars, replacing the entire system with a high-tech system, all because he looked at the entire building instead of quoting a new unit for the second floor.
Yes, i realize you cannot negotiate on a public bid, that you should always bid what they ask for, and that there is no money available for entire system replacements in a public building— just don’t tell Allen that.
in a second case, Allen got a call from an existing customer who was selling a building to another company; they needed some duct modifications for the new owners. Allen met with the new owners, asked questions about their business, how long they were going to be in the building, if their business was on an up cycle—all important factors in looking at the plumbing/ HvAc system in the building. He ended up offering them sev- eral of those high-end systems. they agreed to that proposal and have since talked to Allen about an addition to the build- ing—several more systems needed, another big proposal endorsed.
in both these cases, what many would do is simply offer what the customer asked for. Allen decided to go further, get more info, and offer them a real solution, at a cost that was many times their original budget. in his words, the same strategy can be used in selling commercial as in residential. You may have more people involved, larger projects, but in these cases the final numbers were huge compared to what the minimum, low- cost proposals would have been. people buy emotionally, jus- tifying it with logic later on.
Why the fancy meal for my wife and me? Allen sat in one of my sales classes years ago; he internalized the message, started offering high-end systems with full warranties. What he said was it changed his business forever. So, take a lesson from a fellow contractor, try asking more questions, listen more, talk less. Offer the best system available, even if it is a public bid. it pays dividends. Oh, by the way, Allen has those same high-end systems in his home and office. in his words: it is easy to sell what you actually believe in.
Cast Iron Piping Benefits By Francesca Dunbar We have to make choices every day. Personal preference seems to dominate over objective reasoning and we get complacent in our decision making. When it comes to drain, waste and vent (DWV) plumbing systems there is an ongoing debate over which is a better solution, iron or plastic. Read more
Cast Iron Piping Benefits
By Francesca Dunbar
We have to make choices every day. Personal preference seems to dominate over objective reasoning and we get complacent in our decision making. When it comes to drain, waste and vent (DWV) plumbing systems there is an ongoing debate over which is a better solution, iron or plastic. Both products have their advantages and disadvantages. Designers and contractors are experiencing tremendous pressure to value engineer projects. Most builders are not willing to give up features in their design to bring the project costs down and look to cut corners on building materials to help reduce the overall project cost. These value engineered tradeoffs are typically not seen until a building is occupied.
Life Safety – Making the Right Choice
The superiority of cast iron (CI) over polyvinyl chloride (PVC) piping in fire safety cannot be overstated. Many people who die in fires do not perish from flame or heat, but rather from the gases released during the heating and combustion of typical building materials or furnishings. Slowing or stopping the spread of these gases through aggressive firestopping is a proven life saver. Contractor and building owners today are concerned about liability.
Most experts agree that CI provides unsurpassed fire resistance. Cast iron does not burn, does not off-gas when heated to temperatures normally encountered in structure fires, it is easy to install, and has superior durability often out lasting the life of a building. This resistance to burning has the added benefit of requiring simple, low-cost firestopping between the annular space between the pipe and wall penetration. That is not the case with PVC piping where the initial cost savings are frequently offset by the added perfunctory material costs. Cast iron pipe and fittings are joined together with no-hub couplings consisting of neoprene gaskets and stainless steel shields and bands. These can be assembled or disassembled very easily.
Something else to consider if choosing PVC as it relates to fire wall penetrations. PVC is combustible and requires complex firestopping systems – each penetration between the pipe and wall infiltration must be sealed with an intumescent material. In the case of fire due to heat, PVC piping will melt away. Therefore, firestopping with intumescent product is needed to fill each and every void and penetration. This intumescent firestopping system is significantly more expensive than the simple and low-cost measures required for cast iron.
Sound Attenuation
Cast iron is often referred to as the “quiet pipetm” because of its superior noise suppression unlike PVC piping. Studies have shown CI to be a superior product in controlling noise due to its density. This makes cast iron ideal for condominiums, hotels, healthcare facilities and educational institutions. Unlike PVC, cast iron soil pipe effectively suppresses the sound of swooshing water cascading down from upstairs fixtures. This sound attenuation feature can be a major benefit in quality residential and commercial construction, where building owners and tenants understand the advantage of iron by the very first flush.
On the other hand, PVC used in drain and waste systems is noisy and annoying and often the cause of tenant frustration. If you’ve ever stayed in a hotel plumbed with PVC, you can often hear others showering and flushing toilets depriving guests from the well needed rest they desire. While plastic piping is an inexpensive material, it may not be the right product for every application. The problem with PVC pipe in drain and waste systems is that it produces a lot of noise due to the innate properties of low density plastic and the cementing of pipe and fittings together. To combat the noisy PVC piping system one solution is to wrap the PVC pipes with a good insulating material such as fiberglass or neoprene foam jacketing. The intrinsic properties of cast iron pipe along with the separation of the pipe and fittings by the use of a gasket or coupling is highly effective in reducing the likelihood of sound traveling through the system. Don’t get me wrong, there are special applications for PVC piping, but not in drain and waste applications.
Noise Level Chart
A noise level chart showing examples of sounds with dB levels ranging from 0 to 100 decibels.
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0 = Healthy hearing threshold |
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30 = A voice whisper |
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25 = Cast iron vertical enclosed pipes (average) |
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33 = PVC vertical enclosed pipes (average) |
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50 = Light traffic or sound of a refrigerator |
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70 = A shower or dishwasher running |
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75 = A toilet flushing or vacuum cleaner |
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100 = Riding a motorcycle or operating a hand held drill |
Summary of overall noise levels in dBA emitted by cast iron and PVC pipes while evacuating a 1.6 gallon water flush test. Significant findings that cast iron pipes are quieter than PVC whether or not the pipes are enclosed. This information is based on an independent research study by MJM Acoustical Consultants, Inc.
Listen Up – Noise Pollution is a Problem
Commercial building designers and engineers need to take note of the acoustical performance of the building project and be very cautious of the potentially negative effects of value engineering. Excessive noise from plumbing systems is typically unnoticed until the building is occupied, creating ongoing problems for the occupants. Sound attenuation is regularly value engineered out of jobs, often the result of product substitutions and misguided cost cutting measures. Beware of the unexpected consequences of value engineering.
The World Health Organization (WHO) has done extensive studies in healthcare facilities and has identified noise levels around rooms at night as disruptive to patients. This is especially true in hospitals with multiple levels. These types of structures also have additional noise pollution from waste water evacuation from toilets flushing, showers and storm drains. Excessive noise can lead to sleep disruption and increased levels of stress thus hindering the healing process sought in a hospital setting.
Studies have also concluded classroom noise interferes with the ability for a teacher to educate students effectively, and students to learn. Raising the voice level provides little compensation. ANSI Standard S 12.60-2002 Design Requirements and Guidelines for Schools recommend a maximum of 35 decibels for background noise. There is a direct link between the classroom acoustic environment and the scholastic achievement of students. The result of a US Government Accounting Office survey found that 28% of the nation’s schools reported “acoustics for noise control” as their top environmental problem. This suggests that the 28% figure from this survey may be a substantial understatement of the problem of acoustic barriers in schools since a background noise level of 50 db is 15 dB above the recommended limit included in a US standard for classroom acoustics.
The attributes of cast iron when it comes to sound attenuation cannot be overlooked. Due to its sound-deadening properties, cast iron inherently has a dense molecular structure and a natural heavy mass making it the quieter solution. According to a study by Polysonics Acoustical Engineers, cast iron is 750% more effective in silencing plumbing noise when compared to PVC. With CI, sound is effectively muffled rather than transmitted, as it is with PVC pipe. Noisy PVC piping can be masked by utilizing sound-deadening insulation that is carefully installed with neoprene foam jacketing or other insulation processes but there are again added costs to even come close to the quiet CI piping.
– ADVERTISEMENT –
Friend, Foe or Both?
In conclusion, so do you know which product is better, cast iron or plastic? Both products have their advantages and disadvantages, though cast iron is more environmentally friendly than plastic as it is made from ~100% post-consumer scrap iron while on the other hand, thermoplastic piping is produced using petroleum derived materials. So we go back to which product is better. Well, the answer may be to consider using both together. Plastic pipe is a great choice for the vent system since air doesn’t create vibrations and will be whisper quiet. While on the other hand using cast iron is an ideal solution for underground piping and vertical stacking of indoor pipes. This amalgamated method will benefit the occupants seeking a quiet and durable plumbing system that is a cost effective solution.
Word to the wise, consider the added costs if you choose PVC as it will require more hangers, screws, fasteners, primer, glue, additional labor costs, inspections, neoprene foam jackets to deaden sound, or insulation to muffle the noisy pipes. These supplementary costs are often overlooked when value engineering a project and can cost just as much if not more than a cast iron DWV system.
About the Author:
Francesca Dunbar is the Director of Marketing for the McWane Plumbing Group Division. She can be reached by email at Francesca.Dunbar@McWanePlbGrp.com.
Quiet Pipe is a trademark of Cast Iron Soil Pipe Institute “CISPI”.
REFERENCES
1. The Impact of Classroom Acoustics on Scholastic Achievement by Louis C. Sutherland and David Lubman, 17th Meeting of the International Commission for Acoustics, Rome, Italy, Sept. 2-7, 2001
2. Plumbing Engineer – Features: June 2012: Sound design in drain, waste and vent lines http://www.plumbingengineer.com/june_12/piping_feature.php
3. Acoustic Control LLC http://www.acousticontrol.com/hospital-acoustics.html