 The actual phrase “penny wise, and pound foolish” is often mistakenly credited to Benjamin Franklin, but it actually originated with an Oxford Scholar named Robert Burton in his book, “The Anatomy of Melancholy” written in 1621! Needless to say, in 1621 domestic hot water wasn’t even a thing. It was before the advent of electricity, multi-story distributed hot water systems, and certainly before the advent of modern boilers, computerized boiler controls and mixing valves. And yet the phrase is nowhere more relevant than when it is applied to DHW installations where mixing valves are sometimes omitted for small overall reductions in material cost or piping complexity in a commercial, domestic hot water setting. So here’s “penny wise and pound foolish” as applied to your domestic hot water system . The Purpose of a 3 Way Mixing Valve in DHW In DHW applications using traditional direct-fired storage tank systems, a mixing valve has always been an important part of the overall system design as shown in the graphic below:  The typical 3-way valve serves several primary purposes:
 These numbers are just what is reported of course. The National Academies of Sciences, Engineering, and Medicine estimates that as many as 70,000 people may suffer from the disease each year, according to a report released in August 2019. The disease can cause severe sickness and even death. Individuals with a history of health issues, smoking or who are over 50 are even more at risk. For facilities, the consequences of finding the bacteria can be catastrophic, even if not deadly. The water must be shut off, expensive mitigation strategies can be required, there is almost always negative media coverage often national, and of course, there is the potential for lawsuits or even financial ruin. How Saving Pennies threatens the whole system. It turns out that there is a lot of misinformation out there about what does and doesn’t compromise the integrity of a domestic hot water delivery system. Some of this misinformation is even propagated by manufacturers of tankless system who want you to believe that their on-demand systems are safe to run at much lower temperatures, thus saving energy. The truth is however quite simple and the science behind it is easily available on the websites of Federal regulatory agencies like the CDC, the World Health Organization, and private research companies. Consider the following commonly used table of Legionella growth.  The disinfection of your hot water is dependent on two primary things: The temperature of the hot water and the time it remains at that temperature. Period. And the only way to manage the proper disinfection of hot water, without risking scalding injuries at the fixture, is through management of water temperatures using a 3 way mixing valve.
A Little More Work, A Lot More Safety Heat-Timer® recognized a while ago that installers needed a simpler and faster solution to the installation of 3 way mixing valves. That’s why we developed the Electronic Tempering Valve (ETV) and the Electronic Tempering Station or ETS. The ETS provides installers the convenience of a pre-piped and pre-wired assembly of the ETV valve and module. The installers only need to connect the hot and cold water supply, and provide power to the controller to have a completely safe, pre-plumbed solution to domestic hot water safety. For more information on Heat-Timer’s electronic tempering valve solutions for domestic hot water applications, please contact a Heat-Timer® representative today at: (973) 575 4004. Original blog posted on https://www.heat-timer.com/domestic-hot-water-solutions/
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 Technology marches on and for those of us working every day to bring the best DHW solutions to the market, global and national trends will inevitably drive the adoption of new techniques and new technologies that mostly help, but sometimes hurt us. Digital and IOT based improvements to the tech surrounding DHW abound in 2020 and conversations around the “resident experience” are now common, though studies show that a desire for positive resident experiences has not become a core technology competency for the vast majority of building managers. For DHW used in hotels, apartments, and office buildings, upgrades and conversions continue to be a major source of industry growth despite this, as operators recognize the need for more efficient systems, and the impact of upgrades on bottom line operating costs.  Focus on the Commercial Domestic Hot Water Market
The U.S. commercial water heater market revenue is poised to cross USD 670 Million by 2026, as reported in the latest study by Global Market Insights, Inc. Increasing demand for water heating along with growing installation of various central water heating systems will encourage product deployment across the US in the next five years. Some of the key growth drivers for DHW in the US are related to continued design for increases in efficiency of both boilers, and overall system operation. Government investment toward establishment of energy efficient buildings coupled with rapid expansion of infrastructure have stimulated a considerable growth across the U.S. commercial water heater industry. The growing population and ongoing migration across suburban areas have led to a considerable increase in the product demand. Rapid commercial expansion coupled with urbanization has further instituted a favorable business scenario, though the impact of COVID-19 related economic effects are not fully comprehended in this study and may change the outlook for the better or worse. Tank based water heater solutions prevail in the DHW market, however commercial tankless solutions continue to grow despite concerns over legionella safety and their relatively larger upfront costs. For more information see this discussion on tankless water heater safety. Water heater usage across commercial applications has witnessed a substantial growth in the 30 – 100 liters capacity water heaters segment owing to rising hot water requirements primarily across hospitals, hotels and shopping complexes. Easy installations along with multiple control options will make the product more demanding during the forecast period. Replacement of conventional systems with advanced models and DHW control systems, will further accelerate business growth. Thoughts on US Domestic Hot Water market for 2020 and beyond While most research prior to 2020 showed a period of continuing growth into 2026, the effect of the pandemic on US market growth remains unclear. The general market for capital investment including wholesale HVAC upgrades has diminished, however increased urgency around reducing energy costs and upgrading infrastructure is an offsetting dynamic. Retrofit will become even more popular than replace. Heat-Timer® feels well positioned for these changing market dynamics given that our products almost wholly reside in the energy efficiency space and can be retrofitted easily to existing buildings through use of wireless and mobile connectivity built into our Platinum series products. In a market that may be retracting slightly due to the pandemic, our product offering is ideally positioned to allow energy managers to move ahead with efficiency and energy goals, with minimal up-front or ongoing investment. For more information, visit our website at https://heat-timer.com Original Content posted on https://www.heat-timer.com/commercial-domestic-hot-water-trends-2020/  Because of regulations put in place after the outbreak of legionnaire’s disease in the 90’s, installation of Domestic Hot Water (DHW) systems were changed for the sake of public safety. All DHW systems, whether storage based or tankless, must now meet the conflicting requirements of holding DHW at a minimum of 140°F (60°C) to comply with such standards as OSHA Technical Manual Section 3 Chapter 7, to combat Legionella growth, while delivering hot water at a temperature that prevents scalding injuries in sinks and other fixtures. For decades, commercial plumbing installers have embraced a 3 way mixing valve or “tempering valve” as the perfect solution to the dilemma. Early tempering valves were controlled manually with fixed setpoints, but in 2020 we have evolved to using motorized valves under the direction of a standalone electronic control station that adds flexibility, reduces energy use, provides alerts and alarms, and generally improves the safety of any domestic hot water system. One of the most popular motorized tempering valve solutions continues to be the Heat-Timer ETV Platinum PLUS Electronic Tempering Valve (ETV). The ETV allows building owners to keep their water heaters and storage tanks above 140°F (60°C) while distributing hot water to users within a safe range. The Heat-Timer ETV control also has the ability to control a safety valve which shuts off the supply of hot water whenever the mixed outlet water exceeds an adjustable high temperature limit and provides a remote alarm to building managers. One thing to consider even with a tempering valve system solution as advanced as the ETV, is the amount of time required for a contractor/plumber to plan, stage and install the entire system. Consider that the basic system requires a sturdy frame to support and hold all of the components; the electronic tempering valve, safety valve, multiple pipes, unions, check valves and shut off valves, all need to be mounted to the frame while routing all piping connections in a neat and logical way to the Cold & Hot water supplies, water heater, recirculating loop and Mixed hot water output while allowing easy maintenance of the system. Low voltage wiring connections need to be made between the control module, ETV and temperature probes and a 120v, power wiring connection is needed for the ETV control module. The ability to mount the ETV control Module up to 500 feet from the valve offers increased flexibility for installation of system components. Once completed all piping needs to be leak tested and all wiring needs to be verified for correct installation. Now, the system is ready for operation. From years of experience, we can tell you that commercial plumbing contractors approach the challenge of installing a complete DHW system in one of three primary ways:
Regardless of the skill and experience of the installation team, none of these approaches will eliminate the on-site time and expense needed to fit, assemble and test all of the components required. With Heat-Timer®, there is another, and better alternative – installing a fully integrated, pre-plumbed, pre-wired Electronic Tempering Station. The Heat-Timer ETS Is the Pre-Plumbed Tempering Valve Solution Contractors and Engineers Have Asked For.  The Electronic Tempering Station (ETS) is a factory assembled and fully tested DHW system. Only five piping connections and a single 120V electrical connection are required to complete the installation. The entire compact system is mounted in a sturdy steel frame, ready to be bolted to a pad. Once the mixed hot water requirements (gpm) of the building are known, designing a correctly sized DHW system is as easy as selecting the correct valve size. Once you’ve chosen a location, your only field work is to connect wiring for the 120v power supply and five piping connections. (Recirculation return, water heater/storage tank supply, Hot & Cold water supply and Mixed water outlet). The station also comes in both single and duplex (dual valve) configurations. The duplex models are designed for hot water distribution systems needing large quantities of safe tempered hot water, saving your customer money and you even more work. Using the ETS, is Fast, Efficient, and Yes, Economical
The ETS is designed by an experienced engineering team, which ensures that the systems are fully code compliant. Heat-Timer® also provides detailed assembly drawings to allow contractors to accurately rough in the necessary connections. The money building managers and contractors save in installation time, raw materials, and quality generally pays for the cost of the ETS outright. With the Heat-Timer® ETS, our contractors get the advantage of rapid, trouble-free installation and code compliance, while the building manager gets faster occupancy and an easy to service system with the advanced control and monitoring features of the Platinum Plus ETV control module. The Heat-Timer® ETS is a win-win for everybody! Original content posted on https://www.heat-timer.com/water-safety-for-all-time/  What is a Domestic Hot Water System? A Domestic Hot Water (DHW) system provides potable hot water to our sinks, showers, and tubs and other places where hot water may be ingested by, or come in direct contact with humans. This is as opposed to non-potable water which is not suitable for drinking and other domestic purposes but may be used for hydronic heating, industrial cleaning and other applications. Most plumbing codes specify that all piping, components, and heat-transfer devices in contact with the potable water shall be intended for use in potable water systems. Typical commercial DHW systems consist of one or more boilers that provide a reserve of hot water for use. Since demand for hot water is not uniform across the day, DHW control systems are sized to try to balance the costs of heating large tanks of hot water, while still being able to meet the anticipated demand during a peak period (usually when people are getting ready for work in the morning) Key Parts of a Typical Commercial Domestic Hot Water System The diagram below shows a typical configuration for a domestic hot water system with a single boiler/storage tank. Many configurations for a DHW system are possible depending on the size, age, demand profile and layout of the buildings involved but they all share a few basic components.
 In this system, the hot water tank is providing superheated water at 160F to a 3-way mixing valve that cools it for delivery to the tap at ~110F.
Other Key Design Considerations for a Domestic Hot Water System The bacterium legionella pneumophila is found in both potable and non-potable water systems. Studies have shown that Legionella does not grow in cold water below 89.6F1 but in water temperatures above 90F especially in stagnant water between 95F (35C) and 122F (50C), legionella bacteria begin to multiply. Legionella can cause legionnaires’ disease or legionellosis, a severe, often lethal, form of pneumonia that occurs primarily when steam or water vapor containing legionella is inhaled. The disease’s name was coined in 1976, when American Legion members who attended a convention in Philadelphia, suffered from an unusual lung infection (pneumonia). Legionella cases have been on the rise for over a decade, with several outbreaks identified in large cities, that have caused severe illness and death. Our society is vulnerable to these waterborne bacteria, and the HVAC/plumbing industry is responsible to do what it can to protect the public. Studies show that flushing a water system to effectively kill legionella requires water temperature over 160F (71C) throughout the entire piping network for at least 30 minutes; at lower temperatures, some bacteria can remain protected inside the biofilm lining the pipes. Yet if water at this temperature were to come in contact with your hands, severe scalding would occur in only 2-3 seconds. Key to satisfying both objectives is the use of an ASREE mixing valve which allows systems to maintain high temperatures in the DHW storage tanks, while mixing that water with cold supply to derive just the right temperature. Heat-Timer® Motorized Tempering Valves Get The Job Done A valve like the Heat-Timer Electronic Tempering Valve (ETV) is often used as the mixing valve in domestic hot water applications. Whether the system uses boilers and tanks, or generates hot water instantaneously, the function of this valve is absolutely critical in preserving the safety equation. Water must be heated to 160F kill legionella, and a 3-way mixing valve must be used to scalding at the tap. Under control of a programmable console, the motorized valve is automatically adjusted to drive the perfect temperature of water through the system using temperature sensors placed on piping to record the exact temperatures (1 degree accuracy). Visit our website pages for more information on how domestic how water systems work, or contact a Heat-Timer Representative today
 The relentless march of new technology in the area of boiler design and domestic hot water systems, have given us many new and improved components and strategies for providing safe, and more energy efficient heat and hot water. But the news is not all good: the fact is that since 2000, cases of Legionella as reported by the CDC have actually increased across the USA. While many possible reasons exist for this puzzling fact, the fact is that even the CDC doesn’t fully understand why. Certainly, awareness of the disease has increased. Cases that were previously unknown are now properly diagnosed and easily reported on the internet. The increase in Legionella cases also does not differentiate incidents which are related to domestic hot water systems vs. those involving other systems such as cooling towers and air conditioning systems. And finally, increased aeration in the water due to low flow fixtures along with the aging population and infrastructure could also be contributing factors. Another factor however, could be the widespread adoption of the ASHRAE 90.1 building code standard in 2001 which quickly became the standard for many building codes – both local and state. Within ASHRAE 90.1, it was recommended hot water was not to be stored in a water heater above 120*F, recommended as a means to lower energy consumption. It further states that building recirculation must be controlled during periods of no demand. It turns out that both of these requirements promote the growth of Legionella, as temperatures as low as 120* do not completely kill the bacteria and the resulting stagnant water within the system is an ideal breeding ground for Legionella.  The Flip Side of Legionella Growth Well if Legionella is such a problem, then why not crank up the temperature as recommended in the chart? It might cost a little more but that is better than making folks deathly ill isn’t it? Now however you have a different problem, it turns out that water temperatures above 105F represent a scalding hazard for most people. And if water was delivered at the temperature needed to fully kill legionella, 3rd degree burns would ensue in less than a second of exposure.  Thus the development and widespread usage of the 3-way mixing valves that are so well known to commercial plumbing contractors. In valves like our ETV Platinum Plus, hot water reserves can remain at a temperature that is high enough to kill Legionella bacteria, but can be delivered to end users at the perfect temperature by mixing the supply with cold water. All this is under management of our programmable control which operates our motorized 3-way mixing valve so as to provide the perfect temperature of water under all load conditions.
The Latest Potential contributor to Legionella – Tankless Solutions It is worth mentioning that those exciting new boiler technologies include “tankless systems”. These systems represent potential solutions to domestic hot water heating for smaller commercial enterprises without the cost and complexity of installation that a full commercial boiler may require. While there is nothing wrong with the use of the technology per se, many manufacturers have embraced the selling point that these systems obviate the need for a mixing valve to deliver Legionella free hot water. The problem in this logic is that they have largely embraced the idea that being ASHRAE 90.1 compliant, they are compliant solutions for Legionella prevention when in fact as we’ve just discussed, ASHRAE 90.1 is fundamentally flawed in its recommendations with respect to Legionella safety. In our next blog, we’ll discuss in more detail the danger that these claims can represent for installers, and science behind exactly why these systems can represent a Legionella risk if not installed properly. Original content posted on https://www.heat-timer.com/when-preventing-legionella-in-your-commercial-hot-water-system-there-are-no-shortcuts/  In college campus’ or apartment complexes, multiple boilers, multiple boiler rooms and multiple buildings present a real challenge for a complex manager. The tactics employed to keep energy usage at a comfortable minimum are complex and every campus is different, but here are a few of the common issues and solutions faced by these large, distributed, and often older buildings.
Thermal Shock Thermal shock occurs when water cools down significantly during off times, shocking the boilers with cold water when the system pumps come back on line. Not only does this issue damage the boilers, it can also run the maintenance staff ragged as they fly around the building at all hours of the day and night manually adjusting valves. Heat-Timer® products helped resolve these problems by providing motorized valves and Hot Water Reset (HWR) controls in each of the boiler plants. The Platinum Series HWR control helped resolve the boiler problems by operating the system based on outdoor air temperature, as opposed to an indoor thermostat reading. This greatly reduced the excessive on/off action of the pumps and saved our client so much in fuel and boiler maintenance that the controls paid for themselves through energy and maintenance savings, in the first months of usage. Internet and Mobile Alerts and Control While many campus’ are running some kind of remote connection capability, in some cases a master control room visit is still necessary to visually access information on all boiler rooms and buildings. The state of the art at Heat-Timer® in 2019 has moved way beyond this. Our Building-Net system integrates sensor, valve and boiler control, then provides complete visibility to you through our user friendly mobile app, the internet, or your iPad. Our system provides you instant wireless control of temperature settings while sensor data, diagnostics and alerts can be sent, viewed and changed in real-time. With Heat-Timer® sophisticated self-learning controls, diagnostic routines run constantly and detect issues before they cause damage, reporting conveniently to you on your mobile device. Furthermore our newest systems allow real time access to up to 13 months of historical data, reports can be selected or customized, and emailed to you at a convenient frequency. Heat-Timer® Controls are the Right Partner for HVAC Professionals. If you’re going to spend the time to install and learn a commercial heating control that will address the maximum number and type of commercial jobs, you will never go wrong with Heat-Timer®. From motorized valves, to Steam and Hot Water Heating controls, and Domestic Hot Water Boiler Control solutions, we have the controls to support your best work. For more information on what kinds of savings you can expect from the installation of a Heat-Timer® control, call our team today. Original content posted on https://www.heat-timer.com/solving-the-unique-problems-of-large-distributed-heating-systems/  For hotels, motels, office buildings and other buildings with large hot water demand, domestic hot water systems must deliver water that is always bacteria free, and at the right temperature, even during peak periods. Additionally, increased environmental awareness and sound economics is driving the need for more efficient and durable domestic hot water heating solutions than in the past.
Part of the solution to a better DHW system is certainly the boiler. Traditional direct-fired storage water heaters can have efficiency ratings in the low 60% range as compared to 90% or more for modern condensing boilers. Depending on where they are, these heaters can last less than 5 years due to hard water mineral build-up, adding another burden to our landfill and recycling capabilities. Creating a Domestic Hot Water System for the 21st Century It may go without saying but we’ll say it anyway: when designing a commercial DHW system you first want to contact a commercial HVAC professional with good experience. Unlike residential the solution to DHW especially in older buildings, is way beyond the talented handyman. A good HVAC company will provide a design which takes some important principles into account: Reliability. This is probably the most important consideration for commercial domestic hot water solutions. When the system fails to perform adequately or breaks down repeatedly, the entire building is without hot water and residents/occupants are upset. Reliability is achieved by specifying proven high-quality products and by building redundancy into the design. Efficiency. Operating cost and efficiency (EFUE) are important and have much to do with the design of the boilers, and the control systems that regulate the hot water mixing valves and other motorized valves that may be part of your system design. Longevity and serviceability. A well designed system should have a 15–20 year service life. The system design should take into account future service, maintenance and component replacement. Mechanical components should be accessible. Valves should be installed so that pumps and control valves can be replaced without draining down the entire system. Heat-Timer Solutions for Commercial Domestic Hot Water When looking at domestic hot water solutions your mixing valve and its associated control and monitoring system should be a key part of your design. No one wants a solution that has people running to the mechanical room with wrench in hand because the guy in 14B has no hot water! The Heat-Timer® tempering station is rapidly becoming the solution of choice for DHW applications requiring 3 way mixing. It encapsulates an electronic tempering valve under control of dedicated control module. The entire unit is pre-plumbed for professionals. Just connect the hot and cold water to it and plug it in. The control and valve operate together to quickly restore the desired water temperature, even after large changes in load conditions. The ETS is a great solution for challenging DHW applications being both cost effective, and saving installers a massive amount of time. For more information on state of the art domestic hot water solutions for your commercial building, contact us or find a Heat-Timer® authorized reseller in your area. Original content posted on https://www.heat-timer.com/domestic-hot-water-solutions-for-hotels-and-more/  24/7 availability of hot water at the right temperature is a hot button issue for facility managers in the hospitality, education and healthcare industries. To avoid both scalding and bacteria growth, water must be stored at a high temperature, then mixed with just the right amount of cold water before being delivered to the end user. The valves that provide this mixing are the key to reliable and safe, domestic hot water.
Valve Types There are two types of mixing valves that can properly temper domestic hot water: motorized and thermostatic. Motorized valves use electronic sensors and controls which helps to restore ideal water temperature under peak loads. Thermostatic valves use an internal thermostatic element to control temperature without the need for external power. They both produce a reliable safe supply of domestic hot water. They differ in how they are controlled, and in what features are available to communicate with them remotely. Motorized Valves Motorized valves are meant to interface with electronic controls to precisely dial in the supply temperature. These valves can be provided as stand-alone units, or they can be integrated into the building’s heating control system to provide remote monitoring and control capabilities that allow building operators to monitor and adjust their systems without the need to visit the mechanical room. An example of a robust motorized valve is our Heat-TimerⓇ motorized 3 way mixing valve for DHW that is controlled electronically by our ETV Platinum Plus Control. Using this combination, installers can easily retrofit underperforming mixing valve implementations with a robustly designed valve/control system combo that yields advanced features:
Thermostatic Valves Thermostatic valves are the trusty workhorses of the domestic water mixing valve world. For hospitals and nursing homes they provide the long term steady performance that is needed. What they lack in communication and remote monitoring capability is made up for in simplicity and reliability. They do not require power since they use an internal thermostatic element to control the output temperature to the set-point set via thermostat. These valves are ideal for locations where long term durability and reliability are key, and remote monitoring is not necessary. For more information on Precision Thermostatic Tempering Valves see our product page. HVAC Professionals Trust Heat-Timer® Valves For assistance picking the best domestic hot water valve for your facility come to the experts at Heat-Timer®. Heat-Timer® is dedicated to providing the highest quality domestic hot water valves on the market. Our team of technical experts can help you pick out the right valve for the job, be it a school, retail center or resort. You can rest easy knowing your systems are being reliably controlled for occupant safety and energy savings. Contact us today and speak to a technician or visit our website at https://www.heat-timer.com Original content posted on https://www.heat-timer.com/types-of-domestic-hot-water-valves/   Hotels, hospitals and other businesses with centralized hot water delivery face special challenges with regard to the safe and consistent delivery of hot water to their clients and residents, especially during peak periods. The hotel guest stuck with a cold shower will almost certainly give that hotel the cold shoulder next time they go to book a stay. They must provide hot water to all rooms and areas in all locations while ensuring that excessive boiler duty cycles do not run up heating bills. Key to the operation of these systems are the valves that control the mixing and flow of hot water, and the systems that monitor and control these valves. When properly specified and installed, these domestic hot water systems provide perfect on demand control over hot water distribution throughout your resort, hotel or multi-family building at a constant, set temperature while optimizing energy costs. A Guide to Tempering Valve Products Heat-Timer® provides some of the industry’s go-to products for these applications. In particular, our line of thermostatic tempering valves and controls provide a reliable backbone for all of your building’s domestic hot water needs.
Heat-Timer is a dedicated commercial heating system controls company with a reputation for the finest heating control products in the industry. Our team of technical experts in to help you service commercial buildings of any size, from hotels, apartment buildings and office buildings to schools, resorts and retail centers. While the self-learning, wireless, mobile enabled technology we employ is as good as it gets for building manager convenience, it’s the money you save on heating bills every month that will make you really love us. Please contact us today and speak to a qualified commercial heating control adviser or visit our website at https://www.heat-timer.com Original content posted on https://www.heat-timer.com/domestic-hot-water-systems-for-hotels/ |
AuthorHeat-Timer® corporate office and manufacturing facility is conveniently located in Fairfield, NJ. Here, Heat-Timer® manufactures its electronic controls, sensors, valves and actuator products using specialized computer controlled equipment and automated testing systems. Archives
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