What “Penny Wise & Pound Foolish” says about Domestic Hot Water Solutions

https://www.heat-timer.com/domestic-hot-water-solutions/

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:

https://www.heat-timer.com/domestic-hot-water-solutions/


The typical 3-way valve serves several primary purposes:

  1. It allows hot water storage tanks to be maintained at temperatures high enough to sterilize the water supply (~140F – 160F per OSHA guidelines) and kill bacteria like Legionella and more.
  2. It “mixes” hot water from the tank with part of the cold water supply to insure that no one burns their hands from the hot water supply when it comes out of your sink or shower. (~110 F)
  3. It provides fail-safe operation and can provide alarms for systems in the event of an unexpected failure with the DHW system.

According to the Centers for Disease Control & Prevention (CDC), incidents of Legionnaire’s disease have been on the rise for over a decade.

https://www.heat-timer.com/domestic-hot-water-solutions/

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.

https://www.heat-timer.com/domestic-hot-water-solutions/

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/

Comments

Post a Comment

Popular posts from this blog

How Heat-Timer® Controls Can Make Your Building Management System Better

A  Building Management System  (BMS), also called Building Automation System (BAS) is a system that allows building managers to monitor and control a building’s major mechanical and safety systems in one central, easy-to-use application. A BMS can be thought of as a distributed network of building systems supervised and controlled in one central platform. The network of field controllers and other system controllers are distributed throughout the building and communicate to the BMS through a local area network. Field controllers can be general purpose, supplied by the BMS integrator and used for simple applications like lighting control, ventilation fans and building access. With a BMS, these applications can also be separated by zone, floor or other combinations to yield optimal HVAC performance. Field controllers for mission critical systems like fire alarms and heating are specialized and can act independently, as well as under BMS control. The Heat-Timer® Platinum se...
Read more

Water Safety For all Time

Image
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 ...
Read more

Heat-Timer’s Wireless Sensor Integration Just got a Big Upgrade

Image
  One of the most appealing parts of the Heat-Timer® Platinum Series is the wireless sensor connectivity that comes with our Building Net internet upgrade. There are thousands of clients who own an original, non-internet capable Platinum Series control and when they upgrade the control with our Building Net internet package they actually get two major elements: An Internet/Mobile ready control – The Building Net upgrade gives any platinum control the ability to be controlled via the internet through a simple browser connection to a web management portal, or via our free mobile app. In either case, reports, alarms, control settings, and real-time monitoring are all at your fingertips, wherever those fingertips may be. Wireless Sensor Integration – You can think of this as the second network access that is enabled by the Building Net upgrade. This internal Long Range network allows you to connect our wireless space sensors to the control, which by reporting temperatures in vari...
Read more