• Sign In
  • Create Account
  • Sign Out
  • My Account
  • NEWS
  • PRODUCTS
  • CONTRACTORS
  • ENGINEERS
  • RADIANT & HYDRONICS
  • INSIGHTS
  • MEDIA
  • RESOURCES
  • EMAGAZINE
  • SIGN UP!
cart
facebook instagram twitter linkedin youtube
  • CONTRACTORS
  • BATH & KITCHEN PRO
  • BUSINESS MANAGEMENT
  • HIGH EFFICIENCY HOMES
  • TECHNOLOGY
  • WATER TREATMENT
  • PMC COLUMNS
  • PMC COLUMNS
  • Dave Yates: Contractor’s Corner
  • John Siegenthaler: Hydronics Workshop
  • Kenny Chapman: The Blue Collar Coach
  • Matt Michel: Service Plumbing Pros
  • Scott Secor: Heating Perceptions
  • ENGINEERS
  • CONTINUING EDUCATION
  • DECARBONIZATION | ELECTRIFICATION
  • FIRE PROTECTION
  • GEOTHERMAL | SOLAR THERMAL
  • PIPING | PLUMBING | PVF
  • PME COLUMNS
  • PME COLUMNS
  • Christoph Lohr: Strategic Plumbing Insights
  • David Dexter: Plumbing Talking Points
  • James Dipping: Engineer Viewpoints
  • John Seigenthaler: Renewable Heating Design
  • Lowell Manalo: Plumbing Essentials
  • Misty Guard: Guard on Compliance
  • RADIANT & HYDRONICS
  • RADIANT COMFORT REPORT
  • THE GLITCH & THE FIX
  • INSIGHTS
  • CODES
  • GREEN PLUMBING & MECHANICAL
  • PROJECT PROFILES
  • COLUMNS
  • SPONSOR INSIGHTS
  • COLUMNS
  • Codes Corner
  • Natalie Forster: Editorial Opinion
  • Guest Editorial
  • MEDIA
  • PODCASTS
  • VIDEOS
  • WEBINARS
  • RESOURCES
  • INDUSTRY CALENDAR
  • DIRECTORIES
  • EBOOKS
  • PM BOOKSTORE
  • CE CENTER
  • MARKET RESEARCH
  • CLASSIFIEDS
  • EMAGAZINE
  • EMAGAZINE
  • ARCHIVE ISSUES
  • CONTACT
  • ADVERTISE
  • PME EMAGAZINE ARCHIVES
search
cart
facebook instagram twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
  • NEWS
  • PRODUCTS
  • CONTRACTORS
    • BATH & KITCHEN PRO
    • BUSINESS MANAGEMENT
    • HIGH EFFICIENCY HOMES
    • TECHNOLOGY
    • WATER TREATMENT
    • PMC COLUMNS
      • Dave Yates: Contractor’s Corner
      • John Siegenthaler: Hydronics Workshop
      • Kenny Chapman: The Blue Collar Coach
      • Matt Michel: Service Plumbing Pros
      • Scott Secor: Heating Perceptions
  • ENGINEERS
    • CONTINUING EDUCATION
    • DECARBONIZATION | ELECTRIFICATION
    • FIRE PROTECTION
    • GEOTHERMAL | SOLAR THERMAL
    • PIPING | PLUMBING | PVF
    • PME COLUMNS
      • Christoph Lohr: Strategic Plumbing Insights
      • David Dexter: Plumbing Talking Points
      • James Dipping: Engineer Viewpoints
      • John Seigenthaler: Renewable Heating Design
      • Lowell Manalo: Plumbing Essentials
      • Misty Guard: Guard on Compliance
  • RADIANT & HYDRONICS
    • RADIANT COMFORT REPORT
    • THE GLITCH & THE FIX
  • INSIGHTS
    • CODES
    • GREEN PLUMBING & MECHANICAL
    • PROJECT PROFILES
    • COLUMNS
      • Codes Corner
      • Natalie Forster: Editorial Opinion
      • Guest Editorial
    • SPONSOR INSIGHTS
  • MEDIA
    • PODCASTS
    • VIDEOS
    • WEBINARS
  • RESOURCES
    • INDUSTRY CALENDAR
    • DIRECTORIES
    • EBOOKS
    • PM BOOKSTORE
    • CE CENTER
    • MARKET RESEARCH
    • CLASSIFIEDS
  • EMAGAZINE
    • EMAGAZINE
    • ARCHIVE ISSUES
    • CONTACT
    • ADVERTISE
    • PME EMAGAZINE ARCHIVES
  • SIGN UP!
Columns

Lines Of Communication
John Siegenthaler, PE

By John Siegenthaler, P.E.
August 1, 2005
Networked controls will soon be the norm in hydronics.

Figure 1
For decades, the hydronic heating industry has used “stand-alone” controllers designed for very specific purposes. Examples include:
  • Boiler reset controller.
  • Boiler staging controller.
  • Injection mixing controller.
  • Zoning controller.
Many systems require several such “boxes” to be merged into an overall control system. Doing so requires attention to detail to avoid conflicts (one controller wants the system to “zig” while another wants it to “zag”).

Figure 1 shows an example of a mechanical room with a healthy share of stand-alone controllers that have been merged into such a system.

A system of such complexity usually requires hours to install and “tweak” into smooth operation. Over the years, many of us have spent hours in the truck getting to some remote jobsite to make these adjustments. On the drive home, we've wondered if another trip will be necessary because all the dials and switches are not in just the right position. Needless to say, there is room for improvement.

Figure 2

Let's Talk

New methods for system control hold the potential to greatly reduce installation and final adjustment procedures.

A new generation of communicating control products is currently establishing itself in the residential and light commercial sector of the hydronics industry. These new products allow technicians to monitor and adjust the system operation from a remote location using one or more types of digital communication.

This is probably no surprise to those who have worked with larger commercial or institutional HVAC systems in the last few years. Building automation systems (BAS) now allow the authorized personnel to view and adjust hundreds of system-operating parameters from a PC either on- or off-site. In many cases, these systems control lighting, fire protection, elevators and security functions as well as the HVAC system.

Advances in digital technology including microprocessor capability, size, power requirements and onboard memory have made it possible - both technically and economically - to scale BAS concepts down for smaller systems.

Communication between controllers, sensors and controlled devices is the key difference between the past and future of HVAC controls. The concept of communicating control devices is shown in Figure 2.

The red horizontal line represents a digital communications “bus.” It typically consists of a two-wire pair running between the various devices. The communications bus transmits very low power digital signals, and does not power the devices on the network. Operating power such as line voltage for circulators or 24 VAC for motorized valves is still necessary.

Each device on the network has a unique digital address (e.g., a specific binary “call sign”). Any given device can only send or receive information when its address is active on the communications bus. At other times the encoded instructions flow past that device without invoking any action. Collectively, all devices connected to the bus form a network (or as it's sometimes called, a LAN - local area network).

The speeds at which digital information flows across the communications bus makes it possible for any given device on the network to send or receive information hundreds, if not thousands, of times each second. Given the response characteristics of most HVAC systems, this is more than adequate, even when hundreds of devices share the same bus.

Every device on such a network must be a “smart device.” It must have the embedded hardware and software necessary to listen and speak to the other devices. The physical location of a given device on the network is usually irrelevant; it's the digital address that counts. When a new device is attached to the network, the system controller automatically detects it and assigns it the necessary address for communications. It's akin to how we can now “hot swap” USB or FireWire™ peripherals on modern computer systems.

Full implementation of this concept requires devices such as motorized valves, circulators and heat sources with equipment for network communication. Such smart devices already are on the market if you know where to look, and more are headed your way in the very near future.



Figure 3

Beam Me Up

Besides communication between smart devices on the same LAN, some systems can be equipped with a “gateway” allowing communication over the Internet.

The gateway provides a unique URL address number (such as 12.345.6.78) that can be typed into any Web browser, such as Internet Explorer® or Firefox®, to initiate the login process.

A username and password are required to login. Some users and passwords are restricted in their capability to access or change controller operation.

Once the login is completed, a unique Web page is displayed along with available options:

  • Systems on the network (HVAC, lighting, security).
  • Zone information.
  • Operating schedules.
  • Alarms.
  • Graphs or charts from previous data-logging routines.
With the proper authorization, someone at any Internet-connected computer can access information, such as the current settings, current operating conditions or a log of how the system has performed over the last few days. They could also make changes if necessary. The system controller might even be configured to automatically send e-mails to a designated address if a fault is detected that requires servicing.

An example of how such data can be read from a remote computer screen is shown in Figure 3. Figure 4 demonstrates some of the data-logging capabilities of such a control system.



Figure 4

One's Enough

A very important advantage of communicating control devices is the elimination of redundant components such as:
  • Power supplies.
  • Transformers.
  • Displays.
  • Keypads.
  • Sensors.
Here's an example: Think back to one of your recently installed multiload/multitemperature hydronic systems. Chances are you installed two or more sensors to read outdoor temperature and supply that information to two or more control “boxes” that make up the overall system. I've actually seen systems with 13 separate outdoor sensors! Each one required a separate sensor cable all the way back to the mechanical room. Thousands of feet of 18 AWG cable was required just so the overall system could adjust itself based on outdoor temperature.

In a networked system, a single outdoor sensor can supply the outdoor temperature information to every device that requires it. This is not only possible, it's on the market right now waiting to save you time, cost and lower the probability of malfunctions over time. A communicating control network is also far less prone to control conflicts that can arise when each of several noncommunicating controllers is individually set.

Ready Or Not, Here They Come: In the years ahead, communicating control networks will become the standard in residential hydronic systems. Most will have the ability to be accessed through the Internet. It's also a sure bet that such control networks will talk to devices on the air-side of overall HVAC systems as well as other appliances within a typical home.

Comfort professionals who expect to remain current and competitive in this quickly evolving market should begin “tooling up” on the technology. One reference that I think provides a great generic introduction to these concepts is a book titled “The Fundamentals of HVAC Direct Digital Control, Practical Applications and Design, Second Edition,” by Frank Shadpour, P.E.

Share This Story

Looking for a reprint of this article?
From high-res PDFs to custom plaques, order your copy today!

Siegenthaler

John Siegenthaler, P.E., is a consulting engineer and principal of Appropriate Designs in Holland Patent, New York. In partnership with HeatSpring, he has developed several online courses that provide in-depth, design-level training in modern hydronics systems, air-to-water heat pumps and biomass boiler systems. Additional information and resources for hydronic system design are available on Siegenthaler’s website,  www.hydronicpros.com.

Recommended Content

JOIN TODAY
to unlock your recommendations.

Already have an account? Sign In

  • Worker using the Milwaukee Tool SWITCH PACK drain cleaner

    Pipeline profits: Drain cleaning, pipe inspection create opportunities

    Drain cleaning and inspection services offer lucrative...
    Plumbing News
    By: Nicole Krawcke
  • Uponor employee, Arturo Moreno

    The reinvestment in American manufacturing and training

    Plumbing & Mechanical Chief Editor Nicole Krawcke and...
    Plumbing News
    By: Nicole Krawcke and Natalie Forster
  • March 2024 Women in Plumbing hero image of woman engineer overlayed by circle of hexagon shapes with numbers from 1 to 10

    Celebrating 10 Influential Women in the Plumbing Industry

    Celebrating Women's History Month and Women in...
    Plumbing News
    By: Nicole Krawcke
close

1 COMPLIMENTARY ARTICLE(S) LEFT

Loader

Already a Registered User? Sign in now.

Subscribe For Free!
  • eNewsletters
  • Online Registration
  • Subscription Customer Service
  • eMagazine
  • Manage My Preferences

IPEX celebrates grand opening of new Florida distribution center

IPEX celebrates grand opening of new Florida distribution center

Bell & Gossett Illustrates Path to Net-zero at AHR Expo

Bell & Gossett Illustrates Path to Net-zero at AHR Expo

NIBCO Press Solutions

NIBCO Press Solutions

AI can boost efficiency and profitability for plumbing, HVAC contractors

AI can boost efficiency and profitability for plumbing, HVAC contractors

More Videos

Sponsored Content

Sponsored Content is a special paid section where industry companies provide high quality, objective, non-commercial content around topics of interest to the Plumbing & Mechanical audience. All Sponsored Content is supplied by the advertising company and any opinions expressed in this article are those of the author and not necessarily reflect the views of Plumbing & Mechanical or its parent company, BNP Media. Interested in participating in our Sponsored Content section? Contact your local rep!

close
  • J.J. Keller CMV vehicles on road
    Sponsored byJ. J. Keller & Associates, Inc.

    The dash cam game-changer for small business safety

Popular Stories

The interior of a government building.

President Trump signs executive order promoting skilled trades and apprenticeships

Underfloor heating installation with drain sewer hole in bathroom close up on water floor heating.

Using hydronics to leverage time-of-use electrical rates

Watts Nexa mobile image

Behind the Wall: Where smart plumbing gets smarter

PMCE Home-X April 29 Free Webinar: From Legacy to Leadership: Preparing Your Home Services Business for the Next Generation

Events

November 13, 2024

Future Proofing MEP: Navigating the 2026 High Efficiency Water Heating Standards

Join our deep dive into DOE’s new standards so you can future-proof your MEP practice.

EARN: 0.1 ASPE CEU; 1 AIA LU/HSW; 0.1 IACET CEU*; 1 PDH

View All Submit An Event

Poll

Will business be up or down in 2025?

Do you anticipate business in 2025 to be up or down in comparison to 2024?
View Results Poll Archive

Products

The Water Came To A Stop

The Water Came To A Stop

See More Products

Download the FREE Water Conservation, Quality & Safety eBook: Plumbing Trends Increasing Safe Water Availability

Related Articles

  • Siegenthaler PM

    John Siegenthaler: Modern biomass meets state-of-the-art hydronics

    See More
  • Siggy

    John Siegenthaler: Dos and don’ts of hydronic system design

    See More
  • Residential Propane Tank

    John Siegenthaler: Freedom of (fuel) choice

    See More
×

Keep your content unclogged with our newsletters!

Stay in the know on the latest plumbing & piping industry trends.

JOIN TODAY!
  • RESOURCES
    • Advertise
    • Contact Us
    • Directories
    • Store
    • Want More
    • Supply House Times
  • SIGN UP TODAY
    • Create Account
    • eMagazine
    • eNewsletter
    • Customer Service
    • Manage Preferences
  • SERVICES
    • Marketing Services
    • Reprints
    • Market Research
    • List Rental
    • Survey/Respondent Access
  • STAY CONNECTED
    • LinkedIn
    • Facebook
    • Instagram
    • YouTube
    • X (Twitter)
  • PRIVACY
    • PRIVACY POLICY
    • TERMS & CONDITIONS
    • DO NOT SELL MY PERSONAL INFORMATION
    • PRIVACY REQUEST
    • ACCESSIBILITY

Copyright ©2025. All Rights Reserved BNP Media.

Design, CMS, Hosting & Web Development :: ePublishing

search
cart
facebook instagram twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
  • NEWS
  • PRODUCTS
  • CONTRACTORS
    • BATH & KITCHEN PRO
    • BUSINESS MANAGEMENT
    • HIGH EFFICIENCY HOMES
    • TECHNOLOGY
    • WATER TREATMENT
    • PMC COLUMNS
      • Dave Yates: Contractor’s Corner
      • John Siegenthaler: Hydronics Workshop
      • Kenny Chapman: The Blue Collar Coach
      • Matt Michel: Service Plumbing Pros
      • Scott Secor: Heating Perceptions
  • ENGINEERS
    • CONTINUING EDUCATION
    • DECARBONIZATION | ELECTRIFICATION
    • FIRE PROTECTION
    • GEOTHERMAL | SOLAR THERMAL
    • PIPING | PLUMBING | PVF
    • PME COLUMNS
      • Christoph Lohr: Strategic Plumbing Insights
      • David Dexter: Plumbing Talking Points
      • James Dipping: Engineer Viewpoints
      • John Seigenthaler: Renewable Heating Design
      • Lowell Manalo: Plumbing Essentials
      • Misty Guard: Guard on Compliance
  • RADIANT & HYDRONICS
    • RADIANT COMFORT REPORT
    • THE GLITCH & THE FIX
  • INSIGHTS
    • CODES
    • GREEN PLUMBING & MECHANICAL
    • PROJECT PROFILES
    • COLUMNS
      • Codes Corner
      • Natalie Forster: Editorial Opinion
      • Guest Editorial
    • SPONSOR INSIGHTS
  • MEDIA
    • PODCASTS
    • VIDEOS
    • WEBINARS
  • RESOURCES
    • INDUSTRY CALENDAR
    • DIRECTORIES
    • EBOOKS
    • PM BOOKSTORE
    • CE CENTER
    • MARKET RESEARCH
    • CLASSIFIEDS
  • EMAGAZINE
    • EMAGAZINE
    • ARCHIVE ISSUES
    • CONTACT
    • ADVERTISE
    • PME EMAGAZINE ARCHIVES
  • SIGN UP!