About this course

This is a free lecture presented by hydronics expert John Siegenthaler. The future of hydronic heating is low water temperature. This is necessary to optimize the performance of modern heat sources such as condensing boilers, heat pumps, and solar thermal collectors. With proper design, you can create systems that require supply water temperatures no higher than 120°F under design load conditions. In this lecture, you will learn:
  • Why low operating temperatures are important in modern hydronic systems
  • The differences between high-mass and low-mass heat emitters
  • Details of the operation of micro-fan equipped panel radiators
  • How to describe the construction of radiant wall and ceiling panels
  • How to describe a home-run distribution system serving several panel radiators
  • Why low temperature heat emitters are critical in systems with renewable energy heat sources
  • The best distribution piping system to use with low temperature emitters
  • Simple and reliable methods for room-by-room temperature control
  • Why low temperature emitters are critical in systems using thermal storage

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Course outline

2 modules • 5 assignments • 1:07 hours of video lectures

Module 1 • 2 assignments
Low Temperature Heat Emitter Options in Hydronic Systems

In this one-hour lecture, John Siegenthaler covers numerous topics related to designing hydronic systems for low water temperatures and answers participant questions.

  • Low Temperature Heat Emitter Options in Hydronic Systems (1 hour) (01:05:25 hours)
  • Presentation slides (.pdf)


  • John Siegenthaler

    P.E., Appropriate Designs
    View profile

    John Siegenthaler, P.E., is a mechanical engineering graduate of Rensselaer Polytechnic Institute, a licensed professional engineer, and Professor Emeritus of Engineering Technology at Mohawk Valley Community College. “Siggy” has over 40 years of experience in designing modern hydronic systems. He is a hall-of-fame member of the Radiant Panel Association, and a... Learn more

Frequently asked questions

How does this course work?
This is a free course. Enroll today and get access to all of the materials instantly. The lecture video and other materials are available any time.
How long do I have access to the materials?
For free courses there is no guarantee for how long the course materials will be available.
Is there a certificate of completion?
Certificates of completion are only provided to HeatSpring Membership subscribers. This course has not been approved by any credentialing organizations (NABCEP, AIA, USGBC etc) for Continuing Education Credits (CEUs). This course is for self education purposes only and completion does not indicate a level of professional expertise or credential.
Can I register multiple people?
Yes, this is a free course so you can share this page with other people from your group.


Based on 70 reviews
students have taken this course

You must watch it!


I took the course in 2021, so the presentation is about six years old. But I found it current, interesting, and most helpful. The presenter has extensive experience and knowledge in the subject and is an excellent teacher.

Ron Holland

Yes , really enjoyed the course.

Milind Aghav

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