Pumping Away, Hydronics Changes And Electrification

Moe Hirsch joins the podcast to discuss the hydronics side of the industry, particularly focusing on Dan Holohan’s Pumping Away and exciting developments in the hydronics market, especially regarding electrification.

Pumping Away is many people’s entry point to hydronics. It contains some good basic information about boilers, especially when it comes to learning about the pressures involved in pumping and how the components manipulate pressure throughout the system.

Boilers use many of the same fundamentals as compression-refrigeration HVAC systems; pressure drops are similar, as are phase changes in steam boilers. Boilers also employ pumps instead of compressors, but the processes are similar.

The pump or circulator makes a pressure differential within the boiler, which adds pressure to the circulator outlet and results in negative pressure on the suction side. However, problems like air bubbles and magnetite buildup can negatively impact performance.

The electrification side of the boiler industry is exciting, especially because of the relative safety of electricity compared to combustible fossil fuels. However, electrification comes with its own set of concerns, especially when natural gas prices are low. In some markets, electrical grids also haven’t caught up with the demand for electricity yet.

Moe and Bryan also discuss:

  • Moe’s recent work in the industry
  • Changes in boiler infrastructure over the years
  • Pumping away from the boiler vs. pumping at the boiler
  • Pressure’s role in boiler systems
  • Similarities between parallel racks and boilers
  • Challenges with ECM circulators
  • Evolution of boiler motors and controls
  • Magnetic and hydraulic circulation
  • Low-temperature heat pumps with radiant heated systems
  • Moe’s ideal HVAC system
  • Natural gas health and safety risks (carbon monoxide)


To learn more about what Moe is doing, check out or contact Moe directly at

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