What Is Delta-T?

Delta-T is all the buzz in the heating community. We have personally promoted it as “The Hydronic Revolution”. So, what is this “Delta-T” all about?

A Forced Hot Water (FHW) or Hydronic Heating System is designed to provide controlled heating energy distribution to an acclimated space, and do it efficiently. This is done by burning fuel in a boiler and moving the heated water through radiation to warm the environment. This process is technically referred to as “hydronics” (the science of applying water).

However, to accomplish this most efficiently requires:

  1. A correctly sized and fired boiler.
  2. Properly sized and positioned radiation for each heated area.
  3. Idealized, simultaneous energy delivery of heated water to all radiation, irrespective of its demands.

Practically though, none of these elements are absolutely correct, nor can they be. Boilers and radiation are almost never idealized for efficiency, but the third (energy delivery) is typically the most poorly executed of all. You must deliver heated water at an ideal rate and temperature for maximum heating transfer efficiency, functionally improbable with fixed-speed (set point) circulators.

A contemporary hydronic heating distribution system consists of:

  1. Dedicated fixed-speed circulators, sized for each zone, or
  2. A single fixed-speed circulator with a zone valve for each zone.

Neither of these configurations can perform efficiently in practice, and in particular the latter.

Enter the Delta-T ECM Continuously Variable Speed Circulator, found at this link: http://flopro.taco-hvac.com/media/viridianblast/100-119.pdf

“Delta-T” is a technical connotation. “Delta” (from the Greek letter ∆) is difference, or differential. “T” designates temperature. Thus Delta-T (∆T) is “differential temperature”.

The “ECM” denotes an “Electronically Commutated Motor”. Utilizing rare earth magnets with power-pulsing electronics, they provide superb starting torque, power and speed control. (They don’t stall or “stick” like a conventional AC Circulator Motor.) Their electronics further enable data display to idealize operational condition management.

The Delta-T ECM Circulator therefore continuously measures, controls and maintains the ideal temperature differential of heating water between the supply input and the return lines by using sensors. It then continuously adjusts its speed (water delivery rate) to match the heating load. This method dramatically reduces electric power consumption, and even more so when coupled with new low-energy zone valves, found at this link: http://www.taco-hvac.com/uploads/FileLibrary/100-82.pdf

There is no costly control system required. Just finitely adjust the Delta-T (∆T) on the circulator (shipped preset @ 20°F) if necessary. We slogan this as “putting an ‘Automatic Transmission’ on a Boiler”!

A Delta-T ECM Hydronic Distribution System increases the performance of existing radiation by typically eliminating hydronic whistle from over-sped, heating lag and imbalance from under-sped zones. The remaining discrepancies are then readily identifiable and correctable. More importantly, Delta-T Distribution modifies the heating profile of your radiation, smoothing convective air delivery and increasing comfort. This is the basis for the further claim of reduced fuel consumption by Taco Comfort Solutions®.

So, be rid of all those restrictive “hot head” valves and misapplied circulators while reducing your entire energy bill, both electricity and fuel!

More so, look at our “Neo-Gravity Hydronic (FHW) Heating Appliance™” (U.S. Patent 10,690,356, Canada to follow)  on this site for the ultimate in Delta-T Hydronic Heating Efficiency ….. bar none!

Author’s Note: Updated 07/08/2020