User Guide

Taco Radiant Made Easy Application Guide
Delta T (Temperature) & Setpoint with Delta T Max
OVERVIEW
Once a heat request is present, such as a thermostat calling, the 00-VS operates to provide a fixed differential temperature
(Delta T) between the system return sensor and the system supply sensor.The Variable Speed Setpoint “00” Circulator
(00-VS) can maintain a differential temperature of 5° - 50°F. In applications, such as snow melting, it is desirable to limit
the rate of temperature increase in the system from the system’s starting temperature to its operating setpoint.This is to
prevent thermal shock of the system, causing cracks in the cement or buckling of floors, for example. Delta T operation
can provide a “soft start” of a heating system when sensors are placed across the boiler. If utilizing a condensing boiler, a high
Delta T can be maintained by placing sensors on the supply and return of the boiler. This increases the boiler’s efficien-
cies by optimizing the BTU transfer in the system, no matter the load applied.
The Radiant Mixing Block, when in the
Setpoint Mode, can be adjusted to
maintain a maximum differential tem-
perature of 10° - 70°F. If the Delta T
Max setting is turned on, the variable
speed injection pump is operated to
maintain temperature at the mixing
supply sensor at either the mixing
return temperature plus the Delta T max
setting or the mixing target tempera-
ture set by the installer, whichever is
lower.The RMB can also provide boiler
protection in this mode as well as con-
trolling or enabling the boiler.
Controlling the temperature drop across a system, zone or piece of equipment means never over pumping a system, while
always matching the boiler output to the load applied.
EFFECTIVE: March 1, 2004 SUPERSEDES: New
Products & Applications
OM07
Products:
00-VS - Variable Speed Setpoint “00” Circulator
(available in all models 003-0014)
RMB-1 - Radiant Mixing Block
Benefits:
• Maintains a specific temperature
differential no matter the load
• Uses standard “00” circulators
•Provides soft start of system
• Simplified wiring
•LED status panel or LCD display
•Prevent thermal shock
• Increased boiler efficiencies
• Boiler protection (RMB)
• Solid state microprocessor designed
150
140
130
120
110
100
90
80
70
60°F
Supply Temperature (°F)
Mix Supply = Mix Target
Setpoint
Time
Start
Time
120
110
100
90
80
70
60
50
40
30°F
Mix Target
Delta T Maximum
Mix Supply
Mix Return
Maximum Delta T
Supply Temperature (°F)