User Guide
Applications manual
  | 25 
Panel Radiator 
Applications Manual
Panel Radiator Applications Manual | 07.2017 Technical specifi cations are subject to change without prior notice                         
Balancing the system
 Initial settings of flow setter valves will help to 
ensure proper fl ow through all radiators. Keep in 
mind that this is only a starting point and that the 
system may require further adjustment based on 
the heating characteristics of the structure.
Procedure for setting the fl ow-setter valves.
1. Identify the largest radiator. In the above example it 
would be the master bedroom radiator. The setting for 
this radiator should be “N”. This radiator will have the 
highest pressure drop and requires that the fl ow-setter 
valve be fully open.
2.Using the Pressure Drop Chart on page 30-31, fi nd the 
output for this radiator (at selected ∆T) at the bottom of 
the chart. Based on 6,000 btu/hr at a 20°F ∆T the fl ow 
rate for this radiator is 0.6 GPM. Follow the 0.6 GPM 
line vertically until you intersect the N setting. Reading 
across to the left you will see that the pressure drop for 
this radiator is approximately 12 in. W.C. or 1ft/hd.
3. Draw a horizontal line across the diagram at 12 in. 
W.C.
4. Select the next radiator. Identify its btu/hr output, 
locate 
this fi gure at the bottom of the chart as you did for the 
fi rst radiator. At the corresponding fl ow-rate, move 
vertically on chart until you intersect the horizontal line 
that you drew indicating 12” W.C. Find the appropriate 
fl ow setting. If the value is between two settings, say 3 
and 4, then simply set the valve between 3 and 4.
5. Repeat step 4 for remaining radiators.
6. Use guidelines in Table 10 to size main piping. In this 
case, use 3/4” copper mains with 1/2” copper (or PEX) 
to/from each radiator. Install a thermostat in master 
bedroom. Size circulator based on total fl ow rate and 
install balancing valve for fl ow control.
Piping Lay-out Suggestions:
1. For small systems, use one-pipe system with 
monofl ow tees or diverter valves. 
Btu’s per loop: 
15,000 - 20,000 Btu/hr with 1/2 “ copper 
20,000 - 30,000 Btu/hr with 5/8 “ PEX.
Increasing the overall temperature drop in the system 
from 20°F (11°C) to 30°F (17°C) or 40°F (22°C) 
permits more radiation per loop. (See Table 14). 
Oversize radiators by 20 - 30% at the end of a one-
pipe loop. Always install a balancing valve in each 
loop to regulate the fl ow rate to eliminate possible fl ow 
noise. 
Maximum fl ow rate for diverter valves: 2 GPM 
Maximum fl ow rate per radiator: 2.5 GPM.
2. For larger systems, use two-pipe reverse return or 
multiple one-pipe systems with common supply and 
return manifolds. Refer to Table 10 for pipe sizing. 
Pump Selection: 
1-3 loops: Grundfos UP15-42, Taco 007 or equivalent 
3-6 loops: Grundfos 26-64 or equivalent 
Use pressure bypass valve on two-pipe systems to 
prevent deadheading the pump.
Radiator Selection & System Start-up Suggestions:
1. Size radiators based on heat load, location, available 
space, desired style and system operating 
temperatures.
2. Use of thermostatic sensor heads increases comfort, 
eliminates problems with over sizing the radiation and 
provides individual room control.
3. Balance the system to ensure proper heat output from 
each radiator using the fl ow setter valve on each 
radiator. Shut off thermostatic heads one at a time and 
monitor system response. Make necessary 
adjustments.
4. Retighten compression fi ttings slightly after initial 
start-up.










