Engineering: Return Blend Loop Sizing
Factory Installed Option
 
 
EXAMPLE:  Finding the Loop GPM Flow
Boiler output BTU/HR, (I1) = 16,800,000 BTU
Main loop return temp, (T2) = 130 F
Main loop supply temp, (T1) = 140 F
Boiler supply temp, (T4) = 210 F
Boiler return temp, (T3) = 140 F
 
Results:
Main loop flow, (F1) = I1 / (500 * (T1-T2))
Actual boiler flow, (F3) = F1 * (T1-T2)/(T4-T3)
Boiler flow less circulation flow, (F2) = I1 / (500 * (T4-T2))
Circulator flow, (F4) = F3-F2
 
 
EXAMPLE:  Finding the Boiler Output Load
Main loop flow, (F1) = 3200 GPM
Main loop return temp, (T2) = 130 F
Main loop supply temp, (T1) = 140 F
Boiler supply temp, (T4) = 180 F
Boiler return temp, (T3) = 140 F

Results:
Boiler output BTU/HR, (I1) = F1 * 500 * (T1-T2)
Actual boiler flow, (F3) = F1 * (T1-T2) / (T4-T3)
Boiler flow less circulation flow, (F2) = I1 / (500 * (T4-T2))
Circulator flow, (F4) = F3-F2
  

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