Navien NFB Series User Manual

22 Installing the System Piping
PQ Curve
NFB-175/200
H[ft]
Q[GPM]
0
2
4
6
8
10
12
14
16
0 2 4 6 8 10 12
14 16 18 20 22 24 26 28
Q [GPM] 0 2.6 5.3 7.9 10.6 13.2 15.9 18.5 21.1 23.8 26.4
H [ft] 0 0.3 0.7 1.1 2 3 4.3 5.6 7.4 9.2 11.5
Maximum and Minimum Flow Rates through the Boiler
Model Minimum Pipe Diameter Maximum Flow (GPM) Minimum Flow (GPM)
NFB-175 1
1
/
4
" 23.1 7.0
NFB-200 1
1
/
4
" 26.4 8.0
Temperature Rise Conditions
Model
20°F ΔT @ 100% water 25°F ΔT @ 100% water 35°F ΔT @ 100% water
Flow Rate (GPM) Head (Ft) Flow Rate (GPM) Head (Ft) Flow Rate (GPM) Head (Ft)
NFB-175 16 4.2 13 2.9 9 1.4
NFB-200 18 5.3 15 3.9 11 2.1

Navien NFB Series Specifications

General

Type	Condensing Boiler
Fuel Type	Natural Gas or Propane
Heat Exchanger	Stainless Steel
Vent Type	Direct Vent
Vent Diameter	2" or 3"