RBI HEATNET 3.0 Torus Series, Manual

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CONTROL METHODS HeatNet Control V3
Page 21
Mixed Condensing/Non-Condensing Boiler
System
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MASTER
Condensing
MEMBER 1
Condensing
HNET HNET
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HNET
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MEMBER 2
Non-
Condensing
MEMBER 3
Non-
Condensing
Priority 1 Set Priority 2 Set
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Outdoor Air
Sensor
Note: The example drawings in this section are simplified.
They are meant to illustrate connections to the HeatNet V3
control. Only major components are illustrated. The system
engineer must ensure additional safeties, piping,
maintenance valves, and components meet code
requirements and safe operation.
Mixed Boiler System Examples
System
MMBTU
Effective
Turndown
MOD
MAX
Priority 1
Torus 5:1
Priority 2
MB/MW
7.5 25:1 55% 1500, 1500
4:1
1500,
1500,
1500
10.5 35:1 60% 1500, 1500
5:1
2500,
2500,
2500
18 30:1 55% 3000, 3000
5:1
4000,
4000,
4000
23 26:1 55% 4000,4000
5:1
5000,
5000,
5000
Futera III/Fusion/ Boiler Btu Chart (MBH)
MB/MW
CB/CW
500 750 1000 1250 1500 1750 2000
Max
Input
500 750 1000 1250 1500 1750 2000
Min
Input
4:1
125 188 250 312 375 437 500
Mod
Max
80%
400 600 800 1000 1200 1400 1600
Mod
Max
70%
350 525 700 875 1.05 1220 1400
Mod
Max
60%
300 450 600 750 900 1050 1200
Mod
Max
50%
250 375 500 625 750 875 1000
Futera XLF Boilers
MB/MW 2500 3000 3500 4000 5000
Max Input 2500 3000 3500 4000 5000
Min
5:1
500 600 700 800 1000
Mod Max
80%
2000 2400 2800 3200 4000
Mod Max
70%
1750 2100 2450 2800 3500
Mod Max
60%
300 450 600 750 900
Mod Max
50%
1250 1500 1750 2000 2500
For the examples, the RBI FIII/Fusion series water heaters
will be used. These boilers are non-Condensing, fully
modulating, low mass, and HeatNet compatible.
If CB/CW Fusion boilers are substituted for the MB/MW
Futera III boilers, the efficiency is greatly increased due to
the condensing mode of these boilers. When using CB/CW
Fusion boilers, at lower firing rates, the combustion
efficiency is maximized by running the CB/CW Fusion
boilers from low to middle input rates. See:
Typical
Efficiency of Condensing Boiler graph.