Viessmann VITODENS 200-W Technical Data Manual page 36

Accessories
Accessories for Vitodens 200-W
Low-Loss Header (continued)
Low-loss header design (Type 80/50 or 120/80)
Principle of Operation
36
Vitodens 200-W, B2HA 19 to 80 Technical Data
IMPORTANT
Use only a Viessmann supplied temperature sensor.
Do not use any other manufacturer's temperature sensor.
Legend
AB Air Bleed
BR Boiler Return
BS Boiler Supply
BY Bypass (with laminar flow)
D Debris and/or air
DV Drain Valve
SC Sensor Cable
SR System Return
SS System Supply
TS Viessmann Temperature Sensor
SW Sensor Well
IMPORTANT
When installing a low-loss header, the system mixed
supply temperature (T3) must be calculated as follows:
Legend
T1 Boiler supply temperature
T2 Boiler return temperature
T3 System supply temperature
T4 System return temperature
Vprimary Boiler circuit flow rate
Vsecondary Heating circuit flow rate
Vbypass Bypass flow rate
Qprimary Heat supplied by boiler
Qsecondary Heat consumed by system
Vprimary < Vsecondary
T1 > T3
T2 = T4
Qprimary = Qsecondary
T1 167° F (75° C)
Vsecondary=Vprimary+Vbypass
Model No.
Type 80/60
Type 120/80
Type 160/80 *1
Type 200/120 *1
*1 Floor-mounted version (typically used for
multiple-boiler installations).
Max. system flow rate
19.5 GPM (4.4 m 3 /h)
35.2 GPM (8 m 3 /h)
44 GPM (10 m 3 /h)
80 GPM (18 m 3 /h)