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5784 568 - 13
Vitodens 100-W, B1HA/B1KA 26 to 125 Combi Installation/Service
Connections
Neutralization Unit
Low-loss header design
Principal of operation
IMPORTANT
Low-Loss Header
- Type
80/60
[max. flow rate 19.5 GPM (4.4 m
3
/h)]
- Type
120/80
[max. flow rate 35.2 GPM (8 m
3
/h)]
A low-loss header offers additional benefits not provided
by a pair of closely spaced tees. Viessmann strongly
recommends and prefers the use of a low-loss header
over closely spaced tees. When used in conjunction with
the Vitodens 100-W boiler, the low-loss header acts as
hydraulic break, decoupling boiler and system circuits
from each other (no sensor required). It is recommended
to use the low-loss header in applications in which the
total system flow rate exceeds the maximum or falls
below the minimum flow rate of the Vitodens 100-W
boiler.
The low-loss header is available in the following sizes.
Select the size based on the maximum system flow rate
of your application.
Legend
V
primary
Boiler circuit flow rate
V
secondary
Heating circuit flow rate
V
bypass
Bypass flow rate
Q
primary
Heat supplied by boiler
Q
secondary
Heat consumed by system
V
primary
< V
secondary
T1 > T3
T2 = T4
Q
primary
= Q
secondary
T1 176°F (80°C)
Vsecondary=VVbypass
When installing a low-loss header, system mixed supply
temperature (T3) must be calculated as follows
For maximum boiler flow rates, see the table on page 25
in this manual.
Viessmann strongly recommends the use of a low-loss
header in cases where the system head and flow rates
are unknown.
In addition, the low-loss header helps eliminate air and
debris [D] from the heating system. See illustrations for
Low-loss header design and the principle of operation.
V
primary
V
bypass
V
secondary
AB Air Bleed
DV Drain Valve
BR Boiler Return
SR
System Return
BS Boiler Supply
SS
System Supply
BY Bypass
(with laminar flow)
TS
Viessmann Temp.
Sensor (not used)
D
Debris and/or air
SW Sensor Well
T1 Boiler supply temp.
T3
System supply temp.
T2 Boiler return temp.
T4
System return temp.
Model No.
Max. system flow rate
Type 80/60
19.5 GPM (4.4 m
3
/h)
Type 120/80
35.2 GPM (8 m
3
/h)
T1
T4
T3
T2
Accessories for the Vitodens 100-W
Neutralization Unit for Single-Boiler Applications
with neutralizing granulate for Vitodens 100-W, B1HA 26,
35, 94, 125 and B1KA 35, 125
Part No. 7134 231
Product may not look exactly as illustrated.
