Viessmann VITODENS 100-W WB1B Series Installation And Service Instructions Manual page 27

Installation Examples
Pressure drop (primary circuit) of Vitodens 100-W
The Vitodens 100-W is designed only for closed loop,
forced circulation hot water heating systems.
ft. m
Typical system flow rates
Model WB1B 26
∆ t
83,000
Output Btu/h
30º F rise (GPM) 5.5
35º F rise (GPM) 4.7
40º F rise (GPM) 4.2
Heating circuit pumps
Recommended heating pumps with
Vitodens 100-W, WB1B 26, 35.
Grundfos 15-58 (3-speed)
g
Taco 00R
g
or equivalent
Refer to the graph above for the
proper waterside boiler friction loss
calculations.
(continued)
USGPM
Flow rate
35
108,000
----
6.2
5.4
IMPORTANT
Pump selection must be based on
accurate system flow and pressure
drop calculations (incl. DHW sizing).
L/h
Boiler Connections
A low-loss header must be used
when the system flow rate exceeds
the maximum (or minimum) flow rate
of the Vitodens 100-W boiler. An
alternative method may be used, such
as primary secondary piping using
closely spaced tees.
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.
Please see page 36 for details.
Use standard friction loss method for
pipe sizing. Observe boiler maximum
and minimum flow rate limitations.
If system flow rate exceeds boiler
maximum flow rate (as stated on
page 75) or if system flow rate is
unknown, Viessmann strongly
recommends the installation of a low-
loss header. See page 36 for low-loss
header information or refer to the
Vitodens Venting System Installation
Instructions.
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