Dhw Circulation - Viessmann vitodens Technical Manual

1.4 DHW circulation

1.4 DHW circulation
DHW circulation pipes increase
DHW convenience and reduce
water consumption.
These advantages result from the
immediate DHW availability at the
consumer.
However, poor insulation of the
1
DHW circulation pipe can lead to
substantial heat losses.
Vitodens 200 and 300
WW KW
KW
Wall mounted DHW cylinder
Vitodens 333
DHW circulation without
DHW circulation pump connection set
DHW circulation for gas fired combination boilers
Because of the low water content of plate
heat exchangers, the connection of DHW
circulation pipes is not recommended for
34
From a pipe length of 7 m upwards, we
recommend the installation of a DHW
circulation with appropriate thermal
insulation in accordance with the Energy
Savings Order [Germany].
In accordance with the Energy Savings
Act, the DHW circulation pipe should
include a circulation pump, a check valve
and a time switch for shutting down the
circulation during the night.
WW
KW
Z
DHW cylinder installed below boiler
DHW circulation with
DHW circulation pump connection set
(integrated into boiler)
gas fired combination boilers.
Even the low heat losses of thermally
insulated DHW circulation pipes
Key to symbols
KW Cold water
WW Hot water
Z DHW circulation
WW
Z
KW
DHW cylinders installed adjacent to boiler
(to ENEV) lead to a higher cycling
frequency for gas fired combination
boilers (reheating).
VITODENS
KW