Mains Water Pressure - Vaillant Vantage 120 Installation Instructions Manual

7 Installation requirements
16

7.2 Mains Water Pressure

The DHW performance of an unvented cylinder installati-
on will correspond to the available mains water supply
pressure and flow rate. To achieve optimum performan-
ce from the VANTAGE a suitable cold mains water supp-
ly must be available, i. e. the measured static pressure
from the incoming mains water supply should be at least
2.0 bar. A corresponding flow rate at least 20-25 l/min
should be available.
Note:
Mains water pressures will reduce during periods
of peak demand. Ensure that measurements are
taken during these periods.
Once the available mains supply pressure and flowrate is
known the respective flowrate from the VANTAGE can
be obtained from fig. 7.
Example:
If the measured cold mains supply pressure is 2 bar
static and the cold mains flow rate available is 30 l/min,
the available flow rate of mixed water at 40 °C will be
25 l/min (from 15 l/min hot water from the VANTAGE
k 60 °C together with 10 l/min cold water @ 10°C).
The VANTAGE will operate satisfactorily with water sup-
ply pressures below 2 bar although flow rates will be
reduced. If the supply pressure is below 1 bar the
VANTAGE unvented storage cylinder should not be
installed. Contact Vaillant Ltd for details on alternative
hot water supply systems.
In order to minimise frictional losses minimum 3/4 inch
bore is recommended for new cold mains supply pipe-
work into the dwelling although satisfactory performan-
ce can be achieved with 1/2 inch bore pipework.
Vaillant Vantage 120/150/200