Selection Guide For Dhw Cylinders - Viessmann vitodens Technical Manual

1.3 Selection guide for DHW cylinders

In order to provide the right solution for
every case, Vitodens may be supplied
with integral, direct DHW heating
(gas fired combination boiler) or in
combination with separate DHW
cylinders (gas fired boiler) or with an
integral DHW loading cylinder
(Vitodens 333).
The following versions are available:
Vitodens 200 (8.8 to 26.0 kW)
H as gas fired combination boiler
and
H as gas fired boiler.
Vitodens 300 (6.6 to 26.0 kW)
H as gas fired combination boiler
Vitodens 300 (4.5 to 66.0 kW)
H as gas fired boiler
Vitodens 333 (6.6 to 26.0 kW)
H with integral DHW loading cylinder.
Selection table
DHW demand, convenience DHW demand for an apartement/flat
DHW demand for a detached house
DHW demand for a centralised system for
multi-occupancy buildings
DHW demand for a de-centralised system for
multi-occupancy buildings
Utilisation of the various Utilisation of the various One draw-off point
connected draw-off points connected draw-off points
Several draw-off points, no simultaneous utilisation
Several draw-off points, simultaneous utilisation
Distance between draw-off Distance between draw-off Up to 7 m (excl. DHW circulation pipe)
point and boiler point and boiler
Incl. DHW circulation pipe
Modernisation DHW cylinder installed
Replacement of an existing combi boiler
Space requirement Low space requirement (installation in a niche)
Sufficient available space (boiler room)
+ = recommended
0 = qualified recommendation
= not recommended
VITODENS
1.3 Selection guide for DHW cylinders
Various factors should be taken into
consideration when designing heating
systems and deciding between a gas fired
combination boiler or gas fired boilers
with separate DHW cylinders or an
integral DHW loading cylinder:
H DHW demand, convenience
H Utilisation of the various draw-off points
H Distance between draw-off points
and boiler
H System modernisation
H Space requirement
H Water quality.
Information about water quality:
From a water hardness of 20º dH and
higher, we recommend the use of DHW
cylinders or a water treatment system in
the cold water supply when considering
DHW heating.
Gas fired Gas fired boiler
combination with separate
boiler with DHW cylinder
instantaneous
water heater
+ +
0 +
+
+ +
+ 0
+ +
+
+
+
+
+
+ 0
+ +
1
Vitodens 333
with integral
DHW
loading
cylinder
+
+
0
+
0
+
+
+
29