Supplement For Dhw Heating - Viessmann VITOCAL 200-S AWS Technical Manual

Design information
(cont.)

Supplement for DHW heating

For general house building, a max. DHW consumption of approx.
50 litre per person per day at approx. 45 ºC is assumed.
■ This represents an additional heat load of approx. 0.25 kW per per-
son given a heat-up time of 8 h.
■ This supplement will only be taken into consideration if the sum total
of the additional heat load is greater than 20 % of the heat load cal-
culated in accordance with DIN EN 12831.
Low demand
*5
Standard demand
or
Apartment
(billing according to demand)
Apartment
(flat rate billing)
*5
Detached house
(average demand)
Supplement for setback mode
A supplement for setback mode in accordance with DIN EN 12831 is
not required as the heat pump control unit is equipped with a temper-
ature limiter for setback mode.
In addition, the control unit is equipped with start optimisation, which
means that there is also no need for a supplement for heating up from
setback mode.
Determining the dual mode point
Air source heat pumps are predominantly operated in mono ener-
getic mode. At ultra low outside temperatures, the heat pump heating
output drops, whilst at the same time the heat demand rises.
For operation in mono mode, very large systems would be required,
and the heat pump would be oversized for the majority of the run-
time.
*4 With a DHW cylinder heat-up time of 8 h.
*5 Select a higher supplement if the actual DHW demand exceeds the stated values.
VITOCAL 200-S
DHW demand at a DHW temper-
ature of 45 °C
in l/d per person
15 to 30
30 to 60
Reference temperature of
45 °C
in l/d per person
30
45
50
Specific available heat
in Wh/d per person
600 to 1200
1200 to 2400
Specific available heat
in Wh/d per person
approx. 1200
approx. 1800
approx. 2000
Both functions must be enabled in the control unit. If any of the sup-
plements are omitted because of the activated control unit functions
then this must be documented when the system is handed over to the
operator.
If these supplements are to be taken into account in spite of the control
options, calculate them in accordance with DIN EN 12831.
Above the dual mode point (e.g. -5 °C), the heat pump covers the entire
heat load. Below the dual mode point, the heat pump increases the
return temperature of the heating system and an instantaneous heat-
ing water heater in the heating flow provides additional heating.
The system is sized in accordance with the output diagrams.
Recommended heat load sup-
*4
plement for DHW heating
in kW/person
0.08 to 0.15
0.15 to 0.30
Recommended heat load sup-
*4
plement for DHW heating
in kW/person
approx. 0.150
approx. 0.225
approx. 0.250
VIESMANN
49
4