Supplement For Dhw Heating; Supplement For Setback Mode; Frost Protection; Mono-Energetic Operation - Viessmann VITOCAL 222-G Technical Manual

Design information
(cont.)

Mono-energetic operation

In heating mode, the heat pump system is supplemented by an instan-
taneous heating water heater. The control unit switches this instanta-
neous heating water heater on, subject to the outside temperature
(dual mode temperature) and the heat load.
Note
That part of the electric power drawn by the instantaneous heating
water heater will generally not be charged at special tariffs.
Sizing of typical system configurations:
■ According to DIN EN 12831, the heat output of the heat pump must
be designed for approx. 70 to 85 % of the maximum required heat
load of the building.
■ The heat pump covers approx. 95 % of the annual heat load.
■ Power-OFF periods must not be taken into consideration.

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
*12
Standard demand
or
Apartment
(billing according to demand)
Apartment
(flat rate billing)
*12
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.
11.7 Heat source for brine/water heat pumps

Frost protection

To safeguard a trouble-free heat pump operation, use anti-freeze
based on glycol in the primary circuit. This must protect against frost
down to at least -15 °C and contain suitable anti-corrosion inhibitors.
Ready-mixed solutions ensure an even distribution of concentrate.
For the primary circuit, we recommend Viessmann "Tyfocor" heat
transfer medium which is based on ethylene glycol (ready-mixed down
to -15 °C, light green).
*11 With a DHW cylinder heat-up time of 8 h.
*12 Select a higher supplement if the actual DHW demand exceeds the stated values.
VITOCAL
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
Note
Compared to mono-mode operation, the heat pump will run for longer
due to its smaller size. To compensate for this, increase the size of the
heat source for brine/water heat pumps.
For a geothermal probe system, an extraction rate of
∙ p.a. should not be exceeded.
100 kWh/m
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.
Note
When selecting the anti-freeze, always observe the stipulations of the
authorising body.
If the authorising body does not permit inhibitors for corrosion protec-
tion, the following measures can be taken to ensure frost protection:
■ Use an additional separating heat exchanger (similar to a well circuit
with water/water heat pumps).
■ Extend the probe and fill with water.
Recommended heat load sup-
*11
plement for DHW heating
in kW/person
0.08 to 0.15
0.15 to 0.30
Recommended heat load sup-
*11
plement for DHW heating
in kW/person
approx. 0.150
approx. 0.225
approx. 0.250
VIESMANN
57
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