Viessmann VITOTRONIC SPS Operating Instructions Manual page 33

Terminology
(cont.)
Heating curve
35.0 °C
30.0 °C
25.0 °C
20.0 °C
20.0 °C
-8.0 °C
Fig. 3 Example
Set temperatures, heating, day
A
Minimum set temperature (with very high outside
B
temperature)
Maximum set temperature (with very low outside
C
temperature)
HWB (heating water buffer cylinder)
A heating water buffer cylinder stores thermal energy
for central heating. See also "Buffer cylinder".
Coolant buffer cylinder
A coolant buffer cylinder stores cold water for room
cooling. See also "Buffer cylinder".
Buffer cylinder
A buffer cylinder stores a large quantity of heating
water or coolant. This allows the heating/cooling cir-
cuits to be supplied over a longer period without the
heat pump needing to start up, e.g. during power-OFF.
Due to the large buffer volume, the heat pump contin-
ues to operate to heat or cool the buffer cylinder than it
would if there were no buffer cylinder.
Infrequent starting of the heat pump and long runtimes
ensure long and efficient operation.
By adjusting the time program appropriately, you can
use economical night tariff power to heat the buffer cyl-
inder to a higher level, or cool it to a lower level. During
the daytime, the heating/cooling circuits can be sup-
plied with this cheap energy.
The following buffer cylinders can be built into your
system:
■ Heating water buffer cylinder
Coolant buffer cylinder
■
0.0 °C 10.0 °C
33.0 °C
30.0 °C
28.0 °C
23.0 °C
18.0 °C
20.0 °C
Set temperatures, heating, night
D
Outside temperatures
E
HW
Abbreviation for hot water
Heat source
The entire system can be divided into three areas:
■ Heat source
■ Heat pump
Heat sink
■
The heat source area consists of the system compo-
nents that transfer heat to the heat pump (e.g. geother-
mal probes, coolant buffer cylinder). The heat pump
extracts heat from the heat source. The temperature
level of the extracted heat is raised in the heat pump
so that drinking water can be heated, for example.
Heat sink
The entire system can be divided into three areas:
Heat source
■
■ Heat pump
■ Heat sink
The heat sink area consists of the system compo-
nents which absorb the heat provided by the heat
pump (e.g. heating water buffer cylinder).
Appendix
33