Technical data
130 | Project planning manual for heat pumps for heating and domestic hot water preparation | 01.2012 www.dimplex.de
9 Online Operating Cost Calculator
9 Online Operating Cost Calculator
The operating cost calculator is an effective online tool for de-
signing a heat pump heating system and for determining the op-
erating costs and the seasonal performance factor according to
VDI 4650.
The online tool is divided into 9 steps.
Steps 1-5 comprise the design process of the heat pump heating
system.
Step 6 is the calculation of the seasonal performance factor and
the creation of the calculation sheet.
In steps 7-9, the investment and operating costs of different heat
generators can be compared.
NOTE
The operating cost calculator can be found online at
www.dimplex.de/betriebskostenrechner
Designing the heat pump heating system
The step-by-step design of the operating cost calculator provides
information on the most important heat pump heating system pa-
rameters.
Heat pump design
1. Step: Input of the key building data for the rough design
of the heat pump
This refers to the building itself. The following information is im-
portant here:
Which areas are heated?
Where is the building located?
Which distribution system is used in the building and which
flow temperatures are set?
How does the building envelope look?
Have any insulation measures been carried out?
2. Step: Input of the calculated heat load or estimate based
on the consumption
The heat load is the most important criterion when selecting a
suitable heat pump. It can be entered directly in step 2 when a
heat load calculation according to EN 12831 has been carried
out. Alternatively, the heat load can be estimated based on the
current oil and gas consumption.
3. Step: Selection of the heat source, information on do-
mestic hot water and utility company shut-off times
An additional energy demand must be added to the heat pump
output for possible utility company shut-off times and for domes-
tic hot water preparation. The necessary data are entered in
step 3.
4. Step: Selection of the operating mode
The operating mode is selected depending on the energy source
selected in step 3. Air-to-water heat pumps are normally oper-
ated in mono energy mode, i.e. in addition to the heat pump, sup-
plementary heating is also operated with electricity. The biva-
lence point determines the outside temperature at which the
supplementary heating is switched on.
Brine-to-water and water-to-water heat pumps are normally op-
erated in monovalent mode. This means that the heat pump
alone is used for heating.
A ground heat collector can also be dimensioned with brine-to-
water heat pumps in Germany. For this, the post code of the rel-
evant region and the ground type must be entered in this step.
This enables the maximum abstraction capacity for the relevant
ground type to be determined via a database.
In bivalent operating mode, the heat pump is operated in combi-
nation with a second heat generator which uses a different en-
ergy source, e.g. oil or gas.
5. Step: Information for calculating the seasonal perform-
ance factor
The system parameters, such as the heating flow and return tem-
perature, spread and brine inlet temperature, can be adapted
here for calculating the seasonal performance factor. For brine-
to-water and water-to-water heat pumps, the power consumption
of the brine circulating pump or well pump can also be specified
here, as this is also included in the seasonal performance factor.
6. Step: Selection of the heat pump
A suitable heat pump can now be selected here. The overview
shows all suitable heat pumps with the expected seasonal per-
formance factor. Different information can be called up here for
each heat pump:
PDF document with all relevant data for calculating the sea-
sonal performance factor
PDF document with all information required for filling out a
BAFA funding application
Diagram showing the operating limits of the heat pump
Step 7- 9: Operating costs
In steps 7 and 8 of the operating cost calculator, the operating
costs of different heat generators and the heat pump heating sys-
tem can be calculated.
The overall operating costs (including investment costs) for dif-
ferent systems can be compared in step 9.