Installation manual

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Selection and Design of Heat Pumps 1.3.4.1
1.3.2 Domestic hot water preparation
To meet normal requirements regarding comfort, a peak
domestic hot water consumption of approx. 80-100 litres per
person and per day must be reckoned with based on a hot water
temperature of 45 °C. In this case, allowance should be made for
a heat output of 0.2 kW per person.
NOTE
The maximum possible number of persons should be assumed when
dimensioning and any special usage (e.g. whirlpool) should also be taken
into consideration.
It is not necessary to add the hot water energy consumption to
the heat consumption of the heating system if domestic hot water
is heated with the flange heater at the time of year (e.g. mid-
winter) used as the basis for the calculation.
Circulation pipes
Circulation pipes increase the line-side heat consumption of the
domestic hot water heating. This increase in consumption that is
to be allowed for depends on both the length of the circulation
pipes and the quality of the pipe insulation. If a circulation system
cannot be dispensed with because of long pipe runs, a circulation
pump should be used that can be activated by a flow sensor
according to need. Heat consumption for a circulation pipe can
be considerable.
NOTE
To be in compliance with Paragraph 12 (4) of the German Energy
Efficiency Ordinance, circulation pumps in hot water systems must be
equipped with an automatic switch-on/switch-off mechanism.
The surface-related heat loss of the domestic water distribution
system depends on both the surface area and the position of the
circulation pipework. For a surface area ranging from 100 to
150m and distribution within the thermal envelope, the surface-
related heat losses according to the German EnEV are:
 9.8 [kWh/m
2
a] with a circulation system
 4.2 [kWh/m
2
a] without a circulation system
1.3.3 Hot water heating for a swimming pool
Outdoor swimming pool
The heat consumption for heating the water in an outdoor
swimming pool depends strongly on the respective usage.
In terms of size, it can easily be the same as the heat
consumption of a house - and in such cases must be calculated
separately.
However, if heating is only carried out in the summertime (period
not requiring heating), the heat consumption mentioned above
can be ignored in certain cases.
An approximate estimation of the heat consumption is dependent
on the windage factor, the climatic conditions, the periods of use
and whether or not the pool has a cover.
Table 1.3: Reference values for the heat consumption of outdoor swimming
pools used between May and September
For initially heating the pool to a temperature of over 20 °C, the
quantity of thermal energy required is approx. 12 kWh/m
3
pool
volume. Heating-up periods ranging from one to three days are
required depending on the size of the pool and the output of the
installed heating system.
Indoor swimming pool
 Space heating
Space heating is carried out using radiators or underfloor
heating and/or a heat exchanger in the dehumidification/
ventilation system. In both cases it is necessary to calculate
the heat consumption - according to the system installed.
 Hot water heating for a swimming pool
The heat consumption depends on the pool temperature,
the temperature difference between the pool temperature
and the room temperature, and the pool usage.
Table 1.4: Reference values for the heat consumption of indoor swimming
pools
These outputs can be reduced by up to 50 % for private
swimming pools with a cover that are used for a maximum of 2
hours per day.
1.3.4 Determining the heat pump output
1.3.4.1 Air-to-water heat pump (mono energy operation)
Air-to-water heat pumps are primarily operated in mono energy
systems. The heat pump should fully meet the heat consumption
down to an external temperature (bivalence point) of approx.
-5 °C. In the event of very low temperatures and high heat
consumption, a second, electrically operated heat generator will
be activated.
In the case of mono energy systems, dimensioning of the heat
pump output has a particularly strong influence on the level of the
investment and the annual heating costs. In most cases, the
higher the heat pump output, the higher the initial investment and
the lower the annual heating costs will be.
Water temperature
20 °C 24 °C 28 °C
With cover
1
1. Reduced values for pools with a cover only refer to private swimming pools
used on average up to 2 h per day.
100 W/m
2
150 W/m
2
200 W/m
2
Without cover
Sheltered location
200 W/m
2
400 W/m
2
600 W/m
2
Without cover
Partly sheltered
location
300 W/m
2
500 W/m
2
700 W/m
2
Without cover
Unsheltered location
(subject to high winds)
450 W/m
2
800 W/m
2
1,000 W/m
2
Room
temperature
Water temperature
20 °C 24 °C 28 °C
23 °C
90 W/m
2
165 W/m
2
265 W/m
2
25 °C
65 W/m
2
140 W/m
2
240 W/m
2
28 °C
20 W/m
2
100 W/m
2
195 W/m
2