STIEBEL ELTRON Heat pumps Quick start guide

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Hot water renewables a ir condi t ioning room He at ing
»ISSUE 2009
TEchnIcal GUIdE
hEaT pUmpS

Design/engineeRing anD installation
Issue March 2009
Reprinting or duplication, even partially, only with our express permission.
STIEBEL ELTRON, D-37601 Holzminden
Legal note:
In spite of the care taken in the production of this brochure, no guarantee can be given regarding the accuracy of its contents.
Information concerning equipment levels and specification are subject to modification. The equipment features described in this
brochure are not stated as agreed properties of our products. Due to our policy of ongoing improvement, some features may have
subsequently been changed or even removed. Our advisors will be happy to consult with you regarding the currently applicable
equipment features. Pictorial illustrations in this brochure only represent application examples. The illustrations also contain
installation components, accessories and special equipment, which is not part of the standard delivery.

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Heat pumps protect our energy reserves 6
How does a heat pump work? 7
Energy sources for heat pumps 8
Heat pump operating modes 10
The right heat pump for every application 11
This is could be your solution 12
Energy Savings Order EnEV [Germany] 13
Cost calculation to VDI 2067 21
Terminology and descriptions 23
Summary of formulae 24
System design 25
Regulations and guidelines/directives 26
Heating load calculation 28
Flow temperatures of heating surfaces 29
Sizing of heat pumps 30
Power supply and tariffs 32
Integration into the heating system 33
Heat pumps with buffer cylinder 34
Heat pumps without buffer cylinder 35
DHW heating with heat pumps 36
Freshwater station 38
Modernisation of older buildings 39
Cooling with the heat pump system 40
Cooling load calculation 41
Heat sinks for cooling operation 43
Cooling capacity 44
Distribution system for cooling operation 45
Cooling capacity, underfloor heating system 46
Cooling capacity, fan convectors 47
Cooling capacity, cassettes 48
Passive cooling with the WPC cool heat pump 49
Passive cooling with the WPF...E heat pump 50
Passive cooling with the WPF heat pump 51
Active cooling with the WPC heat pump 52
Active cooling with the WPF heat pump 53
Active cooling with the WPL heat pump 54
Air | water heat pump; external installation 55
Condensate connection 58
Air | water heat pump - internal installation 59
Air routing 60
Condensate connection 61
Checklist 62
Air | water heat pumps 63
Air | water heat pump WPL 5 N 64
Connection WPL 5 N 66
Connection WPL 5 N 67
Air | water heat pump WPL 10 68
Output details WPL 10 70
External installation WPL 10 71
Internal installation WPL 10 72
Heating system connection WPL 10. 76
Power supply WPL 10. 77
Air | water heat pumps WPL 13/18/23 E/cool 78
Output details WPL 13/18/23 E/cool. 80
External installation WPL 13/18/23 E/cool 82
Internal installation WPL 13/18/23 E/cool 83
Air routing of WPL 13/18/23 E for internal installations 87
Heating system connection WPL 13/18/23 E/cool 88
Power supply WPL 13/18/23 E/cool 89
Air | water heat pump WPL 33 90
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Output details WPL 33 92
External installation WPL 33 93
Internal installation WPL 33 94
Heating system connection WPL 33. 95
Power supply WPL 33. 96
Air | water heat pump WPL 14 HT 98
Output details WPL 14 HT 100
Internal installation WPL 14 HT 102
Heating system connection WPL 14 HT 104
Power supply WPL 14 HT 105
Air | water heat pump WPL 20/26 AZ 106
Installation WPL 20/26 AZ 108
Connection WPL 20/26 AZ 109
Notes 110
Geothermal collector 111
Sizing tables, geothermal collectors 115
Geothermal probe 117
Sizing tables, geothermal probes 121
Heat transfer medium 122
Checklist 123
Brine | water heat pumps 125
Brine | water heat pumps WPC 5/7/10/13 (cool) 126
Output details WPC 5/7/10/13 128
Installation WPC 5/7/10/13 130
Heating system connection WPC 5/7/10/13 131
Brine | water heat pump WPF 5/7/10/13/16 E/cool 132
Output details WPF 5/7/10/13/16 E/cool 134
Installation WPF 5/7/10/13/16 E/cool 136
Heating system connection WPF 5/7/10/13/16 E/cool 137
Brine | water heat pumps WPF 5/7/10/13/16 138
Output details WPF 5/7/10/13/16 140
Installation WPF 5/7/10/13/16 142
Heating system connection WPF 5/7/10/13/16 143
Brine | water heat pumps WPF 10/13/16 M 144
Output details WPF 10/13/16 M 146
Installation WPF 10/13/16 M 148
Heating system connection WPF 10/13/16 M 149
Power supply WPF 10/13/16 M (SET) 151
Brine | water heat pumps WPF 20/27/40/52/66 152
Output details WPF 20/27/40/52/66 154
Internal installation WPF 20/27/40/52/66 156
External installation WPF 20/27/40/52/66 157
Heating system connection WPF 20/27/40/52/66 158
Power supply WPF 20/27/40/52/66 160
Well installation 161
Assessing the water quality 164
Well installation with brine | water heat pumps 165
Checklist 166
Water | water heat pumps 167
Water | water heat pumps WPW 7/10/13/18 168
Output details WPW 7/10/13/18 170
Installation WPW 7/10/13/18 172
Heating system connection WPW 7/10/13/18 173
Water | water heat pumps WPW 13/18/22 M 174
Output details WPW 13/18/22 M 176
Installation WPW 10/13/16 M 178
Heating system connection WPW 10/13/16 M 179
Power supply WPW 13/18/22 M (SET) 181
Accessories for heating heat pumps 183
Heat pump manager 184

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Mixer, swimming pool module 186
Remote control unit and sensors 188
Communication 189
Heat meter 191
Underfloor heating control system 192
Low loss header 193
Buffer cylinder SBP 100 Komfort 194
Compact installation for SBP 100 Komfort 195
Buffer cylinder SBP 200 E, SBP 200 E cool 196
Buffer cylinder SBP 400 E, SBP 400 E cool 197
Buffer cylinder SBP 700 E, SBP 700 E SOL 198
Compact installations for SBP 200/400/700 199
Buffer cylinder SBP 1000 E, SBP 1000 E SOL, SBP 1000 E cool 200
Buffer cylinder SBP 1500 E, SBP 1500 E SOL, SBP 1500 E cool 201
Thermal insulation for SBP 1000/1500 E cool 202
Circulation pumps 203
Pump assemblies 206
Pressure hoses 207
Threaded immersion heater BGC 209
Brine kit 210
Brine circuit pumps 212
Brine manifold, heat transfer medium 213
Expansion vessel, antifreeze tester, brine pressure switch 214
Convector heater module LWM 250 215
Cooling module 217
Air hoses and connections 218
Duct silencer, silencer, condensate pump 219
DHW cylinder SBB 301/302 WP 220
DHW cylinder SBB 401/501 WP SOL 221
DHW cylinder SBB 751/1001 222
DHW cylinder SBB 751/1001 SOL 223
DHW cylinder SBS 800/1000/1500 224
DHW cylinder SBS 800/1000/1500 SOL 225
Thermal insulation; DHW cylinder 226
Freshwater station 227
Plate-type heat exchanger 228
Convector replacement 229
Standard circuits 230
DHW heat pumps 247
Hot water out of "thin air" 248
WWK 300 249
Special accessories WWK 300..SOL 252
Installation WWK 300..SOL 253
Installation WWK 300..SOL 254
WWP 300 255
Installation WWP 300 258
Installation WWP 300 259
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HEat pUmpS protEct oUr EnErgy rESErvES
Advanced heat pumps save energy
and reduce emissions
Heat is a fundamental human
need. Many people today not only
consider economy when they think
of heating, but also consider the
environmental impact. That both can
be combined effectively is shown by
the development of the heat pump.
This utilises the energy held in the
air, water and under ground. This it
converts into useful heating energy.
The positive aspect of this type of
"harvesting" available heat is that you
can draw deep without damaging the
environment.
The heat pump is regulated subject
to the outside temperature. This
control unit safeguards the selected
set temperature. As a result, the heat
pump achieves an excellent quotient
of "harvested" heat to expended
primary energy. To put it into figures:
Each kWh electrical energy spent
generates up to 5 kWh available
energy, subject to the respective heat
source, i.e. from the air, from the
groundwater and the ground of your
own property. The compact design
requires little space and ensures
an easy installation. The lowest
installation effort secures the air
|water heat pump the top prize for
easy installation. With internal and
external versions, it can yield heat
for domestic heating from outside
air down to a temperature of –20°C.
Future purchasing decisions will
increasingly favour products with
sound environmental credentials. Heat
pumps from STIEBEL ELTRON already
enable the basic premise of heating
an apartment or entire houses with
environmentally responsible and cost-
effective methods to be achieved.
Future-proof solutions from
STIEBEL ELTRON
Over the last 30 years, STIEBEL ELTRON
has invested a lot of time and energy
in the development of its heat pumps.
This has created a reliable, standard
technology that delivers every
conceivable convenience. Our range
of heat pumps satisfies the most
divers requirements in the heating
technology sector - conveniently and
economically. Our heat pumps are
part of the extensive range of systems
by STIEBEL ELTRON, the predominant
aim of which is to translate our high
quality standards into future-proof,
alternative technologies. As one of
the most important manufacturers of
products in the heating, ventilation,
air conditioning and domestic hot
water equipment sector, we feel a
great sense of responsibility for our
environment. For that reason will we
continue to adhere to our commitment
to this sector.
Exclusive technology -
hot water included.
Hot water and cosy ambience are
our business. You can safeguard
your domestic hot water supply with
DHW cylinders from STIEBEL ELTRON.
Or have you ever considered
separating your hot water heating
from your existing heating system?
For larger DHW demand you
could, for example in commercial
operations, use STIEBEL ELTRON
heat pumps exclusively for heating
your domestic hot water, irrespective
of whether you want to provide a
centralised or decentralised supply.
At STIEBEL ELTRON, a complete range
of energy-efficient electric appliances
awaits you.
26_03_01_0358

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Heat pump principle
The most important contribution to
the heat pump function is made by
the refrigerant (in the following also
referred to as "process medium"). This
evaporates at the lowest temperatures.
If you route outside air or water to a
heat exchanger (evaporator), in which
the process medium circulates, then
that refrigerant extracts the required
evaporation heat from the heat source
and changes from a liquid into a
gaseous state. During this process,
the heat source cools down by a few
degrees. A compressor draws the
process medium in and compresses
it. The increase in pressure also raises
the temperature; in other words,
the process medium is "pumped"
to a higher temperature level. That
requires electrical energy. As the
compressor is of the suction gas-
cooled design, the energy (motor
heat) is not lost, but reaches the
downstream condenser together with
the compressed process medium.
Here, the process medium transfers
its absorbed energy to the circulating
system of the hot water heating
system by being returned into the
liquid state again. An expansion valve
reduces the still prevalent pressure
and the circular process starts again.
Heat pump coefficient of performance
The coefficient of performance εHP
is equal to the quotient of heating
output QHP and electrical power
consumption PHP in accordance with
the following equation
It provides a factor, by which yield
exceeds expenditure. The coefficient
of performance is subject to the
temperature of the heat source
and that of the heat consumer. The
higher the heat source temperature
and the lower the heat consumer
temperature, the higher the coefficient
of performance. It relates, as current
value, always to a specific operating
condition.
How doES a HEat pUmp work?
εHP =
QHP
PHP
Main layout of a heat pump refrigeration circuit
Compressor
Inlet line
Gaseous process medium
low pressure
Pressure line
Gaseous process medium
high pressure
Liquid line
Liquid process medium
high pressure
Injection line
Liquid process medium
low pressure
Expansion valve
Flow
Return
Evaporator
Heating
energy
Environmental
energy

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Heat source air
Air heated by the sun is universally
available. Even at temperatures as low
as –20 °C, heat pumps yield sufficient
heat from the outside air. However, air
as heat source has the disadvantage
that it is coldest when the highest
heat demand arises. Although it is
still possible to extract heat from air
as cold as –20 °C, the heat pump
coefficient of performance is, however,
regressive in line with the outside
temperature. It is for that reason,
that in most cases a combination
with a second heat source is required
that boosts the heating system,
particularly during the colder season.
One particular benefit is the ease of
installation of air|water heat pumps,
as no extensive ground work or well
drilling is required.
Heat source water
Groundwater is a good store of solar
energy. Even on the coldest days in
winter, temperatures of +7 °C to +12
°C are achieved - and this is where
its advantage lies. The near constant
temperature level of this heat source
enables the heat pump to achieve a
favourable coefficient of performance
all the year round. Regrettably,
groundwater of adequate quality is
not universally available. Where it is
available, its utilisation is certainly
worthwhile. The use of groundwater
requires the approval of your local
water board [check local regulations].
Utilising this heat source requires the
drilling of a delivery and return well.
Your local water board will advise you
about the possibility of utilising these
waterways.
EnErgy SoUrcES for HEat pUmpS
Main layout of an air source heat pump system
Main layout a groundwater heat pump system

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EnErgy SoUrcES for HEat pUmpS
Heat source ground with geothermal
collector
At a depth of 1.2 to 1.5 m, the ground
remains warm enough, even on
colder days, to enable an economical
heat pump operation. However, this
requires the availability of a property
large enough to accommodate a
pipe system for collecting the heat
from the ground. In dry, sandy soil,
the collector can extract between 10
and 15 W/m² and up to 40 W/m² in
ground that carries groundwater.
An environmentally-friendly brine
mixture that cannot freeze and which
transports the yielded energy to
the heat pump evaporator courses
through the pipes. As a rule of thumb,
you would need approximately
two to three times as much ground
area as area to be heated. If your
property is large enough, you have an
inexhaustible reserve of energy and
ideal conditions for a STIEBEL ELTRON
brine |water heat pump.
Heat source ground with geothermal
probe
Geothermal probes that are set up
to 100 metres deep into the ground
by specialist drilling contractors,
require less space. Geothermal probes
comprise a probe foot and endless,
vertical probe pipes made from
plastic. As with geothermal collectors,
a brine mixture that extracts heat from
the ground circulates through the
plastic pipework. The extraction rate is
subject to the ground characteristics,
and generally lies between 30 and
100 W per metre geothermal probe.
Subject to heat pump and ground
conditions, several geothermal probes
can be linked up in a single system.
These systems must be notified to and
possibly approved by your local water
board.
Main layout geothermal probe heat source system
Main layout geothermal collector heat pump system

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Operating modes
For the different types of heat pump
operation, the heating technology
world uses the following terminology:
Mono-mode
The heat pump is the sole provider
of heating in the building. This
operating mode is suitable for all
low temperature heating systems up
to +60 °C flow temperature.
Mono-energetic
The heating system uses no second
form of energy. The air | water heat
pump operates down to an outside air
temperature of –20 °C. Upon demand,
an electric booster heater is started at
very low outside air temperatures.
HEat pUmp opEratIng modES
Dual-mode - alternative
Down to a fixed outside temperature
(e.g. 0 °C), the heat pump delivers
the entire heating energy. When the
temperature falls below that value,
the heat pump switches itself OFF
and the second heat source takes over
the heating operation. This operating
mode is suitable for all heating
systems up to 90 °C.
Dual-mode - parallel
Down to a certain outside
temperature, the heat pump alone
delivers the required heating energy.
A second heat source starts at low
temperatures. However, contrary
to the dual-mode alternative
operation, the heat pump proportion
of the annual output is higher.
This operating mode is suitable
for underfloor heating systems
and radiators up to +60°C flow
temperature.
Dual-mode - partially parallel
Down to a certain outside
temperature, the heat pump alone
delivers the required heating energy.
The second heat source starts, if the
temperature falls below that value. The
heat pump is stopped if the heat pump
flow temperature is inadequate. The
second heat source supplies the entire
heating output. This operating mode is
suitable for all heating systems above
60 °C flow temperature.
Illustration of the possible operating modes of a heat pump system
mono-mode dual-mode -
alternative
dual-mode partially
parallel
dual-mode - parallel,
mono-energetic
Heat distribution system tv < 60 °C Heat distribution system tv > 60 °C
HP = Heat pump
QN = Heating load
TU = Changeover point
BV = Dual-mode point
ZH = Booster heater
TE = Booster heater start

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tHE rIgHt HEat pUmp for EvEry applIcatIon
For the use of a water | water heat
pump, groundwater of sufficient
volume and quality must be
available at an economical depth.
You have ideal conditions for a
mono-mode operation, if this heat
source is available to you.
The utilisation of a brine | water
heat pump requires the availability
of property without buildings that
can be used for a geothermal
collector. The property should
be at least two to three times
the area to be heated. These
systems can be operated in mono-
mode in conjunction with a low
temperature heating system.
We help before you start
Take an overview first; our table will
assist you in that. A good analysis,
from the building and heating
technology point of view is crucial.
In new build, generally all kinds of
heat sources can be utilised, i.e. air,
groundwater or ground. You judge
which is the optimum one for you
using the following criteria.
Using an air | water heat pump is
always possible, as the heat source
air is available anywhere. It is
suitable for dual-mode and mono-
energetic operation.
Larger systems can be realised by
connecting several heat pumps
together. The electric and hydraulic
connection of brine | water or
water | water heat pumps is easily
achieved with the appropriate
accessories.
Central heating
Specific heat demand 50
W/m² living space, low
temperature heating
system, max. flow
temperature +60 °C
(desirable is +35 °C)
Heat source
Groundwater
exploration via a well
system
Operating mode
mono-mode
Heat pump size subject to
m2heated living space
up to 120 m2 WPW 7
up to 180 m² WPW 10
up to 220 m² WPW 13
up to 300 m² WPW 18
up to 420 m² WPW 22 M
up to 440 m² WPW 26 SET
up to 520 m² WPW 31 SET
up to 600 m² WPW 36 SET
up to 720 m² WPW 40 SET
up to 840 m² WPW 44 SET
Operating mode
mono-mode
Heat pump size subject to
m2heated living space
up to 100 m
2
WPF/C 5
up to 140 m² WPF/C 7
up to 180 m² WPF/C 10
up to 240 m² WPF/C 13
up to 300 m² WPF 16
up to 360 m² WPF 20 SET
up to 420 m² WPF 23 SET
up to 480 m² WPF 26 SET
up to 540 m² WPF 29 SET
up to 600 m² WPF 32 SET
up to 380 m² WPF 20
up to 500 m² WPF 27
up to 800 m² WPF 40
up t 950 m² WPF 52
up to 1100 m² WPF 66
Operating mode
mono-energetic dual-
mode point -5 °C outside
temperature
Heat pump size subject to
m2heated living space
up to 160 m
2
WPF/C 5
up to 200 m² WPF/C 7
up to 280 m² WPF/C 10
up to 340 m² WPF/C 13
up to 420 m² WPF 16
up to 520 m² WPF 20 SET
up to 640 m² WPF 23 SET
up to 700 m² WPF 26 SET
up to 760 m² WPF 29 SET
up to 840 m² WPF 32 SET
up to 600 m² WPF 20
up to 760 m² WPF 27
up to 1200 m² WPF 40
up to 1560 m² WPF 52
up to 1880 m² WPF 66
Operating mode
mono-energetic dual-
mode point -5 °C outside
temperature
Heat pump size subject to
m2heated living space
up to 80 m² WPL 5 N
up to 120 m2 WPL 10
up to 180 m² WPL 13
up to 220 m² WPL 18
up to 300 m² WPL 23
up to 360 m² WPL 33
Operating mode
mono-mode
Heat pump size subject to
m2heated living space
up to 200 m
2
WPL 14 HT
Heat source
Ground
geothermal collectors -
geothermal probe
Heat source
Air
universally available

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tHIS coUld bE yoUr SolUtIon
General information
Naturally, all compact heat pumps
from STIEBEL ELTRON can be installed
in all new and existing heating
systems. In many cases, a mono-
mode operation is feasible, so that
no additional, conventional heating
system and associated additional
investment is required, even on
those few exceptionally cold days
of the year. When deciding on the
potential Part of this is of a heat
pump, the heat distribution system
too, and in particular the required
flow temperature, must be given due
consideration. Generally speaking,
low temperature and conventional
heating systems (radiators) can
be supplied by heat pumps. When
developing new systems, allow for
low temperature heating systems with
max. flow temperatures of +55°C.
Existing systems with conventional
heat distribution too can generally be
combined with heat pumps without
requiring major changes. Generally,
such heating systems are designed for
maximum flow temperature of 90 °C.
However, most are oversized making
substantially lower flow temperatures
sufficient on account of subsequently
installed thermal insulation of the
building.
Heat pumps not only provide
heating but also produce hot water
economically.
All STIEBEL ELTRON heating heat
pumps also generate domestic hot
water, e.g. with special accessories,
such as the compact installation
and DHW cylinders. The heat pump
manager provides the automatic
changeover between central heating
and DHW heating operation.
Matching solutions for every
application
For many years, STIEBEL ELTRON
has been producing heat pumps
for all applications. Part of this is
an extensive installation accessory
range, e.g. buffer cylinders, pressure
hoses and control equipment. These
enable an easy and consequently
cost-effective installation. In the
following, two examples of heat pump
installations are shown. Naturally,
alternative installation options are
also feasible.
Design example 1
Water|water heat pump
Operating mode: mono-mode
Mono-mode operation is only feasible
in conjunction with a low temperature
heating system (maximum flow
temperature +60 °C). At a specific
heat demand of 50 Watt/m², suitable
heat pumps offer themselves from the
heating system sizes listed in the table
on page 11.
Important information:
A water analysis is part of the first
design phase.
Two results from that analysis are
relevant to the engineering of the
system: free chlorine and chloride.
Iron and manganese content.
Construct the heat pump system in
accordance with the regulations of
your local water board.
The system can be installed
subject to the availability of
groundwater of adequate quantity
and quality.
Design example 2
Air|water heat pump without
additional boiler
The mono-energetic air | water heat
pump WPL from STIEBEL ELTRON. As
the description suggest, the heating
system requires no second form of
energy. This heat pump operates with
outside air temperatures down to –20
°C where the outside air provides the
heat source. Between –5 °C and –20
°C, the heating water is additionally
heated by a small electric booster
heater integrated into the heat pump.
STIEBEL ELTRON offers the air | water
heat pump WPL in different versions,
from 10 to 30 kW heating output. This
produces adequate heating for small
to large houses with a living space of
up to approx. 500 m².
Installation information:
The unrestricted air flow through
the inlet and discharge apertures
must be assured at all times.
A thermal "short circuit" between
the inlet and discharge apertures
must be prevented. The direction
of the air flow should be in line
with the main wind direction,
where possible. An installation
in a corner is advisable when
selecting an internal installation.
Design the air ducts as directly and
as short as possible.
Maintain as small a clearance as
possible between heat pump and
house to keep pipe runs short.
Select the installation location so
that no noise pollution is caused,
even though these appliances are
extremely quiet.
The heat pump by necessity
creates condensate that must be
drained off in a suitable manner.
For internal installations via a
drain, possibly with a condensate
pump.

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EnErgy SavIngS ordEr EnEv [gErmany]
Energy Savings Order
The EU Energy Performance of
Buildings Directive obliged Member
States to translate measures regarding
energy and CO
2
reductions by
2006 into their national laws. The
EnEV 2002/2004 already laid down
requirements for new buildings and
introduced the energy performance
certificate. Adhering to the required
limits meets the energy-technical
requirements for new residential
properties to obtain planning
permission [in Germany]. The
EnEV 2007 introduces the energy
performance certificate for existing
residential buildings as well as for
non-residential buildings. The energy
performance certificate details the
energy-technical quality of a building
and retains its validity for ten years.
EnEV for residential properties
Calculation of the primary energy
demand Q
P
Energy requirements made of
residential buildings and the system
technology employed are considered in
unison. This global approach enables
an overall statement appertaining
the building envelope and the
system technology to be established
and is based on the primary energy
which allows losses during energy
generation and transmission to be
taken into consideration. To calculate
the annual primary energy demand Q
P
and the system expenditure of energy
value e
P
, the annual heat demand
Q
h
of the building and the available
surface area A
N
must be known. The
system expenditure of energy value
e
P
, which has no dimension and
which relates to the primary energy
for heating, ventilation and DHW,
enables the assessment of the entire
system technology. Furthermore,
this parameter forms the basis for
calculating the annual primary energy
demand Q
P
of a building, and describes
the system efficiency. The lower the
system expenditure of energy value,
the greater the scope for the building
envelope, i.e. the physical building
characteristics. This highlights the
importance of the cooperation between
all engineers and all those involved in
the process.
Calculation of the primary energy demand
Effects of standards
Optional compensations between the building and the system
Total energy demand
Energy efficient version
Energy inefficient version
Ratio external surface area / volume (1/m)
Qp,max = permissible annual energy demand (kWh/
(m² p.a.)) relative to the area of available space
Energy savings
calculation
System engineering
calculations
Calculating the structural
physical parameters
Max. annual energy demand
Annual heat demand
System expenditure of energy value
Primary energy
demand Heating energy
demand
DHW
demand
System expenditure
of energy value
* (QtW fixed value 12.5 kWh/m² p.a. acc. to EnEV)
Q
P
= ( Q
h
+ Q
tW
* ) x e
P
( )
= + x
Building
System

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EnErgy SavIngS ordEr EnEv [gErmany]
Outline DIN V 18599
Part 1 General statement procedure, terminology,
zoning and assessing fuel types
Part 2 Demand for useable energy for heating and cooling building zones
Part 3 Demand of useable energy for air treatment with energy
Part 4 Useable energy and net energy demand for lighting
Part 5 Net energy demand of heating systems
Part 6 Net energy demand of domestic ventilation systems
and air heating systems for residential buildings
Part 7 Net energy demand for air handling and air conditioning systems
for non-residential buildings
Part 8 Useable energy and net energy demand for DHW heating systems
Part 9 Net and primary energy demand of CHP systems
Part 10 Utilisation framework conditions, climate data
Supplement 1 Examples
System description - reference system technology
Central Low temperature boilers
heating Pressure-jet boilers
Natural gas
Installation outside the thermal envelope
System temperature 55/45 °C
Hydraulically balanced
Twin-pipe heating system
Distribution lines - unheated area
Riser and connection lines, internal
Dp constant
Pump sized in accordance with demand
WWB Common heat generation with the heating system
(central) Indirectly heated cylinder
Installation outside the thermal envelope
with DHW circulation
Dp constant
Pump sized in accordance with demand
Compensation options
The better the equipment performs,
the lower the requirement for thermal
insulation of the building envelope.
The EnEV opens up interesting
compensation options. The optimum
use of primary energy is ensured
by systems such as heat pumps or
domestic ventilation systems with heat
recovery.
System technology
It is generally recommended to
calculate the heat source expenditure
of energy value in accordance
with the detailed procedure in DIN
4701-10 applying manufacturer's
details. Subject to heat source,
performance factors are applied at
different operating conditions that
can sometimes vary significantly from
standard values. This also applies to
the expenditure as a result of losses
and auxiliary energy, for example
caused by components such as
cylinders and auxiliary drives. STIEBEL
ELTRON offers you a calculation
service or the calculation basics and
software free of charge on CD ROM.
EnEV for non-residential buildings
As part of the EnEV 2007 update,
applicable from the 1st October
2007, the EU Energy Performance of
Buildings Directive" for the statement
of non-residential buildings was
adopted in the form of the extensive
standard DIN V 18599 that determines
the calculations principles.
DIN V 18599 - Energy assessment of
buildings
Contrary to the calculation for
residential buildings to DIN 4108
part 6 and DIN 4701 part 10, the
DIN V 18599 provides a statement
not only for the energy demand for
heating, DHW heating and domestic
ventilation, but also for cooling and
lighting. It comprises 10 parts that
are linked through cross-references.
The essential difference when
considering non-residential buildings
is the assessment of the respective
utilisation profile. The primary energy
demands are no longer simply
dependent on the area and volume
covered by the building envelope,
but additionally relate to different
room temperatures, lighting, air
changes, times of utilisation, density
of occupation and the internal heating
loads. A further update of the EnEV
2007 (scheduled for 1 January 2009)
envisages replacement of the currently
applicable method of calculation for
residential buildings through that
specified in the DIN V 18599.
The reference building procedure
To determine the permissible annual
primary energy demand of a non-
residential building, a reference
building is determined that in
geometry, net floor area, orientation
and utilisation profile matches the
building to be assessed perfectly.
The energy quality of the building
envelope of the reference building
is specified in the EnEV via default
transmission heat transfer coefficient
HT ‘. System technology is also
specified for the reference building
covering heating, DHW heating, air
conditioning, air handling technology
and lighting. For this reference
building, in the first instance the
permissible annual primary energy
demand is determined. Then the
actual value is determined applying
the actual building characteristics
and system technology. To meet the
requirements of the EnEV the existing
annual primary energy demand must
be below the maximum permissible
value of the reference building. Heat
pumps are particularly suitable heat
sources for heating and DHW heating,
as they deliver a more favourable
primary energy statement than the
reference system technology. This
enables the EnEV requirements
to be met quite easily, given a
corresponding quality of the building
envelope.

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The DIN V 18599 provides a
segregation of the overall building
into various zones, since diverse
areas within the building are used for
various purposes and these require
different conditioning. A zone includes
those rooms within a building that
demand similar parameters on
account of their use (temperature,
ventilation, illumination, internal
loads, daylight provision, technical
equipment) with similar framework
conditions. Every zone has one of
33 programmed utilisation profiles
applied to it (e.g. office, hotel room,
kitchen, toilet, transit areas). The
energy demand for heating and
cooling must be defined separately
for each conditioned zone. Up to
a proportion of 3% of the overall
available floor area, living space may
be appropriately assigned to different
zones than those to which they should
be designated, as long as the internal
loads are not substantially different.
To simplify the calculation process it is
permissible to determine the annual
primary energy demand in accordance
with a single zone model for the
following types of building: Schools,
kindergartens, office buildings, hotels
(without internal swimming pool),
pubs and commercial premises.
However, different framework
conditions must still be applied.
Main areas of use and passages must
account for at least one third of the
total area; the building must only be
equipped with a central system used
to provide DHW and central heating
and must not be cooled. Illumination
must largely correspond to the
reference lighting technology.
The calculations according to DIN V
18599 are extensive and can, because
of the interactions that occur can
only be resolved by iterative means,
only be done with computer-aided
support. STIEBEL ELTRON offers
software solutions for this calculation.
This enables complex calculations
to be carried out, and even includes
manufacturer's data. In this
connection, our specialist department
offers support in all areas concerning
the Energy Savings Order 2007.
EnErgy SavIngS ordEr EnEv [gErmany]
Primary energy demand for non-residential buildings
Primary energy
demand = heating + cooling + steam + DHW + light + auxiliary energy
Q
P
= Q
P.h
+ Q
P.c +
Q
P.m
+ Q
P.w +
Q
P.l +
Q
P.aux

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ExpEndItUrE of EnErgy valUES of HEat pUmpS
EnEV – calculation to DIN V 4701-10
The EnEV provides three possible
certification processes:
Diagram process
Tabular process
Detailed process
For the detailed certification process,
verification can be provided using
standard values or manufacturer's
details. Generally, the certification
process with standard values is
sufficient for heat pumps, since their
high efficiency level allows results to
fall below the required expenditure of
energy value.
Where better expenditure of energy
values are demanded by more
stringent subsidy stipulations, e.g.
KFW 40 or KFW 60, these may possibly
be achieved with verification based on
the manufacturer's details.
IT programs or the calculation process
of the EnEV should be applied where
manufacturer's details are to be used.
For calculating the epfigure, STIEBEL
ELTRON offers the software "Energy
efficiency in residential buildings".
Where the certification utilises the
tabular process, draw the expenditure
of energy value egfrom the
DIN V 4701-10 according to "Table
C3-4c expenditure of energy value eg
and drive auxiliary energy qg, HE for
heat pumps with electric drive".
Electrically operated heating heat pumps
The heat generation expenditure of energy value is calculated using the annual
performance factor in accordance with the following equation:
eH,g = 1 : βHP
eH,g = Expenditure of energy value for the heat pump
βHP = Seasonal performance factor of the heat pump, calculated subject to
type of heat pump
Brine|water heat pumps
The seasonal performance factor of brine | water heat pumps is calculated in
accordance with the following equation:
βHP = εNx Fϑx F∆ϑ
βHP = Annual performance factor of heat pump
εN= Coefficient of performance to EN 14511 at B0/W35
Fϑ= Correction factor to table 5.3.7
F∆ϑ= Correction factor to table 5.3.8
Water|water heat pumps
The annual performance factor of water|water heat pumps is calculated in
accordance with the following equation:
βHP = εNx Fϑx F∆ϑ
βHP = Annual performance factor of heat pump
εN= Coefficient of performance to EN 14511 at W10/W35
Fϑ= Correction factor to table 5.3.7
F∆ϑ= Correction factor to table 5.3.8
Air|water heat pumps
The annual performance factor of air|water heat pumps is calculated in
accordance with the following equation:
βHP = (εN
(A-7/W35)
x F
ϑ
+ εN
(A2/W35)
x F
ϑ2
+ εN
(A10/W35)
x F
ϑ10
) x F
∆ϑ
βHP = Annual performance factor of heat pump
εN= Coefficient of performance to EN 14511 at A-7/W35
εN= Coefficient of performance to EN 14511 at A2/W35
εN= Coefficient of performance to EN 14511 at A10/W35
Fϑ-7 = Correction factor to table 5.3.10
Fϑ2= Correction factor to table 5.3.10
Fϑ10 = Correction factor to table 5.3.10
F∆ϑ= Correction factor to table 5.3.8

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ExpEndItUrE of EnErgy valUES of HEat pUmpS
Table 5.3.8 - Correction factors FDϑ for deviating temperature differentials at the condenser
Operation
DϑB
(K)
Temperature differential at the test bed DϑM (K) DIN EN 255
3 4 5 6 7 8 9 10 11 12 13 14 15
3 1.000 0.990 0.980 0.969 0.959 0.949 0.939 0.928 0.918 0.908 0.898 0.887 0.877
4 1.010 1.000 0.990 0.980 0.969 0.959 0.949 0.939 0.928 0.918 0.908 0.898 0.887
5 1.020 1.010 1.000 0.990 0.980 0.969 0.959 0.949 0.939 0.928 0.918 0.908 0.898
6 1.031 1.020 1.010 1.000 0.990 0.980 0.969 0.959 0.949 0.939 0.928 0.918 0.908
7 1.041 1.031 1.020 1.010 1.000 0.990 0.980 0.969 0.959 0.949 0.939 0.928 0.918
8 1.051 1.041 1.031 1.020 1.010 1.000 0.990 0.980 0.969 0.959 0.949 0.939 0.928
9 1.061 1.051 1.041 1.031 1.020 1.010 1.000 0.990 0.980 0.969 0.959 0.949 0.939
10 1.072 1.061 1.051 1.041 1.031 1.020 1.100 1.000 0.990 0.980 0.969 0.959 0.949
Table 5.3.7 - Correction factor Fϑfor brine | water heat pumps
Minimum brine temperature at the
evaporator inlet (°C)
Heating circuit design temperature
35°C / 28°C 55 °C / 45 °C
2 1.113 0.917
1 1.100 0.904
0 1.087 0.890
–1 1.074 0.877
–2 1.062 0.864
–3 1.051 0.852
Table 5.3.9 - Correction factor Fϑfor water | water heat pumps
Minimum water temperature at the
evaporator inlet (°C)
Heating circuit design temperature
35°C / 28°C 55 °C / 45 °C
12 1.106 0.892
11 1.087 0.873
10 1.068 0.853
9 1.049 0.834
8 1.030 0.815
Table 5.3.10 - Correction factor Fϑfor air | water heat pumps
Outside air inlet (°C) Heating circuit design temperature
35°C / 28°C 55 °C / 45 °C
–7 0.103 0.080
+2 0.903 0.745
+10 0.061 0.053
Table C3-4c - Expenditure of energy value egand auxiliary drive energy qgHE for electric heat pumps
Electric heat pump Heating circuit temperature Expenditure of energy value Auxiliary energy
egqgHE (kWh/m² p.a.)
Water/Water 55 °C / 45 °C 0.23 3.2 x AN-0.1
35°C / 28°C 0.19
Ground/Water 55 °C / 45 °C 0.27 1.9 x AN-0.1
35°C / 28°C 0.23
Air/Water 55 °C / 45 °C 0.37 0
35°C / 28°C 0.30

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ExamplE 1: brInE | watEr HEat pUmp
Diagram system expenditure of energy value ep
System description
Brine | water heat pump WPF with 100
litre buffer cylinder and 300 litre DHW
cylinder
DHW heating
Centralised provision; no DHW
circulation; distribution outside the
thermal envelope; indirectly heated
cylinder; installation outside the
thermal envelope; heating heat pump
brine|water powered by electricity.
Ventilation
No mechanical ventilation.
Central heating
Integral heating surface (e.g.
underfloor heating system); individual
room regulation with two-point
controller, switching differential
Xp=2 K; heating system design 35/28
°C; centralised system; horizontal
distribution outside the thermal
envelope, lines running internally;
regulated pump; buffer cylinder
installed; installation outside the
thermal envelope; heating heat pump
brine | water powered by electricity.
Example:
Annual heat demand
60 kWh/m² p.a.
Heated living space 200 m²
Result:
System expenditure of energy value =
1.04
System layout
Diagram system expenditure of energy value ep
Annual
heating
demand
Heated available area in ANin m²
kWh/m² p.a. 100 200 300 400 500
40 1.42 1.17 1.08 1.04 1.01
50 1.31 1.09 1.02 0.98 0.96
60 1.22 1.04 0.98 0.95 0.92
70 1.16 1.00 0.94 0.93 0.90
80 1.11 0.96 0.91 0.89 0.87
90 1.07 0.94 0.89 0.87 0.86
Underfloor heating
system
Ground
Heated available area in ANin m²
System expenditure of energy value ep

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ExamplE 2: aIr | watEr HEat pUmp
Diagram system expenditure of energy value ep
System description
Air | water heat pump WPL with 200
litre buffer cylinder and 300 litre DHW
cylinder
DHW heating
Centralised provision; no DHW
circulation; distribution outside the
thermal envelope; indirectly heated
cylinder; installation outside the
thermal envelope; heating heat pump
brine | water powered by electricity;
peak load: Electric heater rod.
Ventilation
No mechanical ventilation.
Central heating
Integral heating surface (e.g.
underfloor heating system);
individual room regulation with
two-point controller, switching
differential Xp=2 K; heating system
design 35/28°C; centralised system;
horizontal distribution outside the
thermal envelope, lines running
internally; regulated pump; buffer
cylinder installed; installation outside
the thermal envelope; heating
heat pump air | water powered by
electricity. Electric heater rod.
Example:
Annual heat demand
60 kWh/m² p.a.
Heated living space 200 m²
Result:
System expenditure of energy value =
1.31
System layout
Diagram system expenditure of energy value ep
Annual
heating
demand
Heated available area in ANin m²
kWh/m² p.a. 100 200 300 400 500
40 1.72 1.44 1.35 1.30 1.27
50 1.60 1.37 1.29 1.25 0.23
60 1.52 1.31 1.25 1.23 1.20
70 1.46 1.28 1.22 1.20 1.17
80 1.41 1.25 1.20 1.18 1.16
90 1.37 1.23 1.18 1.16 1.14
Underfloor heating
system
Air
Heated available area in ANin m²
System expenditure of energy value ep

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ExamplE 3: aIr | watEr HEat pUmp wItH Solar
Diagram system expenditure of energy value ep
System description
Air | water heat pump WPL with 200
litre buffer cylinder and 300 litre DHW
cylinder
DHW heating
Centralised provision; no DHW
circulation; distribution outside the
thermal envelope; indirectly heated
dual-mode cylinder; installation
outside the thermal envelope; heating
heat pump air|water powered by
electricity; peak load: Electric heater
rod; with solar DHW heating.
Ventilation
No mechanical ventilation.
Central heating
Integral heating surface (e.g.
underfloor heating system);
individual room regulation with
two-point controller, switching
differential Xp=2 K; heating system
design 35/28°C; centralised system;
horizontal distribution outside the
thermal envelope, lines running
internally; regulated pump; buffer
cylinder installed; installation outside
the thermal envelope; heating
heat pump air | water powered by
electricity. Electric heater rod.
Example:
Annual heat demand
60 kWh/m² p.a.
Heated living space 200 m²
Result:
System expenditure of energy value =
1.00
System layout
Diagram system expenditure of energy value ep
Annual
heating energy
demand
Heated available area in ANin m²
kWh/m² p.a. 100 200 300 400 500
40 1.17 1.04 1.00 0.97 0.95
50 1.13 1.02 0.98 0.96 0.94
60 1.10 1.00 0.97 0.95 0.94
70 1.08 0.99 0.97 0.95 0.94
80 1.06 0.98 0.96 0.94 0.93
90 1.05 0.98 0.96 0.94 0.93
Underfloor heating
system
Air
SOLAR
Heated available area in ANin m²
System expenditure of energy value ep