STIEBEL ELTRON Engineering and system cylinders Technical Guide

01 | 01

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Engineering and Installation 2013 | STIEBEL ELTRON

DHW Renewables Air conditioning Central heating

Engineering and installation

System cylinders

March 2013

SALES CENTRES

WEST

Max-Planck-Ring 33 | D-46049 Oberhausen

Tel. +49 (0)0208 88215 10

Fax +49 (0)0208 88215 188

oberhausen@stiebel-eltron.de

MID

Rudolf-Diesel-Straße 18 | D-65760 Eschborn

Tel. +49 (0)6173 602 10 | Fax +49 (0)6173 602 38

frankfurt@stiebel-eltron.de

NORTH

Georg-Heyken-Straße 4a | D-21147 Hamburg

Tel. +49 (0)40 752018 10 | Fax +49 (0)40 752018 88

hamburg@stiebel-eltron.de

SOUTH | Bavaria

Hainbuchenring 4 | D-82061 Neuried

Tel. +49 (0)89 899156 10 | Fax +49 (0)89 899156 88

muenchen@stiebel-eltron.de

EAST

Magdeborner Straße 3 | D-04416 Markkleeberg (Leipzig)

Tel. +49 (0)34297 985 10 | Fax +49 (0)34297 985 188

[email protected]

SOUTH | Baden-Württemberg

Motorstraße 39 | D-70499 Stuttgart

Tel. +49 (0)711 98867 10 | Fax +49 (0)711 98867 88

stuttgart@stiebel-eltron.de

System cylinders

304335

D0000032742-b

STIEBEL ELTRON GmbH & Co. KG | Dr.-Stiebel-Straße

37603 Holzminden | www.stiebel-eltron.de

Engineering and installation

Reprinting or duplication, even partially, is only allowed with our express permission.

STIEBEL ELTRON GmbH & Co. KG, 37603 Holzminden

Legal note

In spite of the care taken in the production of this technical guide, 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 technical guide are not binding properties of our products. Due to our policy of ongoing

improvement, some features may have subsequently been changed or even removed. Our experts will be happy to

advise you about currently applicable equipment characteristics. Pictorial illustrations in this technical guide only

represent sample applications. The illustrations also contain installation components, accessories and special equip-

ment, which is not part of the standard delivery.

Speciﬁcation

Dimensions in the diagrams are in millimetres unless stated otherwise. Pressure ﬁgures may be stated in pascals

(MPa, hPa, kPa) or in bars (bar, mbar). The details of threaded connections are given in accordance with ISO228. Fuse

types and sizes are stated in accordance with VDE. Output details apply to new appliances with clean heat exchang-

ers.

www.stiebel-eltron.com System Cylinder Technical Manual | 3

www.stiebel-eltron.com System cylinder Technical Manual | 3

CONTENTS

INTRODUCTION ______________________________________________________5

System cylinders made in Germany _____________________________6

System ﬂexibility for all application areas ______________________7

Purpose of this technical manual ________________________________8

Selection matrix for system cylinders ___________________________9

DHW heating ______________________________________________________ 10

Application requirements _____________________________________ 10

Requirements concerning hygiene __________________________ 10

Sizing ______________________________________________________________ 10

Buffer cylinder principles _______________________________________ 12

Water as storage medium _____________________________________12

Heat transfer and ﬂuid mechanics __________________________ 13

PROtemp-Flow system _________________________________________ 14

Relevant standards ______________________________________________ 15

Requirements of the DVGWW551 (2004-04) Code of

Practice ____________________________________________________________ 16

Summary of formulae ___________________________________________ 17

BUFFER CYLINDER ________________________________________________ 19

SBP 100 ____________________________________________________________ 20

Function description ___________________________________________ 20

System solutions ________________________________________________ 21

Speciﬁcation _____________________________________________________ 22

SBP200-700E/ ESOL/ Ecool ________________________________ 24

Function description ___________________________________________ 24

System solutions ________________________________________________ 25

Sizing ______________________________________________________________ 29

Speciﬁcation _____________________________________________________ 30

SBP1000-1500E/ESOL/Ecool _____________________________ 34

Function description ___________________________________________ 34

System solutions ________________________________________________ 35

Sizing ______________________________________________________________ 39

Speciﬁcation _____________________________________________________40

Thermal insulation accessories ______________________________ 45

Further accessories_____________________________________________46

DHW CYLINDER ____________________________________________________ 47

SBB150WPF _____________________________________________________ 48

Function description ___________________________________________48

System solutions ________________________________________________ 49

Sizing ______________________________________________________________ 50

Speciﬁcation _____________________________________________________ 51

Accessories _______________________________________________________ 51

SBB301-501WP/WPSOL _____________________________________ 54

Function description ___________________________________________ 54

System solutions ________________________________________________ 55

Sizing ______________________________________________________________ 59

Speciﬁcation _____________________________________________________ 60

Further accessories_____________________________________________ 65

SBB300-500WPbasic _________________________________________ 66

Function description ___________________________________________ 66

System solutions ________________________________________________ 67

Sizing ______________________________________________________________ 69

Speciﬁcation _____________________________________________________ 70

SBB 600-1000WPSOL __________________________________________ 74

Function description ___________________________________________ 74

System solutions ________________________________________________ 75

Sizing ______________________________________________________________ 77

Speciﬁcation _____________________________________________________ 78

Further accessories_____________________________________________ 83

SBB751-1001/SOL _____________________________________________ 84

Function description ___________________________________________84

System solutions ________________________________________________ 85

Sizing ______________________________________________________________ 88

Speciﬁcation _____________________________________________________ 89

Accessories _______________________________________________________94

COMBI/INSTANTANEOUS WATER CYLINDER ___________________ 97

SBS601-1501W/WSOL _______________________________________ 98

Function description ___________________________________________ 98

System solutions ________________________________________________ 99

Sizing _____________________________________________________________103

Speciﬁcation ___________________________________________________ 104

Accessories ______________________________________________________109

SBK600/150 _____________________________________________________ 110

Function description __________________________________________110

System solutions _______________________________________________111

Sizing _____________________________________________________________115

Speciﬁcation ____________________________________________________116

4 | System Cylinder Technical Manual www.stiebel-eltron.com

CONTENTS

SOLAR DHW CYLINDER ___________________________________________ 119

KS150SOL _______________________________________________________ 120

Function description _________________________________________ 120

System solutions _______________________________________________121

Sizing _____________________________________________________________122

Speciﬁcation ___________________________________________________ 123

SBB300-600plus ______________________________________________ 126

Function description __________________________________________126

System solutions _______________________________________________127

Sizing ____________________________________________________________ 130

Speciﬁcation ____________________________________________________131

SBB300-500basic _____________________________________________ 136

Function description _________________________________________ 136

System solutions _______________________________________________137

Sizing ____________________________________________________________ 140

Speciﬁcation ____________________________________________________141

Accessories ______________________________________________________145

www.stiebel-eltron.com System Cylinder Technical Manual | 5

INTRODUCTION

www.stiebel-eltron.com System cylinder Technical Manual | 5

INTRODUCTION

Introduction

26_03_20_0119

6 | System Cylinder Technical Manual www.stiebel-eltron.com

INTRODUCTION

SYSTEM CYLINDERS MADE IN GERMANY

System cylinders made in Germany

STIEBELELTRON is a group of companies

with a decidedly international outlook, and

can rightly claim to be a market leading

supplier of technology worldwide for do-

mestic technology and equipment for the

utilisation of renewable energy. For more

than 80years, the company's policies have

been based on its level of technical compe-

tence, high quality standards, innovation,

reliability and customer-oriented service.

Five national and international production

facilities, 16 subsidiaries around the world

plus sales organisations and representa-

tions in 120 countries add up to a truly

global presence for STIEBELELTRON.

6 STIEBEL ELTRON offers convenient and

energy efﬁcient solutions for renewables,

domestic hot water, air conditioning and

room heating. The Holzminden site is the

head ofﬁce of the STIEBELELTRON Group –

and also its largest production facility. Not

only is it home to the worldwide adminis-

tration and sales organisation, it's also the

production site of many millions of electri-

cal DHW and heating appliances as well as

plants and systems that use renewables.

STIEBELELTRON started to develop ap-

pliances that use renewables more than

35years ago. Today the company is one

of the leading suppliers of heat pumps for

heating, cooling and DHW, ventilation sys-

tems with heat recovery as well as solar

thermal systems, covering an output range

from 5 to 500kW.

The group invests particularly in its manu-

facturing sites in Germany. Between 2007

and 2009, one of the most advanced and

sizeable heat pump production facilities

in the world was created in Holzminden,

representing an investment of around €20

million.

The expansion of renewables necessitat-

ed a substantial extension in the range of

DHW and buffer cylinders required for this

sector. Different systems require accord-

ingly designed DHW and buffer cylinders.

Traditionally the company has been ori-

ented towards wholesalers and contrac-

tors. This focus remains the company's

philosophy today. STIEBEL ELTRON val-

ues the active support of its partners and

provides training plus sales and service

support. The retail trade, contractors

and engineers/designers have access to

the training academy in Holzminden for

product support. Every year, more than

20.000participants make good use of its

wide range of courses. The whole product

range is showcased in six sales centres in

Germany, including permanent exhibitions

- mostly with 'live' systems.

During 2010, the Group investments in

the production sites in Germany climbed

above the €10million barrier once again.

Investments were targeted at the develop-

ment of new products and the installation

of new production lines. A new logistics

centre for ﬁnished products in Holzminden

contributes to even greater availability for

our customers.

An ambitious research, development and

investment program has been designed to

equip STIEBELELTRON for the years ahead.

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INTRODUCTION

SYSTEM FLEXIBILITY FOR ALL APPLICATION AREAS

www.stiebel-eltron.com System cylinder Technical Manual | 7

INTRODUCTION

SYSTEM FLEXIBILITY FOR ALL APPLICATION AREAS

System ﬂexibility for all application areas

With STIEBEL ELTRON's system cylinders,

almost any application can be implement-

ed reliably and economically, with heating,

cooling or DHW along with a wide variety

of heat generators, whatever the building

type. The product range includes the fol-

lowing:

Buffer cylinder

»Cylinder volume from 100 to 1500litres

»Wall mounted or ﬂoorstanding appli-

ances

DHW cylinder

»Cylinder volume from 150 to 1000litres

»High grade enamelled steel cylinders

Combi/instantaneous water cylinder

»Cylinder volume from 600 to 1500litres

»PROtemp-Flow system

Solar cylinder

»Cylinder volume from 150 to 600litres

»Wall mounted or ﬂoorstanding appli-

ances

»Solar charging for cylinders up to

1500litres

STIEBELELTRON was the ﬁrst manufac-

turer to obtain the EEA (European Enamel

Authority) quality certiﬁcate for its DHW

cylinder enamel coating.

Example:

Buffer cylinder in a dual mode combination with heat pump and oil/gas boiler

Example:

DHW cylinder with solar and heat pump connection

Example:

Combi/instantaneous water cylinder with solar and oil/gas boiler connection

Example:

Solar cylinder with solar and oil/gas boiler connection

S%20Boiler%20SBS%20HK2%20SOL

S%20Solar%20SBB-SOL-basic%20SBP-SOL%20Oel

S%20WPL57%20SBP-G%20HK1%20Oil

S%20WPLa%20SBP%20HK1%20SBB%20SOL2

8 | System Cylinder Technical Manual www.stiebel-eltron.com

INTRODUCTION

PURPOSE OF THIS TECHNICAL MANUAL

Purpose of this technical manual

Contents and scope

This technical manual is designed to serve

as a technical reference and guide for the

sizing and selection of STIEBEL ELTRON

system cylinders for your speciﬁc appli-

cation.

In addition to extensive information re-

garding our product range, the technical

guide contains engineering instructions,

sizing recommendations, sample calcu-

lations and considerations, as well as a

selection of system solutions for the ap-

plications we consider the most pertinent.

The "Renewables" engineering depart-

ment at STIEBEL ELTRON will be happy to

provide you with individual support in your

building project.

The selection matrix

To aid selection and facilitate the alloca-

tion of STIEBEL ELTRON system cylinders

to your speciﬁc applications, we have la-

belled the system cylinders with the rele-

vant symbols.

The selection criteria are the building type,

the required functions of heating, cooling

and DHW, and the heat generators with

which they can be combined.

The meaning of the individual symbols is

explained below.

Diagrams and examples

Diagrams in this manual should be viewed

as schematic illustrations. To keep illus-

trations simple, some safety assemblies

are not shown and must be installed on

site depending on the locally applicable

regulations.

The sizing samples shown should be rec-

ognised as examples only, they cannot

replace the need for speciﬁc system en-

gineering.

Building type Function Heat source

Detached house Heating Heating heat pumps

Two-family house Cooling Solar thermal system

Apartment buildings Domestic hot water Gas/oil condensing boiler

Non-residential buildings Solid fuel heat generator

Key to symbols

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INTRODUCTION

SELECTION MATRIX FOR SYSTEM CYLINDERS

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INTRODUCTION

SELECTION MATRIX FOR SYSTEM CYLINDERS

Selection matrix for system cylinders

Cylinder type

Buffer cylinder

SBP 100 • • •

SBP 200 E • • • •

SBP 200 E cool • • • • •

SBP 400 E • • • •

SBP 400 E cool • • • • •

SBP 700 E • • • • • •

SBP 700 E SOL • • • • • • •

SBP 1000 E • • • • • •

SBP1000Ecool • • • • • • •

SBP1000ESOL • • • • • • •

SBP 1500 E • • • • •

SBP1500Ecool • • • • • •

SBP1500ESOL • • • • • •

Heat pump DHW cylinders

SBB150WPF • • •

SBB301WP • • •

SBB302WP • • •

SBB401WPSOL • • • • • • •

SBB501WPSOL • • • • • • • •

SBB300WPbasic • • •

SBB400WPbasic • • • •

SBB500WPbasic • • • • •

SBB600WPSOL • • • • • • •

SBB800WPSOL • • • • • • •

SBB1000WP SOL • • • • • • •

SBB751 • • • • • • • •

SBB751SOL • • • • • • • •

SBB1001 • • • • • • •

SBB1001SOL • • • • • • •

Combi/instantaneous water cylinder

SBS601W • • • • • •

SBS601WSOL • • • • • • •

SBS801W • • • • • •

SBS801WSOL • • • • • • •

SBS1001W • • • • • • •

SBS1001WSOL • • • • • • • •

SBS1501W • • • • • • •

SBS1501WSOL • • • • • • • •

SBK600/150 • • • • • • •



KS150SOL • • •

SBB300plus • • • • •

SBB400plus • • • • • •

SBB600plus • • • • • • •

SBB300basic • • • • • •

SBB400basic • • • • • • •

SBB500basic • • • • • • • •

10 | System Cylinder Technical Manual www.stiebel-eltron.com

INTRODUCTION

DHW HEATING

DHW heating

Application requirements

Research has shown that approx. 50 % of

the potable water in domestic households

is heated. Contrary to central heating, DHW

is used all the year round in almost con-

stant amounts and with almost the same

temperature. When designing system

solutions, the following questions should

be considered by the system engineer:

»Requirements concerning hygiene and

safety

»Required temperature levels, consump-

tion and consumption proﬁle

»Ratio of heating load and structure of

cylinder volume

»DHW heating concept

»Integration of peak load heat generators

»Auxiliary energy consumption and ener-

gy losses in the distribution system

»Overcoming long distances efﬁciently in

the distribution system

Requirements concerning hygiene

For the deﬁnition of hygiene requirements

in Germany, the DVGW Code of Practice

W551 is decisive. This Code of Practice

differentiates between small and large

systems, and formulates requirements for

hygienic operation and for pasteurisation,

such as, for example:

— Large systems are those with central

DHW cylinders >400l and/or a pipework

capacity >3l per line between the DHW

cylinder outlet and the draw-off point.

At the DHW outlet of the DHW cylinder,

a temperature of ≥60°C must be main-

tained at all times.

— Small systems are all systems with DHW

cylinders or a centralised instantaneous

water heater in detached or two-family

houses, independent of the cylinder size

and pipework capacity, as well as sys-

tems ≦400 l and with pipework capacity

≦3 l per line between the DHW cylinder

connector and the draw-off point. In

small systems the operating temperature

should not fall below 50°C. Like large

systems, small systems must be able to

maintain a DHW temperature ≧60°C.

— The DHW content of preheating stages

must be heated to ≥60°C at least once

a day. This determination applies to ex-

ternal and integral preheating stages.

— The water temperature in DHW circula-

tion systems and self-regulating ribbon

heaters must not be more than 5K below

the DHW cylinder outlet temperature.

— DHW circulation systems may be

switched off for up to 8hours in any

24hour period to save energy. However,

this is only permissible subject to abso-

lutely hygienic conditions.

Sizing

Residential buildings

The heat demand in central systems for

DHW heating can be determined by var-

ious means.

The recognised technical rule [in Germa-

ny] is still DIN 4708. This is based on the

principle of a "Standard residential unit".

This comprises four rooms with an occu-

pation level of 3.5, i.e. 3 to 4 occupants,

and a standard bath as the most signiﬁcant

draw-off point. This enables several apart-

ments in a single building to be converted

to a speciﬁc number of standard residen-

tial units. Design size is the resulting de-

mand factor, used for determining the heat

source and the DHW cylinder.

The sizing principles for the standard res-

idential unit are up to 40years old and

reﬂect the habits of that time. Today, sig-

niﬁcantly fewer occupants live in each res-

idential unit. In today's apartment build-

ings, single and two-occupant households

dominate. Germany is one of the countries

with the lowest water consumption per cit-

izen in the European Union. Signiﬁcantly

increased costs for drinking water and

waste water disposal, growing awareness

of environmental issues and technical ad-

vances in tap design have all contributed

to this development.

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INTRODUCTION

DHW HEATING

www.stiebel-eltron.com System cylinder Technical Manual | 11

INTRODUCTION

DHW HEATING

1 4

2 3

31l

44l 59l

38l

Models acc. to sheet 12 of VDI2067

Total demand Total DHW demand per person Total energy demand per person

V

N, ttl, d

l/d

V

N, ttl, p.a.

m

3

/h

Q

N, ttl, d

kWh/d

q

N, ttl, p.a.

kWh/p.a.

Model 1

15 – 47 5.2 – 16.2 0.5 – 1.6 190 – 570

Average value 31 10.7 1.1 380

+ demand 1: 4 1.3 0.2 60

+ demand 2: 3 – 6 1.0 – 2.1 0.1 – 0.2 40 – 70

Model 2

33 – 56 11.4 – 19.3 1.1 – 1.9 400 – 680

Average value 44 15.7 1.5 540

+ demand 1: 4 1.3 0.2 60

+ demand 2: 3 – 6 1.0 – 2.1 0.1 – 0.2 40 – 70

Model 3

48 – 71 16.6 – 24.5 1.7 – 2.5 580 – 860

Average value 59 20.7 2.1 720

+ demand 1: 4 1.3 0.2 60

+ demand 2: 3 – 6 1.0 – 2.1 0.1 – 0.2 40 – 70

Model 4

22 – 54 7.5 – 18.6 0.7 – 1.9 270 – 650

Average value 42 14 1.5 520

+ demand 1: 4 1.3 0.2 60

+ demand 2: 3 – 6 1.0 – 2.1 0.1 – 0.2 40 – 70

Sizing heat pump systems

Engineers can often only rely on DIN4708

to a limited extent when sizing heat pumps,

and sometimes not at all. This is ﬁrstly due

to the absence of standard principles for

determining the performance factor of

cylinders and heat generators with ﬂow

temperatures <60 °C, and secondly to the

outdated principles on consumption and

sizing, which which have led to oversized

and economically unattractive solutions.

Where the continuous DHW output exceeds

the building heat load, sizing the heat gen-

erator in accordance with DIN4708 would

result in sizing only according to DHW de-

mand. This method of sizing is no longer

appropriate, since the investment outlay

for heat pump and source system is a key

factor. The heat pump engineer will in-

stead adjust the cylinder volume or peak

load heat generator subject to the con-

sumption proﬁle and may, if appropriate,

shift the heat-up times.

It would be more realistic to size the heat

generator and DHW cylinder in accordance

with sheet 12 of the VDI2067 directive.

Four models, differing in terms of type

and number of draw-off points, form the

basis for sizing.

Non-residential buildings

The DHW demand and the associated de-

mand proﬁle in non-residential buildings

must be assessed and designed individu-

ally. In many cases, a low demand for DHW

(e.g. in ofﬁce buildings) would not war-

rant the installation of a centralised supply

system. In such cases, decentralised heat

sources should be considered.

Centralised systems such as those found in

sports facilities, swimming pools or care

homes are large in size. These need to

meet stringent hygiene standards as well

as speciﬁc standards and directives appli-

cable to such buildings. Sizing is provided

by the sum curves method. An adequate

knowledge of demand, distribution and

consumption proﬁles form the basis for

this, and these determine the concept as

well as the output of the heat source and

the cylinder volume.

Explanations on additional demand

+ demand 1: Washing up only by hand

+ demand 2: Bidet

1 Shower

2 Standard bath tub

3 Large bath tub

4 Standard bath tub and shower

26_03_01_1267

The DHW distribution and generation con-

cept for non-residential buildings must

also be assessed on an individual basis. It

is rarely economically viable to maintain

high temperatures over longer distances,

particularly for a heat pump. This would,

for example, be the case in local heating

networks. The permanently high temper-

ature level reduces the overall efﬁciency

even when heating, and generates unnec-

essarily high losses in summer. Frequent-

ly, decentralised heat sources or even heat

pumps would offer a better solution.

12 | System Cylinder Technical Manual www.stiebel-eltron.com

INTRODUCTION

BUFFER CYLINDER PRINCIPLES

Buffer cylinder principles

Water as storage medium

Due to its physical properties water is an

ideal medium for storing heat. In addition

to its high speciﬁc heat storage capacity,

it possesses further highly advantageous

characteristics which allow cold and hot

water to be stored separately in a single

cylinder. Hot water stratiﬁes above cooler

water. If this is utilised effectively, several

beneﬁts result for heat generator and heat

consumer operation.

In most cases, the term "buffer cylinder"

denotes a cylindrical container that stores

sensible heat in water. Sensible heat, also

referred to as tangible heat, is deﬁned by

the rise in temperature according to the

following formula:

Q = m

.

c

p

.

(ϕ

max

- ϕ

min

)

Due to the heat storage medium deployed,

water cylinders offer several beneﬁts:

»Water, as a pure substance, is non-toxic

and therefore ecologically sound.

»Water is available in practically limitless

quantities. The initial outlay is therefore

very low compared to alternative heat

transfer media.

»Water possesses favourable physical

properties, and in particular a high spe-

ciﬁc thermal capacity.

»The density of water is temperature de-

pendant. Density diminishes with rising

temperature. One litre of water at 90 °C

weighs approximately 3.5% less than it

would at 20 °C.

»Water has low thermal conductivity. This

impedes the heat exchange by thermal

conduction between two volumes of

water with a different temperature.

x ϕ [°C]

972

1000

968

964

10 20 30 40 50 60 70 80 90

976

980

984

988

992

996

y ρ [kg/m

3

]

X

Y

Density of water subject to temperature

X Temperature [°C]

Y Density [kg/m

3

]

84_01_20_0026

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INTRODUCTION

BUFFER CYLINDER PRINCIPLES

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INTRODUCTION

BUFFER CYLINDER PRINCIPLES

1 3

2

4

5

ϕ

h

Heat transfer and ﬂuid mechanics

Directly charged and discharged buffer

cylinders (see illustration) are generally

operated as displacement cylinders. Dur-

ing charging, water is fed into the cylinder

from the top and the equivalent amount

of water is drawn off at the bottom. Dis-

charge takes place against the direction

of ﬂow.

In an operational buffer cylinder, convec-

tion ﬂow patterns can occur which are

detrimental to the evenness of ﬂow. A

differentiation should be made between

natural and forced convection. Natural

X

h

Convection ﬂow as a result of heat loss-

es

Forced convection through unhindered lateral ingress

Directly charged and discharged buffer cylinders

convection is caused by heat losses to the

environment. When heat losses occur, the

ﬂuid near the wall cools down and ﬂows

downwards.

As a result of these ﬂow patterns the dis-

tinct temperature distribution is further

reduced; the cylinder content is mixed.

Natural convection can be virtually elim-

inated with adequate thermal insulation.

Forced convection is caused by ﬂow being

fed into or drawn from the cylinder.

26_03_20_0120

26_03_20_0121

26_03_20_0122

1

2

x Distance from the cylinder wall

h Cylinder height

1 Heat source

2 Cylinder

3 Consumer

4 Discharging

5 Charging

h Cylinder height

ϕ Cylinder temperature [°C]

1 Temperature pattern after 2 minutes

2 Temperature pattern after 3 minutes

14 | System Cylinder Technical Manual www.stiebel-eltron.com

INTRODUCTION



improved

efﬁciency

extended runtime

of renewable

energy sources

temperature-sensitive stratiﬁcation

improved cylinder heating

greater amount of available heat

reduced runtime of additional heat generators

higher coverage reduced emissions

Beneﬁts of the PRO temp-Flow system

continually colder temperature level

in the lower cylinder section

higher yields

An unhindered, high velocity ﬂow into the

cylinder mixes the content in the upper

cylinder section thoroughly, due to the

hotter, unrestricted incoming jet. Forced

convection occurs.

As the simulation progresses, the mixed

zone extends through the entire upper

third of the cylinder.

Any higher usable temperature level in

the upper section of the cylinder would

be destroyed when colder water ﬂows in.

The design of the inlet device is crucial

here. A suitable device enables charging

and discharging with almost no distur-

bance.

In our cylinders, this is ensured by the

PROtemp-Flow system.

26_03_20_0125

Location of the PROtemp-Flow system inside the

cylinder.

View from behind the entry point.

The heat pump ﬂow meets the

PROtemp-Flow and is split into

partial ﬂows by ﬂowing through

the open cross sections.

Depiction of an indi-

vidual partial ﬂow as it

crosses the PROtemp-

Flow to enter the cylin-

der interior.

View from the cylinder interior of the

PROtemp-Flow. The total ﬂow has split

into radial partial ﬂows. The radially

directed ﬂow with reduced velocity mini-

mises unregulated mixing of the temper-

ature strata inside the cylinder.

PROtemp-Flow system

www.stiebel-eltron.com System Cylinder Technical Manual | 15

INTRODUCTION

RELEVANT STANDARDS

www.stiebel-eltron.com System cylinder Technical Manual | 15

INTRODUCTION

RELEVANT STANDARDS

Relevant standards

Siting and installation

The siting, installation, adjustment and

commissioning of a system must be car-

ried out by a qualiﬁed contractor, giving

due consideration to the operating and in-

stallation instructions. The electrical con-

nection must only be carried out by a con-

tractor authorised by the relevant power

supply utility, giving due consideration to

the relevant VDE regulations as well as the

instructions of the relevant power supply

utility (technical connection conditions or

local regulations).

DIN and DIN EN standards

»DIN EN 806 Technical rules for DHW in-

stallations

»DIN EN 806 Part 1: General information

»DIN EN 806 Part 2: Engineering

»DIN EN 806 Part 3: Calculating the inter-

nal pipe diameter – Simpliﬁed procedure

»DIN 1988 Technical rules for DHW instal-

lations: Observe national supplements.

»DIN 1988 Part 2: Design and implementa-

tion; components, appliances, materials

– Technical rules of the DVGW

»DIN 1988 Part 4: Protection of drinking

water, maintaining the drinking water

quality – Technical rules of the DVGW

»DIN 1988 Part 7: Prevention of corrosion

damage and scaling; technical rules of

the DVGW

»DIN 4708 Central water heating instal-

lations

»DIN 4708 Part 1: Terminology and calcu-

lation principles

»DIN 4708 Part 3: Rules on checking the

output of water heaters in domestic

buildings

»DIN EN 1717 Protection of drinking water

from contamination in drinking water in-

stallations and general requirements of

safety equipment for the prevention of

drinking water contamination by back-

wash – Technical rules of the DVGW

»DIN 50930 Metal corrosion – Corrosion of

metallic materials inside pipework, cyl-

inders and appliances due to corrosive

attack by water

»DIN 50930 Part 6: Effects on drinking

water quality

»DIN EN 12828 Heating systems in build-

ings – Engineering hot water heating

systems

»DIN EN 12897 Water supply – Provisions

governing indirectly heated, unvented

(sealed) DHW cylinders

»DIN 4753 Water heaters and water heat-

ing installations for drinking and process

water: Observe national supplements

»DIN 4753 Part 1: Requirements, identiﬁ-

cation, equipment and testing

»DIN 4753 Part 3: Corrosion protection on

the water side through enamelling – Re-

quirements and testing

»DIN 4753 Part 6: Cathodic corrosion pro-

tection for enamelled steel cylinders –

Requirements and testing

»DIN 4753 Part 8: Thermal insulation of

water heaters up to 1000l nominal ca-

pacity – Requirements and testing

VDI guidelines

»VDI 2067 Efﬁciency of technical building

systems

»VDI 2068 Measuring/monitoring and

control equipment in heating systems

with water as heat transfer medium

»VDI 2078 Cooling load calculation for air

conditioned rooms

DVGW technical standards

»DVGW technical standard W501 Drinking

water heating and distribution systems

»Measures to reduce the growth of le-

gionella bacteria – Design, installation,

operation and modernisation of drinking

water installations

»DVGW technical standard W551 Drinking

water heating and distribution systems;

technical measures to reduce the growth

of legionella bacteria – Design, instal-

lation, operation and modernisation of

drinking water installations

16 | System Cylinder Technical Manual www.stiebel-eltron.com

INTRODUCTION



no

Pipe content

downstream

> 3 litre

Decentralised

draw-off point

DNM, DEM, DHM

SN

SNU

UFP

Decentralised

group supply

DHE

DHB

DEL

Centralised supply

FWS 1

SBS

Decentralised group supply

SH / SHU

SHZ / HFA

LWA 100

Centralised supply

SBB

SHW / SHO AC

WPC

WWK / WWP

HSBB

LWZ

Capacity

> 400 litre

Installed in a

detached or

two-family

house

Small system in accordance with DVGW W 551 (04-2004)

Requirements (extract):

» A DHW temperature ≧ 60 °C must be possible.

» A temperature setting ≧ 50 °C is required.

» A DHW circulation line is required for line content

> 3 litres.

» The temperature spread in the DHW circulation line

must not exceed 5 K.

Large system in accordance with DVGW W 551 (04-2004)

Requirements (extract):

» The DHW temperature at the outlet must be ≧ 60 °C.

» The entire cylinder content including all pre-heating stages

must be heated to 60°C once every day.

» A DHW circulation line is required for line content > 3 litres.

» The temperature spread in the DHW circulation line must not

exceed 5 K.

No requirements in

accordance with

DVGW W 551 (04-2204)

yes

no

yes

no

yes

Instantaneous water heater DHW cylinder

Pipe content

downstream

> 3 litre

D0000024048

The following provides an overview of the requirements to DVGWW551.

Requirements of the DVGWW551 (2004-04) Code of Practice

www.stiebel-eltron.com System Cylinder Technical Manual | 17

INTRODUCTION

SUMMARY OF FORMULAE

www.stiebel-eltron.com System cylinder Technical Manual | 17

INTRODUCTION

SUMMARY OF FORMULAE

Summary of formulae

Heat amount

Q = m

*

c

*

(t

2

- t

1

)

Q Heat amount [Wh]

m Amount of water [kg]

c Speciﬁc heat Wh/kgK [1,163Wh/kgK]

t

1

Cold water temperature [°C]

t

2

DHW temperature [°C]

Heating output

Q = A

*

k

*

∆ϑ

Q Heating output [W]

A Area [m²]

k Heat transfer coefﬁcient [W/m²K]

∆ϕ Temperature differential [K]

k value

k =

1

+ +

1

α

i

d

λ

1

α

a

k k value [W/m²K]

α

i

Heat transfer coefﬁcient, internal [W/m²K]

α

a

Heat transfer coefﬁcient, external [W/m²K]

λ Thermal conductivity [W/mK]

Connected load

P =

m

*

c

*

(t

2

- t

1

)

T

*

η

P Connected load [W]

m Amount of water [kg]

c Speciﬁc heat [Wh/kgK]

t

1

Cold water temperature [°C]

t

2

DHW temperature [°C]

T Heat-up time [h]

η Efﬁciency

Duct work curve

∆p

1

∆p

2

V

1

2

V

2

=

( )

∆p

1

Pressure differential [Pa]

∆p

2

Pressure differential [Pa]

V

1

Flow rate [m³/h]

V

2

Flow rate [m³/h]

Heat-up time

T =

m

*

c

*

(t

2

- t

1

)

P

*

η

T Heat-up time [h]

m Amount of water [kg]

c Speciﬁc heat [Wh/kgK]

t

1

Cold water temperature [°C]

t

2

DHW temperature [°C]

P Connected load [W]

η Efﬁciency

Pressure drop

∆p = L

*

R + Z

∆p Pressure differential [Pa]

R Tubes frictional resistance

L Pipe length [m]

Z Pressure drop of the individual resistances [Pa]

Individual resistances

Z =

ζ

2

∑z

*

v

2

*

z Drag coefﬁcient

(The drag coefﬁcient "Z" can be taken from the

tables, using the sum "z" and the velocity in the

pipework.)

ς Density

v Flow velocity [m/s]

Mixed water temperature

t

m

=

(m

1

*

t

1

) + (m

2

*

t

2

)

(m

1

+ m

2

)

t

m

Mixed water temperature [°C]

t

1

Cold water temperature [°C]

t

2

DHW temperature [°C]

m

1

Amount of cold water [kg]

m

2

Amount of DHW [kg]

Amount of mixed water

m

=

m

2

*

(t

2

- t

1

)

t

m

- t

1

m

Amount of mixed water [kg]

m

1

Amount of cold water [kg]

m

2

Amount of DHW [kg]

t

m

Mixed water temperature [°C]

t

1

Cold water temperature [°C]

t

2

DHW temperature [°C]

DHW volume

m

2

=

m

*

(t

m

- t

1

)

t

2

- t

1

m

Amount of mixed water [kg]

m

1

Amount of cold water [kg]

m

2

Amount of DHW [kg]

t

m

Mixed water temperature [°C]

t

1

Cold water temperature [°C]

t

2

DHW temperature [°C]

Notes

18 | System cylinder Technical Manual www.stiebel-eltron.com

www.stiebel-eltron.com System Cylinder Technical Manual | 19

BUFFER CYLINDER

SUMMARY OF FORMULAE

www.stiebel-eltron.com System cylinder Technical Manual | 19

BUFFER CYLINDER

SUMMARY OF FORMULAE

BUFFER CYLINDER

Buffer cylinder

26_03_20_0118

20 | System Cylinder Technical Manual www.stiebel-eltron.com

BUFFER CYLINDER

SBP 100

Function description

Connection for quick-action

air vent valve in upper sec-

tion for optimum pressure

conditions

Highly efﬁcient thermal in-

sulation for lowest standby

losses

Functions

The SBP 100 is the perfect companion

for small heat pump systems in detached

houses.

It acts primarily as a hydraulic separator

between the heat pump circuit ﬂow and

the heating circuit ﬂow.

As a compact wall mounted cylinder it can

be ﬁtted almost anywhere in the home and

is easy to install, for example above the

heat pump.

Product features

»Wall mounted buffer cylinder

» Designed for the connection of heat

pumps

» Equipped for optional retroﬁtting of a

ﬂanged immersion heater

» Connector for quick-action air vent valve

(standard delivery) in the cylinder top

» Cleaning aperture with drain & ﬁll valve

» Wall mounting bracket for wide range of

installation options

» Highly effective thermal insulation for

low heat losses

Engineering and installation beneﬁts

»Little space required, may be installed

anywhere, including utility rooms, re-

cesses, bathrooms or attics

»Wall mounting above the heat pump

possible, subject to model

»Straightforward installation of the indi-

rect coil connections to the side

PIC00000598

D0000026077

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STIEBEL ELTRON Engineering and system cylinders Technical Guide

STIEBEL ELTRON Engineering and system cylinders Technical Guide

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