Danfoss FlatStations - SAV Systems · Danfoss FlatStations - 1 Series BS ... However, in 2012 BS...

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Design & Product Guide

Danfoss FlatStations

About SAV Systems

SAV has been operating in the UK since 1988.

SAV Systems is a leading provider of innovative building services solutions designed to boost energy efficiency and cut carbon emissions.

Products vary from sophisticated mini-CHP systems to simple water meters, but all are purpose-developed to serve a better internal environment and a greener world.

Used as individual products, or integrated into custom-designed systems, the SAV range makes a perfect partner for low energy technologies from renewables to central plant and even district heating systems.

It’s a full family of choice sourced from some of the world’s leading specialist companies - our Partners in Technology. Product groups cover the full spectrum of modern building services.

www.sav-systems.com

UK CUSTOMER SUPPORT CENTRE SAV Systems, Scandia House, Boundary Road, Woking, Surrey GU21 5BX Telephone: +44 (0)1483 771910 EMAIL: [email protected]

GENERAL INFORMATION: Office Hours: 9.00am - 5.00pm Monday to Friday.

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FLATSTATION DESIGN GUIDE

ContentsDesign Guide1. INTRODUCTION ...............................................................................................................................4

2. CLIENT BENEFITS ..............................................................................................................................4

3. DELTA T DESIGN ..............................................................................................................................5

4. FLATSTATION SELECTION .................................................................................................................6

5. SYSTEM LAYOUT .............................................................................................................................7

5.1 Primary circuit and buffer vessel (A)..................................................................................................8

5.2 Mains cold water supply (B) .............................................................................................................8

5.3 Secondary pump (C) ........................................................................................................................8

5.4 Differential pressure sensor (D) .........................................................................................................8

5.5 Top of riser (E) ..................................................................................................................................8

5.6 Flushing and commissioning provisions (F) .......................................................................................9

5.7 2 zone compliance kit (G) ................................................................................................................9

5.8 Heating circuit balancing .................................................................................................................9

6. SYSTEM SIZING ..............................................................................................................................10

6.1 Module selection ...........................................................................................................................10

6.2 District heating pipe sizes ...............................................................................................................10

6.3 Sizing of heat source .....................................................................................................................12

6.4 Buffer tank sizing ...........................................................................................................................13

6.5 Sizing example ...............................................................................................................................13

7. METERING .....................................................................................................................................15

8. COMMISSIONING ..........................................................................................................................17

8.1 Pre-commissioning checks .............................................................................................................17

8.2 Flow balancing in district heating circuits and radiator circuits ........................................................17

8.3 Capacity testing – individual FlatStations ........................................................................................18

8.4 Capacity testing - district heating system .......................................................................................18

9.0 Specification ..................................................................................................................................18

Product GuideDanfoss FlatStations - 1 Series BS .............................................................................................................20

Danfoss FlatStations - 1 Series DS Fully Insulated ......................................................................................21

Danfoss FlatStations - 3 Series BS .............................................................................................................22

Danfoss FlatStations - 3 Series BS Basic ....................................................................................................23

Danfoss FlatStations - 3 Series BS Basic Fully Insulated ..............................................................................24

Danfoss FlatStations - 4 Series Cooling .....................................................................................................25





Danfoss FlatStations - 7 Series BS Dual Heat Source .................................................................................30

Zooming in…Danfoss IHPT - Self-acting DHW Controller ...............................................................................................32

Danfoss AVTB - Self-acting DHW Controller .............................................................................................34

Danfoss RAVK - Self-acting Heating Circuit Controller ..............................................................................36

Danfoss AVPL - Self-acting Differential Pressure Controller........................................................................37

Danfoss Sonometer 1100 - Ultrasonic Compact Energy Meter ..................................................................38

Izar Center - M-Bus Master ......................................................................................................................39

Micro Plate Heat Exchanger (MPHE) .........................................................................................................40

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1. INTRODUCTION

This guide explains how to design and commission heating systems for apartment blocks and district heating schemes incorporating Danfoss FlatStations. These are heat interface units (HIUs) that incorporate plate heat exchangers for transferring heat from a piped distribution main to localised heating and hot water systems.

Danfoss FlatStations significantly outperform alternative products due to their patented valve technology and energy saving features, including:

• specialised valves for accurate control of hot water pressure and temperature

• energy efficient primed temperature set-back function for periods of zero demand

• thermally insulated casings to minimise heat losses.

To maximise the energy saving benefits of the units, proper system design is essential. This guide provides recommendations for:

• unit sizing

• heating system layout

• integration of low carbon heat sources

• prediction of hot water simultaneous demands

Please also see CHP Design Guide for considerations related to CHP and plant room design specifically and Delta T Design Guide for considerations regarding optimization of system delta t.

2. CLIENT BENEFITS

For client organisations, the particular benefits of Danfoss FlatStations are as follows:

Minimal space requirement – Danfoss FlatStations are provided in compact, well designed, casings. They therefore take up far less room than an equivalent thermal store or an equal capacity combi-boiler.

Low maintenance – Unlike combi-boilers, Danfoss FlatStations do not require extensive servicing and maintenance.

Easy to incorporate individual metering and billing services – In a sub-tenanted apartment block that requires separate metering and billing of energy used, Danfoss FlatStations can be integrated with intelligent heat metering that automatically monitors and records energy consumption and enables automatic billing of tenants based on energy used. Experience shows that individual billing, based on actual consumption, also leads to behavioral changes resulting in lower consumption and reduced energy costs.

Improved SAP ratings - The SAP rating achievable by using Danfoss FlatStations in dwellings, fed from a community heating system with low carbon heat source, will be significantly better than for systems with distributed combi-boilers or hot water cylinders. This will also help to achieve target ratings under the Code for Sustainable Homes.

Ease of integrating with low or zero carbon technologies – The centralisation of the heat source, and inclusion of a thermal store, makes it easier to incorporate a low or zero carbon technology such as combined heat and power (CHP), solar thermal or biomass boilers.

Improved efficiency of heat sources – Danfoss FlatStations enable low heating return water temperatures which are crucial to maximising the energy efficiency of heat sources such as combined heat and power, or gas fired condensing boilers. It is recommended that the return water temperature from a community heating scheme should not exceed 25˚C for hot water systems and 40˚C for radiator systems. During hot water generation, Danfoss FlatStations typically return heating water around 20˚C easily complying with the recommendations.

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Minimised risk of legionella – Because there is no stored hot water the risk of legionella bacteria multiplying in the system is minimised.

Thermostatic temperature control – Danfoss FlatStations provide thermostatic control of hot water temperature at varying inlet pressures. Hence, hot water can be supplied at whatever temperature setting is required, and this temperature is unaffected by the subsequent opening or closing of additional taps off the same system.

Low heat losses from casings – Danfoss FlatStations can be provided in thermally insulated casings in order to minimise the uncontrolled loss of heat. This ensures that all of the heat delivered to each apartment is used for useful heat production and that there are no uncontrolled heat emissions during summer months.

Lower energy bills – Correct system design and high efficiency FlatStations ensures energy bills are kept to a minimum.

3. DELTA T DESIGN

District and community heating systems utilising low carbon heat sources (such as condensing boilers, biomass boilers, CHP units, heat pumps, etc.) should be designed to achieve the lowest possible flow temperature and the maximum possible flow to return temperature differential (i.e. delta T). This will enable low carbon heat sources to operate more efficiently and for longer periods whilst minimizing pipe sizes, pipe emissions and thermal store volumes.

Full details of “delta T design” is provided in the SAV Delta T design guide.

In order to maximize secondary circuit delta T values, terminal units must be able to dissipate as much heat as possible from the circulating water. For hot water production, heat interface units have been specifically designed with this in mind.

When the benefits of delta T design were first realized, manufacturers set about designing high efficiency heat exchangers, capable of very high rates of heat transfer but with manageable dimensions. This led to the development of plate heat exchangers that are now a critical component of heat interface units.

Heat interface units incorporate plate heat exchangers to transfer heat from the heating distribution system to hot water for use at taps. Heating water entering at up to 70°C can be cooled to temperatures in the range 15-30°C as it by heats incoming cold water.

Heat interface units are essential for the operation of many district and community heating systems, as reflected in the latest industry guidance. For example, CIBSE’s AM12/2013 “Combined heat and power for buildings” section 9.16, Design of district heating states:

“It is recommended that, for new systems, radiator circuit temperatures of 70°C (flow) and 40°C (return) are used with a maximum return temperature of 25°C from instantaneous domestic hot water heat exchangers.”

Furthermore, Greater London Authority’s “District Heating Manual for London” (2013) specifically recommends that return temperatures from hot water generating heat interface units do not exceed 25°C.

These requirements make hot water cylinders unacceptable since, due to the legionella risk associated with hot water storage, return temperatures have to be kept above 60°C. The only feasible solution is the utilisation of heat interface units such as Danfoss FlatStations. These units incorporate accurate temperature and pressure control valves that ensure uninterrupted hot water supplies and consistently low system return temperatures.

For further guidance, please also refer to “Heat Networks: Code of Practice for the UK” by ADE/CIBSE.

Early heat exchanger plate (source: Danfoss)

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4. FLATSTATION SELECTION

The appropriate Danfoss FlatStation is the one that can meet the anticipated kW heating and hot water requirements for the project at the design district heating circuit operating temperatures. Each FlatStation has a specific product datasheet which gives sizing examples based on different district heating operating temperatures.

Heating demand

The estimation of heat losses and consequent heating loads for dwellings is explained in BS EN 12831:2003 Heating Systems in Buildings – Method for calculation of the design heat load. Similar advice is provided in the CIBSE Domestic Heating Design Guide. Peak heating demands should be calculated based on this guidance.

Hot water demand

The peak simultaneous demand from the hot water outlets to be served by the FlatStation must be estimated.

For many system designers BS 6700 used to be the usual source of simultaneous demand values for multiple fittings. However, in 2012 BS 6700 was superseded by BS 8558 together with BS EN 806 part 1-5 as the new standard for DHW systems.

The current standard states “the designer is free to use a nationally approved detailed calculation method for pipe sizing”, such as the Danish Standard DS 439, which is also the standard recommended in CIBSE AM12:2013. Section 6 “System sizing” of this Design Guide will show how to apply the Danish Standard DS 439.

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5. SYSTEM LAYOUT

A typical layout for a complete heating and hot water system incorporating Danfoss FlatStations is shown below. Some valves have been omitted for clarity.

E

D

FLATSTATION

BOOSTED MCW

A PRIMARY CIRCUIT

P

HTG F&R

H&CW

B

C

F

HTG F&R

H&CW

HTG F&R

H&CW

G

The following sections 5.1 to 5.8 describe the main design issues which need to be considered to ensure effective and efficient performance of both heating and hot water supplies.

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5.1 Primary circuit and buffer vessel (A)The primary circuit should incorporate heat sources (such as boilers, CHP units etc) with primary pumps sized to circulate water to a low loss header. The circuit should be planned and sized in accordance with the advice provided in the SAV Delta T design guide.

It is essential that the primary circuit includes a suitably sized buffer vessel. It may be the case that a buffer vessel is required to improve the performance of low carbon heat sources such as CHP units and biomass boilers, enabling them to run for longer periods. However, a buffer vessel is also essential for the operation of any system serving Flatstations since it serves as an energy store, catering for high but short term hot water demands. Without a buffer store, the central heat sources may be unable to react with sufficient speed to the load imposed by high but temporary hot water demands.

The buffer tank should be dimensioned such that temperature stratification is encouraged. Hence, an elongated vertical cylinder is appropriate with primary and secondary flow pipes located near the top of the tank, whilst primary and secondary return pipes are located near the bottom. The secondary return temperature should be maintained at as low a value as possible. Temperature sensors located in the side of the vessel can be used for on/off sequencing of multiple heat sources, as described in the SAV Delta T design guide.

5.2 Mains cold water supply (B)A minimum mains cold water supply of at least 0.5 bar is required for the BS range of FlatStations whereas a minimum pressure of 1.0 bar is required for the DS range of FlatStations. However, the actual pressure provided should also depend on the requirements of the hot water outlets fittings which may require higher pressures to operate correctly. In tall buildings the required cold water pressure will typically be achieved by provision of a boosted main with pressure reducing valves set to the required pressure on each floor branch.

5.3 Secondary pump (C)The secondary pump should be variable speed to take advantage of pump energy savings when the heating system is operating at part load. Pump speed should be controlled such that there is always sufficient pressure available

to satisfy the most remote Danfoss FlatStation. The heating side pressure loss value for each Danfoss FlatStation is provided in the appropriate product brochure.

5.4 Differential pressure sensor (D)A differential pressure sensor installed across the most remote Danfoss FlatStation will minimise pump energy consumption. Pump speed should be controlled to maintain the required minimum pressure differential across the most remote FlatStation.

5.5 Top of riser (E)The ADE/CIBSE Heat Networks: Code of Practice for the UK (draft version at time of print) states in its minimum requirements:

“where bypasses are required to maintain flow temperatures above a minimum level at times of low demand, temperature controlled bypass valves are preferred. Where fixed bypasses are used, the flow rate shall be limited by means of a differential pressure control valve and regulating valve to no more than 1% of peak demand flow at all times, unless a detailed calculation shows that a higher rate will be required. In residential schemes the standby flow rate through instantaneous hot water heat exchangers will normally be sufficient to maintain the flow temperatures without the need for other bypasses” (…) “the use of bypasses shall be minimised - where instantaneous heat

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exchangers are used, the standby flow will normally result in a sufficient bypass flow. Fixed bypasses shall not be used and any bypasses shall be temperature controlled so that the bypass only operates when flow temperatures are below a minimum set point”

As described later in this guide, the Danfoss FlatStations include a “primed DHW function”, allowing a small by-pass as referred to above.

If no system by-pass is installed at the top of the riser a valve should be in place which can be opened for system flushing.

It is important for any system that there are no system by-passes allowing excessive flows of “un-cooled” water back to the central plan compromising the system return temperature.

5.6 Flushing and commissioning provisions (F)The features shown are as recommended in BSRIA Application Guide BG29/2012 Pre-commission Cleaning of Pipework Systems. Each FlatStation should be treated as a terminal unit fed from the main heating system pipework. In accordance with the BSRIA guide, SAV provide all FlatStations with their own flushing by-pass and flushing drain cock. The flushing by-pass will enable the main system pipework to be flushed and cleaned whilst the FlatStation remains isolated. The drain cock will enable the FlatStation to be flushed if required.

These provisions should protect the heating water side of each unit but it is also possible that debris could be carried into the plate heat exchanger with the incoming mains cold water. It may therefore also be prudent to install a strainer on the mains cold water supply to the heat exchanger in areas where water is known to contain some level of suspended solids.

Pressure test points are required to facilitate commissioning. Each module requires a minimum pressure differential across it in order to function correctly. Pressure tappings across the primary heating circuit flow and return pipes will enable the available pressure to be measured and confirmed as adequate.

5.7 2 zone compliance kit (G)The 2010 edition of the Domestic Building Services Compliance Guide requires that new dwellings are divided into at least 2 heating zones, each with programmable room thermostats connected to actuators in the pipes serving each zone. This can be achieved using SAV’s 2 zone compliance kit which comprises a two port manifold with integral zone valves, actuators and wiring box. Programmable room thermostats can be added for full temperature and time control.

5.8 Heating circuit balancingSystem return temperatures – and consequently system efficiencies – will inevitably depend on heating circuit return temperatures secondary side of the heat interface unit. This is the reason underfloor heating works so well with central plant systems, as they operate at low temperatures and thereby contribute to low system return temperatures.

In any system heating circuit balancing is paramount.

For radiator circuits a single uncontrolled radiator or towel rail can jeopardise the system efficiency. It is therefore crucial that heat emitters are both balanced and specified with the right controls.

Specifying pre-settable TRVs with variable Kv values at design stage will help achieve low system return temperatures in practice as lockshield valves are very seldom balanced correctly on site. Pre-settable TRVs will allow the site engineer to simply pre-set each valve relative to the heat output from the radiator schedule and leave the lockshield valve fully open.

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6. SYSTEM SIZING

6.1 Module selectionAs discussed in section 4, individual FlatStations must be selected based on an assessment of the maximum heating demand and maximum simultaneous hot water demand for each dwelling under consideration. It is also necessary to know the intended operating temperatures for the district heating system.

6.2 District heating pipe sizesEach district heating system pipe must be sized to accommodate the maximum heating and hot water demands of the FlatStations served by that pipe.

The maximum heating demand is relatively predictable, this being the summation of the calculated heating loads for each of the dwellings served. However, the estimation of maximum hot water demand is less obvious. It is extremely unlikely that all of the hot water taps in all of the dwellings served will be open simultaneously. Therefore, some allowance for the diversity in usage is required.

The degree of diversity for multiple dwellings is expressed as a “coincidence factor” and is defined as:

(1)

Where

F = coincidence factor

DFR = design flow rate for downstream hot water outlets (l/s)

MFR = maximum possible flow rate for downstream hot water outlets (l/s)

The diversity factors recommended for sizing supplies to multiple dwellings by CIBSE AM12:2013 are shown in the graph opposite.

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0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 11 21 31 41 51 61 71 81 91 101 111 121 131 141 151 161 171 181 191

Coincide

nce factor

Number of dwellings

Coincidence factor for DHW

Danish Standard DS 439

NOTE: The Danish Standard DS 439 calculation method has been approved in BS 8558/BS EN 806-3 stating “the designer is free to use a nationally approved detailed calculation method for pipe sizing”. Furthermore CIBSE AM12:2013 states: “Experience from continental schemes indicates that the BS 6700 (BSI, 2009a) factors are too conservative and Danish Standard DS 439: 2009 (Dansk Standard, 2009) diversity factors are recommended for sizing supplies to multiple dwellings.”

Other guidance, such as “A technical guide to district heating” (BRE, 2014) and the “Heat Networks: Code of Practice for the UK” (ADE/CIBSE, 2015 - draft at time of print) likewise advocate the use of the Danish Standard DS 439 for application of an appropriate coincidence/diversity factor.

Calculation of flow rates for pipe sizing

Using the appropriate coincidence factors estimated from the above graph, the maximum design flow rate for each section of heating pipe can be determined. The flow rate for each pipe must be capable of delivering the peak heating demand for the dwellings served by the pipe, plus the peak simultaneous hot water heating demand for those dwellings. The overall design flow rate for each section of pipe will be:

QT = (FQ

DHW)+(Q

HTG)

(2)

Where,

QT = total design flow rate in district heating pipe (l/s)

F = coincidence factor

QDHW

= heating water flow rate required to meet peak domestic hot water demand (l/s)

QHTG

= heating water flow rate required to meet peak heating demand (l/s).

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The value QDHW

can be calculated from the equation:

QDHW

= P

DHW

4.2 x ΔTDH

(3)

Where,

PDHW

= power requirement (kW) for all downstream FlatStation hot water heaters

TDH

= design temperature drop across the district heating side of the heat exchanger during hot water production (typically around 60˚C, i.e. 80˚C in, 20˚C out).The value Q

HTG can be calculated from the equation:

QHTG

= P

HTG

4.2 x ΔTHTG

(4)

Where,

PHTG

= power requirement (kW) for all downstream apartments (typically 3-10kW each)

THTG

= design temperature drop across the district heating system (typically 10-30˚C).

6.3 Sizing of heat sourceThere is no necessity for the power output of the central heat source to match the calculated peak heating and hot water demand from the district heating system. This is because the peak demand should only occur for relatively short periods, this being when all heating systems are on and there is peak hot water draw-off. This condition is unlikely to be sustained for a prolonged period.

On this basis, two factors enable the heat source capacity to be reduced:

• When there is a draw-off of hot water, each FlatStation prioritises the hot water circuit, temporarily reducing the flow of water to the heating circuit. Since hot water demand periods are relatively short, this does not affect internal temperatures.

• A central buffer tank (see sections 5.1 and 6.4) provides a thermal store to enable the system to cope with large but short term hot water demands. The store empties during peak demand and then re-fills when the demand has passed.

Hence, the heat source power capacity can be sized such that it is sufficient to cope with the entire heating load (P

HTG), plus an additional allowance sufficient to re-heat the volume of water in the buffer tank within

1 hour (PBUFFER

).

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The power required to heat the contents of the buffer tank within 1 hour can be calculated from the equation:

PBUFFER

= 3600

V x 4.2 x ΔTHTG

Where,

V = heated (and hence useful) volume of buffer tank

6.4 Buffer tank sizingThe buffer tank should be sized to deal with the anticipated peak heating and hot water demand sustained over a notional period of 10 minutes (i.e. 600 seconds). Assuming that the boiler is controlled to maintain the required heating flow temperature at a point two thirds of the way down the tank, then the tank will need to accommodate 900 seconds of flow. Hence the equation for sizing the tank is as follows:

V = 900FQDHW

Where,

V = tank volume (litres).

6.5 Sizing exampleSystem design for a development comprising 40 identical 2 bedroom apartments, each with the following appliances requiring hot water: basin, sink, shower, washing machine, and each with a heating load of 5kW. 7 Series FlatStations are required and are to be fed from a district heating system with a designed primary flow temperature of 70˚C.

SolutionFlatStation selection:

Feeding one bath and one shower at the same time requires a mass flow rate of ~0.37 kg/s of water at 50˚C, using a design temperature differential of 40K (10˚C – 50˚C), secondary side of the plate heat exchanger.

The power required to heat this volume of water to the required flow temperature (i.e. QDHW

) is ~60kW per FlatStation.

Therefore this unit should just meet the requirements of each apartment.

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Pipe sizing

Each pipe must be sized individually. For the main pipe from the secondary pumps serving all 40 apartments the procedure is as follows:

From the graph in section 6.2 above (accepting the DS 439 values) the coincidence factor F can be determined as 0.12.

From equation (2) the total flow rate for the pipe can be calculated as:

QT = (0.12 x Q

DHW ) + (Q

HTG)

Given a design temperature drop of 49K (i.e. from 70˚C to 21˚C) across the primary side of the DHW heat exchanger,

QDHW

= (60kW x 40 apartments) / (4.2 x 49K) = 11.66 l/s

Assuming a 20K temperature drop (i.e. from 70˚C to 50˚C) across the primary side of the heating plate heat exchanger,

QHTG

= (5kW x 40 apartments) / (4.2 x 20K) = 2.38 l/s

Hence,

QT = (0.12 x 11.66) + (2.38) = 3.78 l/s

Buffer tank

The buffer tank volume will be:

900 x 0.12 x 11.66 = 1259 litres

Heat source sizing

The heat source must be sized to meet the peak heating load plus sufficient power to re-heat the hot water buffer contents in 1 hour,

i.e. (40 apartments x 5kW) + (1259 x 4.2 x 40K)/3600 = 259kW

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7 METERINGA metering and billing strategy should be developed for any multi occupancy scheme and it is therefore important that the FlatStations installed are equipped with an approved energy meter. The addition of an energy meter coupled with a data collection system allows the accurate monitoring and recording of the energy used to provide the heating and hot water or cooling. This data can then be used to for billing purposes.

Danfoss FlatStations can be supplied with an MID class 2 and 3 approved ultrasonic energy meter. The energy meter can be fully integrated into an AMR system with data transfer through a fixed wire.

Automatic Meter Reading (AMR)

To future-proof the metering and billing system hardware and software installed should be in an open protocol format allowing choice of service provider. This can be specified separate to a propriety billing system, e.g. by specifying two Mbus cards in the energy meter (one for an open protocol datalogger and the other for the propriety billing system). This will ensure peace of mind for the client, even if there should be a future fall out with the billing provider.

Two common AMR system options are:

1. Hard-wired Mbus metering system

2. Radio/Mbus hybrid metering system

Hard-wired Mbus metering system Radio/Mbus hybrid metering system

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Hardwired Mbus (European Standard EN 13757): Mbus is the most widely used protocol and was specifically developed for the reading of heat and other utility meters being flexible and ideal for expansion with additional meters and monitoring software added as required.

Radio/MBus hybrid: This is a combination of radio meters transmitting to receivers hard wired back to a central data logger. Can be very useful in challenging buildings i.e. refurbishment projects.

ADE/CIBSE’s “Heat Networks: Code of Practice for the UK” (draft version at time of print) states “Direct data readings should be obtained using M-bus communications or other proven AMR technology. Heat meters that provide data via pulsed outputs are not normally recommended for use with AMR systems “.

Credit or Pre-Payment

Credit billing is presently the most widely used, however there are a number of advantages with a prepayment system. For the client or landlord one of the most obvious advantages is the elimination of debt risk, as residents are paying for their energy in advance.

The energy meter should be mains powered if a prepayment system is chosen. As a prepayment unit would connect to the energy meter at much shorter intervals than a standard datalogger it might otherwise rapidly drain the battery of the energy meter.

FlatStations can be specified as “prepayment ready” with the inclusion of an integrated shut off valve which is suitable for connection to proprietary prepayment systems.

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8. COMMISSIONING

8.1 Pre-commissioning checksBefore system commissioning commences an inspection should be undertaken to ensure that:

• the pipework installation is complete, and all components are correctly positioned, correctly installed, easily accessible, properly identified (NB: refer to CIBSE Code W: 2010 Water distribution systems for more comprehensive and detailed installation check-lists)

• the system has been filled, thoroughly vented and pressure tested in accordance with HVCA TM6 Pressure Testing of Pipework.

• the system has been flushed and chemically cleaned in accordance with BSRIA Guide BG29/2011 Pre-commission Cleaning of Water Systems.

• the pumps and associated variable speed drives are installed, inspected and tested in accordance with the manufacturer’s instructions and are ready to operate.

• a closed head pump test has been carried out on each pump and the results plotted on the manufacturer’s pump performance graph.

8.2 Flow balancing in district heating circuits and radiator circuitsEach FlatStation serving either a direct or indirect fed heating system, is fitted with its own differential pressure control valve (DPCV). These DPCVs are pre-set to maintain a fixed pressure differential across the heating circuit (if direct fed) or the plate heat exchanger (if indirect fed).

The distribution circuit pumps should be controlled to vary their speed such that the pressure differential across the most remote FlatStation is maintained at a value that is sufficient to operate the DPCV in that FlatStation. (Hence, the recommendation to locate a differential pressure sensor close to the most remote FlatStation for pump speed control, as explained in section 5.4)

If there is sufficient pressure differential across the most remote FlatStation, then all other DPCVs located in FlatStations closer to the pump will also be satisfied. The DPCVs will then effectively balance the flows throughout the system, allowing sufficient flow to pass through when radiators are calling for heat, but closing when room temperatures are satisfied and thermostatic radiator valves begin to close. There will be no need to proportionally balance the flows in the district heating system branches feeding to the FlatStations.

The only balancing required will be between radiator branches in the heating circuits fed from each FlatStation. As described in section 5.8 radiators should be balanced by setting the pre-settable TRVs according to the heat output of the radiator schedule. (If pre-settable TRVs are not available the radiator circuit would need to be balanced by means of a “temperature balance” whereby the lockshield valves are regulated until the return temperature from each radiator is at approximately the same temperature.)

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8.3 Capacity testing – individual FlatStationsHaving established adequate temperature, flow and pressure conditions in the main heating system, the hot water outputs from individual FlatStations can be adjusted and tested as required:

1. Set the pressure reducing valves on the boosted mains water supply branches to the required value for each apartment (i.e. typically 3bar minimum such that there is sufficient pressure available to satisfy the FlatStation and downstream hot water outlets).

2. In each apartment (or selected representative apartments) open sufficient tap outlets to simulate the anticipated peak simultaneous hot water demand for the dwelling.

3. Measure the hot water temperature from the tap outlets to ensure that the temperature obtained is within expected limits, and that flow rate (and hence pressure) is adequate.

8.4 Capacity testing - district heating systemIn setting up the pump, it should be possible to establish maximum and minimum load operating conditions for the pump. This test should demonstrate a significant reduction in pump speed at minimum load conditions.

With the system operating at its design temperature, the procedure for carrying out these tests is as follows:

1. Ensure that all radiator circuits are set to full flow i.e. all zone control valves, and radiator valves are fully open.

2. Open a sufficient number of tap outlets, starting with the most remote outlets and working back towards the pump, until the measured flow rate through the pump is equal to the calculated maximum load flow rate for the system (as calculated following the guidance in section 6.2).

3. Measure the differential pressure being generated by the pump by reference to inlet and outlet pressure gauges. Confirm and record the total flow rate leaving the pump using the flow measurement device installed on the secondary circuit main return pipe.

4. Record how long it takes to empty the buffer tank at this condition. This should be a minimum of 10 minutes.

5. Next, close all tap outlets. Override the controls to force all 2 port heating zone control valves into their fully closed positions.

6. Measure the differential pressure being generated by the pump as before, and re-measure the total flow rate leaving the pump. If the pump is being controlled properly, the pump pressure value should be close to the controlled value at the differential pressure sensor. Furthermore the flow rate should be close to the flow rate passing through the by-pass at the top of the riser.

9. SpecificationPlease contact SAV Systems for further information and specification templates.

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tried and tested

globally

fast closing times

hydraulic

balancing

minimal service

requirements

Product Guide

20

FLATSTATION PRODUCT GUIDE

Danfoss FlatStations - 1 Series BS

Self-acting instantaneous DHW only FlatStation

DHW

CVM

DH 1

1

supply

DHreturn

1 Series BS

B Plate heat exchanger DHW1 Ball valve7 Thermostatic valve62B Pressure Absorber

TP

TP 62B

Circuit diagram - example

Technical parameters:Nominal pressure: PN 16DH supply temperature: Tmax = 120 °CDCW static pressure: pmin = 0,5 barBrazing material (HEX): Copper

Weight incl. cover: 10 - 12 kg (incl. packing)

Cover: Grey-lacquered steel sheet

Dimensions (mm):Without cover:H 428 x W 312 x D 155 (One-1;One-2)H 468 x W 312 x D 155 (One-3)

With cover:H 430 x W 315 x D 165 (One-1;One-2) H 470 x W 315 x D 165 (One-3)

Connections:1 Domestic cold water (DCW)2 Domestic hot water (DHW)3 District heating (DH) supply4 District heating (DH) return

Connections sizes:DH + DCW + DHW: G ¾” (ext. thread)

Options:• Booster pump (increases DH flow)• Safety valve • DHW recirculation pump

DHW: Capacity examples, 10°C/50°C

FlatStation type One

DHWcapacity

[kW]

Supply flow Primary

[°C]

Return flow Primary

[°C]

Pressure loss Primary

[kPa]

DHW tap load

[l/m]

One-129.3 60 23.0 20 10.537.8 70 20.0 20 13.652.3 70 22.4 45 18.8

One-2 34.7 60 24.4 20 12.445.1 70 21.3 20 16.265.6 70 23.8 45 23.5

One-360 60 23.0 35 21.380 70 20.3 35 28.890 70 21.0 45 32.3

Higher capacities available on demand

Wall

Seen from above

21


Danfoss FlatStations - 1 Series DS Fully Insulated

Self-acting instantaneous DHW only FlatStation

B

72

9

Technical parameters:

max

min

Weight incl. cover: (incl. packing)

Cover: Grey full-insulation

Dimensions (mm):

Connections:

3 District heating supply (DH) 4 Distric

With metal cover:

t heating return (DH)

Connections sizes:

Options:

DHW recirculation pump

DHW: Capacity examples

FlatStation

Novi

type

Supply

[kW][ºC] [ºC]

[ºC][kPa]

[l/m]

�ow

Primary

Return �ow

Primary

Pressure loss

Primary tap

16.621.812.618

load

Novi-FI-140,3

DH supplyDHW

Seen from above

CWM DH return

B Water heater

9 Str1 Ball valve

ainer62B Pressure Absorber72 IHPT

Novi-FI-2

22,2 303232

44 24,1 3232

15.720.123.315.922.2

TP

TP

1

162B

22


A Heat exchangerM Electrical wiring box2 Single check valve4 Safety valve7 Thermostatic valve9 Strainer

DH supply

DH return


Technical parameters:Nominal pressure: PN 10*DH supply temperature: Tmax = 120 °CBrazing material (HEX): Copper* PN 16 versions are available on enquiry

Weight incl. cover: 25 kg (incl. packing)

Cover: White-lacquered steel sheet

Dimensions (mm):Without cover:H 750 x W 525 x D 330With cover:H 800 x W 540 x D 430

Connections sizes:DH + HE: G ¾” (int. thread)

Options:

• Room thermostat• Pipe insulation

Heating: Capacity examples

FlatStation typeHeating Capacity

[kW]

Heating circuitPrimary

[°C]

Heating circuitSecondary

[°C]

Pressure lossPrimary

[kPa]

Flow rateSecondary

[l/m]

Residualpump head

[kPa]

VX-Z-115 80/53 50/70 50 10.7 1215 80/41 40/60 30 11.3 128 80/66 65/75 40 12.2 10

VX-Z-2


20 80/53 50/70 50 15.1 2120 80/41 40/60 35 15.1 2110 80/66 65/75 50 15.2 21

VX-Z-325 80/53 50/70 35 18.9 1625 80/41 40/60 25 18.9 1613 80/66 65/75 35 19.8 13

26 Manometer31 Di�erential pressure controller38 Expansion tank41 Fitting piece, energy meter48 Air escape, manual69 On/o� valve

10 Circulation pump14 Sensor pocket, energy meter18 Thermometer20 Filling/drain valve21 To be ordered separately24 Delivered loose with unit

Cylinder supply

HE supply

HEreturn

Cylinder return

Border of delivery

Connections:1 Cylinder supply2 Heating (HE) + cylinder

common return3 District heating (DH) return4 District heating (DH) supply5

Heating (HE) supply

1

11

1 1


Self-acting indirect heating and cylinder feed FlatStation


FlatStation typeVX-Z

Heating capacity

[kW]

Supply flow Primary

[°C]

Return flow Primary

[°C]

Heating circuit

[°C]

Flow rate Primary

(l/m)

Min. diff. pressure Primary*

[kPa]

Flow rate Secondary

[l/m]

Residual pump head Secondary

[kPa]

VX-Z-16 80 66 75/65 6.5 30 9.1 20

10 80 52 70/50 5.4 25 7.6 3520 80 45.8 70/40 8.8 50 10.0 30

VX-Z-29 80 66.1 75/65 9.9 40 13.7 20

15 80 52.2 70/50 8.2 30 11.4 3025 80 45.6 70/40 11.0 45 12.6 25

VX-Z-312 80 66 75/65 13.1 45 18.3 1020 80 52 70/50 10.8 35 15.1 2030 80 44.9 70/40 12.9 45 15.1 20

Higher capacities available on demand. *Energy meter not included.

23



Technical parameters:Nominal pressure: PN 10*DH supply temperature: Tmax = 120 °CBrazing material (HEX): Copper* PN 16 versions are available on enquiry


Cover: White-lacquered steel sheet


Non-standard sizes available on request

Connections:1 District heating (DH) supply 2 District heating (DH) return3 Heating (HE) supply4 Heating (HE) return

Connections sizes:DH + HE: G ¾” (int. thread)

Options:• Separate mixing circuit• Room thermostat• Pipe insulation

1 Ball valve4 Safety valve7 Thermostatic valve9 Strainer

24 Delivered loose with unit26 Manometer31 Differential pressure controller38 Expansion tank

10 Circulator pump14 Sensor pocket, energy meter18 Thermometer20 Filling/drain valve

48 Air escape, manuel69 On/off valve

41 Fitting piece energy meter

1

47

9

910

14

18

20

24

26

4 bar

31 38

18

DH return

HEreturn

HEsupply

DH supply

A

Heatexchanger41

48

48

48

Wiring BoxElectrical

M

69M1 1

1

Danfoss FlatStations - 3 Series BS Basic

Self-acting indirect heating only FlatStation


FlatStation typeVX

Heating capacity

[kW]

Supply flow Primary

[°C]

Return flow Primary

[°C]

Heating circuit

[°C]

Flow rate Primary

(l/m)


[kPa]

Flow rate Secondary

[l/m]


[kPa]

VX-1 3.5

60 36 45/35 2.2 15 5.3 3570 35 60/30 1.5 15 1.8 3080 44 70/40 1.5 15 1.8 3080 52 70/50 1.9 15 2.7 30

VX-2 7

60 36 46/35 4.3 20 10.6 3070 37 60/30 3.2 15 3.5 4580 46 70/40 3.1 15 3.5 4580 54 70/50 4.0 25 5.3 35

VX-3 10

60 36 45/35 6.1 40 15.1 1570 37 60/30 4.5 25 5.0 4080 46 70/40 4.4 25 5.0 4080 53 70/50 5.7 35 6.4 30


24


Danfoss FlatStations - 3 Series BS Basic Fully Insulated

Self-acting indirect heating only FlatStation

DHsupply

DHreturn

HESupply

HEReturn

20 Filling / drain valve24 Delivered loose with unit26 Pressure gauge31 38 Expansion tank41 Fitting piece, energy meter48 Air vent, manual69 On /

A Heat exchanger HEM Electrical wiring box4 Safety valve7 Thermostatic valve9 Strainer10 Circulation pump14 Sensor pocket, energy meter18 Thermometer


Technical parameters:Nominal pressure: PN 10*DH supply temperature: T

max = 120 °C

Brazing material (HEX): Copper*PN 16 versions are available on enquiry

Weight: 30 kg (incl. packing)

Insulation: Anthracite grey EPPDimensions (mm):With insulation: H 765 × W 530 × D 375


FlatStation

type

Heating

capacity

[kW]

Supply flow

primary

[°C]

Heating

circuit

[°C]

Pressure loss

primary

[kPa]

Pressure loss

secondary

[kPa]

Flow rate

primary

[l/m]

Flow rate

secondary

[l/m]

Residual pump pressure

secondary[kPa]

VX-1-FI

5 80 25/35 10 15 1.4 7.5 20

18 80 70/40 40 20 8.3 9.1 15

20 90 70/40 30 20 6.5 10 15

VX-2-FI

9 80 23/35 10 15 2.5 13.5 30

29 80 70/40 40 15 12.9 14.6 30

33 90 70/40 30 20 10.6 16.6 25

VX-3-FI

13 80 25/35 10 15 3.6 19.5 25

46 80 70/40 35 20 20.6 23.1 15

50 90 70/40 25 20 16.1 25.1 15

Connections sizes: DH + HE: G ¾” (int. thread)

Options:• Possibility for electronic controller,

weather compensation• Room thermostat• Safety thermostat, surface type

on UFH units

Connections:1 District heating (DH) supply2 District heating (DH) return3 Heating (HE) supply4 Heating (HE) return


FlatStation typeVX-FI

Heating capacity

[kW]

Supply flow Primary

[°C]

Return flow Primary

[°C]

Heating circuit

[°C]

Flow rate Primary

(l/m)


[kPa]

Flow rate Secondary

[l/m]


[kPa]

VX-FI-1 3.5

60 36 45/35 2.1 15 5.1 3570 37 60/30 1.5 15 1.7 3080 46 70/40 1.5 15 1.7 3080 53 70/50 1.9 15 2.5 30

VX-FI-2 7

60 36 45/35 4.2 25 10.1 3070 40 60/30 3.4 25 3.4 4580 49 70/40 3.3 25 3.4 4580 55 70/50 4.2 30 5.1 40

VX-FI-3 10

60 36 45/35 6.1 35 14.5 1570 40 60/30 4.8 35 4.8 4080 49 70/40 4.7 30 4.8 4080 55 70/50 6.0 45 7.3 35


25


Indirect FlatStation for cooling

14 Sensor pocket, energy meter16 Outdoor sensor19 Surface sensor20 Filling/drain valve24 Delivered loose with unit

A Heat exchanger COF Electronic controller4 Safety valve9 Strainer10 Circulator pump

DCsupply

DCreturn

COsupply

COreturn

26 Pressure gauge27 Actuator29 2 - way motorized valve31

controller

38 Expansion tank41 Fitting piece, energy meter48 Air vent, manual

14

41 31

9

29

2719 48

16 230 V

F

A

4

20

10 48

19

38 26

4 bar 24

9


Technical parameters:Nominal pressure: PN 16DC supply temperature: T

max = 50 °C

Tmin

= 0 °CBrazing material (HEX): Copper

Weight incl. cover: Approx. 50 kg (incl. packing)

Cover: Fully insulated galvanized steel

Dimensions (mm):Without cover:H 605 x W 580 x D 270

With cover:H 675 x W: 625 x D 295

Connections:1 District cooling (DC) supply2 District cooling (DC) return3 Cooling (CO) supply4 Cooling (CO) return5 Safety relief discharge connection

Cooling: Capacity examples

FlatStation

typeVX-C

Cooling

capacity

[kW]

Supply flow

Primary

[°C]

Return flow

Primary

[°C]

Flowrate

Primary

[l/m]

Pressure loss

Primary*

[kPa]

Supply flow

Secondary

[°C]

Return flow

Secondary

[°C]

Flowrate

Secondary

[l/m]

VX-C-3 3 6 11.50 7.8 45 8 14 7.2

VX-C-6 6 6 11.50 15.6 45 8 14 14.3

VX-C-9 9 6 11.45 23.6 45 8 14 21.5

*Energy meter not included


Connections sizes: DC + CO: G ¾” (int. thread)

Options:• Outdoor temperature sensor

Danfoss FlatStations - 4 Series Cooling

26



Self-acting direct FlatStation

62B

DHW

DCW

DH supply

HEsupply

HEreturn

DH return


Technical parameters:Nominal pressure: PN 10DH supply temperature: Tmax = 120 °CDCW static pressure: pmin = 0,5 barBrazing material (HEX): Copper


Cover: White- lacquered steel sheet

Dimensions (mm):Without cover:H 760 x W 525 x D 110 mmWith cover (mount on wall variant):H 800 x W 540 x D 242 mm

Connections:1 District heating (DH) supply2 District heating (DH) return3 Domestic hot water (DHW)4 Domestic cold water (DCW)5 Heating (HE) supply 6 Heating (HE) return

Connections sizes:DH + HE: G ¾” (int. thread) DCW + DHW: G ¾” (int. thread)

Options:• Mounting rail with ball valves• Safety valve (8 bar)• Room thermostat• Connection for hot water circulation• Hot water circulation pump• Thermometer

B Water heater1 Ball valve7 Thermostatic valve9 Strainer14 Sensor pocket, energy meter31 Differential pressure controller41 Fitting piece, energy meter62B Pressure absorber w/non-return valve69 On / off valve


FlatStation typeVMTD-F-B

DHW capacity [l/min]

DHW capacity

[kW]

Supply flow Primary

[°C]

Return flow Primary

[°C]

CW/DHW [°C]

Flow rate Primary

[l/m]

Pressure loss Primary*

[kPa]

VMTD-F-B-1 12.5 30.6 60 19.5 10/45 10.8 3535.0 70 19 10/50 9.8 30

15 42.0 80 16.7 10/50 9.5 20

VMTD-F-B-2 15 36.8 60 18 10/45 12.5 3542.0 70 17.4 10/50 11.4 30

21 58.8 80 15.9 10/50 13.1 30

VMTD-F-B-3 21 51.5 60 19.5 10/45 18.2 4558.8 70 19.5 10/50 16.5 40

27 75.6 80 17.1 10/50 17.2 25

VMTD-F-B-4 2766.2 60 19.1 10/45 23.15 5575.6 70 18.6 10/50 21.05 50

32 89.6 80 16.3 10/50 20.1 25 Higher capacities available on demand. *Energy meter not included.

27



Self-acting direct FlatStation


Technical parameters:Nominal pressure: PN 10DH supply temperature: Tmax = 120 °CDCW static pressure: p min = 1 barBrazing material (HEX): CopperMax pri. pressure Pmax = 4.5 barDHW setting range: T = 45-65 °C


Insulation cover: Anthracite grey EPP

Dimensions (mm):With insulation (mounted on wall variant)H 555 × W 528 × D 255

Connections:1 District heating (DH) supply2 District heating (DH) return 3 Domestic hot water (DHW) 4 Domestic cold water (DCW)5 Heating (HE) supply6 Heating (HE) return

Connections sizes:DH + HE: G ¾” (int. thread) DCW + DHW: G ¾” (int. thread)

Options:• Safety valve (8 bar) • Room thermostat• Thermometer

* Energy meter not included


FlatStationtype

DHW Capacity

[kW]

Supply �ow

Primary[°C]

Return �ow

primary [°C]

DHW [°C]

Pressure loss

Primary [kPa*]

DHW Tap load

[l/m]

VMTD-I-1-FI

32,3 60 19 10/45 22 13.340,3 60 20 10/45 32 16.636,5 70 18 10/50 20 13.255 70 21 10/50 39 19.8

VMTD-I-2-FI

32,3 55 19 10/45 22 13.338 55 20 10/45 30 15.7

32,3 60 16 10/45 18 13.347 60 18 10/45 32 19.4

39,5 70 16 10/50 20 14.359 70 19 10/50 33 21.3


HeatingCapacity

[kW]

HeatingCircuit ∆t

[°C]

Pressureloss*

[kPa]

Flow rate[l/m]

10 20 25 7.2VMTD-I-x-FI 10 30 25 4.8

15 30 25 7.2

528

100 180 60

70

560

518

1 2 3 4

5 6

45

255

FlatStationtype

B Heat exchangerM Electrical wiring box 2C Single check valve incl. circulation pipe9 Strainer14 Sensor pocket, energy meter21 To be ordered separately31 41 Fitting piece, energy meter ¾” x 110 mm

63 Sieve62B Pressure absorber w/non-return valve

69 72 TPV

DHW

DHWrecirc.

DHsupply

DHreturn

HEsupply

HEreturn

DCW

MountingrailOption

62B


FlatStation type

VMTD-I-FI


DHW capacity

[kW]

Supply flow

Primary [°C]

Return flow

Primary [°C]

CW/DHW [°C]

Flow rate

Primary [l/m]

Pressure loss

Primary* [kPa]

VMTD-I-FI-112.5

30.6 60 20 10/45 11.1 2035.0 70 19.9 10/50 10.2 25

1536.8 60 21 10/45 13.7 3542.0 80 18 10/50 9.9 15

VMTD-I-FI-215 42.0 60 23.1 10/50 16.6 45

2158.8 70 20 10/50 17.2 4558.8 80 17.2 10/50 13.8 30

Higher capacities available on demand*Energy meter not included.


FlatStation type

VMTD-I-FI

Heatingcapacity

[kW]

Heating c i r c u i t

Δt [°C]

Pressure loss Primary*

[kPa]

Flow ratePrimary

[l/m]

VMTD-I-FI-1/2 10 20 25 7.2VMTD-I-FI-1/2 10 30 25 4.8VMTD-I-FI-1/2 15 30 25 7.2


28



Self-acting indirect FlatStation

Electrical wiring box

24

62B

Connections sizes: G ¾” (int. thread)


Technical parameters:Nominal pressure: PN 10*DH supply temperature: Tmax = 120 °CDCW static pressure: pmin = 0,5 barBrazing material (HEX): Copper* PN 16 versions are available on enquiry


Cover: White- lacquered steel


14 Sensor pocket, heat meter18 Thermometer20 Filling/drain valve24 Delivered loose with unit26 Manometer31 38 Expansion vessel41 Fitting piece, heat meter48 Air escape, manual62B Pressure absorber w/non-return valve69

Connections:1 District heating (DH) supply2 District heating (DH) return3 Domestic hot water (DHW)4 Domestic cold water (DCW)5 Heating (HE) supply6 Heating (HE) return

DHW: Capacity examples, 10°C/50°C Heating: Capacity examples

FlatStationtype

DHWCapacity

[kW]

Supply�owPri.[°C]

Return�owPri.[°C]

DHW/DCW[°C]

Pressure lossPri.*[kPa]

DHW Tap load[l/m]

FlatStationtype

HeatingCapacity

[kW]

Supply �ow Pri.

[°C]

Heatingcircuit

[°C]

PressurelossPri.*[kPa]

PressurelossSec.

[kPa]

FlowratePri.

[l/m]

FlowrateSec.[l/m]

Available pump

pressureSec.

[kPa]

VVX-B-1-x

VVX-B-2-x

VVX-B-3-x

VVX-B-4-x

33 60 19 10/45 25 13.9VVX-B-x-1

5 80 35/25 10 15 1.4 7.5 2041 70 19 10/50 25 15.2 18 80 70/40 40 20 8.3 9.1 1550 60 21 10/45 40 21.2 20 90 70/40 30 20 6.5 10 1560 70 21 10/50 35 22.2

VVX-B-x-2

9 80 35/25 10 15 2.5 13.5 3060 60 20 10/45 30 25.3 29 80 70/40 40 15 12.9 14.6 3075 70 20 10/50 30 27.8 33 90 70/40 30 20 10.6 16.6 2590 70 20 10/50 35 33.6

VVX-B-x-313 80 35/25 10 15 3.6 19.5 2546 80 70/40 35 20 20.6 23.1 1550 90 70/40 25 20 16.1 25.1 15

A Plate heat exchanger HEB Water heater1 Ball valve2B Double check valve, WRAS4 Safety valve6 Thermostatic/non-return valve7 Thermostatic valve9 Strainer10 Circulation pump

DHW

DCW

DHsupply

DHreturn

HEsupply

HEreturn

* Heat meter not included

Options:• Cover, white-lacquered steel (Design

Jacob Jensen)• Safety valve• • Pipe insulation•

heating• • Safety thermostat surface type• Weather compensation, electronic

controls•

circuit• Room thermostat


FlatStation type

VVX-B


DHW capacity

[kW]

Supply flow

Primary [°C]

Return flow

Primary [°C]

CW/DHW [°C]

Flow rate

Primary [l/m]

Pressure loss

Primary* [kPa]

VVX-B-1-x12.5 30.6 60 19.5 10/45 10.8 3512.5 35.0 70 19 10/50 9.8 3015 42.0 80 16.7 10/50 9.5 20

VVX-B-2-x15 36.8 60 18 10/45 12.5 3515 42.0 70 17.4 10/50 11.4 3021 58.8 80 15.9 10/50 13.1 30

VVX-B-3-x21 51.5 60 19.5 10/45 18.2 4521 58.8 70 19.5 10/50 16.5 4027 75.6 80 17.1 10/50 17.2 25

VVX-B-4-x27 66.2 60 19.1 10/45 23.15 5527 75.6 70 18.6 10/50 21.05 5032 89.6 80 16.3 10/50 20.1 25

Higher capacities available on demand*Energy meter not included


FlatStation type

VVX-B

Heating capacity

[kW]

Supply flow

Primary [°C]

Return flow

Primary [°C]

Heating circuit

[°C]

Flow rate Primary

(l/m)


[kPa]

Flow rate Secondary

[l/m]


[kPa]

VVX-B-x-1 3.5

60 35.7 45/35 2.2 15 5.3 3570 35.1 60/30 1.5 15 1.8 3080 44.3 70/40 1.5 15 1.8 3080 52.1 70/50 1.9 15 2.7 30

VVX-B-x-2 7

60 35.5 45/35 4.3 20 10.6 3070 36.7 60/30 3.2 15 3.5 4580 45.8 70/40 3.1 15 3.5 4580 53.5 70/50 4.0 25 5.3 35

VVX-B-x-3 10

60 35.5 45/35 6.1 40 15.1 1570 36.6 60/30 4.5 25 5.0 4080 45.8 70/40 4.4 25 5.0 4080 53.2 70/50 5.7 35 6.4 30


29



Self-acting indirect FlatStation


Technical parameters:Nominal pressure: PN 10*DH supply temperature: Tmax = 120 °CDCW static pressure: pmin = 1 barBrazing material (HEX): Copper* PN 16 versions are available on enquiry


Insulation: Anthracite grey EPP

Dimensions (mm):With insulation (mounted on wall variant):H 765 x W 530 x D 375

2B Single check valve, WRAS2C Double check valve, WRAS 4 Safety valve7 Thermostatic valve9 Strainer10 Circulation pump14 Sensor pocket, heat meter20 Filling/drain valve21 To be ordered separately24 Delivered loose with unit26 Manometer31

controller38 Expansion vessel41 Fitting piece, energy meter48 Air escape, manual

63 Sieve

62B Pressure absorber w/non-return valve

69 72 TPV valve

Connections:1 District heating (DH) supply2 District heating (DH) return3 Domestic hot water (DHW)4 Domestic cold water (DCW)5 Heating (HE) supply6 Heating (HE) return

Connections sizes:All connections: G ¾” (int. thread)

Options:• Booster pump (increases DH • Separate mixing circuit• Safety valve (10 bar)• Safety valve with thermostatic

circulation set• Electronic controller• Room thermostat• Connection for circulation


FlatStationtype

DHW Capacity

[kW]

Supply/R w

primary [°C]

DHW [°C]

Pressure loss

primary* [kPa]

DHW Tap load[l/m]

VVX-I-1-x-FI

VVX-I-2-x-FI

32,3 60/19,8 10/45 23 13.340,3 60/20,7 10/45 33 16.636,5 70/19,1 10/50 20 13.255 70/21,5 10/50 39 19.8

32,3 55/21,9 10/45 26 13.338 55/22,2 10/45 34 15.7

32,3 60/19,6 10/45 20 13.347 60/19,6 10/45 34 19.4

39,5 70/19 10/50 20 14.359 70 10/50 34 21.3

A Plate heat exchanger HEB Plate heat exchanger DHWM Electrical wiring box1 Ball valve

DHW

DCW

Circ.

DHsupply

DHreturn

HEsupply

HEreturn

Side viewFront view


FlatSta -tiontype

HeatingCapacity

[kW]

Supply / Return

primary [°C]

Heating circuit

[°C]

Flow rate

primary [l/m]

dp min [kPa]

Flow rate sec-ondary

[l/m]

Residu-al pump

head [kPa]

VVX-I-x-1-FI

VVX-I-x-2-FI

VVX-I-x-3-FI

12 70/40 60/35 5.9 30 7 3124 90/45 70/40 7.8 45 11.7 19

19 70/40 60/35 9.2 30 11 5235 90/45 70/40 11.2 45 17 30

31 70/40 60/35 15.1 30 18 4150 90/45 70/40 15.9 45 24.3 25

* Heat meter not included

62B


FlatStation type

VVX-I-FI


DHW capacity

[kW]

Supply flow

Primary [°C]

Return flow

Primary [°C]

CW/DHW [°C]

Flow rate

Primary [l/m]

Pressure loss

Primary* [kPa]

VVX-I-FI-1-x12.5

30.6 60 20 10/45 11.1 2035.0 70 19.9 10/50 10.2 25

1542.0 70 20.9 10/50 12.5 3542.0 80 18 10/50 9.9 15

VVX-I-FI-2-x15 42.0 60 23.1 10/50 16.6 45

2158.8 70 20 10/50 17.2 4558.8 80 17.2 10/50 13.8 30

Higher capacities available on demand*Energy meter not included


FlatStation type

VVX-I-FI

Heating capacity

[kW]

Supply flow

Primary [°C]

Return flow

Primary [°C]

Heating circuit

[°C]

Flow rate

Primary (l/m)


[kPa]

Flow rate Secondary

[l/m]

Residual pump head

Secondary [kPa]

VVX-I-FI-x-1 3.5

60 36.1 45/35 5.2 15 5.1 3570 36.6 60/30 1.7 15 1.7 3080 45.9 70/40 1.7 15 1.7 3080 53 70/50 2.5 15 2.5 30

VVX-I-FI-x-2 7

60 35.8 45/35 10.1 25 10.1 3070 39.7 60/30 3.4 25 3.4 4580 48.8 70/40 3.4 25 3.4 4580 55.3 70/50 5.1 3 5.1 40

VVX-I-FI-x-3 10

60 35.9 45/35 14.5 35 14.5 1570 39.7 60/30 4.8 35 4.8 4080 48.8 70/40 4.8 30 4.8 4080 55.4 70/50 7.3 45 7.3 35


30


Indirect FlatStation for two separate heat sources


Technical parameters:Nominal pressure: PN 10*DH supply temperature: Tmax = 120 °CDCW static pressure: pmin = 0,5 barBrazing material (HEX): Copper* PN 16 versions are available on enquiry


Cover: White- lacquered steel


Connections:1 Domestic cold water (DCW)2 Domestic hot water (DHW) 3 Heat source 2 (DH 2) return4 Heat source 2 (DH 2) supply5 Heat source 1 (DH 1) return6 Heat source 1 (DH 1) supply7 Heating (HE) return 8 Heating (HE) supply

DHW (Heat Source 1): Capacity examples Heating (Heat Source 2): Capacity examples

FlatStationtype

VVX-B-DHS

DHWcapacity

[kW]

Supply�ow

Primary[°C]

Return�ow

Primary[°C]

DCW/DHW[°C]

Pressure loss

Primary*[kPa]

DHW tap

load[l/m]

FlatStationtype

Heatingcapacity

[kW]

Supply �ow

Primary[°C]

Return �ow

Primary [°C]

Flow rate

Primary [l/m]

Pressure loss

Primary* [kPa]

Supply �ow

Secondary [°C]

Return �ow

Secondary [°C]

Flow rate

Secondary [l/m]

Residual pump pressure

Secondary [kPa]

VVX-B-DHS-1-x 30 60 24 10/50 40 11.2VVX-B-DHS-x-1

3.5 50 31.3 2.8 20 40 30 5.26 3040 70 20 10/50 40 14.9 3.5 50 37.3 4.15 25 45 35 5.26 30

VVX-B-DHS-2-x35 60 22 10/50 40 13.1 3.5 60 35.7 2.17 25 45 35 5.26 3055 70 19 10/50 55 16.8

VVX-B-DHS-x-2

7.0 50 31.0 5.53 35 40 30 10.52 30

VVX-B-DHS-3-x45 60 23 10/50 45 20.6 6.5 50 36.8 7.40 50 45 35 9.79 3565 70 20 10/50 50 24.3 7.0 60 35.5 4.30 25 45 35 10.52 30

VVX-B-DHS-4-x55 60 23 10/50 50 20.6

VVX-B-DHS-x-3

10.0 50 31.0 7.92 50 40 30 15.03 2575 70 19 10/50 50 28.0 7.0 50 36.6 7.83 50 45 35 10.52 35

10.0 60 35.5 6.13 35 45 35 15.03 25

Connections sizes: G ¾” (int. thread)

Options:• Cover, white-lacquered steel (Design

Jacob Jensen)• Safety valve• • Pipe insulation• • Safety thermostat surface type• Weather compensation, electronic

controls•

circuit• Room thermostat

DH 1 return

DH 1 supply

DH 2 supply

DH 2 return

HE supply

HE return



Danfoss FlatStations - 7 Series BS Dual Heat Source

31

tried and tested

globally

fast closing times

hydraulic

balancing

minimal service

requirements

Zooming in…

32


DHW ComfortHigh valve authorityThe self-acting pressure and temperature controller is specifically designed to generate hot water within ±2°C accuracy under fluctuating pressure, temperature and tapping conditions.

Plate heat exchanger protectionFast acting closure of DH supply when tapping stops ensures protection of the heat exchanger against scaling.

Self-acting DHW controllerThe Danfoss IHPT is a state-of-the-art flow-compensated temperature controller with built-in differential pressure controller. It has been developed specifically to control instantaneous heating of DHW by means of a heat exchanger.

Danfoss IHPT Self-acting DHW Controller

Domestic Hot Water

Time [sec]

Varying Domestic Hot Water Tapping

Primary Flow Primary Return

Domestic Hot Water Cold Water Mains

Time [sec]

System Temperatures

33


8°C set-back functionIn standby function, the IHPT valve incorporates a further energy saving “primed 8C set-back” feature. The self-acting control valve throttles the primary flow to a minimum thereby further increasing system efficiencies while maintaining DHW comfort for the user. The flow through the controller is reduced to an amount just sufficient to keep the plate heat exchanger warm at a temperature 8C lower than the set DHW flow temperature. In practice, this enables occasional slugs of heated water to enter the plate heat exchanger meaning that the pipes feeding the unit do not become dead legs and ensuring that hot water is available as soon as taps are opened.

Low return temperaturesThe rapid closing times and efficiency of the TPV controller in combination with purpose-designed Micro Plate heat exchangers ensure very low return temperatures.

B Water Heater9 Stainer72 IHPT control valve

B

9

72

DHW DH Supply

DCWDH Return

Danfoss IHPT ControllerConnection Example

Best Practice and ComplianceReturn temperaturesThe low return temperatures from the FlatStations ensure compliance with CIBSE:AM12 and GLA recommendations (maximum return temperatures of 25°C from DHW instantaneous heat exchangers).

System Efficiency Primed DHW functionIn standby function, when there is no DHW demand, the DH flow rate is minimized to just keep the heat exchanger primed ready for DHW tapping.

SAV FlatStation - 7 Series DS

Technical parameters:

Picture DNNominal pressure

(PN)kvs (m3/h) Max prim. diff.

pressure (bar)Min. CWM

pressure (bar)Setting range

(°C)Standby temperature

(°C)

45 … 65 Tset -- 8°C63 115 16

34


DHW ComfortHigh valve authorityThe self-acting mechanical pressure and temperature controller is specifically designed to generate hot water within ±2°C accuracy under fluctuating pressure, temperature and tapping conditions.

Plate heat exchanger protectionSelf-acting closure of DH supply when tapping stops ensures protection of the heat exchanger against scaling.

Best Practice and ComplianceReturn temperaturesThe low return temperatures from the FlatStations ensure compliance with CIBSE:AM12 and GLA recommendations (maximum return temperatures of 25°C from DHW instantaneous heat exchangers).

System Efficiency Primed DHW functionIn standby function, when there is no DHW demand, the DH flow rate is minimized to just keep the heat exchanger primed ready for DHW tapping.

Low return temperaturesThe efficiency of the AVTB controller and the plate heat exchanger ensures very low return temperatures, benefiting the central plant and system efficiencies.

Danfoss AVTB Self-acting DHW Controller

0100200300400500600700800900

1000

0 100 200 300 400

l/h

Domestic Hot Water

Time [sec]

Flow

0102030405060708090

100110

0 100 200 300 400

°C

Primary Flow Primary Return

Domestic Hot Water Cold Water Mains

Time [sec]

Temperature

District hea�ng supply: 70°C

Differen�al pressure: 0.5 bar

35


Technical parameters*:

Picture DNNominal

pressure (PN)Max prim. diff. pressure (bar)

Min. CWM pressure (bar)

Setting range (°C)

kvs (m3/h) Standby temperature (°C)

15 1.9

* Alternatives available for different specifications

=Tset 20 3.4

16 10 0.5 20 … 60

SAV FlatStation - 7 Series BS

The sensor of the self-acting AVTB valve is placed in the Sensor Accelerator and will keep the plate heat exchanger primed for instantaneous DHW delivery at the set DHW temperature.

The sensor accelerator improves the closing time and reduces the closing temperature of the AVTB valve.

Danfoss AVTB Controller

36


Danfoss RAVK Self-acting Heating Circuit Controller

Design

1. Handle for temperature setting

2. Setting spring 3. Bellows 4. Valve stu�ng box 5. Bottom screw 6. Valve body 7. Valve cone 8. Temperature sensor 9. Sensor stu�ng box10. Housing of sensor stu�ng box11. Gasket of sensor stu�ng box12. Sealing bolt of sensor stu�ng box

9

12

10

11


Picture DN Nominal pressure (PN) kvs (m3/h) Max prim. diff. pressure (bar) Setting range (°C)

*Combined with Danfoss VMT zone valve

10 0.8 35 751.515

Heating circuit controlThe self-acting thermostatic RAVK actuator is used to control the temperature of the dwelling heating circuit. By setting the handle of the valve the primary flow rate will be controlled according to the desired secondary heating flow temperature irrespective of primary pressure and temperature fluctuations.

RAVK Example

37


Danfoss AVPL Self-acting Differential Pressure Controller (DPCV)

System efficiency

Hydraulic balancing of the District Heating network

By controlling differential pressures, and thereby also controlling flow rates, the use of DPCVs ensures hydraulic balancing of the district heating network. This is a precondition for a well-functioning network with a large DT where variable speed pumps are ramping up and down according to real-time, actual demand of the building – using neither more nor less energy than required. The results are reduced heat losses, improved variable speed pump performance, and lower primary return temperatures.

System reliability

Constant pressure differential (DT) across the control valve

The correct use of DPCVs also enables accurate heating circuit control by

keeping a constant pressure differential across the heating control valve improving the valve authority. Even when differential pressures rise in the primary system the DPCV ensures that the control equipment will still work as intended.

Differential pressure control

The AVPL is a self-acting differential pressure control valve (DPCV).

For optimal performance the valve is located in the primary circuit but dedicated to the secondary heating circuit controls. This design is important as an alternative location of the DPCV across both DHW and heating would result in an over-sized DPCV, as it would have to meet the requirements of the higher flow rates required for DHW, allowing excessive flow rates through the FlatStation when there is demand for heating, but no demand for DHW. The positioning of the valve dedicated to the heating circuit controls allows a lower differential pressure setting, improving control and reducing flow rates and primary return temperatures.


Picture DN Nominal pressure (PN) kvs (m3/h) Max prim. diff. pressure (bar) p Setting range (bar)

1

1.6

*Note: As unit capacities increase, different DPCVs will be selected for optimal performance

4.515 16 0.05-0.25

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Danfoss SonometerTM 1100 Ultrasonic Compact Energy Meter

Measuring accuracy to EN 1434 MID Class 2

Energy meterThe Sonometer 1100 is an ultrasonic energy meter. This not only permits a very high measuring accuracy, but also makes the energy meter insensitive to dirt. With two communication module slots there is a high degree of flexibility in terms of input/output communication - also if billing and datalogging requirements change in the future. The calculator/display of the energy meter can be located integral to the FlatStation or on a nearby wall if preferred.

‘DELTA T’ ENERGY METER CALCULATION METHODOLOGY

The following example shows the methodology for calculating the average ‘delta T’ between two points in time using energy meter data.

Reading 1

m3 MWh

Reading 2

Reading 1

Reading 2

m3 00120 MWh

Cubic Meter Consumption in period: 1340 – 870 = 470 m3

Energy Consumption in period: 120 – 101 = 19 MWh

‘Delta T’ calculated as follows:

MWh x 860 = heating in °C m3

The 860 is a constant, and is defined as the quantity of m3

of water that will be heated by 1ºC by 1 MWh

So in this example the ‘delta T’ calculation is as follows:

19 x 860 = 34.77°C470

The average ‘delta T’ in this example is therefore 34.77ºC

870

01340

00101

· Ultrasonic

· MID approved

· RHI compliant

· Battery or mains option

· 2 communication module slots

· Mbus, pulse and radio options

39


Izar Center M-Bus Master

Izar CenterThe Izar Center is used for remote reading of Mbus devices to store energy consumption, e.g. of energy meters and cold water meters. The collection of consumption data can be initiated manually by the operator or automatically by the Izar Center which can be programmed to take the meter readings at specified intervals.

Connections

· Manages up to 60, 120 or 250 M-Bus

Energy meters

· Further energy meters can be added

by using repeaters

· Automatic transmission of

consumption data via internet

connection

· Direct connection to either PC or

laptop possible

· IP66 Enclosure as standard

· Up to 1000 devices connected

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Micro PlateTM Heat Exchanger (MPHE) Plate heat exchanger

Optimised for district heatingWhether for domestic hot water, heating or cooling, Danfoss plate heat exchangers are designed especially for use with district heating systems. With a wide range of sizes each Danfoss FlatStation can be designed with plate heat exchangers suiting each individual project based on its specific design criteria.

Patented plate heat exchanger designThe Micro Plate heat exchanger includes a patented “dimple” plate design (as opposed to the traditional “fish-bone” pattern). This design is the next generation of plate heat exchangers optimising the heat transfer across the plates, lowering primary return temperatures and increasing system efficiencies.

Up to 10% better heat transfer due to optimised flow velocity from the innovative plate design.

LOWER CO2 FOOTPRINTMPHEs require fewer plates and therefore less raw material to produce. Low pressure loss reduces the pump power needed. Enhanced heat transfer leads to more efficient operation, and a longer life-span reduces waste. All these factors add up to a significantly lower overall CO

2 footprint than you get with traditional

heat exchanger models.

UK CUSTOMER SUPPORT CENTRE SAV Systems, Scandia House, Boundary Road, Woking, Surrey GU21 5BX Telephone: +44 (0)1483 771910 EMAIL: [email protected]

GENERAL INFORMATION: Office Hours: 9.00am - 5.00pm Monday to Friday.

…for maximised CHP % share

Combined Optimised Heat and Power...

Lean Heat NetworksFlatStationsTM - Performance guaranteed!

Designed for AM&Tand ongoing commissioning

FloCon WatchmanTM

Tempered Fresh Air… …with the windows wide shut!

Danfoss FlatStations - SAV Systems · Danfoss FlatStations - 1 Series BS ... However, in 2012 BS...

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