Flat stations - EvoFlat 4.0

  • Overview
  • How it works
  • Tools and apps
  • Documents
  • Related products
  • Software
  • FAQ

The modern replacement for traditional centralized heating and domestic hot water solutions

Flat stations are decentralized heating systems installed in flats and apartments to provide residents comfortable heating and on-demand domestic hot water with the highest energy efficiency. The stations incorporate a compact plate heat exchanger, which delivers instantaneous hot water on demand and a differential pressure control valve to control the heating flow to the tenants’ radiators and underfloor heating.
The modular concept allows to order the station exactly as needed; nothing more, nothing less

Efficient Flat Stations for Direct Heating and Domestic Hot Water

Our flat stations offer seamless integration for direct heating with or without mixing loop and domestic hot water systems. With a direct flow from the network into the building, flat stations ensure swift and efficient operation. Underfloor heating variant comes specialized mixing loop that grants you precise control over the supply temperature for the apartment.

Direct substations are the ideal choice for networks operating at maximum PN10 or PN6 levels.


Efficient distribution systems - floor heating for flat stations

Our prefabricated underfloor distribution units cater to both floor heating and cooling applications. These versatile systems can be installed separately or directly connected to the Danfoss flat station range, in combination with a boiler or as an extension of the existing heating system. In addition, we offer recess boxes with mounting rails for seamless installation experience.

Experience a new level of efficiency and flexibility in floor heating distribution with our advanced solutions.

Features and benefits of flat stations

Cost-effective solution ideal for new installations, refurbishment and renovation projects offering low service and maintenance cost

Quick and easy installation.

Less space used, can be seamlessly integrated into walls, stairwells, or shafts

Precise energy metering and consumption monitoring

EvoFlat 4.0 - Better | Lighter | Easier

Completely new, industrial & modular, design to help you win project tenders. The modern replacement for traditional centralized heating and domestic hot water solutions.

EvoFlat 4.0 is the cost-effective choice for new build as well as renovation and refurbishment projects, thanks to its ease of installation in existing buildings. EvoFlat 4.0 stations are designed to align with diverse project needs. With the flexibility to connect to any available energy source, your investment remains secure, unaffected by the unpredictabilities of the future.

Within EvoFlat 4.0 flat stations lies a new innovative heat exchanger Danfoss XB05, designed with a revolutionary dimple pattern. It is complemented by a new TPC-M proportional controller that ensures instant domestic hot water. Additionally, two separate differential pressure controllers for DHW and heating guarantee a consistent heating experience.

How it works

Discover the features of EvoFlat 4.0: 

Features

SAC

Energy Saving

 
Investment

Body material

Composite (PPS + 30% glass-fiber)

DHW Capacity

Up to 80 kW (Type 4)

Differential pressure controller

Two: DHW & heating

Heating and DHW control

Mechanical

HEX principle

Cold HEX

Internal pipe connections

Leakage-free click-fit

Modular EPP insulation

Yes

Commissioning

Mechanical valves

Remote control and monitor

No

Software updates

No

Smart heating & DHW

No

EvoFlat 4.0 is designed to be customized. We have 90 main variants to choose from and many options to add all based on three main models:

  • EvoFlat 4.0 W for domestic hot water
  • EvoFlat 4.0 M for domestic hot water and underfloor heating
  • EvoFlat 4.0 F for domestic hot water and radiator heating

Main features of EvoFlat 4.0:

Modular design enables all applications with one platform

Reinforced PPS composite body for reduced internal heat transfer and decreased weight

No need of re-tightening after transportation or other vibrations due to the improved Click-fit connections

Two separate ΔP controllers for DHW and HE bring best-in-class hydronic balancing for stable hot water temperatures and energy efficient heating operation

New HEX and hot water controller for up to 70 kW hot water capacity at high tapping rate

Prepared for low supply temperature

Easy access during installation and maintenance, for example for heat exchanger

Lightweight PPS composite body

Build-in or wall-mounted variant

Redefining Heat Pump Excellence with Evoflat 4.0

In the world of heating and cooling technology, the Evoflat 4.0 stands out as the perfect choice for heat pump systems.

Engineered with innovation and precision, this advanced flat station is designed to elevate the performance of heat pumps while optimizing efficiency and comfort in your building.

  • With enhanced insulation, the Evoflat 4.0 minimizes heat loss, ensuring that the energy generated by your heat pump is directed precisely
    where it's needed and optimizes chilled water distribution.
  • Boasting a remarkable combination of high capacity, high flow, and smaller dimensions, the XB05 heat exchanger redefines what's possible.
    With its innovative dimple design, heat transfer is taken to new heights, resulting in a lower temperature difference (dT) and maximizing the
    effectiveness of your heat pump system. This groundbreaking innovation is currently unmatched in the market.
  • Designed for heat pumps, the 4-pipe variant features separated risers for both heating and domestic hot water. This separation ensures optimal
    performance and distribution, allowing your heat pump to operate at its peak efficiency while delivering comfortable hot water whenever needed.
  • Finally, the advanced electronic controller guarantees quick responses to changing demands, precise supply temperature, and optimal
    return temperature control.


Embrace the future of heating and cooling technology by choosing the EvoFlat 4.0.

Tools and apps

Documents

Documents
Type Name Language Valid for Updated Download File type
Brochure EvoFlat 4.0 - Industrial and modular designed flat station that help you win project tenders English Multiple 12 Oct, 2023 3.8 MB .pdf
Brochure EvoFlat 4.0 - Industrial and modular designed flat station that help you win project tenders German Multiple 08 Aug, 2022 6.6 MB .pdf
Brochure EvoFlat 4.0 - Industrial and modular designed flat station that help you win project tenders French France 21 Feb, 2022 9.9 MB .pdf
Brochure EvoFlat 4.0 - Industrial and modular designed flat station that help you win project tenders Spanish, Castilian Spain 12 Oct, 2023 3.7 MB .pdf
Brochure EvoFlat 4.0 - Industrial and modular designed flat station that help you win project tenders Slovak Slovakia 24 Jan, 2023 2.1 MB .pdf
Data sheet EvoFlat 4.0 F (Data Sheet) Slovak Slovakia 06 Oct, 2023 709.0 KB .pdf
Data sheet EvoFlat 4.0 F (Data Sheet) Ukrainian Ukraine 13 Oct, 2023 2.3 MB .pdf
Data sheet EvoFlat 4.0 F (Data Sheet) Czech Czech Republic 22 May, 2023 803.6 KB .pdf
Data sheet EvoFlat 4.0 F (Data Sheet) German Multiple 15 May, 2023 735.4 KB .pdf
Data sheet EvoFlat 4.0 F (Data Sheet) English Multiple 15 May, 2023 681.4 KB .pdf
Data sheet EvoFlat 4.0 F (Data Sheet) French France 31 Mar, 2023 1.3 MB .pdf
Data sheet EvoFlat 4.0 F (Data Sheet) Italian Italy 21 Sep, 2023 693.4 KB .pdf
Data sheet EvoFlat 4.0 M (Data Sheet) Slovak Slovakia 01 Nov, 2023 1.0 MB .pdf
Data sheet EvoFlat 4.0 M (Data Sheet) French France 04 Nov, 2022 1.0 MB .pdf
Data sheet EvoFlat 4.0 M (Data Sheet) Ukrainian Ukraine 13 Oct, 2023 7.2 MB .pdf
Data sheet EvoFlat 4.0 M (Data Sheet) Italian Italy 21 Sep, 2023 1.0 MB .pdf
Data sheet EvoFlat 4.0 M (Data Sheet) Spanish, Castilian Spain 12 Oct, 2023 1.0 MB .pdf
Data sheet EvoFlat 4.0 M (Data Sheet) Czech Czech Republic 22 May, 2023 931.3 KB .pdf
Data sheet EvoFlat 4.0 M (Data Sheet) English Multiple 09 Aug, 2023 1.0 MB .pdf
Data sheet EvoFlat 4.0 M (Data Sheet) German Multiple 15 May, 2023 933.2 KB .pdf
Brochure Evoflat 4.0 Overview English Multiple 06 Mar, 2023 1.4 MB .pdf
Data sheet EvoFlat 4.0 W (Data Sheet) Slovak Slovakia 06 Oct, 2023 744.3 KB .pdf
Data sheet EvoFlat 4.0 W (Data Sheet) English Multiple 21 Dec, 2022 721.2 KB .pdf
Data sheet EvoFlat 4.0 W (Data Sheet) Italian Italy 21 Sep, 2023 735.3 KB .pdf
Data sheet EvoFlat 4.0 W (Data Sheet) German Multiple 21 Dec, 2022 770.7 KB .pdf
Data sheet EvoFlat 4.0 W (Fiche technique) French France 21 Dec, 2022 746.6 KB .pdf
Data sheet EvoFlat™ 4.0 FSF fully insulated (Data Sheet) English Multiple 11 Aug, 2023 1.1 MB .pdf
Data sheet EvoFlat™ 4.0 FSF fully insulated (Data Sheet) German Multiple 23 Mar, 2023 1.1 MB .pdf
Data sheet EvoFlat™ 4.0 FSF fully insulated (Data Sheet) Italian Italy 21 Sep, 2023 1.1 MB .pdf
Brochure Specifying the right district heating substation makes commercial sense German Multiple 16 Mar, 2020 3.1 MB .pdf
Brochure Specifying the right district heating substation makes commercial sense Croatian Croatia 06 Aug, 2015 2.5 MB .pdf
Brochure Specifying the right district heating substation makes commercial sense Ukrainian Ukraine 18 Sep, 2015 2.2 MB .pdf
Brochure Specifying the right district heating substation makes commercial sense Slovenian Slovenia 21 Jul, 2015 5.2 MB .pdf
Brochure Specifying the right district heating substation makes commercial sense Romanian, Moldavian, Moldovan Romania 29 Aug, 2015 2.3 MB .pdf
Brochure Specifying the right district heating substation makes commercial sense Slovak Slovakia 21 Jul, 2015 2.4 MB .pdf
Brochure Specifying the right district heating substation makes commercial sense Bulgarian Bulgaria 31 Jul, 2015 11.3 MB .pdf
Brochure Specifying the right district heating substation makes commercial sense English Multiple 05 Mar, 2015 2.4 MB .pdf

Related products

Software

The BIM tool helps you to find the right products fast and easy

Always up to date! With the Revit plug-in, products are instant added to the project with file download running in the background. In case you are not a Revit user, you’re still well-served with the tool. It runs as a standalone desktop app which includes all product information and allows you to download the required BIM files instantly.  

FAQ

General functionality

The Danfoss flat station concept "EvoFlat 4.0" comprises an installation, for which flat stations that are supplied from a central energy source, are built into each flat. These units normally incorporate a compact plate heat exchanger, which delivers instantaneous hot water on demand and a differential pressure control valve to control the heating flow to the tenants’ radiators.

The main difference between traditional heating systems and decentralized ones with flat station is that in decentralized systems the process of domestic hot water preparation is moved from central heat source (traditional systems) to flat station units in each apartment. In traditional systems 5 main ascending pipes are using instead of 3 in decentralized heating systems.

There are two typical applications which depend on the type of heating installation in the apartment – Radiator heating and Floor heating.

The heat source to the decentralized system can be oil, gas or wood-fired boiler, district heating, heat pumps or a combination of these. Furthermore, the system can also be supported by solar energy. It is important that the energy source(s) is/are capable of generating a sufficient minimum supply temperature with the object of producing acceptable domestic hot water temperatures in the heat exchanger, placed in each apartment. Furthermore, the installation includes a buffer tank.

The buffer tank avoids frequent starts and stops of the burner in Or the compressor in a heat pump installation and is thereby contributing to increasing the service life of the heat pump and reducing its harmful emissions. The buffer tank also stores an adequate volume of energy that allows an instant supply of sufficient flow to the water heaters in each flat during peak load intervals. The buffer tank is then loaded to the desired supply temperature for the distribution system. In principle, the buffer tank is not required for a large number of flats as the entire piping system and the larger boilers will provide a sufficient buffer volume to accommodate the large load changes in domestic hot water use. The actual limit will depend on the volume in pipes and boiler as stated previously, but it does also relate to the boiler load.

In the EvoFlat 4.0 concept for decentralized system the heat exchangers are used mainly for producing domestic hot water. The operating principle of instantaneous water heating/the flow principle can be described as follows:

  • Heating water circulates on one side of the plate heat exchanger transferring heat to cold water passing through on the other side. The heated water is then fed straight to local hot water taps
  • To control the domestic hot water capacity of the unit a self-acting control valve, especially developed for this purpose, is used to regulate the flow across both sides of the plate heat exchanger
  • For instantaneous water heaters various DHW control valves with control principles, which each incorporate advantages and disadvantages, can be implemented
    These are typically grouped accordingly: temperature-controlled, pressure-controlled, temperature and pressure controlled.

Danfoss offers a comprehensive product range, which includes flat station variants with ALL control principles.

The advantages of the instantaneous DHW preparation are:

  • Minimized risk of legionella bacteria
  • Added comfort due to a continuously high output
  • Very little space required for installation
  • Low return temperatures, which increase the overall efficiency in systems including condensing boilers, solar energy etc.
  • Operates at as low supply temperatures as e.g. 50 - 55 °C

Alternatively, a domestic hot water cylinder, placed in each flat, could be implemented. This solution, however, does not offer the same advantages as the flow system. The cylinder solution cannot be excluded on account of not being operational and can be incorporated in the concept at the request of the client.

In the EvoFlat concept for the decentralized system the heating circuit of a flat station can be configured in 3 ways:

  • Directly – controlled only by a differential pressure controller and optionally by a zone valve controlled by a programmable room thermostat. This principle is applicable mainly for radiator heating in supply systems with maximum PN10.
  • Directly with mixing circuit – controlled by a differential pressure controller and a mixing circuit. This principle is applicable mainly for floor heating and systems with maximum PN10.
  • Indirectly - a plate heat exchanger is controlled by a 2-way thermostatic valve and optionally by a zone valve, controlled by a programmable room thermostat. This principle is applicable mainly for floor heating and systems with maximum PN16.

Designing

An estimation of the domestic hot water requirement is part of the total evaluation, which is the reason why the term coincidence factor is relevant in this context. Briefly stated, only a part of all tap points is used in actual practice, based on a 99.9 % confidence interval in a statistic probability distribution.

In the Danish standard for domestic hot water installations DS439 and the specifications from TU-Dresden the consumption pattern of a “standard flat”, which by definition includes 3.5 persons, constitutes the basis for the factors. Deviations may occur if the dwelling for example is inhabited by residents for which an atypical consumption pattern can be expected. Therefore, the application of these factors must be supported by an estimation of the composition of the residents of the building. In the EvoFlat Selector the following factors can be selected: Danish Norm DS439, Danfoss-Redan, Swedish and German factor.

The total flow is formed by the heating loop flow rate and the primary supply flow rate for the water heaters, reduced by the relevant coincidence factor and a flow rate to compensate for other heat losses.

The size of pipes is determined by maximum flow rates in each partials section. Criteria are normally a certain velocity and a certain pressure loss per running meter. For visible pipes typically v≤1m/s and <100 Pa/m has been recommended, but for other sections and pipes covered in shafts other criteria can be used for dimensioning.

Yes, Danfoss offers a software for dimensioning flat stations. It is called "EvoFlat Selector" and can be found from EvoFlat Selector

This dimensioning has to be viewed in a context, as the buffer tank and the boiler/HEX size can be adapted according to each other to cover the energy requirement for domestic hot water and heating. A major quality of the buffer tank is to cover domestic hot water peak loads and to reduce the number of boiler starts and stops and thereby ensure a more economical operation. Finally, a buffer tank is the automatic choice, if solar heating supports the other heat sources. In such situations the size of the solar collector area will often be dimensioning, and it is recommended that separate calculations are made.

Following advantages compared to traditional system installation designs can be listed:

  • The flat station concept can be implemented in both new buildings as well as by refurbishments.
  • The system is independent of the energy supply – gas, oil, district heating, heat pump, biomass or solar.
  • Individual, fair energy bills for each flat or tenancy are possible.
  • The system enables remote monitoring of the energy consumption of each flat with the proper energy meter.
  • Only three ascending pipes are required in the building – cold water, supply and return heating.
  • Minimum space requirements for fitting the unit in the flat - comprising possible integration in wall construction.
  • Individual adjustment of room temperature over time and independent domestic water production is possible.
  • Bacteria-free domestic water production with the flow principle – minimized risk of the legionella bacteria.
  • Added hot domestic water comfort compared with traditional gas-fired water heaters (35 – 80 kW against 22 kW).
  • Increased energy efficiency through improved boiler or district heating installation operation and through possibly low operational temperatures.
  • Reduced heat loss in the distribution network compared to the classic solution as the hot water and domestic water circulation line is not required.
  • A minimum of maintenance in each flat thanks to the simple technique.
  • Relatively safe system as electrical short circuits and gas leakages are not possible.
  • Suitable for operation with condensing boilers and solar energy owing to the low return temperatures of the system.

Electronically controlled flat stations have automatic domestic hot water priority.

In mechanical stations, if the DHW control valve turns off mechanically the supply of heat for the radiators/floor heating, the existence of 100% DHW priority may be assumed. In case control valves for DHW without mechanical changeover function are used, it must be calculated, whether DHW priority may be assumed (Hydraulic priority).

  • when ΔpDHW < Δp Heating DHW priority in the unit can be assumed

  • when ΔpDHW ≥ ΔpHeating DHW priority cannot be assumed

Installation

Summer bypass is applicable with NC DHW controllers – PM2+P, PTC2+P and TPC+M. When the units are mounted more than 2-3 meters away from the main risers, a thermostatic bypass (FJVR) is recommended. During the summer the bypass keeps supply pipes warm and enables tapping of hot water without any delay – ensuring the best possible efficiency and economy during summer when the heating system is in reduced operation. The bypass can be mounted before or after a heat meter.

When the unit is mounted far from hot water taps, a DHW re-circulation is recommended to increase customer comfort by shortening the waiting period during hot water tapping. DHW re-circulation sets are available as accessories for flat stations.

To guarantee customer comfort according to design parameters, mounting a flow limiter on the DHW outlet pipe is recommended.

There are 2 ways to install Danfoss flat stations:

The unit is mounted directly on the wall (on-wall mounting concept).
The unit is mounted in the wall, using recess boxes (in-wall mounting concept).
Stations can be mounted in shafts, but one of above-mentioned concepts is always used. Please ask your local Danfoss sales office for more information.

No, it is not always possible. Follow the mounting instructions exactly - or ask your local Danfoss sales office for support.

Yes, it is possible. Ask your local Danfoss sales office for more information and support.

Products

Product naming of the EvoFlat 4.0 series is as follows:

EvoFlat F1/2/3/4 – a compact and simple to operate flat station for direct radiator heating and instantaneous domestic hot water with an innovative self-acting TPC – M controller for control of heating and DHW temperature. Digit behind the name shows the type of HEX:

  • type 1 for XB05H 36 (up to 45kW)
  • type 2 for XB05H 46 (up to 53kW)
  • type 3 for XB05H 54 (up to 60kW)
  • type 4 for XB05H 70 (up to 80kW)

EvoFlat M1/2/3/4 – a compact and simple to operate flat station for direct heating with mixing loop and instantaneous domestic hot water with an innovative self-acting TPC – M controller for control of heating and DHW temperature. Digit behind the name shows the type of HEX:

  • type 1 for XB05H 36 (up to 45kW)
  • type 2 for XB05H 46 (up to 53kW)
  • type 3 for XB05H 54 (up to 60kW)
  • type 4 for XB05H 70 (up to 80kW)

Both product types cover up to 17,5 kW for heating

  • Two differential pressure controllers for heating and domestic hot water

  • EPP insulation box

  • Composite body

  • Danfoss XB05H Heat exchanger

  • Valves and sensors for heating and DHW control

  • Summer by-pass

  • Zone valve

  • Air vent

The main parts are:

  • Room thermostat

  • Safety valve

  • Ball valves (60mm)

  • Ball valves with connection for pressure gauge ¾”(120mm)

  • Energy and water meters (3/4” x 110mm)

  • Mounting rail for mount-on-wall variant

  • Recess box for build-in variant incl. mounting rail

  • High-temperature connection set

  • Circulation set

  • SG, SGC and SGCI distribution units

  • Reduced heat loss due to insulation cover, insulated back-plate and less radiating surfaces inside the station.
  • No need of re-tightening after transportation or other vibrations due to the improved Click-fit connections
  • Two separate ΔP controllers for DHW and HE bring best-in-class hydronic balancing for stable hot water temperatures and energy efficient heating operation
  • New HEX and hot water controller for up to 70 kW hot water capacity at high tapping rate
  • Prepared for low supply temperature
  • Easy access during installation and maintenance, for example for heat exchanger
  • Lightweight PPS composite body

Build-in or wall-mounted variant