FH Guide - English - Heavy

Energy Efficient and Comfortable Floor Heating

2

INDIVIDUAL TEMPERATURE REGULATION IN

ROOMS WITH UNDERFLOOR HEATING 4

BASIC ELEMENTS FOR REGULATION

OF AN UNDERFLOOR HEATING SYSTEM 8

FLOOR CONSTRUCTIONS 12

COMBINED HEATING SYSTEMS 16

REGULATION METHODS USING

DANFOSS CONTROL SYSTEMS 18

EXAMPLES OF USE 22

PRODUCT CATALOGUE 26

Flexibility

Less energy

Optimal temperatu

re

More comfort

Perfect control

3

Preface

In recent years, underfloor heating has become

increasingly popular. This is due to the fact that

underfloor heating provides a range of opportun-

ities not offered by traditional heating methods –

in both residential and commercial buildings.

However, it is essential to regulate underfloor

heating correctly in order to make the very most

of the opportunities it provides. That is why

Danfoss has developed a versatile range of

controls that pave the way to energy savings and

optimal comfort.

This guide contains a general introduction to

setting up underfloor heating systems. It also

provides an explanation of why the option of

regulating temperature individually in the

separate rooms is so important to the optimal

utilisation of underfloor heating. Finally, the last

section of this guide contains a list of the

products in the Danfoss range for regulating

underfloor heating systems as well as a number

of examples of use.

We hope you find this guide useful.

Danfoss A/S

Individual

temperature in

each room

4

Individual temperature regulation in rooms withunderfloor heating

Activities and clothing vary from

room to room, which is why the

temperature should be adjusted

accordingly.

Typical room temperatures in a

residential building

Kitchen ~ 20 ºC

Living room ~ 20 ºC

Bathroom ~ 23 ºC

Bedroom ~ 17 ºC

Hall ~ 17 ºC

Comfort

The temperatures in the rooms in which we live

and work play an important role in our well-

being. It should not be too hot or too cold, and

the temperature must be adjusted in relation to

what we are wearing and what we are doing at

the time. For example, office workers typically

wear lighter clothes and have a lower body tem-

perature than personnel packing products in the

warehouse. The room temperature should there-

fore be higher in the areas where office workers

carry out their tasks.

Room temperature can be regulated in a number

of ways. One of the most commonly used methods

involves regulating the supply temperature to

the heat emitters – such as underfloor heating

systems, radiators and convection heaters. This

can be done using self-acting regulation

valves with fixed temperature settings. Electronic

regulators, which take into account the tempera-

ture outside can also be used. These methods

can be made even more efficient by the installa-

5

tion of a reference sensor in the room you wish

to use as the basis for regulating the supply tem-

perature.

The use of such methods allows some degree of

regulation, but it does not make it possible to

regulate temperature precisely or individually in

different rooms. Even if the same temperature is

required in all rooms, these methods are still not

the best options. This is because they do not

allow for corrections to be made to accommod-

ate the special conditions of the different rooms –

conditions such as user patterns, heat loss and

heat supply from PCs and sunlight through

windows, for example. This means that if regula-

tion of the supply temperature is the only method

used, a suitable temperature can be obtained in

some rooms, but not in others. Some rooms will

be too hot – which is not only unpleasant, but

also results in excessive energy consumption –

while others will be too cold.

In short, it is essential to be able to regulate the

temperature individually in the separate rooms to

make sure that they are all pleasant to be in, and

to save energy.

By regulating the temperature individually in the

separate rooms, it is possible to ensure that all

areas of the building are pleasant to be in as the

temperature suits the activities in each room.

This applies to both private and commercial

buildings and offers the dual benefits of optimal

comfort and minimal energy consumption.

Individual room temperature regulation ensures optimal comfortin all rooms.

6

Independent tests and simulations have been

carried out with the purpose of establishing the

importance of regulating temperature in individ-

ual rooms for people's comfort and for energy

consumption. The results vary, depending on the

house/apartment in question, its construction

and user patterns, as well as on the test method

used. However, the results are all clear on one

point – namely, they generally support the

importance of individual room temperature regu-

lation for both comfort and energy consumption.

It has been shown that energy savings of

20-40% can be made without compromising

on comfort.

Energy consumption and energy savings

The ultimate goal of temperature regulation is to

ensure maximum comfort combined with minimal

energy consumption. This means that the

heating system must constantly ensure that the

temperature is always suitable in the different

rooms, without noticeable variations. There are a

range of factors that must be taken into account,

such as the activities and clothing of the people

in the room, heat loss and heat gain through

windows, lights, computers and other sources of

heat. As a minimum, the temperature must be

regulated individually in the separate rooms or

zones.

Temperature distribution in aroom with underfloor heating.

•·································20°C

3 6 9 12 15 18 21 24

20

23

17

°C temperature

Hour (1 day)

Bathroom

Living room

Bedroom

Temperature achieved with individual room temperature regulation.

Temperature achieved without individual room temperature regulation.

Desired temperature

Desired temperature

Desired temperature

• Approximately 70% of the heat supplied by

underfloor heating is radiated heat, a form of

heating that suits people very well.

• The heating surface covers the entire floor, thus

ensuring even distribution of the heat.

• Heat loss through windows, walls and ceilings is

kept to a minimum because the underfloor

heating ensures an uniform temperature

throughout the room.

• Underfloor heating can be connected to a range

of heating sources – such as boilers, direct

district heating, district heating with heat

exchangers, solar heating and heat pumps.

Heat deviations

In all rooms, the temperature will vary from floor

to ceiling and from one end to the other. It is

important to personal well-being that these

temperature variations are minimal. In the worst

cases, major variations can lead to draughts.

By definition, underfloor heating has a large

surface for radiating heat, and so heating

requirements can be covered with only a very low

surface temperature on the floor. Underfloor

heating also makes it possible to achieve the

same temperature in all areas of the room from

the horizontal perspective. In addition, it is

possible to make sure that the difference in

temperature between floor and ceiling is typically

only 1-2 ºC (see the illustration on the previous

page).

7

8

Basic elements for regulation ofan underfloor heating system

1

2

3

4

M1

DN15PN10KV 1

M1

DN15PN10KV 1

AMV 100

M1

DN15PN10KV 1

M1

DN15PN10KV 1

AMV 100

Underfloor heating systems can be built up in a

range of ways. The illustrations below show four

typical examples of underfloor heating systems.

The systems and the components they contain

are described in more detail on the following

pages.

Heat sources

In examples 1 and 3, the heat source consists of

a boiler, while in examples 2 and 4, the heat

source is direct district heating.

The underfloor heating systems are low-tempera-

ture systems with a typical supply temperature of

30-45 °C. This means that they can be supplied

from other sources of heat such as solar heat,

heat pumps and the like.

The heat source and mixing loop can be

controlled using various types of electronic and

self-acting regulators.

In examples 3 and 4, an electronic weather

compensator (ECL) is used, while in examples 1

and 2 a self-acting flow temperature regulator

(FTC) is used to control the supply temperature.

Mixing loop

We recommend always using a mixing loop in

connection with underfloor heating as today, this

is the best way to ensure a correct and stable

supply temperature, irrespective of the heat

source used.

In example 3, a weather compensator (ECL) is

used. This regulates the supply temperature by

changing the position of the 3-way valve in the

mixing loop. This electronic regulator also con-

trols the circulation pump and starts/stops the

boiler according to heating requirements. There

are benefits to be gained by replacing the 3-way

valve with a 2-way valve on the return pipe as

shown in example 4, where the supply comes

simply from direct district heating. When using

direct district heating, it is important to fit a

differential pressure regulator ∆p (AVPL) over the

valve so that the valve works at a constant

differential pressure within the regulation range.

A number of different parameters can be chosen

for regulation – outdoor temperature, room

temperature or return temperature, for example

– depending on the type of weather compensator

(ECL) used. A weather compensator is a propor-

tional-integral (PI) regulator. This means that it

will always set itself to the desired supply tempe-

rature.

The illustrations refer to the overview on page 32.

9

In examples 1 and 2, a self-acting regulator

(FTC) is used to regulate the supply temperatu-

re. A self-acting regulator is a proportional (P)

regulator. This means that it will always regulate

with a small deviation. The scale is divided into

ºC to make it simple to set and adjust the regu-

lator. In the same way as electronic regulators

(ECL), self-acting regulators (FTC) ensure the

correct mix so that the desired supply tempera-

ture to the underfloor heating system always

remains constant, irrespective of load.

In example 2, a differential pressure regulator

∆p (AVPL) has also been fitted. This makes sure

that the differential pressure across the self-

acting regulation valve (RA-C/RA-N) remains

constant and within the regulation range.

The choice of self-acting and electronic regulators

depends on the user's needs and requirements to

the system. Electronic regulators are very flexible

regarding connections and settings, thus they are

generally more expensive to buy and to install.

Some countries have legal requirements concer-

ning the use of weather compensators for the

regulation of the supply temperature in heating

installations.

Mixing pumps (P2) are available as variable

pressure pumps (example 4) and constant

pressure pumps (examples 1, 2 and 3).

The advantage of variable pressure pumps

(example 4) is that they ensure optimal flow and

constant differential pressure. They maintain a

constant differential pressure internally and thus

also over the valves in the manifold (CFD) of the

underfloor heating system irrespective of how

many of the valves are open or closed. This is a

considerable advantage because the individual

pre-settings on the manifold valves – which

ensure the flow distribution between the different

underfloor heating circuits – are based precisely

on a constant differential pressure.

It is important to pre-set the manifold valves so

that the heat is distributed evenly to the different

rooms with underfloor heating. Variable pressure

pumps always deliver precisely the flow needed

thus reducing power consumption, and, as a

result, electricity costs.

Constant pressure pumps (examples 1, 2 and 3)

can also be used to ensure a constant differen-

tial pressure over the manifold valves to the circu-

its of the underfloor heating system if an auto-

matic bypass valve (AVDO) is fitted. When the

valves in the manifold (CFD) close, the automa-

tic bypass valve (AVDO) will open more and more

because the pressure rises when the flow through

the system falls. The pump must always be able

to cover the total flow, and therefore provides the

same output irrespective of how many valves are

open in the manifold (CFD). This means that

power consumption remains constant when

pumps of this kind are used.

10

Manifold: the underfloor heating pipes, which are

cast into the floor, are individually connected to a

valve on the manifold or distributor (CFD), which

regulates the water flow in each separate under-

floor heating circuit. The size of the manifold

chosen depends on the number of circuits used in

the installation. The manifold typically consists of

a return pipe with valves and a supply pipe. The

pre-setting can be located on either the supply

pipe or the return pipe, and both can be fitted

with end sections including draining, filling, and

air vent functions.

For underfloor heating systems with a pipe dia-

meter of 15-20 mm, it is recommended to lay a

new pipe circuit connected to a separate manifold

valve for every 25-30 m2 in large rooms. This is

to prevent excessive pressure loss and cooling in

the separate circuits. The pipes must be distribu-

ted evenly throughout the room, with each cove-

ring a similar share of the total area. For smaller

pipe diameters, the area covered by each pipe

will naturally decrease.

Thermal actuator: a thermal actuator is fitted to

each manifold valve. This opens and closes the

valve according to the heating requirement. The

actuator is controlled by a room thermostat (CFR

or FH-WT/S/P) set to the desired room tempera-

ture. In principle, this works in the same way as

a radiator thermostat, the only difference being

that in this case, all the valves are collec-

ted together in the manifold (CFD) and the

sensors in the separate rooms. If there are

several underfloor heating circuits in a room, the

room thermostat (CFR or FH-WT/S/P) can

control several outputs with associated thermal

actuators (TWA).

Pre-setting and calculating flow: the pre-setting

of the manifold (CFD), which takes care of distri-

buting the flow between the underfloor heating

circuits in the separate rooms, has an important

role to play for both comfort and the efficiency of

the regulation itself. The longest circuit demands

the greatest flow, and its pre-set position must

therefore be completely open.

Underfloor heating systems

Danfoss has a wide range of functional and effici-

ent products for regulating room temperatures in

underfloor heating systems. These include both

electronic and self-acting regulation systems. The

electronic regulation systems are available as both

wireless and hard-wired systems.

Wireless regulation system: in wireless systems

(CF-system) the thermal actuators (TWA) are

connected to the outputs on what is known as a

master regulator (CFM). Here, it is possible to

choose which output or outputs are to be regula-

ted by the different room thermostats (CFR).

When a room thermostat (CFR) "calls for" heat, a

radio signal is sent to the master regulator

(CFM), which activates the appropriate output.

A thermal actuator (TWA) then opens the associ-

ated manifold valve for the room in question. This

allows the room temperatures in the separate

rooms to be regulated individually.

Hard-wired regulation system: in principle,

traditional, hard-wired systems operate in the

same way as wireless systems. The difference is

that in these systems, the regulation is per-

formed by room thermostats (FH-WT/S/P) that acti-

vate the thermal actuators (TWA) directly on the

manifold valves. The wires from the room thermo-

stats (FH-WT/S/P) and the thermal actuators

(TWA) are connected in a connection box (FH-

WC) where it is also possible to connect a relay

(FH-WR) to the boiler or pump control and a

timer. It is also possible to use room thermostats

(FH-WS/P) and a floor sensor (FH-WF) to regula-

te the surface temperature of the floor.

Self-acting regulation system: self-acting

systems (FHV), which are designed to be built

into walls, are often used to regulate underfloor

heating in a single room – such as a bathroom or

utility room. Regulation can be carried out on the

basis of the room temperature or the return tem-

perature from the underfloor heating circuit,

depending on whether you would like a constant

temperature in the room or a constant surface

temperature on the floor.

11

Calculation of the flow (Q) in underfloor heating

circuits:

Q =

Heat

demand: value that states how much energy that

needs to be used in a room to maintain

a specific temperature. The value also

provides an indication of the ability of

the room to retain the heat supplied.

This depends on factors such as how

well the room is insulated. This value is

typically between 35 and 50 W/m2 for a

well-insulated building.

Room area: the size of the room in m2.

∆T: cooling over the underfloor heating

circuit – typically 5 ºC in residential

buildings.

*1.16 Conversion factor.

In the following section, we will examine an example

involving an installation covering four rooms of 25, 18,

12 and 7 m2. The heating demand has been set at 40

W/m2 and cooling at 5°C.

The first step is to calculate the flow to the largest room

(25 m2):

Q25 = = 172 l/h

Next, we calculate the flows to the other rooms:

Q18 = = 124 l/h,

Q12 = = 83 l/h and

Q7 = = 48 l/h

The calculated values for Q and the applicable differential

pressure are then entered into the capacity diagram for

the manifold (CFD) to find the pre-setting values.

Heat demand x room area

∆T x 1,16*

40 x 25

5 x 1,16

40 x 18

5 x 1,16

40 x 12

5 x 1,16

40 x 7

5 x 1,16

System not in balance.

System in balance.

12

When designing the floor, it is important to take

into account a range of factors that affect the

efficiency and comfort level of the underfloor

heating system. These include level of insulation,

layout pattern, pipe dimension, distance between

the pipes, installation depth and cooling over the

circuits. The surface temperature must be evenly

distributed over the entire floor area to ensure

optimal comfort.

Layout patterns

The choice of layout pattern depends on the

chosen method of regulation – electronic (On/Off

or timed pulse modulation) or self-acting

(P-regulator).

b) Double parallel pattern.

a) Double parallel spiral pattern.

There are three typical layout patterns:

The double parallel spiral pattern (figure a) can

be laid from the middle outwards or from the

point where the pipes enter the room. The supply

and return pipes are laid at the same time. The

supply pipe should be the one closest to the

exterior wall. The pipes are laid parallel to the

walls and with the same length proportions. This

pattern provides optimal distribution of the heat

across the floor as the supply and return pipes lie

side by side. This pattern should always be used

for systems with self-acting regulators, where the

flow varies depending on the deviation in tempe-

rature. The pattern is also ideal for systems

involving electronic regulation, but the other

patterns can be used for such systems, too.

When laying the double parallel pattern (figure

b), the supply pipe is installed first, with

double spacing. At the end of the pattern, the

pipe is bent 180º and the return pipe is then laid

in the gaps between the supply pipe so that every

other section switches between a cold return area

and a hot supply area. This double parallel pat-

tern distributes the heat better than the single

parallel pattern.

The single parallel pattern (figure c) should only

be used for installations with electronic regula-

tors that control on the basis of On/Off or timed

pulse modulation. It should never be used for

systems with self-acting regulators.

Floor constructions

c) Single parallel pattern.

13

Correct distance between pipes and correct installation depth.

Excessive distance betweens pipesand insufficient installation depth.

Timed pulse modulation completely opens the

manifold valve and then closes it completely after

a period that depends on the deviation from the

desired room temperature. On/Off regulation

opens the manifold valve completely when the

room temperature falls below the desired level,

and then closes it again when the room tempera-

ture is as desired. The flow in the underfloor

heating pipes is thus so great when heat is

"called for" that the temperature drop across the

pipes is minimal and therefore does not affect

comfort.

Cold zones

It is a good idea to lay underfloor heating pipes

closer together in those areas of the room that

contain "cold zones". These are typically located

near large window sections, sliding doors and the

like. In such zones, the distance between pipes

with a diameter of 15-20 mm should not be less

than 50 mm and the total width of the layout

pattern in the cold zone should not exceed

300-500 mm out of consideration for the overall

pressure drop across the circuit.

Pipe dimensions

Underfloor heating pipes supply heat to the floor

through their surfaces. The area of the surface,

which is dependent on the pipe dimension, thus

has an important role to play in underfloor

heating systems. If the dimension is reduced, the

supply temperature must be raised correspon-

dingly to ensure the transfer of the same amount

of energy. Another option, however, is to reduce

the distance between the pipes, thus

increasing the total length of the pipe.

Remember that pressure drop increases in

relation to the length of the pipe.

Resistance in the pipes is affected by the pipe

dimension, so pressure drop problems can occur

if the diameter of the pipes is too small, or if the

pipes themselves are too long. Today it is typical

recommended using pipes with an exterior dia-

meter of 15-20 mm and a maximum length of

100-120 m. This corresponds to an area of

approximately 25-30 m2 per circuit.

Distance between pipes and installation depth

If the distance between the pipes is too great, the

temperature will be unevenly distributed across

the floor. This means that the floor will be warm

right over the pipes but cold in between them.

The same applies if the pipes are laid too close to

the surface of the concrete.

A pipe diameter of 15-20 mm, a distance of 250

or 300 mm and an installation depth of 30-90

mm (in concrete) will ensure an uniform surface

temperature. For installations in concrete, the

uniformity of the surface temperature increases

in step with the installation depth, however, the

reaction time of the floor is equally increased.

14

Wooden floors

Wooden floors and heat emission panels/plates

are normally sold with instructions stating the

recommended pipe dimensions and distance

between pipes for underfloor heating circuits.

Pipes are installed directly beneath the wooden

floor itself, and as wood is a very poor heat con-

ductor, it is necessary to install heat emission

panels/plates. Most of these panels/plates are

supplied ready to fit with grooves for the under-

floor heating pipes. They are generally made of

aluminium, which spreads the heat evenly across

the entire floor. Today, heat emission panels/

plates are very efficient, and underfloor heating

pipes with a diameter of 15-20 mm can be laid

with a distance of 250 or 300 mm between them.

The thickness of wooden floor constructions can

vary, so the supply temperature will have to be

raised or lowered correspondingly. Here, it is

important to follow any guidelines from

the manufacturer of the wooden floor concerning

maximum surface temperature. Otherwise,

there is a risk of causing permanent damage to

the wooden floor. The supply temperature will

typically be 10-15 °C higher than the maximum

surface temperature, depending on construction

dimensions and heating requirements.

Wooden floors can be installed with underfloor

heating in many different ways, so it is important

to consult professional fitters for advice when

dimensioning and installing the systems. It is

also important to ensure that such floors are laid

correctly and in accordance with all the appli-

cable laws and regulations. It is especially impor-

tant to make sure that there is sufficient insula-

tion under the pipes to ensure optimal comfort

and energy efficiency.

Concrete floors

When installing underfloor heating in concrete

constructions, there should be at least 30 mm of

concrete above the underfloor heating pipes with

a dimension of 15-20 mm. This will ensure an

even distribution of heat throughout the floor. If

the pipes – with a distance between the pipes of

250-300 mm – are not installed at sufficient

depth, there is a risk of temperature variations in

the floor surface.

It is also important to make sure that there is a

layer of concrete under the pipes. This can be

done by laying a steel grid or similar and tying the

pipes to it. It is then simply a matter of using

spacer blocks or similar to raise the grid slightly

to allow the concrete to flow under the pipes

during the pouring process. The advantage of this

method is that the pipes are completely enclosed

in the concrete and therefore cannot expand

when heated, as this may eventually result in

leaks or burst pipes. At the same time, this

method ensures the best possible transfer of heat

to the concrete – and thus to the floor.

Concrete transfers heat better than wood, so it is

not necessary to use any form of heat conductor.

Generally speaking, concrete floors allow the

application of a lower supply temperature. If the

depth of concrete above the pipes is 30-90 mm,

the supply temperature can generally be set to

Example of a tiled concrete floor construction.Example of a wooden floor construction.

15

30-35ºC for normal heating requirements.

Concrete floors are normally finished with tiles,

linoleum, wood or carpet, and the optimal sur-

face temperature will be 19-29ºC (30-33ºC in

bathrooms).

Concrete constructions with underfloor heating

can be built up in several ways (see the illustra-

tion below).

Cooling across underfloor heating circuits

Cooling is equivalent to the difference in tempe-

rature between the supply and return flow in the

pipes and it influences a number of different factors.

Underfloor heating in normal residential applica-

tions is typically dimensioned for cooling of 5ºC

because this results in an uniform floor surface

temperature and a pleasant indoor climate.

Cooling is one of the reasons why it is necessary

to use double parallel patterns for underfloor

heating pipes, when using self-acting regulators

to ensure that temperature differences are not

transferred to the floor surface. However, this

does not apply to the same extent for systems

involving electronic regulation as the flow in such

systems is more constant and temperature diffe-

rences are not as noticeable.

In warehouses, sports halls, production facilities

and other rooms where the demand for comfort

is not normally as high as in residential buildings,

a higher level of cooling is acceptable. Doubling

the cooling will halve the flow, thus cutting the

necessary effect for the pump correspondingly.

Insulation

It is important to choose the right insulation as

early as the construction stage. This will help to

optimise the energy efficiency and comfort level

of the underfloor heating. Choosing the right

level of insulation will also reduce heating costs

throughout the lifetime of the building. The

relatively modest extra costs linked to using

sufficient insulation in the building phase will be

covered several times in the long term.

The supply and return flows of the underfloor

heating pipes must be insulated at the points

where they are led through adjoining rooms to

minimise heat loss and to ensure that these

adjoining rooms are not heated. If they are not

insulated correctly, it will also be difficult to regu-

late the temperature of separate rooms individu-

ally, and thus to save energy. Pipes must always

be laid within the weather screen to prevent

unnecessary heat loss.

It is also important to put plenty of insulation

under the pipes and along the edges of the

various rooms.

Suitable insulation also has the advantage of

allowing operation with the lowest possible sup-

ply temperature by reducing heat loss in the

entire underfloor heating system. Reducing the

supply temperature by just a few degrees will

result in appreciable savings on heating costs

without adversely affecting the level of comfort.

Please note that all legal requirements on

insulation, etc. must always be followed.

The level of insulation is of considerable importance to theefficiency of underfloor heating systems.

10

20

30

40

50

60

70

80

Con

cret

e flo

or

Conc

rete

floo

r with

car

pet

16 m

m w

oode

n flo

or

22 m

m woo

den f

loor

22 mm wooden flo

or with ca

rpet

Heating demands (W/m2)

Supply temperature (ºC)

With different floor coverings, the underfloor heating system requiresdifferent supply temperatures to convey the same heat output tothe room.

16

During the past 5-10 years, underfloor heating

has become the preferred form of heating for

residential buildings in many countries. It is

therefore important to be able to regulate the

underfloor heating system considering the indoor

climate and energy utilisation.

Underfloor heating systems do not normally react

as quickly to changes in temperature, so it is not

possible to raise or lower the room temperature

significantly within relatively short periods. After

all, these systems have to heat large masses –

such as concrete floors – rather than small radia-

tors. The material used and the floor construction

itself also have roles to play with regard to the

amount of heat accumulated in the floor.

In the past, underfloor heating was generally

reserved exclusively for bathrooms and utility

rooms because these rooms typically have tiled

floors. In wet rooms, underfloor heating had two

functions: to heat the floor and to keep the floor

dry.

Today, it is common in homes to use systems that

combine underfloor heating and radiators. This is

an ideal solution as the heating of the different

rooms in the home is subject to a range of diffe-

rent requirements. For example, it is desirable to

be able to change the room temperature in hobby

rooms, guest rooms and the like quickly to make

sure that they are warm and comfortable whene-

ver they need to be used. Radiators operate with

a higher surface temperature (50-70ºC) than

heated floors (19-29ºC), so radiators are often

the best solution for rooms of this type. In addi-

tion, an increasing number of homes feature

underfloor heating on the ground floor and radi-

ators on the first floor.

It is possible to combine heating systems by, for

example, installing underfloor heating in the

kitchen, bathrooms/toilets, utility room, living

room and hallway and then using radiators in the

other rooms – hobby room, guest room, etc. This

creates a set-up that has the high comfort level

and architectural advantages of underfloor

heating along with the rapid heat-up capability of

the radiators.

Combined heating systems

AMV 100

M1

DN15PN10KV 1

M1

DN15PN10KV 1

17

Combining underfloor heating and radiators

These two heating systems require different

supply temperatures – a factor that must be

taken into consideration when planning the

installation.

In the example illustrated, an electronic weather

compensator (ECL) is used to regulate the tem-

perature of the supply flow to the radiators. This

system is regulated on the basis of the outdoor

temperature, and the supply temperature will

typically be 40-70ºC depending on the season.

The differential pressure regulator ∆p (AVPL)

makes sure that the dimensioned differential

pressure across the motor valve on the supply

side is kept constant. This is important to ensure

the balance of the system and to make sure that

the motor valve operates within the regulation

range. The underfloor heating system involves a

separate mixing loop with a self-acting flow

temperature regulator (FTC) because here,

the supply temperature must be lower – usually

30-40ºC depending on the floor construction, the

level of insulation, floor covering, etc.

The rooms in the underfloor heating system is

regulated by an electronic control system (CF or

FH-Wx) in order to ensure the best possible

indoor climate in the separate rooms as well as

optimal energy utilisation throughout the entire

system. The radiators can be fitted with Danfoss'

well-known radiator thermostats, as this part of

the heating system operates independently of the

underfloor heating system.

Underfloor heating

The illustration above shows an example of an

underfloor heating system built up according to

the same principles as used in previous illustra-

tions. The heat source is direct district heating,

and the mixing loop is controlled by a self-acting

supply flow temperatur regulator (FTC). The

pressure across the valve (RA-N/FN/C) is kept

constant by a differential pressure regulator ∆p

(AVPL). The values for setting the differential

pressure are listed in the data sheet for the

differential pressure regulator. These values are

used as the basis for the dimensioning of both

the ∆p regulator (AVPL) and the flow temperature

regulation valve (FTC + RA-N/FN/C).

The supply temperature can also be controlled by

an electronic weather compensator (ECL). In this

case, a gear motor is fitted to the 2-way valve

and a number of sensors are used.

The manifold (CFD) is connected to the separate

underfloor heating pipes that supply the rooms

according to the heat "called for" by the room

thermostats (CFR). It is important to draw a

sketch of which underfloor heating circuits are

placed in which rooms when the pipes are instal-

led. This sketch is to be used when subsequently

fitting and setting the various self-acting heating

controls, and when pre-setting the water flow for

the separate circuits in relation to the sizes of the

individual rooms. This sketch will also be very

useful if, at a later stage, holes need to be drilled

in the floor to secure furnishings or the like.

Installations of this type can be room temperature

regulated by electronic, wireless (CF system) or

hard-wired (FH-Wx) control systems.

CFM

FTC

ECL

∆ p

FTC∆ p

CFR

TWA

CFD

CFR

CFM

TWA

CFD

18

The choice of regulation method for individual

room temperature control depends on how many

rooms the underfloor heating system is to cover,

and on how large these rooms are. In addition, it

is important to decide on the regulation method

before starting work on the floor construction as,

this may well be a defining factor in determining

the optimal layout pattern for the underfloor heating

pipes, for example.

Electronic regulation systems

Wireless system

The illustration above shows Danfoss' wireless

CF system. The master regulator (CFM) in the

system makes sure that the radio signals from

the room thermostats (CFR) are processed, and

that the necessary regulations are implemented.

A room thermostat is fitted in each room.

If the room temperature deviates from the tem-

perature setting of a given room thermostat

(CFR) this thermostat sends a wireless radio

signal to the master regulator (CFM), which, in

turn, either opens or closes the flow to the under-

floor heating circuit in the room in question. This

regulation is carried out via a thermal actuator

(TWA) fitted to the associated valve in the mani-

fold (CFD).

The wireless room thermostats (CFR) are easy to

fit as they do not need to be connected via wires

or cables. It is also possible to set back the

temperature manually on the room thermostats

(CFR).

The manifold (CFD) consists of a supply pipe and

a return pipe. The flow to the separate under-

floor heating circuits can be pre-set in the supply

side of manifold. In this way, it is possible to

ensure that all the underfloor heating circuits are

pre-set for precisely the right volume of water

(flow). The regulation valves for the underfloor

heating circuits are located in the return side of

the manifold, and every valve is equipped with a

thermal actuator (TWA), which is controlled by

the master regulator (CFM).

If required, the system can also be fitted with a

zone regulator (CFZ), which can divide the regu-

lation of the different rooms into as many as six

zones. The zone regulator (CFZ) is connected to

the master regulator (CFM) via a bus cable. The

zone regulator (CFZ) can send signals about, for

example, running at a lower room temperature in

the different zones at different times – such as

during holidays.

The master regulator (CFM) has eight outputs

and can therefore control eight separate room

temperatures at the same time. The room ther-

mostats (CFR) can be assigned to multiple out-

puts in large rooms with more underfloor heating

circuits.

The system can be extended through one or two

slave regulators (CFS) with eight outputs each.

This means the system can comprise up to 24

outputs. In office environments, for example,

where it may be necessary to use even more

room thermostats (CFR), it is possible to fit add-

itional master regulators (CFM) and thus to

increase the number of outputs even further.

The outputs of the slave regulators (CFS) are

equivalent to those of the master regulator

(CFM), but the slave regulators do not contain

radio receivers and therefore cannot be used on

their own. The master and slave regulators

Regulation methods using Danfoss control systems

CFZ

TWA

CFD

CFM

CFR

CFZ

CFM

CFS 1

1 - 8

9 - 16

17 - 24

CFS 2

CFRCFDwith TWA

19

(CFM/S) are connected through a bus cable and

all the room thermostats (CFR) are assigned to

outputs via the master regulator (CFM). The

system is easy to install as there is no need to

run wires to every single room. All that is

required is the installation of a wireless room

thermostat (CFR) assigned to the master regula-

tor (CFM). The costs associated with installing

the wireless system (CF system) are significantly

lower than the installation costs for hard-wired

systems (FH-Wx).

Hard-wired system

Danfoss also supplies a 24V hard-wired electronic

solution (FH-Wx) with an integrated transformer

for direct connection to a 230V power supply (see

illustration). In the hard-wired system, each

individual room thermostat (FH-WT/S/P) is con-

nected to the connection box (FH-WC) via wires.

In the connection box (FH-WC), the wires from

the thermal actuators (TWA) are connected to

the associated wires from the room thermostats

(FH-WT/S/P). It is possible to connect up to

12 room thermostats. A boiler or pump relay

FH-WT FH-WS

Remotesensor (optional)

Remotesensor(optional)

FH-WP

FH-WC

Connection box with 12 inputs/outputs and timer

(FH-WR) can also be fitted. This uses a potential-

free switch to start and stop the boiler or pump.

Finally, a timer module/kit (FH-WN) can be fitted

if required. This unit divides the rooms in the

building into two zones and controls them on the

basis of different user patterns – such as tempera-

ture set back.

The room thermostats (FH-WS/P) can be connec-

ted to an external floor sensor that can be used

for regulation on the basis of the floor tempera-

ture, thus overriding the room temperature set-

ting. This option is often used in bathrooms, etc.

The cost price of a hard-wired system is often

lower than for a wireless system, but the instal-

lation costs are higher due to the time needed to

run the wires from room to room.

All three patterns for laying out underfloor

heating pipes mentioned in the "Floor construc-

tions" section can be used for electronic regula-

tion systems. However, there can be advantages

in choosing the double parallel spiral pattern.

M1

DN15PN10KV 1

M1

DN15PN10KV 1

Min

IkPa/r

20

Self-acting regulation systems

Two models of the self-acting regulator (FHV) are

available for building into walls. One model (FHV-A)

regulates according to room temperature while

the other (FHV-R) does so on the basis of the

return temperature in the underfloor heating

circuit and must therefore be fitted in the return

pipe (see illustration). Choosing the model that

regulates on the basis of the temperature of the

return water (FHV-R), please note that – in con-

trast to model FHV-A – the regulator will never

shut off the heat supply completely, even though

there may be free heat in the room, as

it is designed to keep the floor temperature

constant.

The regulators close as the temperature rises,

which, in the case of the FHV-R model, means

that when the water has transferred its heat to

the floor and therefore has been cooled to below

the pre-set temperature, the regulator will let the

water pass. At the same time, new hot water will

be let into the circuit from the supply side so the

temperature begins to rise again, and when it

reaches the FHV-R it will begin to close slightly

once more. The whole process then starts again.

If the self-acting regulator (FHV) is used

without a recommended mixing loop – because

there is only underfloor heating connected to a

radiator in an utility room, for example – it is

important to make sure that you do not exceed

the maximum allowable temperature for the

floor.

Self-acting regulators (FHV) reduce the flow in

the circuit proportionally to the deviation from

the set temperature. It is therefore important to

take this into account when selecting the layout

pattern – which should ideally be of the double

parallel spiral pattern type.

It may be a good idea to lay the first metres of

the underfloor heating supply pipe along an

exterior wall, as it is in such areas that the

radiant cooling is highest.

Self-acting regulators (FHV) are particularly well-

suited to regulate underfloor heating temperature

in single rooms, such as bathrooms and utility

rooms.

FHV-R

∆pFTC

M1

DN15PN10KV 1

M1

DN15PN10KV 1

Min

IkPa/r

FHV-A

FTC∆p

21

Product Item no. Description

CFM-24 088H0041 Master regulator, 24 V outputs

CFR 088H0203 Wireless room thermostat, battery-powered, calls for heat via radio signals

CFZ 088H0004 Zone regulator

CFD 4+4 088H1004 Manifold with four regulation valves

TWA-A 088H3110 Thermal actuator, RA valve connection, 24 V, no-current closing (NC)

22

Examples of use

Areas of use and description

The wireless CF system is usually used in instal-

lations with individual room temperature regula-

tion of several rooms that have underfloor

heating. It is likewise commonly used in instal-

lations that combine underfloor heating and radia-

tors, and it is ideal for renovation projects, as it

is generally cheaper and easier to install than

hard-wired systems. The battery-powered room

thermostats are very sensitive and react – via

radio signals – to very small deviations from the

desired room temperature. The system has a

simple, stylish and functional design that blends

seamlessly into its surroundings. The system

makes no specific requirements to the layout of

the underfloor heating circuits as the flow is con-

stant. The supply temperature is controlled via

the motor valve by a weather compensator. When

setting the supply temperature, remember to

take into account the floor design and surface

covering.

Components and functions

CFM: Electronic master regulator with outputs for

eight thermal actuators. The master regulator

receives and processes the radio signals from the

room thermostats. It can be extended with up to

two slave regulators (CFS) with eight outputs

each.

CFR: Wireless room thermostat for fitting in each

room where the room temperature is to be con-

trolled by the regulation system. This regulation

is done via radio signals to the master regulator.

CFZ: Zone regulator (optional) is used for time

and zone control (temperature reduction during

pre-defined periods) of the underfloor heating

system by dividing the rooms into zones.

TWA:Thermal actuator connected by a wire to an

output on the master regulator. When heat is

"called for" the actuator opens the regulation

valve in the manifold.

CFD: Manifold connected to the underfloor

heating pipes. Available in a range of sizes with

various numbers of regulation valves.

M1

DN15PN10KV 1

M1

DN15PN10KV 1

AMV 100

CFM

CFD

TWA

CFR

Wirelessregulationsystem

ECL

∆p

CFZ

23


The hard-wired FH-Wx system is typically used

for individual room temperature regulation of

underfloor heating in several different rooms. The

system also makes it possible to regulate on the

basis of floor temperature and to override room

temperature control via a remote sensor in the

floor (often used in bathrooms, for example). The

system can be used in underfloor heating instal-

lations and in combined systems – consisting of

radiators and underfloor heating, for example.

The system makes no specific requirements to

the layout of the underfloor heating circuits as

the flow is constant. The self-acting flow

temperature regulator (FTC) can be set to the

desired supply temperature when initially

commissioning the installation. Remember that

the supply temperature is subject to different

requirements in combined heating systems.


FH-WC: Electronic connection box in which room

thermostats are connected with up to 12 thermal

actuators. Available with or without a timer module

that makes it possible to divide areas into two zones

with different timing patterns. A relay for boiler or

pump control is available as an accessory.

FH-WT/S/P: Hard-wired thermostats. Available

in a standard version and a featured version with

a manual local night set-back feature and the

option of connecting a floor sensor (a tamper-

proof model of the latter for institutions etc. is

also available).

TWA: Thermal actuator connected by a wire to

an output on the connection box. When heat is

"called for" the actuator opens the regulation

valve in the manifold.

CFD: Manifold connected to the underfloor

heating pipes. Available in a range of sizes with

various numbers of regulation valves.


FH-WC 088H0020 Connection box, 12 x 24 V outputs and integrated timer module

FH-WT 088H0022 Wired room thermostat, standard model

FH-WP 088H0023 Wired room thermostat, institution model

FH-WS 088H0024 Wired room thermostat, featured model

FH-WF 088H0025 Floor sensor

CFD 4+4 088H1004 Manifold with four regulation valves

TWA-A 088H3110 Thermal actuator, RA valve connection, 24 V, no-current closing (NC)

FH-WC

FTC∆p

TWA

CFD

FH-WT/S/P

Hard-wiredregulationsystem

24


This system is designed for controlling underfloor

heating in individual rooms such as bathrooms

and utility rooms, where a constant floor tempe-

rature is required. It is also often used in com-

bined installations involving radiators and under-

floor heating in one or more rooms, each with its

own individual control. It is important to lay out

the underfloor heating pipe in a double parallel

pattern – ideally a spiral. The self-acting return

temperature regulator is fitted in the return flow

as shown in the illustration.


FHV-R: Used with a FJVR thermostat to regulate

the temperature on the surface of the floor on the

basis of the return temperature in the underfloor

heating pipe.

M1

DN15PN10KV 1

M1

DN15PN10KV 1


FHV-R 003L1000 Underfloor heating valve for FJVR thermostat, for fitting in the return flow

FJVR 003L1040 FJVR thermostat, 10-50 °C, return temperature limiter

FTC∆p

FHV-R

Self-actingregulationsystem

25


This system is designed for underfloor heating in

individual rooms where a constant room tempe-

rature is required. The regulation is self-acting

and it is therefore important that the underfloor

heating pipe is laid out in a double parallel

pattern – ideally a spiral. The self-acting room

temperature regulator is fitted in the supply flow

as shown in the illustration. Please note that

the regulation will result in a decrease in floor

temperature if the room receives free heat from

the sun or other sources of heat.


FHV-A: Used with a radiator thermostat to

regulate the room temperature in a single room.


FHV-A 003L1001 Underfloor heating valve for RA 2000 thermostats, for fitting in the supply flow

RA 2000 Various versions RA 2000 radiator thermostat

M1

DN15PN10KV 1

M1

DN15PN10KV 1

FHV-A

FTC∆p

Self-actingregulationsystem

26

Product catalogue

Product Description Item no.

CFM-24(1) Master regulator, 8 x 24V outputs incl. installation cable 088H0041

CFS-24(1) Slave regulator, 8 x 24V outputs incl. bus cable 088H0042

CFM-230 Master regulator, 8 x 230V outputs incl. installation cable 088H0001

CFS-230 Slave regulator, 8 x 230V outputs incl. bus cable 088H0002

CFR Room thermostat, wireless (battery-powered) 088H0203

CFZ Zone regulator, incl. bus cable 088H0004

CF system - wireless

Is used for individual room temperature regulation in residential buildings with underfloor heating and can be adap-

ted to installations of all sizes. The room thermostats send data via radio signals, which allow maximum freedom

of choice for fitting and installation. This also makes the system ideal in connection with renovation and retrofit. The

battery-powered room thermostats are very sensitive and react to even minor deviations from the desired room

temperatures. As standard, the master regulator can be associated to a maximum of eight room thermostats and the

system can be extended through the addition of up to two slave regulators (each with eight outputs). Also, a zone regu-

lator can be added to provide the option of dividing the rooms up into time or temperature zones (for night set-back or

reducing the temperature during holidays, etc.). The system is typically connected with a CFD manifold and TWA-A

thermal actuators. The system has a simple, stylish and functional design that blends seamlessly into its surroundings.

Electronic regulators for controlling individual room temperatures in underfloor

heating systems

Accessories Description Item no.

Bus cable 1 m, used to connect CFM, CFS, CFZ 088H0051

Bus cable 5 m, used to connect CFM, CFS, CFZ 088H0055

Installation cable Used for assigning CFR to CFM 088H0092

External antenna 1.8 m 088H0093




FH-WC Connection box, 12 x 24V outputs 088H0019

FH-WC Connection box, 12 x 24V outputs, with integrated timer module 088H0020

FH-WT Standard room thermostat, 24V 088H0022

FH-WS Featured room thermostat, 24V, with manual local night set-back option 088H0024

and the possibility to connect a floor sensor, FH-WF

FH-WP Tamperproof version of FH-WS for institutions, etc. 088H0023

Accessories Description Item no.

FH-WN Timer module/kit for subsequent installation on FH-WC (088H0019) 088H0021

FH-WF Floor sensor, 3 m, can be used with FH-WS and FH-WP 088H0025

FH-WR Pump/boiler relay 088H0026

FH-Wx system - hard-wired

Is typically used for individual room temperature regulation of underfloor heating in multiple rooms and can be con-

nected to up to 12 room thermostats. Available with or without a timer module that makes it possible to divide areas

into two zones with different timing patterns. A relay for boiler or pump control is available as an accessory. The

system also makes it possible to regulate on the basis of floor temperature - with room temperature override - via

a remote sensor in the floor (used in bathrooms, for example). The system is typically connected with a CFD mani-

fold and TWA-A thermal actuators. Simple, stylish and functional design that blends seamlessly into its surroundings.

(1) CFM-24 & CFS-24 have integrated transformers and can be connected directly to a 230V power supply.

27

TWA thermal actuator

A range of versions of TWA thermal actuators – which open and close the regulation valves – are available for use

with both Danfoss' CFD manifold and RA valves, as well as with other manifold and valve products. The thermal

actuators all feature visual and touchable position indicators. Available with 24V or 230V supply voltage and in no-

current closed (NC) and no-current open (NO) versions. The no-current closed (NC) versions are very easy to fit as

a small locking split pin, which is easy to remove after installation, fixes the resistance of the spring force.


FH-WT 230 Room thermostat, 230V 088H0127


CFD 2+2 Supply+return flow sections, pre-setting and regulation valves (RA connection), 2 circuits 088H1002











CFE 2 x end pieces with draining, filling, and automatic air vent functions 088H1020

Connection pieces 2 x connection pieces for assembling different manifold sizes 088H1021

Reduction pieces 2 x reduction pieces, G 5/4" A x Rp 3/4" 088H1034

Reduction pieces 2 x reduction pieces, G 5/4" A x Rp 1" 088H1044

Assembly brackets 2 x assembly brackets for mounting the manifold on a wall 088H1022

CFD underfloor heating manifold

The CFD manifold is used for regulating underfloor heating systems involving multiple underfloor heating circuits.

Available with 2-12 circuits which can all be combined by connection pieces. Considering hydraulic balance, it is

possible to pre-set the flow in the manifold supply side to the separate circuits. The regulation valves are

fitted in the return flow, where TWA-A thermal actuators can be fitted and connected to one of Danfoss' electronic

room temperature regulation systems – a CF (wireless) or FH-Wx (hard-wired) system.

FH-WT 230V room thermostat - hard-wired

Danfoss also offers a hard-wired 230V thermostat that can be connected directly to TWA thermal actuators (230V)

fitted to a CFD manifold or valve.


TWA-A Thermal actuator, 24V, NC, Danfoss RA connection 088H3110

TWA-A Thermal actuator, 24V, NC/S, end switch, Danfoss RA connection 088H3114

TWA-A Thermal actuator, 24V, NO, Danfoss RA connection 088H3111

TWA-A Thermal actuator, 230V, NC, Danfoss RA connection 088H3112

TWA-A Thermal actuator, 230V, NO, Danfoss RA connection 088H3113

TWA-K Thermal actuator, 24V, NC, connection to Heimeier/Oventrop/MNG valve types (2) 088H3140

TWA-K Thermal actuator, 24V, NO, connection to Heimeier/Oventrop/MNG valve types (2) 088H3141

TWA-K Thermal actuator, 230V, NC, connection to Heimeier/Oventrop/MNG valve types (2) 088H3142

TWA-K Thermal actuator, 230V, NO, connection to Heimeier/Oventrop/MNG valve types (2) 088H3143

(2) M30x1.5 mm valve connection and similar closing measure.

Compression fittings for CFD manifold

Compression fittings are important components in the context of assembling and installing underfloor heating pipes

on CFD manifolds or other Danfoss RA valves. Danfoss supplies a comprehensive range of compression fittings for

many different types of underfloor heating pipes – such as PEX plastic pipes or ALU-PEX pipes.

FHV-R regulator (floor temperature regulation)

The FHV-R self-acting regulator valve is a simple and elegant solution for building into walls. In combination with a

FJVR thermostat, it controls the floor temperature by regulating the return flow temperature through the underfloor

heating pipe. It is often used in systems that combine underfloor heating and radiators – where, for example, a con-

stant floor surface temperature is required in the bathroom or utility room. Available with a round or squared front

cover.

FHV-A regulator (room temperature regulation)

The FHV-A self-acting regulator valve is a simple and elegant solution for building into walls. Used with conventional

radiator thermostats to control room temperature and available with a round or square front cover.

28

Self-acting regulators for controlling individual room or floor temperatures

in underfloor heating systems


Compression fittings G 3/4", diameter 12 x 2 mm, for PEX plastic pipes 013G4152


Compression fittings G 3/4", diameter 15 x 2.5 mm, for PEX plastic pipes 013G4155






Compression fittings G 3/4", diameter 12 x 2 mm, for ALU-PEX pipes 013G4182






FHV-R Underfloor heating valve for FJVR, 3/4" connection, round front cover, air vent 003L1000

FHV-R Underfloor heating valve for FJVR, 3/4" connection, squared front cover, air vent 003L1006

FHV-R Underfloor heating valve for FJVR, 3/4" connection, round front cover, air vent 003L1015

+ draining and filling options

FJVR Return temperature limiter, 10-50 °C 003L1040


FHV-A Underfloor heating valve for RA 2000 radiator thermostats, 3/4" connection, 003L1001

round front cover, air vent

FHV-A Underfloor heating valve for RA 2000 radiator thermostats, 3/4" connection, 003L1007

squared front cover, air vent

RA 2000 RA 2000 radiator thermostat Various versions

29


ECL Comfort Weather compensator for boiler or district heating installation, incl. timer and socket, 230V 087B6828

100 M regulator Weather compensator for boiler or district heating installation, without timer, socket, 24V 087B1114

Analogue clock Analogue clock for ECL Comfort 100 M 087B1147

Socket Socket for ECL 100 087B1154

ECL Comfort 200 Regulator including digital clock and socket, 230 V 087B6868

(Program package to be ordered separately) Regulator including digital clock, without socket, 24 V 087B1124

ECL Comfort 300 Regulator including digital clock and socket, 230 V 087B6869

(Program package to be ordered separately) Regulator including digital clock, without socket, 24 V 087B1134

Socket Socket for ECL 200 and 300 087B1149

ECA 61 Remote setting panel with built-in sensor for ECL Comfort 087B1141

ESM 10 Room temperature sensor 087B1164

ESM T Exterior temperature sensor 084N1012

ESM 11 Installation temperature sensor 087B1165

ECL Comfort

Regulators that can be used both as weather compensators and constant temperature regulators. Available in a range

of versions to suit all needs. The settings and parameters of the regulators can be remotely controlled via a panel

with a bus port. The regulators can be used with 3-point gear motors (types AMV and AMB) and with On/Off ther-

mal motors (type ABV). ECL is available in 24V and 230V models with PT1000/0 °C sensors.

Electronic regulators for supply temperature control


FTC Self-acting flow temperature regulator, 15-50°C 013G5081

Valves

RA-C 15 Straight valve with integrated pre-setting, Kv = 0.30-0.90 m3/h 013G3094

RA-C 20 Straight valve with integrated pre-setting, Kv = 0.80-2.60 m3/h 013G3096

RA-N Straight valve with integrated pre-setting Various versions

RA-FN Straight valve without pre-setting Various versions

FTC with attachable surface sensor

Flow temperature regulator for underfloor heating system with two-way valves of type RA-N, RA-FN or RA-C.

The choice of valve depends on flow requirements. The FTC is equipped with a surface sensor that is easy to fit on

the supply pipe.

Self-acting regulators for supply temperature control

For additional details, see data sheets for the individual products.

30

RAVK with immersion sensor

Supply temperature regulator that matches type RAV/VMT 2-way valves and type VMV 3-way valves.


RAVK Self-acting flow temperature regulator, 25-65°C 013U8063

Valves

RAV 10/8 2-way valve for RAVK and type ABV thermal actuator, Kvs = 1.2 013U0012




VMT 15/8 2-way valve for RAVK and type ABV thermal actuator, Kvs = 1.5 065F0115



VMV 15 3-way valve for RAVK and type ABV thermal actuator, Kvs = 2.5 065F0015

VMV 20 3-way valve for RAVK and type ABV thermal actuator, Kvs = 4.0 065F0020

For additional details, see data sheets for the individual products.


AVDO 15 Self-acting pressure regulator, G 3/4" A connection 003L6020

AVDO 20 Self-acting pressure regulator, G 1" A connection 003L6025

AVDO 25 Self-acting pressure regulator, G 5/4" A connection 003L6030

AVDO 15 Self-acting pressure regulator, Rp 1/2" - R 1/2" connection 003L6018

AVDO 20 Self-acting pressure regulator, Rp 3/4" - R 3/4" connection 003L6023

AVDO 25 Self-acting pressure regulator, Rp 1" - R 1" connection 003L6028

AVDO

Self-acting automatic bypass regulator that can be used in underfloor heating systems having a constant pressure

pump. The AVDO shown here is a self-acting differential pressure regulator for fitting in a bypass.

Accessories


ATC Safety thermostat, electro-mechanical, surface sensor 041E0010

ATC - safety thermostat

Thermostat that can be fitted to pipes and set as required. Often used as a safety thermostat for disconnecting the

boiler or pump in the event of errors in the installation.

31

32

Basic elements for regulation ofan underfloor heating system

1 23 4

M1

DN15PN10KV 1

M1

DN15PN10KV 1

AMV 100

M1

DN15PN10KV 1

M1

DN15PN10KV 1

AMV 100

Heat source Mixing loop Underfloor heating system Heat source Mixing loop Underfloor heating system

FTC FTC

P2

P2

ECL ECL

P2

P2

∆ p

∆ p

TWAAVDOAVDO

TWA

CFD CFD

TWA TWAAVDO

CFD CFD

33

www.danfoss.com

Documents

FH Guide - English - Heavy