• Welcome to the ABB i-bus KNX training programme from ABB STOTZ KONTAKT.

In this module you will learn about room climate control with ABB i-bus KNX. If you

need help navigating through this module, please click the Help button. To view the

presenter notes as text, click the Notes button in the bottom right-hand corner. You

can also download this presentation in printable format by clicking the attachment

button in the top right-hand corner.

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• At the end of the first part of this eLearning module we will have detailed

knowledge of

• the capabilities of KNX in heating, ventilation and climate control applications,

• ABB's product range for these applications and

• ABB solutions for individual room heating control and for operating blower

convectors, which are also known as Fan Coil Units.

ABB products and solutions for room climate control will be in the second part of

the unit.

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• ABB i-bus KNX makes it possible to integrate room temperature control, ventilation

and climate control into a networked building infrastructure.

• A modern building can only be operated efficiently when all the technical aspects in

a building (lighting, sun protection, heating- ventilation-climate ) are networked and

work in perfect harmony.

• This applies in particular to the energy efficiency, but also to the management,

maintenance and the flexibility needed when requirements change.

• Most of the energy consumption in a building can be traced back to the climate

control, depending of course on climatic region and season and the different

focuses (heating, cooling, ventilation ) and applications (Fan Coil Unit, hot water

heating, electric heating, air conditioning, cooling systems with activation of

building units etc.).

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• Besides the heating and cooling sources themselves, artificial light and natural light

also affect the room temperature.

• People and electrical devices, such as computers, heat the room.

• Although opening windows and doors improves the quality of the air, it also

changes the temperature within the room. Walls, ceilings and windows produce a

thermal exchange with the surroundings and also with adjacent rooms inside the

building.

• The room climate in rooms for living and working plays a role in the health,

efficiency and comfort of the occupants. Besides room temperature, another

decisive factor in determining the indoor air quality and thus the room climate, is

the carbon dioxide content of the air in the room.

• In the following slides we will become acquainted with solutions to this problem

using ABB i-bus KNX.

• Next to lighting control, room climate control is the most important function in

building technology.

• The main application is the individual room control of hot water heating involving

radiators and floor heating or cooling rooms with Fan Coil Units.

• A reliable control system is a prerequisite for the efficient, comfortable use of

buildings.

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• The slide shows the unsatisfactory situation of a conventional thermostat mounted

on the radiator of a hot water heating system.

• For a pleasant room temperature the thermostat is on setting 3.

• The problem is the accuracy. Which setting corresponds to which temperature ?

• If setting 5 is activated because it is too cold in the room, although the valve is

completely open, further control is not possible.

• Normally the user forgets to reset the old value on the thermostat, so it will

probably become too warm in the room and energy is wasted.

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• ABB’s products for KNX offer a wide range of solutions in this area

• such as room temperature controller,

• valve drives with the corresponding actuators,

• Fan Coil actuators for Fan Coil Units and valve actuators, but also special

components such as analogue inputs and outputs and

• air quality sensors for the CO2 concentration of the room.

• Using presence detectors and push buttons, the room temperature can be

controlled as needed and the sensors and actuators work extremely accurately.

• When a window is opened a magnetic reed contact initiates to close e.g. the

radiator valve.

• With a time function various temperature setpoints can be activated at specified

times, which is extremely useful in a bathroom, for instance.

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• We can take a look now at some typical solutions for temperature control with ABB

i-bus KNX. There will be a detailed version of this later in the eLearning module.

In a dwelling a room temperature controller records the temperature and,

specifying a setpoint, transmits a control value to the electronic switch actuator

controlling the thermoelectric valve drive of the floor heating circuit or drives an

electromotor valve on the radiators in the room.

• ABB’s room temperature controller also allow additional heating or cooling to be

activated.

In this room e.g. the floor heating is the basis stage and the radiator is switched on

for more rapid heating of the room when the room temperature is low.

• To save energy, when the window is opened, the window contact initiates closing of

the valve by means of ABB’s universal interface via KNX.

• Other devices on the Bus, such as push buttons or displays, give continuous

access to the control system, e.g. an operating mode switch-over from day to night

mode with a reduced setpoint.

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• In an office the demands on the room climate control are very exacting as, in many

cases, the room must be heated as well as cooled.

A supply of fresh air is also important, but opening a window for ventilation

purposes is often not foreseen.

• The room temperature controller uses a Fan Coil actuator to control the heating or

cooling valve as well as the speed of the ventilation.

• When it is necessary an electric heating unit can also be switched on with a relay.

• A condensation sensor, connected to one of the actuator’s binary inputs, raises the

setpoint on cooling or closes the valve to protect the Fan Coil Unit.

• To save energy a window contact can use the binary input in the Fan Coil actuator

to close the valve. Thanks to the bus technology with ABB i-bus KNX a conference

room in an office building can, for example, be cooled at any time via a

visualisation in the foyer.

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• The same solution can also be achieved in an hotel room with another device, the

Room Master. The Room Master also enables the control of room functions such

as lighting and blind control.

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• Let’s look at the individual components more closely:

• The room temperature controller measures the current temperature in the room

and, on the basis of the setpoint and the control algorithm, sends a control value in

a 1 or 8 Bit format to the Bus.

• The setpoint can be changed in the application, on the device itself or externally

e.g. via a visualisation.

• Besides display options such as setpoint, actual value and operating mode, control

functions are also possible on the device e.g. operating mode switch-over.

Other buttons on the thermostat enable independent functions for lighting and blind

control to be programmed, so that often no other operating elements are needed in

the room.

• ABB offers a variety of components tailored to the existing design lines: solo, triton

and priOn.

• The room temperature controller Fan Coil was designed specifically for use with

Fan Coil Units, with the buttons intended exclusively for room temperature

functions.

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• Here we have an overview of the actuators, in other words, devices for controlling

valves and fan motors. First, the components used for valves :

• Electronic switch actuator ES/S with thermoelectric or motorised valve drive

• Valve drive actuator VAA/S with thermoelectric valve drive

• Electromotor KNX valve drive ST/K

• Universal interface with electronic relay and thermoelectric valve drive

• There are also KNX devices which are deployed for use with Fan Coil Units, in

other words, which can control both valve actuation as well as multi-speed fans :

• Room Master RM/S

• Fan Coil actuators LFA /S and FCA/S

• Room Controller RC/A

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• Besides the thermoelectric valve and the electromotor KNX drive there are also

motorised valve drives without KNX-interface, the so-called 3-point valve drives.

• These are controlled by two independent contacts, whereby the Fan Coil actuator

FCA/S 1.1M and the Room Master RM/S already have the appropriate software

and hardware.

• Another motorised valve drive on the market is driven by a 0…10 V signal.

• For this we have ABB's Fan Coil Actuator FCA/S 1.2.2.1.

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• To further our understanding and to learn how to select the different valve drives

we can now examine the operating mode, particularly the aspects of control and

behaviour. An actuator for controlling electrothermal valve drives can only work

digitally, in other words, it is either on or off. This is a 1 Bit signal. A 2-step control

can be configured in all KNX room temperature controllers.

• After specifying a setpoint and a tolerance band for the room temperature the room

temperature controller will try to control the room temperature by switching off and

on, in other words by opening and closing the valve.

• Due to the slow response behaviour of the thermoelectric valve drive the valve

opens or closes slowly, the time between open and closed being 2 to 3 minutes.

• The actual temperature in the room may possibly fluctuate because of the situation

we have just described, but this can be minimised by decreasing the temperature

limits and tolerance band.

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• Another setting often used in the room temperature controller is the pulse width

modulation PWM. which also works with thermoelectric drives and their switch

actuators.

• During an adjustable cycle time of e.g. 15 minutes the room temperature controller

opens and closes the valve for a specified time, depending on the control value

calculated.

• We can look at a short example: with a cycle time of 15 minutes and a control

value of 60 % the valve is opened for 9 minutes and closed for 6.

• In this case the reaction of the valve is delayed due to the system inertia of the

valve drive and, depending on the power-on / power-off time, the valve is also

perhaps not fully closed or opened. Because of the thermal inertia of the whole

room temperature control system, PWM control is widely-applicable in classic

heating and cooling systems. Its advantages are its low-price, as well as the low-

maintenance and low-noise valve control.

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• Continuous control is activated in the thermostat when the motorised KNX valve

drive or the 3-step valve drive is used.

• In the valve drive the control value calculated is converted rapidly into a direct

positioning of the valve.

In contrast to the 1 bit telegram in 2-step control or in pulse width modulation, this

is an 8 bit value telegram.

While the advantages are the faster, more exact positioning of the valve, higher

investment costs and the drawbacks of a mechanical system must also be taken

into account.

The same occurs when we use the 3-step and 0…10 V valves we mentioned

earlier.

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• What have we learnt so far?

• Climate control integrated into the system KNX is logical and supports the

interaction of all the components and functions

• The principle of individual room heating control and of Fan Coil Actuators for

climate control and an overview of the corresponding ABB sensors and actuators

• Have you understood everything so far ?

If you have, please click ”continue”. If you would like to repeat the topic, please

click “No”

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• At the end of this, the second eLearning module we will have detailed knowledge of

the operating mode of the different valve drives and the corresponding KNX

actuators the functionality of Fan Coil actuators and the capabilities of an air quality

sensor

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• Thermoelectric valve drives are used for radiators, cooling ceilings, floor heating.

• Fan Coil Units and are standard components in room climate control.

ABB offers these valve drives for 230 V- or 24 V-valves in a “Normally closed“

version. The opening and closing time is about 3 minutes.

A wide range of valve adapters is available for the most common valves

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• The functional principle is as follows:

• The expansion element is heated by applying operating voltage of 230 V or 24 V

and expands

• the integrated push rod performs the travel

• the travel (about 4 mm) is transferred to the valve push rod,

• the valve is opened or closed and this can be seen in the function display.

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Switch actuators with electronic relays are used to control thermoectric valve drives.

Switch actuators with mechanical relays can be used, as this application is already

available for this use.

The disadvantage is the noise behaviour as well as the mechanical load on the relay

resulting from the large number of switching operations over the operating period.

Consequently, preference is given to actuators with electronic relays which are noise

and wear-free. ABB offers 2 different electronic actuators, the electronic switch actuator

ES/S and the valve drive actuator VAA/S. With a supply voltage of 24 or 230 V the

electronic relay, a Triac, switches the valve on or off. The number of parallel

connectable thermal valve drives depends on the load current of the devices and must

be taken into account correspondingly. In rooms with several heating circuits and

valves, this means that often only one channel of the actuator per room needs to be

occupied.

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• The electronic switch actuator ES/S comes with 4 or 8 channels.

• And thermoelectric valve drives for 24 or 230 V AC or DC can be connected.

• A plastic foil keypad with LEDs is available for manual operation and status display.

• One special feature of the electronic switch actuator is the provision for connecting

motorised 3-point valves. In this case 2 outputs needed for each valve and the

number of channels is reduced accordingly.

• One channel can also be parameterised as a normal switching channel. This

means that a noise and wear-free switch relay up to 1 A load current is available for

special applications.

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• The valve drive actuators with 6 and 12 channels are an extension to our product

range of thermoelectric valve drives controllers.

• They are a cost-effective solution for thermoelectric valve drives and boast almost

all the functions of the electronic switch actuators we have just met.

• The permitted nominal voltage is between 24 and 230 V AC

• The maximum nominal current per output is 160 mA which normally drives a

maximum of two valve drives parallel to an output.

• Please do not forget: the device is has been designed for thermoelectric valve

drives, it is not possible to operate motorised 3-point valve drives or the switch

actuator function.

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• Since the electromotor valve drive ST/K 1.1 as an KNX component is connected

directly to the Bus, installation is simple and rapid. The main advantage is the fast

control with exact positioning of the valve. However the potential noises resulting

from the mechanical parts of the valve drive must also be taken into account.

• Another feature are 2 integrated binary inputs where window contacts or even

conventional presence detectors can be connected.

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• The electromotor valve drive ST/K 1.1 is mounted directly on the valve with the

appropriate mechanical adapter, power is supplied by the bus, so the installation is

quite straightforward.

• The automatic valve travel detection aligns the device to the actual stroke of the

valve, which ensures safe operation.

• 5 LEDs show the actual position of the valve, which is extremely useful for

commissioning and diagnostic purposes.

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• One other important component in room climate control is the blower convector,

which is also known as the Fan Coil Unit.

• This is used mainly in cooling applications but also for heating purposes and is

actually a heat exchanger.

Hot or cold water from a central supply is controlled by a valve.

• A step-regulated ventilator circulates the air in the room past the low-noise heat

exchangers and the room temperature changes.

• If a building is usually cooled and only rarely heated, it is often not worth installing

hot water heating with a Fan Coil.

• In this case electric heating can be integrated into the Fan Coil, which is activated

by a switch actuator. The room temperature is raised using the 3-speed fan.

• ABB's Fan Coil actuators have the appropriate relay.

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• This chart shows the control value of the room temperature controller with control

of the valve and the fan depending on room temperature and using a Fan Coil

actuator. This is assuming the system is using both the heating and the cooling

mode, and the heating setpoint is 21 degrees, and the cooling setpoint 24 degrees.

In other words, between 21 and 24 degrees there is neither heating nor cooling

being performed, this is known as the dead zone. The valve is driven according to

the red characteristic for heating and the blue characteristic for cooling. The valve

opening is dependent on the control value and is executed by a motorised valve

drive or by pulse width modulation of a thermoelectric valve drive.

• For example, in the cooling mode, if the room temperature is 26 degrees the valve

is set with a 35 % opening and the fan revolves at speed 2.

• The threshold values of the different speed steps can be set in the Fan Coil

actuator software.

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• We can move on to examine the Fan Coil actuators in more detail.

The LFA/S is a Blower/Fan Coil actuator, which not only allows the operation of

Fan Coil Units but also fan control with up to 5 speeds.

• The hardware provides for 6A switch actuators with 4 and 8 outputs, which can be

used as 1-fold actuator for 3-speed fan control (Type LFA/S 1.1) or as a 2-fold

actuator (Type LFA/S 2.1) for two 3-speed fans or as a 1-fold actuator for 5-speed

fan control. Classic manual operation is not foreseen on the device itself.

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• The schematic diagram illustrates the interaction between the Blower/Fan Coil

actuator LFA/S 2.1 and the KNX devices via the communication objects and also

the outputs with their connected loads.

• The first 3 outputs activate the various fan speeds, while the 4th output shows

optional higher-level motor control with a separate relay.

• The thermoelectric valve drives for heating and cooling are connected to the next 2

outputs. These outputs are normally controlled in such a way that with a control

value greater than zero the contact is closed and the valve is opened completely.

Temperature control is then performed exclusively by the fan speed.

Whenever necessary PWM modulation can also be used for approximate

positioning.

• Other free outputs can be used as needed, in this case to connect luminaires.

• One important part is the room temperature controller which communicates mainly

with the Blower/Fan Coil actuator via the control value.

Other optional communication objects, such as status messages or operating–

mode switchover, are also available.

• A KNX button switches the two lighting outputs.

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• The Fan Coil actuator FCA/S 1.1M is a further development of the Blower/Fan Coil

Actuator LFA/S.

• The device has 3 outputs for fan control and a total of 4 electronic outputs for

connecting thermoelectric and motorised valve drives.

• Two binary inputs and a second switching output are also available.

• The plastic foil keypad enables the familiar manual operation und status display.

• The application is based on the functionality of the LFA/S with a number of

enhancements.

• With a commissioning power supply connected to the bus connecting terminal, the

device can also be manually operated without KNX-Bus for testing Fan Coil Units.

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• The diagram shows the inputs and outputs of the Fan Coil actuator FCA/S 1.1M.

While the switching output can be used for example for auxiliary electrical heating,

the binary inputs can be used to connect a window contact or condensation

sensors.

• The outputs for valve drives for heating and cooling are separate. As each channel

has two independent electronic outputs both thermoelectric and motorised drives

can be implemented. This results in low-noise and low-wear but also offers further

options in valve control, as we will see in the following slides.

• In place of electronic outputs the Fan Coil actuator FCA/S 1.2.2.1 offers two 0-10 V

outputs for the corresponding valve. The functionality of this solution is the same

as the one we have just described.

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• One interesting aspect of Fan Coil Unit control is the control of the valve depending

on the control value.

• With the Blower/Fan Coil actuator LFA/S, when the valve is opened at a control

value greater than zero, the temperature control in the room is executed by the

change in fan speed. The valve is only closed when the thermostat sends no more

control values.

• The FCA/S has more options. The standard characteristic has a linear behaviour,

in other words, with e.g. a 30 % control value the valve is also controlled by this

value.

When a thermoelectric valve drive is connected the pulse width modulation (PWM)

is implemented, while for motorised drives the valve can be positioned directly by a

value.

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• Which opportunities emerge when functions are used to adjust or restrict this

characteristic?

First of all, the characteristic can be changed via four adjustable pairs of values for

control value and valve position.

We can look at some practical examples of this :

• If the valve is only opened with a control value of 20 %, the fan runs, but at speed

1, so the room is neither heated nor cooled, only ventilated.

A stronger heating and cooling effect is reached when the valve is completely

opened with a control value greater than 80 %.

• If the valve is opened a minimal 20 % with very small control values, possible

whistling noises can be avoided, caused by small water flow.

If the valve is opened no more than 80 % with higher control values the number of

valve positions can be reduced, because the non-linearity of the valve prevents a

more powerful flow of water.

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• Besides room climate control with heating and cooling the quality of the air is

another parameter for physical comfort in a building, whereby the CO2 content is

particularly crucial. Above a concentration of 1000 ppm the quality of the air falls,

while higher values can cause lapses in concentration or headaches

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• Humidity and, of course, the room temperature are also important. This graph

shows the relationship between the two.

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• This is where air quality sensor comes into action, measuring the CO2

concentration, relative humidity and room temperature. The values measured can

be transmitted to the Bus for further processing or display and other functions can

be carried out when the set values are reached.

• Two LEDs show in different colours in which area humidity and CO2 concentration

are situated, so the user can intervene manually in the control of the functions

mentioned

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• In this overview we can see the interaction of the air quality sensor with different

KNX devices:

• The central device is the air quality sensor which measures the CO2 concentration,

the relative humidity and the room temperature.

• When set thresholds are exceeded or underrun logically linked actuators can

perform functions such as increasing the fan speed or opening or closing a

ventilation flap or window to increase the supply of fresh air.

• Independently of the air quality sensor, higher-level KNX components, such as

pushbuttons, presence detectors or timer modules can of course influence the

functions we have just examined

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What have we learnt so far ?

• The operating principle of the thermoelectric valve drive with KNX actuators with

electronic outputs

• The differences between an electronic switch actuator and a valve drive actuator

• The alternative motorised valve drive as a direct KNX device

• The properties of Fan Coil actuators LFA/S and FCA/S with the options

• of characteristic curve adjustment in the FCA/S

• The new opportunities offered by the use of the air quality sensor LGS/A 1.1 in a

KNX installation

Have you understood everything so far ?

If you have, please click ”continue”. If you would like to repeat the topic, please click

“No”

• Thank you very much for taking this first unit of the eLearning course about room

climate control. We hope that this course has been interesting and helpful in

extending your knowledge of room climate control, the technologies involved and

their areas of operation.

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