Introduction
Danfoss Training Module-1
* * * * * *
Understanding Thermostatic Radiator Valves
for Commercial Heating
Systems
Introduction
Hello and welcome to the Danfoss training module 1
‘Understanding Thermostatic Radiator Valves for
Commercial heating systems.’
The purpose of this training module is to give you the knowledge required to select, specify, and understand Danfoss
products.
We will examine the benefits, operation, and selection of Thermostatic Radiator Valves.
We also want to give you an
understanding of the systems they are part of.
Introduction
This module takes around 20 minutes and forms part of a ‘Continuous Professional Development’ training course.
Once 3 modules are complete you can apply to Danfoss for a certificate of your achievement.
Now let us begin….
Introduction
The History of Danfoss
1933 1943 1952 2010
Mads Clausen establishes his company Dansk Køleautomatik – og Apparat Fabrik, and began by producing expansion valves for refrigeration plant
1933 1943 1952 2010
In 1943 Mads Clausen invented the very first radiator thermostat and in 1952 production began of the RA type radiator thermostat.
1943
1952
The History of Danfoss
1933 1943 1952 2010
The Danfoss Group is a global producer of components and solutions for Refrigeration &
Air Conditioning, Heating &
Water, and Motion Controls.
Danfoss employs approx.
22,000 people worldwide and produces more than 250,000 items daily, in more than 50 factories located in 20
countries.
This includes a factory based in Bedford, UK which makes Electronic Room Controls.
The History of Danfoss
1933 1943 1952 2010
Danfoss thermostats have been leading the market ever since Mads Clausen invented the first TRV…
…and radiator thermostats are still a core business for
Danfoss
to this very day.
By selecting Danfoss products you have over 75 years of expertise behind you.
The History of Danfoss
What is a Thermostatic Radiator Valve?
A thermostatic radiator valve is a control device
for individual radiators.
They use a thermostatic sensor to control the
water flow.
TRV’s consist of two parts…a valve...
and a sensor.
The valve is connected between the pipe- work
and the radiator…
and the sensor sits on top of the valve.
Danfoss has the widest range of radiator valves
on the market…
Thermostatic radiator valves control the temperature on each radiator throughout a building.
This means than each room is individually controlled to give the required temperature for its use.
By keeping each room at the correct temperature
we improve comfort for it’s occupants.
Danfoss Thermostatic Radiator valves also save energy….
and we have lots more on this later in the module.
What is the benefits of using Radiator
Thermostats?
How do Commercial TRV’s Operate?
The valve has a stem and a cone which are moved by the sensor to control flow.
The sensor is filled with gas and as the room temperature rises the gas expands . This pushes the valve stem down to reduce flow.
How do Commercial TRV’s Operate?
The temperature is set in the sensor using numbers which correspond to temperatures. For example
setting the sensor to number 3 gives a room temperature of 20 ℃.
As the room temperature falls the sensor allows the valve stem to move up.
This increases flow and temperature to the room.
How do Commercial TRV’s Operate?
Danfoss RA sensors are unique in that they are the only sensors on the market which are gas filled.
Gas filled sensors react quicker to changes in temperature in the room.
This reduces overheating and utilises more ‘free heat’.
All other manufacturers offer only liquid or wax filled heads.
By using RA sensors the user will have a more comfortable room temperature…
…and the system will use less energy.
Summary of Different Media Types:
How Gas Filled Sensors Compare with Liquid Filled
Advantage Disadvantage Comments Utilization of free heat
Wax Low price Slow reaction. Setpoint moves over time.
Relatively short lifetime. High hysteresis.
Old-fashioned
technology Approx. 75%
Liqui
d Stable setpoint.
Long lifetime.
Reacts with medium
speed. Reacts on average
temperature. Approx. 80%
Gas Stable setpoint.
Long lifetime. Fast Reaction.
Reacts on coldest
spot in room. Approx. 85%
RA-2912 Remote Sensor
The basic knowledge this module can give you will make selecting the correct sensor a simple process.
Let us talk you through it….
Sensors for Commercial systems come in four main types…
Selecting the correct sensor
RA-2910 Built-in Sensor
RA-2920
Tamperproof Sensor
RA 5062
Remote Adjuster Sensor
Danfoss RA-2910
The Built-in Sensor is the most commonly used sensor for
commercial systems, such as offices, in the UK.
This sensor features a locking and limiting function to prevent the temperature being turned up too high.
It is connected to the valve using a small allen key connection, this makes it hard to remove by un- authorised users.
Selecting the correct sensor
Danfoss RA-2020
Tamperproof Sensor used in public buildings and spaces, such as council offices, doctor
surgeries and libraries.
The sensor is set and locked by the installer to keep a specific temperature. The tamperproof lock means no un-authorised persons can change the
temperature.
The Danfoss RA2020 tamperproof sensor is recognisable as having a
grey shroud at its base.
Selecting the correct sensor
Danfoss RA-2912
Low Surface Temperature
Radiators are commonly used in care homes, where the radiator and valve are boxed in to prevent people from scalding themselves.
In this situation, the temperature sensed using a standard head would be artificially high.
To prevent this incorrect
temperature reading, the Danfoss RA2912 sensor
is connect to the valve by a 2 metre Capillary Tube. This can be placed
to sense the correct room temperature without giving access
Selecting the correct sensor
Remote Adjuster Thermostats are used where the valve is
completely boxed in, and mostly installed on Radiant Panels.
Radiant panels are often used in schools.
The sensor is a thermostat which has a capillary tube connecting it to the valve, allowing the
temperature to be set remotely.
The last digit in the name indicates the length of the capillary tube, i.e. the RA-5062 has a 2 metre tube.
Selecting the correct sensor
Danfoss RA-5062, RA-5065, and RA-5068.
To select the correct valve the information required is as follows:
-The valve size
-The angle pattern of the valve
-The pipe-work configuration
Selecting the correct valve
Valves sizes: 3/8”, ½”, 3/4”, and 1”.
Danfoss valves are suitable for iron pipe-work or copper pipe-work using fittings.
Each valve size is selected based upon
the radiator capacity.
A sizing chart is used to select the correct valve.
Selecting the correct valve
For a 2000W or 2Kw Radiator using a
temperature loss across the radiator of 11℃…we would draw a red line.
Allowing a valve pressure loss of 10 kPa
(also described as 0.1 Bar) we would
draw a green line.
The two lines meet in the chart area for
DN15 valves (blue lines).
We therefore require a ½” valve.
Selecting the correct valve
Two types of pipe configuration exist for radiator systems:
- one pipe systems…
- two pipe systems…
Different types of valves are used on the two different configurations.
Selecting the correct valve
2-Pipe System 1-Pipe System
A two pipe system is where the flow and return pipes are separate.
The flow is attached to one connection on the radiator, and the return the other.
This gives a parallel connection between the flow and return pipes.
For two pipe systems Danfoss offer RA- FN type valves. These require a lower flow capacity than one-pipe valves.
Two-pipe systems are energy efficient and provide better temperature
control to radiator systems.
Selecting the correct valve
2-Pipe System
A one-pipe system is where both radiator connections are attached to the
same pipe run. Giving the radiators a series type configuration.
For one-pipe systems Danfoss offer the high capacity RA-G type valves.
Danfoss are one of few radiator valve manufacturers who still offer valves for one-pipe systems.
This is because the Danfoss RA valves and sensors installed in one-pipe sensors are beginning to need replaced…
…30-40 years after they were installed!!
Selecting the correct valve
1-Pipe System
Both the RA-G and RA-FN valves come in either angled or straight patterns.
This refers to the direction the water flows through the valve.
The angled valve feeds the water in and out of the radiator at a 90 ° angle.
Selecting the correct valve
The RA-FN angled valves are available with either a horizontal or vertical mounting sensor.
A horizontal sensor is mounted away from the heat provided by the radiator which ensures we are measuring room temperature and not radiator
temperature.
Vertical sensors sit closer to the radiator. This makes them able to fit in confined spaces.
Danfoss recommend the use of
horizontal angled valves where possible.
Selecting the correct valve
Straight pattern valves feed the water in and out of the radiator in a straight line.
By having different patterns we can give installers as many options as possible to ensure neat and easy valve connection.
Selecting the correct valve
Use the following diagram to determine which valve is required.
Selecting the correct valve
Horizontal
Vertical
Straight Angled
Straight Angled Two Pipe
One Pipe Start
Code
3/8”=013G002100
½”=013G002300
¾”=013G002500 1”=013G002700
Code
3/8”=013G014100
½”=013G014900
¾”=013G014500
Code
½”=013G338400
¾”=013G338600 1”=013G338800
Code
½”=013G338300
¾”=013G338500 1”=013G338700
Code
3/8”=013G002200
½”=013G002400
¾”=013G002600 1”=013G002800
To get our Danfoss Randall Valve Selection Chart,
you can either call us on: 0845 1217 400 and ask for literature
You can also call us and speak to our technical helpdesk, they would be able to help you determine which valve you need.
Or you can send us a request via our website:
www.danfoss-randall.co.uk / service &
support / How to contact us, select the
‘literature request’ at the bottom of the page.
Selecting the correct valve
Lock-Shield valve.
The Lock Shield valve is used to isolate and balance a radiator, and is located on the return pipe connection.
Radiator Balancing
Lock-Shield valve.
By turning the lock-shield valve down with an allen key, the maximum flow is reduced, hence balancing the radiator.
Radiator Balancing
By balancing the radiators they all get the correct
temperature…
thus preventing the first radiator in the system getting too much heat, and the last radiators getting too little heat.
If you remember in our example we wanted an 11℃temperature loss across our radiator?
Well by balancing, using a lock- shield, we can ensure the most efficient radiator temperatures.
Lock-shield valves are Danfoss model: RLV
Too hot!
Too cold!
Radiator Balancing
Danfoss lock-shield valves have an optional drain-cock adapter to drain the radiator system
with.
This drain-cock adapter is Danfoss code: 003L015200
Drain-cock adapter
Now we have chosen the
radiator valves to give maximum comfort
to our users…
…let us see how Danfoss Thermostatic Radiator Valves can save energy!
Danfoss have studied the energy used when manual radiator valves are
replaced with thermostatic radiator valves.
Saving Energy
When using a manual (i.e. non- thermostatic) radiator valve, the flow to the radiator is fixed
manually (by hand).
Saving Energy
By using a Thermostatic Radiator Valve, the flow of water varies, based upon the room temperature.
This means the sensor reacts to the changes in that room temperature, caused by external factors such as the sun.
Saving Energy
By using a Thermostatic Radiator Valve to reduce flow,
as the room temperature increases, we save energy.
Danfoss have found that by using a thermostatic
radiator valve instead of a manual radiator valve,
minimum energy savings of 20% can be achieved.
Energy saving is not just about saving the planet, it’s also about saving money on our heating bills!
Saving Energy
You have now completed the Danfoss Training Module
‘Understanding Thermostatic Radiators Valves for
Commercial Applications.’
I’d just like to highlight some key points before we finish.
Final Review
Thermostatic radiator valves are designed to save energy and provide comfort to users.
Final Review
Valves are designed for use in 1 or 2 pipe configurations.
We use RA-FN valve for 2-pipe applications…
and RA-G valves for 1-pipe applications.
As the room temperature changes, the sensor reacts to keep our
set temperature.
Final Review
Danfoss offer four types of sensors:
RA-2912 Remote Sensor RA-2910
Built-in Sensor
RA-2920
Tamperproof Sensor
RA 5062
Remote Adjuster Sensor
Gas filled sensors react faster than liquid filled heads, this saves energy by using more
‘free-heat.’
Final Review
Thermostatic valves are available in angled or straight pattern.
Danfoss valves are available in 3/8”, ½”, ¾”
and 1” sizes.
They can be used on either copper or iron pipe-work.
To balance our radiators we need an RLV lock-shield valve.
Final Review
By using thermostatic valves in place of manual valves
we can save a minimum of 20% of the systems energy.
By using Danfoss you will have all radiator applications covered.
Congratulations for
completing your first training module!
You now have all the information required to select
and specify Danfoss thermostatic radiator valves.
Module 2 has a title of ‘Balancing Valves for Heating and Cooling Systems’
Once you have completed three modules you
can apply to Danfoss Randall for your
‘Continuous Professional Development’
Certificate.
For more information on Danfoss products or
for Danfoss-Randall’s contact details please visit our
