Gareth Ash, Marketing and Technical Support Manager at Danfoss, charts the evolution of the thermostatic radiator valve (TRV), from the early manual products to the latest electronic devices, and considers their role in the trend towards smart home heating and the Internet of Things.
Around 500 million radiators in EU homes are still fitted with simple manual radiator valves according to a study by the European Building Automation Controls Association (eu.bac). In the UK alone, the report estimated that the potential energy savings of installing modern TRVs over manual radiator thermostats could be as high as 18,111 GWh (Gigawatt hours). Clearly, these figures represent a huge untapped market for TRVs. By providing temperature control in individual rooms and so reducing wasted energy, fitting TRVs could lead to fuel cost savings of up to 30% or even higher. This level of control could also help to ensure that the energy saving potential of increasing home insulation or upgrading a domestic boiler is actually achieved.
As any professional heating installer knows, an uncontrolled radiator valve runs non-stop, even when the room has become warm. A TRV can be set to heat a room to the required setting. Once the room temperature reaches that setting, the valve turns the radiator off. When the room temperature drops again, the TRV turns the radiator back on. The lack of modern heating controls in many homes, which was highlighted in the eu-bac report, has recently been addressed with targeted amendments to the Energy Performance of Buildings Directive (EPBD). Among the requirements under the revised EPBD is the fitting of devices that regulate temperature at room level, such as TRVs. The Directive states that, subject to being technically and economically feasible, the installation of this type of self-regulating device should be considered for the separate regulation of the temperature in each room or, where justified, in a designated heated zone of the building unit. With so much evidence and regulations to support the benefits, it seems obvious that every radiator should be fitted with a TRV. So what’s the history behind these familiar heating controls?
One of the world’s first radiator thermostats for regulating heating was invented by the founder of Danfoss, Mads Clausen, in the 1940s. Since then Danfoss has remained at the forefront of TRV innovation and applied its unique legacy to develop new products for our increasingly digital world. The arrival of electronic, programmable TRVs, with advanced functions like Holiday and Open Window settings, are a far cry from the first basic manual valves and what are considered ‘old’ devices of 15+ years, which offer limited efficiency.
When it comes to efficiency, it is important to note that the time it takes for a TRV to react to a change in room temperature comes down to the type of material used in the sensor. Typically, a wax-filled sensor takes 40 minutes, while a lighter liquid filling will react in 22 minutes. Gas-filled sensors have a 12-minute reaction time but electronic sensors are the clear winners at just 1 minute. The sensor should, therefore, be an important consideration when installers are choosing TRVs as this will have an impact on product performance and avoid potentially costly call backs from dissatisfied customers.
Having looked at a brief history of TRVs, let’s consider more recent innovations. In line with the growth in wireless connected devices, some of the latest TRVs are designed for use with a smartphone app, allowing consumers to program individual thermostats for optimum convenience and flexibility. This functionality is now being complemented with the next generation in smart heating for the home with products like Danfoss Link™ which is a central controller that provides convenient wireless control of the heating system, via individual electronic TRV’s.
This type of central control reflects the growing trend towards the interconnection of devices within the home, enabling them to connect, collect and exchange data. The ability to link all the elements of a home’s heating controls, including room sensors and electronic TRVs, is particularly ideal for larger homes or apartments where individual control is required. Consumers can take control of their energy consumption whilst maintaining the comfort of their home. Individual room temperatures can be set, or rooms can be grouped together to create different heating zones. Even better, users can control heating remotely and create a comfortable, energy efficient home temperature wherever they are.
The TRV has come a long way in the 75 years since Danfoss introduced the first radiator thermostats. Today’s TRVs come with many practical features, such as click-on coupling for fast, no-tools mounting, and menu-driven user interfaces that make them easy to install and to use. They can even become part of the Internet of Things in the modern, interconnected home. So our message to installers is clear, encourage those customers with old, manual radiator valves to replace them with modern TRVs and they will feel the benefits of increased energy savings, comfort and convenience. For more information visit www.heating.danfoss.co.uk