The added value of thermostatic radiator valves in energy saving
The role of a thermostatic radiator valve
A thermostatic radiator valve regulates the flow of hot water through a radiator. A sensor inside the TRV reacts to the surrounding temperature and expands or contracts, depending on the set value on the TRV dial, to either restrict or increase the amount of hot water flowing to the radiator. Our Evosense thermostatic head, for example, has an integrated Ecobrass sensor with Wmotion enclosed technology. This technology helps to guarantee the highest control accuracy class possible within European standards so that it’s easy to combine optimal energy consumption with maximum comfort.
Contrary to manual radiator valves, thermostatic radiator valves automatically adjust the radiator to the pre-set value. So instead of having a non-stop flow of hot water, the TRV turns the radiator off once the room temperature corresponds to the setting. When the sensor detects that the room temperature has dropped, the thermostatic radiator valve will open automatically to increase the flow of hot water again so that the radiator can reheat the room. This results in more efficient heating without having to compromise comfort.
Saving energy with thermostatic radiator valves
When a radiator system is designed, the radiators are dimensioned based on their ability to heat a room when the outdoor temperature is at its coldest. However, during the months that a heating system is being used, typically there are only a few days with an outside temperature that requires every radiator in the building to be fully on. On other days, the radiators would be producing excess heat, resulting in overheated rooms and wasted energy.
Individual room temperature control prevents this. When radiator valves are installed on every radiator throughout a building, it’s easy to control the temperature in each room. Whereas manual valves need to be physically adjusted to maintain this control, thermostatic radiator valves open or close automatically to retain the desired room temperature.
By pre-setting the TRV it’s easy to define a preferred temperature for each individual room. You can, for example, keep the living room comfortably warm when you’re watching TV but easily lower the temperature in the kitchen when you’re cooking. A thermostatic radiator valve is thus an easy means to get more control over the room temperature and helps to ensure rooms aren’t heated more than they need to be. This way spaces aren’t overheated and no energy is lost on unoccupied rooms so that ultimately TRVs help to save energy as well as increase indoor climate comfort.
Energy saving with TRVs on a pan-European scale
A EUBAC analysis on room temperature control(1) shows that in about 41% of EU homes with radiators there are only manual radiator valves installed. That amounts to about 70 million homes and an estimate of 500 million radiators that can potentially be upgraded with thermostatic radiator valves. Based on an average energy saving of 18 %, the EUBAC study concludes that installing TRVs on all the radiators that don’t have them could save 130 TWh of energy every year. Upgrading TRVs that are over 20 years old would increase this to 160 TWh. With a reduction of 29 million tonnes of EU CO2 emissions and nearly € 12 billion in savings on the energy bills that’s a win for both the planet and EU citizens.
Although TRVs undoubtedly help to heat a building efficiently, it’s important to note that there are multiple factors involved in just how much energy can be saved. The degree of insulation, the heat source, the heat output of the radiators as well as the number of rooms where a TRV is used, it all affects the energy consumption, and thus the potential energy savings.
Low temperature heating & thermostatic radiator valves
In view of energy efficiency, many people are also switching to low temperature heating. This means the water circulating in the radiators is somewhere between 30 and 50°C, instead of 70 to 80°C. In addition to a lower surface temperature for the radiators, the lower water temperature also means that the fluid flow increases. In an existing pipe system, the friction can therefore increase significantly, which in turn increases the need for hydronic balancing.
The balancing can easily be done with adjustable thermostatic radiator valves. These limit the mass flow to the radiator whenever necessary so that an unbalanced water distribution is avoided. A self-actuated adjustable thermostat, such as the Evosense thermostatic head, automatically provides the best possible temperature regulation while the valve insert, such the Flamingo valve insert, controls the actual flow of water to the radiator with great accuracy. Together these elements ensure stable pressure conditions and help to create the ideal operating conditions for a hydronic heating system.
TRVs made of environmentally friendly materialsThe icing on the cake for everyone looking to create a sustainable and optimally balanced heating system is a TRV made of environmentally friendly materials. The Evosense thermostatic head, for example, is, among other things, made of Ecobrass or low-lead brass. This is a more sustainable material than traditional brass as it is characterised by a minimum percentage (less than 0.1%) of lead. It can also be recycled, which makes it a sustainable choice all-round. On top of that, the Evosense thermostatic head is available in both black and white so that it can be easily matched to the interior around it.
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