House owners, housing associations and tenants are experiencing that expenses for heating are rising considerably. A development which probably will not change in the future and which has made it more attractive to save energy and money by improvement of the heating system. What is a radiator thermostat?
The radiator thermostat consists of a valve on which a thermostatic sensor is mounted. It is easy for the installer to replace the old manual valve with a new radiator thermostat. And for the tenants it is even easier: they set the radiator thermostat on the wanted temperature by turning the dial of the thermostat; e.g. approx. 20° C in the living room, approx. 17° C in the bed room etc. The radiator thermostat will then maintain this temperature until the setting of the thermostat again is changed by the tenants.
Why and how much will be saved with such a simple change of the heating system?
Radiator thermostats cut down the heating bill with up to 20%
The most essential reason for achieving considerable energy saving with a radiator thermostat is the fact that the radiator thermostat only uses the quantity of energy which is necessary to keep the wanted temperature. The thermostat is saving energy with the so called "free heat". The radiator thermostat exploits "free heat" if the weather changes from cloudy to sunshine. Then the radiator thermostat will lower the energy consumption as the sun gradually heats the room. The same will happen when heat emits from people in the room, switched on light, television etc. and the other way around the radiator thermostat will increase the energy consumption when for example it is getting darker and the sunshine is no longer filling the room with heat or when the temperature outside drops.
Danfoss which is the leading manufacturer of radiator thermostats in the world has tested possible energy saving using alone radiator thermostats. The result showed savings of up to 20%! That means that the investments typically will be recovered in less than two years. On average a radiator thermostat works for 20 years without maintenance: the sums saved on the energy consumption are therefore quite considerable during the life of a radiator thermostat. Not only financial advantages are obtained, but also the environment which we exploit using more energy than necessary benefits from radiator thermostats.
What is inside a radiator thermostat?
The handle of a thermostat contains fluid which is extended when the temperature of the room is increased. When the temperature drops the fluid contracts.
When the fluid of the thermostatic sensor is extended the spindle of the valve is pushed gradually closing for the flow of warm water for the radiator. And the fluid contracts when it becomes cool and the flow of water for heating will be increased - simple, automatically and without use of energy for the regulation. Different kinds of fluids can be used. Danfoss has chosen gas for its RTD sensors as it has a number of advantages: Gas reacts faster on the change of temperature than other fluids thus the temperature of the room is maintained with as small fluctuations as possible. In that way the free heat is exploited better. Moreover, the gas maintains its fine regulation abilities during the whole life of the thermostat; in other words the quality of the gas is not changed as it gets older.
Complete district heating solution
Danfoss invented the radiator thermostat more than 50 years ago and has through all the years improved the operation and the design of the radiator thermostat.
This article has dealt a lot with the heating automatic control devices which are installed in the home of the end user. However, the know-how of Danfoss within heating controlling equipment includes many other areas. If we go down to cellar level Danfoss has developed a number of products which together with the radiator thermostat ensure optimal operation of heating systems based on water.
We can among many other products mention flow limiter type ASV-Q and automatic riser valve type ASV-P which ensures an optimal water distribution in a system with more risers. With a weather compensator type ECL an automatic adjustment of the operation of the heating system for the weather type can be obtained, automatic reduction of flow temperature over night etc.
There are a number of possibilities and the optimal solution differs from system to system. As one of the most experienced suppliers of district heating controlling equipment Danfoss analyses the possibilities in each case to find the optimum solution.