Are Smart radiator valves worthwhile?

In a previous blog, I wrote about how to get started with Smart Home technology.

One topic that comes up frequently in discussions with people is the use of smart radiator valves (TRVs). Will the energy savings outweigh the costs?

In colder locations the savings can be more significant than in a similar house in the south of England and it is far more important to investigate these solutions.

The first thing to realize about this issue is that it is not just a cost issue. If you have a room that is always too hot then a smart TRV may be more effective than a regular TRV. On the other hand, if there are heating pipes under the floor of that room and they are not insulated, neither type of TRV will be able to completely limit the heat.

With that in mind, you could start with a single smart TRV in the room where temperature control is most difficult before deciding whether to buy more of them.

Integrated with a centralized control system, as described in my previous blog, the boiler can be switched on and off on demand. Yet this functionality isn't essential: many of the smart TRVs can run standalone, without activating their wireless connectivity. Each TRV has a built-in thermometer so it can monitor the temperature of the room and control the valve. At times when the boiler is running, the TRV will control that room on a standalone basis and when the boiler is off, the TRV does nothing.

Modern boilers may operate with lower fuel consumption at times when many of the radiators are shut down. Older boilers may continue to burn gas at the same rate whether all the radiators are in use or just one. Before buying smart TRVs, you can simply measure gas consumption for an hour with all radiators on and then measure gas consumption for a further hour with all but one radiator switched off.

Instead of buying these TRVs, you may find other algorithms for controlling the boiler are more effective at saving money, even on old boilers. For example, if your smart home system can detect those nights when nobody is home, it can choose not to start the boiler in the morning. This logic could be achieved with motion sensors and door sensors.