Are there specific types of radiators or heating systems that are best suited for thermostatic radiator valves?

Thermostatic radiator valves (TRVs) can be used with most types of radiators and heating systems, but their effectiveness and compatibility depend on the specific system and radiator type. 
Panel Radiators: TRVs work well with standard panel radiators (the most common type in residential heating). These radiators have a large surface area that allows the TRV to effectively control the temperature by regulating the flow of hot water into the radiator.
Cast Iron Radiators: Cast iron radiators, though slower to heat up and cool down due to their mass, can also be equipped with TRVs.However, the responsiveness may be slower compared to lighter, more modern radiators. It's important to ensure that the TRV is appropriately sized for the radiator to achieve optimal control.
Column Radiators: TRVs can also be used with column radiators, which are popular in period homes. As with cast iron radiators, the response time might be slightly slower, but the TRV will still regulate the room temperature efficiently.
Towel Radiators: TRVs are commonly installed on towel radiators, often found in bathrooms. The TRV allows for better control of bathroom temperature, ensuring it doesn't overheat and is energy-efficient.
Designer Radiators: Designer radiators, including flat-panel or decorative models, can also benefit from TRVs, provided the TRVs are compatible with the radiator's pipework and size.
Wet Central Heating Systems (Hydronic): TRVs are most commonly used in wet central heating systems, where hot water circulates through pipes and radiators. TRVs are ideal for these systems because they control the flow of water into each radiator based on the room’s temperature, enhancing energy efficiency and comfort.
Heat Pump Systems: TRVs can be used in systems powered by air-source or ground-source heat pumps. They help manage the temperature in each room, ensuring that the relatively low-temperature water produced by heat pumps is used efficiently.
Underfloor Heating: TRVs are less commonly used in underfloor heating systems, which typically rely on room thermostats or zonal controls to regulate temperature. However, in hybrid systems where radiators and underfloor heating are combined, TRVs can be used for the radiator sections to maintain consistent room temperatures.
Combination Boilers (Combi Boilers): In homes with a combination boiler system, TRVs work well because they regulate the flow of hot water through individual radiators, providing room-by-room temperature control without the need for a central control system.
Zoned Heating Systems: In multi-zone heating systems, TRVs can be integrated into each zone to control individual radiator temperatures based on the specific needs of each area. This is especially beneficial in large homes or buildings with multiple rooms requiring different temperatures.
Smart Thermostatic Controls: Modern TRVs can be integrated with smart heating systems that allow remote control through apps or smart home hubs. This works well with most radiator types and heating systems, offering greater flexibility and energy savings.
TRVs are particularly effective in improving energy efficiency in systems where the heat output can vary, such as in low-temperature heating systems (e.g., underfloor heating or heat pumps) or in multi-radiator systems. By adjusting the heat output of individual radiators based on room temperature, TRVs help maintain a comfortable temperature without over-heating or wasting energy.
In summary, thermostatic radiator valves can be used with a wide variety of radiator types and heating systems. However, for optimal performance, they are most effective in wet central heating systems, particularly when the system is well-balanced and properly sized for the radiators. If using TRVs in a mixed heating system or with unconventional radiators, it’s important to consider the specific requirements of each setup to ensure efficient operation.