Efficient operation of heat networks is dependent on low system temperatures, yet not all systems live up to their design intent.
This is often due to poor control (that is not pressure independent), combined with hasty installation where the focus is on completing the job in the minimum time.
“Achieving low return temperatures starts with correct selection and balancing of radiators and other heat emitters within the building, which is often the responsibility of the building owner and designer and not the heat network owner/operator.”
CIBSE’s Heat Networks: Code of Practice for the UK (2015)
When a radiator is poorly controlled it becomes an unintentional bypass. The result is uneven heat distribution and reduced efficiency of the heat network.
Even when heat interface units provide hydraulic separation between the heat network and the space being heated, the return temperature of the heat network distribution system is still dependent on the return temperature of the heated spaces.
The answer is to establish effective control of each radiator.
SAV’s PT40 TRV sets are pressure and temperature compensated. This enables them to respond quickly and dynamically to changes in the system, ensuring that only the required flow passes through the radiator.
Thanks to the integral differential pressure controller, the correct flow rate is achieved – in both full and part load conditions – irrespective of pressure variations from the variable speed pump or changing demand conditions from individual rooms/spaces.
PT40 TRVs are designed for low flow rates and can be pre-set to the required flow rate using the integral adjustable apertures. As a result, they prevent any single radiator from acting as a system bypass. Which means that return temperatures remain low and differential pressure is maintained to support effective operation.
PT40 valves have been designed to minimise installation risk and optimise the performance of heat networks, in accordance with the compliance requirements of CIBSE Heat Networks: Code of Practice for the UK (2015).