Systems designed to support ongoing commissioning and energy monitoring make it easy for building operators to understand the energy performance of their hydronic heating and cooling systems and fine-tune them in line with changes to building usage.
Ultrasonic energy meters are installed in the main return pipes from valve modules to enable a number of ongoing commissioning and energy monitoring functions that could form part of a “Soft Landings” framework.
These meters measure the flow rate through the module and the temperature differential (delta T) across the main flow and return pipes. Values can be obtained manually at individual modules, or can be logged automatically by a BMS.
The measured data can be used for the following purposes:
- Energy monitoring and targeting: The energy consumptions for each part of the building can be monitored and logged. Any unexplained increases in energy consumption identified by such localised monitoring can be quickly investigated.
- Occupant billing: With localised monitoring, occupants can be billed accurately for the energy used by the terminals located in the areas they occupy.
- Temperature differential measurement (delta T): Evidence of low delta T values is often indicative of excessive (uncontrolled) flows through terminal devices resulting in poor occupant comfort and inefficient plant operation. By measuring and monitoring delta T values over prolonged periods, problems can be identified and investigated. Where necessary, set-point flow rates can be adjusted to give more efficient performance.
- Trouble-shooting: Operating problems such as fan failures or pipe circuit blockages can be easily identified from measurements of flows and operating temperatures
The diagram below shows how the localised monitoring of temperature differential would work. Due to the localised nature of valve modules, operating problems can be traced to the precise location within the system. This would be impossible in rigid systems.
The data processing below shows how delta T calculations are made based on energy meter readings.
Where heating and chilled valve modules are located side by side, the commissioning modules can share a single junction box to enable automatic energy monitoring via a BMS. Each module can have its own control set points and energy monitoring targets. This arrangement is shown in the diagram below: