Hevasure in Action
Pressure stability is critical in maintaining the health of closed heating and chilled water systems, whether it be in commercial buildings or heat networks. When pressure fluctuates and drops to negative values at the top of the system, the impact can directly contribute to increased corrosion risk and reduced system lifespan. Gaseous air is effectively sucked into the system through air vents and weak seals/joints raising dissolved oxygen to dangerous levels.
In real-world operation, pressure issues are not theoretical risks. They are common events that the Hevasure monitoring systems actively detect and help resolve before significant damage occurs.
Fluctuations in pressure can be due to several reasons. Often, we will see sudden pressure drops caused by partial system drain-down during maintenance. Sometimes we see pressure decreasing on cooling, indicating that the pressurisation unit is not properly set up. And, as in the recent case of a large commercial office in London, we see pressure fluctuating on a periodic 24-hour cycle with corresponding increases in dissolved oxygen (figure 1). In this particular case, Hevasure alerted the maintenance team, who were able to quickly deduce the root cause by looking at the BMS activity at the relevant times. The problem was caused by pumps being switched off overnight, reducing the dynamic pressure in the system. In effect, the static pressure was insufficient to hold up 30m of water, resulting in air being sucked into the system at the upper levels of the building. Having identified the root cause, the solution was obvious: either increase the static pressure or, preferably, keep all the pumps running.
Conventional water sampling would not have picked this issue up. However, with the Hevasure Aquila-2c system in operation, simultaneous changes in multiple parameters (pressure, dissolved oxygen and corrosion rates) made it relatively straightforward to notice that something was wrong and deduce an appropriate corrective action.
With over 12 years of experience and more than 175 installations across the UK, our Aquila system is designed specifically to detect these complex, time-dependent behaviours. Now in its fourth generation, it delivers not just alerts, but a deep understanding of how systems are performing in real time.
This allows operators to move from reactive maintenance to proactive intervention, reducing corrosion risk, lowering maintenance costs, and extending overall system lifespan.
If you suspect pressure fluctuations may be affecting your system, get in touch to see how real- time monitoring can reveal hidden patterns and help protect your asset before damage occurs.
