Faucet issue involving preheating valve leakage
In a significant discovery, a leaking preheat valve in an air handling unit (AHU) was identified as the root cause of energy waste, increased operational costs, elevated carbon emissions, thermal comfort issues, and system wear and maintenance. This issue was uncovered on June 28, 2018, by Cimetrics, a leading provider of energy management and analytics solutions.
The leaking valve, as depicted in Figure 1, failed to close properly, leading to a continuous flow of hot water or steam through the heating coil even when heating was not required. This leakage resulted in the discharge air temperature from the preheat coil exceeding 100F, necessitating the use of mechanical cooling to compensate.
The root cause analysis, conducted by Cimetrics, identified several potential reasons for the valve leakage, including mechanical failure such as valve seat damage, debris preventing full closure, actuator faults, or improper valve positioning/control logic errors.
Despite the final discharge from the AHU meeting the setpoint due to mechanical cooling, the issue was not detected on site. However, it was identified and analyzed remotely using Analytika algorithms, a testament to the power of advanced analytics in energy management.
Cimetrics collaborated with the facilities personnel of the Greater Houston Partnership (GHPF) to replace the faulty equipment. The cooling coil valve was opened to provide mechanical cooling to maintain the final AHU discharge temperature at the setpoint, while the preheat valve was replaced to stop the continuous heating.
The replacement of the faulty equipment resulted in significant annual energy savings of $55,027 and a reduction of 264 metric tons in annual carbon emissions. The issue was addressed from the O&M budget, highlighting the importance of regular maintenance and timely diagnostics in energy management.
In conclusion, addressing such valve leaks through timely diagnostics and control optimization can recover significant energy savings and reduce carbon emissions in building HVAC systems. This case study serves as a reminder of the importance of proactive energy management and the potential benefits it can bring.
Energy management solutions provider Cimetrics' discovery and remote analysis of a leaking preheat valve in an air handling unit (AHU) revealed its detrimental impact on the industry, finance, energy, and technology sectors. The leak resulted in increased operational costs, elevated carbon emissions, and system wear and maintenance, affecting the financial performance of the facility and its environmental footprint. Furthermore, the undetected leak jeopardized the effectiveness of the energy management system, demonstrating the necessity for advanced technology in detecting and rectifying such anomalies.
