is your building deadly? 4 steps to avoiding disaster within bems
TRANSCRIPT
Is Your Building Deadly?
4 Steps to Avoid Disaster Within BEMS Water Supply Systems
When considering a building energy management system (or BEMS), primary concerns are usually to do with cost, func>onality, and long-‐term effec>veness.
When considering a building energy management system (or BEMS), primary concerns are usually to do with cost, func>onality, and long-‐term effec>veness.
But are you aware of other risks associated with water supply systems?
Presen>ng substan>al poten>al risk, if systems are not carefully managed and kept within specific temperature ranges, both hot and cold water systems can provide perfect condi>ons for bacteria such as Legionnaires’ disease.
Legionnaires’ is a waterborne, occasionally fatal type of pneumonia that can develop in stagnant water, so minimising risk must be a priority to ensure the safety of a building’s occupants.
Leading the way in illness preven@on
Case example: For Leeds Teaching Hospitals NHS Trust, infec>on and illness preven>on is the highest priority.
Aware of the threats posed by ineffec>vely managed systems, the Trust are leading the way in risk mi>ga>on and compliance; using their legacy BEMS to monitor and control water supply systems across mul>ple trust buildings.
So what does establishing a safe water supply solu>on entail?
4 steps to avoiding disaster within BEMS water supply systems
Step One: SeEng cold water alerts
For the NHS hospital trust, seOng alerts was the first stage of the plan.
The Health Technical Memorandum 04-‐01 (HTM-‐04) and The UK Health and Safety Commission’s Approved Code of Prac>ce (ACoP) L8 gives guidance on preven>ng illnesses like Legionnaires presen>ng a problem.
To stop water becoming stagnant, it’s recommended that water stored in tanks is turned every 12 hours, with alarms set to trigger if this does not happen.
Regarding temperature, domes>c cold water (DCW) storage tanks across the Trust were monitored to check that water temperature remained below 24°C. Email and text alerts were also set to trigger if temperatures rose beyond the threshold, giving advanced warning of faults and preven>ng disease incuba>on.
Step Two: SeEng hot water alerts
Domes>c hot water (DHW) systems as well as cold were monitored too, with hot water flow and return temperatures observed across buildings, wards and departments.
Alarms were set to trigger if any hot water return temperature ran below 50°C for
longer than 15 minutes.
Step Three: Monitoring chlorine levels
As an added preventa>ve, Chlorine Dioxide should be added to water systems.
These alerts should be sent to building managers as well as the water treatment
company originally contracted.
Chlorine dioxide levels should be frequently monitored, and alerts set if chlorine levels drop under 0.2ppm (parts per million), or if chlorine gas levels rise above 0.3ppm.
Step Four: Preven@ng stagna@on
Leeds Teaching Hospitals NHS Trust used a BEMS solu>on from Trend Controls, which gave an addi>onal benefit of poor circula>on avoidance.
Similar to regularly turning water, the system’s outputs were connected to solenoid valves to regularly flush sec>ons of the system that are not frequently used.
These steps, combined with con>nuous monitoring, checks, and alarms, allow the Leeds Teaching Hospital NHS Trust to comply with HTM-‐04 and ACoP L8 guidance, and work with building infrastructure to minimise the risk of waterborne infec>on.
Find out more about how a BEMS can control and maintain your environment at:
www.trendcontrols.com
