One of the primary objectives of an EMS is to reduce costs through improved operational and energy efficiency. To achieve that objective, one must invest the time & resources necessary to ensure that the EMS is performing properly.
System Management Programs provide an effective strategy to ensure EMS value is maximised without creating an extra ordinate drain on resources. These strategies include reconciliation of system changes by store level personnel, maintenance of long-term performance, and protection of the decisions and investments initiated on behalf of EMS programs.
Challenges to achieving maximum ROI
System overrides: Given that the primary focus of local site managers is to maintain store operations and comfort, overriding the system settings for temperature and lighting controls is often the quick fix to a complaint.
Lack of documented standards/enforcement: Standard configurations may not be well documented or enforced; therefore, the optimal settings, staggered start times or other energy saving program parameters may not be properly configured in the EMS programming.
Sensor location: Proper sensor locations within the facility can have a huge impact on the performance of EMS routines. Sensors are often found to be in less than optimal locations within facilities that are not performing efficiently.
Nuisance alarms: When any of the above or other issues exist, an excessive number of nuisance alarms can occur. It is easy for site managers to become complacent and ignore these nuisance alarms. Failure to actively monitor and prioritise system alarms can result in missed opportunities to take the proper corrective action in a timely fashion, resulting in increased energy costs, unnecessarily reducing asset life, and causing other important alarms to go unmanaged.
Improper maintenance: Periodic re-commissioning of the EMS is not always performed at a reasonable frequency; therefore, proper configuration settings may have been altered. Energy saving control algorithms can become out-of-date and out-of-sync with current operating standards of efficiency, or out-of-sync with actual site conditions. These all lead to a higher cost of operation.
Manage user interaction & permissions
A properly commissioned EMS is designed to optimise the balance between human comfort and energy savings, but what happens when human interaction inhibits system capabilities? Consider the daily routine of onsite managers. In addition to their many daily tasks and responsibilities, they are the recipients of any facility related issues or complaints. When a building feels too warm, or too cold, they are the ones who receive a notice or call. Given the pressure to respond, these onsite managers often take it upon themselves to override system settings and adjust temperature controls. To avoid these costly changes from adding up, close management of user permissions and a plan to systematically restore proper settings are essential.
The best practice is that site-level management significantly impacts EMS performance. It must limit access to authorised personnel only, and ensure that systems are set properly through continued monitoring and management. When manual overrides are identified, quick corrective action should be taken and system settings must be brought back to standard levels, according to business rules. Education & training of site level personnel on proper EMS management should be supported.
Prioritise system alarms
A key function of an EMS is to monitor energy-consumption and notify users of potential issues as they arise via alarms. These can include simple alarms, such as a dirty filter or occupancy mode change, or more critical alarms, such as a chilled water pump failure. In any given day, a single site in the portfolio could produce 50 to 100 alarms, depending on the amount of equipment being controlled. While system alarms play a critical role in supporting quick identification of potential building and equipment issues, it is not uncommon to see EMS performance degrade as site personnel become less responsive to these alarms.
Similar to the previous concern of unwanted human interaction, the inaction of site-level personnel can also degrade EMS performance. System notification alarms can be so numerous as to become unmanageable, eventually being considered nothing more than a nuisance to building managers. Excessive alarms may cause building personnel to ignore or simply turn off system alarms, rather than respond to them.
The best practice here is smart monitoring and documented process for alarm triage. These are essential to manage EMS alarm notifications and ensure that corrective action is taken in a timely fashion. There are varying levels of operational, financial, and efficiency impacts dependent on the severity of the alarm. It is important to develop & maintain a protocol that escalates the most critical alarms and prioritises less critical alarms that require different response time.
Pinpoint sensor location
Picture a site after an extensive heating, ventilation, and air conditioning (HVAC) renovation. A new HVAC unit should be operating at peak efficiency, but a cursory review of EMS data suggests otherwise, perhaps indicating that the unit is not running at all. This leads to a costly maintenance visit, which only concludes that the HVAC unit is fully functional. If supply air is blowing directly on the sensor, it registers cold air and causes the HVAC equipment to turn off. This in turn causes a false alarm, an unnecessary truck roll, and an uncomfortable environment for building occupants. Similar instances often occur as renovations take place; sensors are knocked off a wall or repositioned to an improper location, or interference-causing equipment is installed nearby without any thought to relocation of the sensors.
Best practice here is to review and verify that system sensors are placed in optimal locations, and are reflective of actual conditions being controlled. There should be regular test & maintainence of EMS sensor calibrations to ensure that integrity of sensors is not compromised and that equipment & sequences will perform as expected.
Perform periodic system backup
Configuration settings and EMS program files should be backed-up at every site. The consequences of not performing backups are obvious when a failure occurs. These situations can arise when a local uninterruptible power supply (UPS) fails and the battery goes dead, or when a controller fails and previous programs are no longer accessible. The best practice is to implement a schedule for periodic backup of the configuration and program files for the EMS at every site.
Re-commission energy management systems
Improper maintenance and failure to conduct timely re-commissioning can cause suboptimal operation and lead to increased maintenance costs & energy usage in comparison with similar sites. A good re-commissioning program can be of great value, particularly at those sites where EMS has not been properly maintained, users have been able to compromise the EMS settings and renovations or the addition of new system technologies have changed the building design.
Re-commissioning services not only correct existing problems, but also optimise system operation, so EMS functions perform as effectively as possible according to business needs. These efforts are often cost justified based on energy savings alone. In some cases, one can apply for utility incentives to provide additional financial support. A re-commission of the EMS typically includes complete audit and testing, repair & recalibration and re-programming.
The best practice here is to implement a schedule of periodic EMS recommissions. This is critical to preserve the life of the system. Other benefits include improved energy efficiency, more comfortable environment with fewer occupant complaints, reduced operating costs, and an overall improvement in EMS & equipment performance.
While compliance with the mentioned best practices standards can take a significant amount of work and resources, active management will pay for itself. At opposite ends of the spectrum, one can choose to adopt either a complete PM program or subscribe to a run-to-failure philosophy. Over the past two decades, PM programs have fallen out of favour due to resource constraints. Many companies have reduced maintenance labour due to budget cuts and instead implemented a run-to-failure philosophy. In the short term, running-to-failure can reduce maintenance costs. Often, it also leads to higher energy costs. Over the long term, equipment failures become more frequent. This, combined with higher energy costs, results in a higher total cost of operation. So, implement a cost-effective system-monitoring program inclusive of these best practices.