Best practices for making your HVAC systems more efficient—and less costly
With the heating season in full swing, it’s a great time for facilities to address their HVAC needs and do something about rising energy bills, inefficiency, and temperature-specific concerns. With advancements in building automation systems, facility managers have an opportunity to capitalize on the digital age with rapid data collection and transmission. Software such as Energy Monitoring Control Systems (EMCS) or Fault Detection Diagnostics (FDD) can now easily gather input from equipment controls over boilers, chillers and variable speed drives, along with overall building automation systems. With all this centralized awareness and control, the energy usage of HVAC systems can, and should, be optimized by facility teams that prioritize proper function and efficiency.
Even though few companies take a proactive approach to optimizing their HVAC systems, proper care and maintenance can cut your HVAC costs, extend equipment life, improve comfort and maximize uptime. Facility operators can use the following best practices to confirm the system is operating at peak efficiency.
Understanding exactly how well your HVAC is functioning is essential to getting the most out of your building system. Start with obtaining informed measurements; use your EMCS and FDD to provide you with key insights into where electrical usage is occurring, and when demand reaches its peak. Consider sub-metering your HVAC systems if you currently have only a single utility meter point. These can capture timely and accurate data points, and provide alerts when components malfunction or burnout. Facility teams can then verify their systems are operating well across multiple building zones, and identify intervention opportunities to save energy and costs.
In addition, be sure to track the performance of the system overall and determine if there are any unusual fluctuations or deviances. It is vital to benchmark the facility’s energy usage and costs in relation to previous years’ performances, as well as comparable buildings, to determine an operational baseline for potential improvement. Over time, occupancy usage of spaces and schedules can change within a facility, causing certain system set-points, such as HVAC, to drift – and ultimately leading to increased energy consumption and cost. Completing this diagnostic process should allow you to identify how efficiently your system is operating, and provide the foundation for realistic and achievable strategies for saving energy.
Once you have identified the level of HVAC efficiency for your facility through accurate data and intelligent benchmarking, it is time to determine potential causes for your system’s sub-optimal energy performance. Bear in mind that these causes may vary widely from building to building. While many causes can quickly be determined through the EMCS and FDD software, some may require the help of experts to identify. Common causes of HVAC inefficiency include:
- Poor/irregular equipment maintenance
Even the most advanced HVAC systems and equipment require diligent and regular maintenance to perform at their best. For example, if components such as air filters are not regularly checked and changed, systems will perform up to 15% below peak efficiency.
- Sub-optimal control strategies
Improperly programmed control systems, informed by poorly logged trends in HVAC energy use, can often account for a large amount of system inefficiency. Thoroughly identifying and addressing these factors may require the assistance of a Controls Contractor with expert knowledge of control sequences.
- Old equipment
Equipment nearing the end of its lifecycle may not be functioning as well as it once did, and may not benefit greatly from ordinary maintenance protocols. An old, poorly functioning piece of equipment may be costing a facility a great deal in terms of energy use and operating cost.
- Poor insulation / leaky ductwork, windows, and doors
Air escaping through windows and doors or along the building’s ductwork can cause systems to have to work harder to meet desired conditions throughout a facility. Leaks can be identified through a complete energy assessment, blower door test, visual inspection, and building pressurization test.
There is a variety of actions you can take to ensure HVAC systems are fully optimized. These actions can range in scale from replacing air filters and regular duct cleaning, to recommissioning the full system, all the way to replacing outdated equipment. The solutions will inherently depend on the unique needs of your facility and on the areas where it can be improved.
Having a regular energy audit performed by a third party can help you verify whether equipment is functioning properly and within energy parameters. Facility teams should implement a comprehensive maintenance regimen that addresses their specific HVAC system and is adaptable to changing operational needs. If the equipment is reaching the end of its useful lifespan of 15 to 20 years, it will be time for facility managers to evaluate it and prepare the business case for a replacement. At that point, it might also be wise to have an expert engineer or technician review the system for deficiencies. Connecting these steps to capital planning exercises can also ensure the facility has a solid plan for long-term cost consistency and reliability.
The financial benefits from diagnosing issues, identifying causes, and implementing solutions for the HVAC system cannot be overstated. Making these decisions today will go a long way toward improving your organization’s profitability and enhancing the satisfaction of your building’s occupants.