ASHRAE recognizes four levels of energy audit. At the lowest level (Level 0), you basically do a walk-through to identify low-hanging-fruit types of opportunities.
If you’re serious about saving energy, you may hire an expert to conduct a higher-level audit such as a Level 3 or Level 4. But in a facility where minimal effort has been expended to identify energy waste, such an audit typically identifies far more items than the typical facility can reasonably be expected to act upon.
Rather than generate a big list of items you can’t do, it makes more sense to get some initial energy savings that can help bankroll subsequent improvements. So before conducting that big formal audit, look for these opportunities:
- Shut things off. Surprisingly, this is often overlooked. Task lights are left on, hallways are left fully lighted, and chilled-water drinking fountains are left on — long after everyone has gone home. Take a survey of which items can be put on their own circuits, so that you can add manually operated off switches (if administrative procedures will be followed) or automatic timers. Occupancy sensors also may help here.
- Upgrade the lighting. How old are those fluorescent lamp/ballast systems, and how do they perform compared with the energy-efficient versions on the market today? What about replacing entire lighting systems with LED systems (new fixtures, new layout, new controls)? Do you light areas with bay doors that let in sunlight? If so, what about light sensors to cut back on artificial lighting when the doors are open? And, again, consider occupancy sensors.
- Fix your heat exchangers. When is the last time someone cleaned the condensors of HVAC units and combed the cooling fins of condensors, evaporators, chillers, and similar equipment? This simple maintenance may reduce energy waste considerably. Also inspect roof curbings for leaks, using a thermographic camera.
- Fix compressed air leaks. A huge energy drain in nearly any industrial facility is leaks in the compressed air system. This air is very expensive. Producing and drying it is a huge energy user. Pressure anomalies caused by leaks also may interrupt production. Ultrasonics can help you find leaks, so they can be repaired. Even a 10% reduction in leaks could result in a significant energy savings. Carry out this step until all leaks are found.
- Use variable drives instead of bypass systems. A common method of controlling pressure in a hydraulic system is to run the pump motor at full speed, then bleed off extra output via a pressure valve. Rather than waste energy this way, simply throttle back the motor speed automatically using a VFD that responds based on the pressure in the system.