In this subsection, various energy conservation measures (ECMs) commonly recommended for commercial and industrial facilities are discussed. It should be noted that the list of ECMs presented below is not exhaustive or comprehensive. Rather, it is provided to indicate options that energy auditors can consider during energy analyses.
However, it is strongly advised that energy auditors keep abreast of new technologies that can enhance facility energy efficiency. Moreover, ECMs should be recommended only after performing an economic analysis for each measure.
1. Building Envelope
The building envelope, comprising walls, roofs, floors, windows, and doors, significantly impacts a facility’s energy consumption. The energy auditor should ascertain the actual characteristics of the building envelope. During the survey, comprehensive information about the materials of construction (e.g., insulation levels in walls, floors, and roofs) and the specifications of various envelope assemblies (e.g., window types and page numbers) should be documented. Additionally, observations regarding repair needs and recent replacements should be noted.
Commonly recommended ECMs to enhance the thermal performance of the building envelope include:
1.1. Addition of Thermal Insulation
Cost-effective for surfaces lacking thermal insulation.
1.2. Replacement of Windows
Installation of energy-efficient windows (high R-value, low-emissivity glazing, airtight, etc.) to reduce energy usage and enhance indoor comfort.
1.3. Reduction of Air Leakage
Mitigation of leakage areas through cost-effective weather-stripping techniques is especially crucial for residential buildings where weather-related energy consumption is predominant.
For commercial buildings, improvements to the building envelope may not always be cost-effective due to their potentially high expense. Nevertheless, auditing envelope components is recommended to identify energy-saving potential and ensure structural integrity. Thermal bridges, if present, should be addressed promptly to prevent increased heat transfer and moisture condensation, which can compromise the envelope’s integrity.
2. Electrical Systems
In most commercial and industrial facilities, electrical energy costs constitute a significant portion of the utility bill. Major energy-consuming components include lighting, office equipment, and motors.
2.1. Lighting
Accounting for approximately 40% of total electrical energy use in office buildings on average, lighting systems can be made more efficient through measures such as using energy-efficient lamps and ballasts, incorporating reflective devices, and implementing daylight controls.
2.2. Office Equipment
With office equipment being a rapidly growing part of electrical loads, energy-efficient options such as those meeting U.S. EPA Energy Star specifications should be considered.
2.3. Motors
Operating electric motors entails significant energy costs, which can be reduced through measures like optimizing motor systems, using controls to match motor output with demand, and installing energy-efficient motors.
Retrofitting electrical systems not only reduces total energy usage but also decreases cooling loads, contributing further to energy savings. Evaluating cooling energy reductions and potential increases in thermal energy use is essential when assessing the cost-effectiveness of lighting and office equipment improvements.
3. HVAC Systems
HVAC systems typically account for 40% of the total energy consumed by commercial buildings. To improve energy performance, the energy auditor should gather information about major HVAC equipment, including its condition, operating schedule, maintenance quality, and control procedures.
Some ECMs to enhance HVAC energy efficiency include:
3.1. Setting up/back thermostat temperatures
Adjusting heating and cooling temperatures during occupied and unoccupied periods.
3.2. Retrofit of constant air volume systems
Considering variable air volume (VAV) systems for improved efficiency.
3.3. Installation of heat recovery systems
Utilizing heat exchangers to recover heat from HVAC equipment.
3.4. Retrofit of central heating plants
Upgrading boilers for improved efficiency.
3.5. Retrofit of central cooling plants
Installing energy-efficient chillers suitable for retrofit projects.
A holistic approach should be taken when retrofitting HVAC systems to optimize energy use and reduce heating and cooling loads.
4. Compressed Air Systems
Compressed air is vital in manufacturing but often suffers from significant waste. To enhance efficiency, auditors should assess factors such as the suitability of compressed air for the task, application methods, delivery, control, and overall system management.
5. Energy Management Controls
Automated control systems, like energy management and control systems (EMCS), offer efficient energy consumption monitoring and adjustment. Regular system tune-ups, including sensor calibration, are crucial to ensure optimal operation and occupant comfort.
6. Indoor Water Management
Water-saving equipment and leak elimination can lead to significant water and energy savings in buildings. Utilizing water-efficient fixtures can result in up to 50% reduction in water usage, contributing to overall resource efficiency.
In conclusion, implementing these ECMs can lead to substantial energy and cost savings while promoting environmental sustainability in commercial and industrial facilities.