ASHRAE Level 2 Energy Audit: Energy Survey and Analysis Guide
Introduction
The ASHRAE Level 2 Energy Audit, also known as an Energy Survey and Analysis, represents a crucial step beyond the preliminary Level 1 audit in identifying and quantifying energy-saving opportunities within commercial and institutional buildings. This comprehensive assessment provides a detailed breakdown of energy consumption, evaluates building systems, and offers specific recommendations for Energy Conservation Measures (ECMs) with associated cost-benefit analyses. It is designed for building owners, facility managers, and energy professionals seeking to significantly improve energy efficiency, reduce operational costs, and enhance building performance. Unlike the simpler Level 1 audit, a Level 2 audit delves deeper into the operational characteristics of energy-using systems, offering a more robust foundation for investment decisions in energy efficiency projects.
Core Technical Content
An ASHRAE Level 2 Energy Audit involves a thorough investigation of a building’s energy profile, extending beyond historical utility data analysis to include detailed on-site surveys and engineering analyses. The primary objective is to identify all readily apparent low-cost/no-cost ECMs and to provide a more detailed analysis of potential capital-intensive ECMs. This includes an evaluation of the building envelope, HVAC systems, lighting, domestic hot water, and other significant energy-consuming systems.
Key components of a Level 2 audit typically include:
- Detailed Building Description: A comprehensive overview of the building’s physical characteristics, operational schedules, and occupancy patterns.
- Utility Data Analysis: A more granular analysis of 12-36 months of utility bills to establish baselines, identify consumption patterns, and calculate energy use intensity (EUI).
- On-Site Survey: An in-depth inspection of all major energy-consuming systems, including HVAC equipment (boilers, chillers, air handling units, pumps), lighting fixtures, control systems, and building envelope components (windows, insulation, roofing).
- System-Specific Analysis: Detailed examination of the operational efficiency of individual systems. For HVAC, this involves assessing equipment condition, control strategies, and distribution losses. For lighting, it includes evaluating fixture types, lamp efficiencies, and control mechanisms.
- Identification of ECMs: Development of a comprehensive list of potential ECMs, categorized by type (e.g., operational changes, equipment upgrades, control improvements).
- Energy Savings Calculations: Detailed engineering calculations to quantify the energy savings associated with each recommended ECM. These calculations often involve using industry-standard methodologies and software tools.
- Cost Estimation: Preliminary cost estimates for implementing each ECM, including material, labor, and installation costs.
- Financial Analysis: Evaluation of the economic viability of each ECM, typically including metrics such as simple payback period, return on investment (ROI), and net present value (NPV).
- Reporting: A comprehensive report summarizing findings, recommended ECMs, estimated savings, costs, and financial analyses. The report also includes a breakdown of energy use by end-use category (e.g., heating, cooling, lighting).
Comparison Tables
To better understand the scope and depth of an ASHRAE Level 2 Energy Audit, it is helpful to compare it with Level 1 (Walk-Through Analysis) and Level 3 (Detailed Analysis of Capital-Intensive Modifications) audits. Each level serves a distinct purpose and provides varying degrees of detail and financial analysis.
| Feature | ASHRAE Level 1 (Walk-Through Analysis) | ASHRAE Level 2 (Energy Survey and Analysis) | ASHRAE Level 3 (Detailed Analysis of Capital-Intensive Modifications) |
|---|---|---|---|
| Objective | Identify obvious ECMs, preliminary energy use | Identify all low-cost/no-cost ECMs, detailed analysis of capital ECMs | Provide investment-grade analysis for complex, capital-intensive ECMs |
| Methodology | Visual inspection, utility bill analysis, interviews | Detailed on-site survey, engineering analysis, utility data analysis | Sub-metering, trend logging, simulation modeling, detailed engineering |
| Data Collection | 12 months of utility data, basic building info | 12-36 months of utility data, detailed system info, operational data | Extensive data collection, real-time monitoring, system performance |
| ECMs Identified | Simple, low-cost operational improvements | Comprehensive list of operational and capital ECMs | Complex, integrated system modifications |
| Financial Analysis | Simple payback period, rough cost estimates | Simple payback, ROI, NPV, detailed cost estimates | Investment-grade financial analysis, life-cycle cost analysis |
| Report Detail | Summary report, general recommendations | Detailed report with specific ECMs, savings, costs, financial metrics | Highly detailed report, engineering specifications, project plans |
| Typical Cost | Low | Medium | High |
| Target Audience | Initial screening, basic understanding | Decision-makers for energy efficiency projects | Investors, project developers for major retrofits |
Application Guidelines
Choosing the appropriate level of energy audit is critical for effective energy management. An ASHRAE Level 2 Energy Audit is typically recommended when:
- Initial Energy Savings Potential: A Level 1 audit has identified significant energy-saving opportunities, and a deeper analysis is required to quantify these savings and assess their economic viability.
- Budgeting for Capital Projects: Building owners or managers are planning capital improvements and need detailed information to justify investments in energy efficiency measures.
- Performance Improvement: There is a desire to improve overall building performance, reduce operating costs, and enhance occupant comfort beyond basic operational adjustments.
- Compliance and Certification: The building needs to meet specific energy performance standards, certifications (e.g., LEED-EB), or regulatory requirements that necessitate a comprehensive energy assessment.
- Understanding Energy Use: A thorough understanding of how energy is consumed within the building is needed, including breakdowns by end-use and system-specific inefficiencies.
- Pre-requisite for Level 3: A Level 2 audit often serves as a necessary precursor to a Level 3 audit, providing the foundational data and initial ECM identification before delving into highly complex, investment-grade analyses.
Selection Criteria:
When deciding to proceed with a Level 2 audit, consider the following:
- Building Size and Complexity: Larger, more complex buildings with diverse energy-consuming systems often benefit most from the detailed analysis provided by a Level 2 audit.
- Energy Spend: Buildings with high annual energy expenditures have a greater potential for significant savings, making a Level 2 audit a worthwhile investment.
- Organizational Goals: If the organization has specific sustainability targets, carbon reduction goals, or mandates for energy efficiency, a Level 2 audit provides the roadmap to achieve these.
- Available Resources: Ensure that there are sufficient resources (time, budget, personnel) to implement the recommendations that will arise from a Level 2 audit.
Sizing Rules:
While there are no strict "sizing rules" in terms of building square footage that mandate a Level 2 audit, it is generally considered appropriate for most commercial, institutional, and industrial facilities where energy costs are a significant operational expense. The value derived from a Level 2 audit increases with the complexity of the building’s systems and the magnitude of its energy consumption. It is less common for very small, simple buildings, where a Level 1 audit might suffice, or for buildings undergoing major retrofits requiring the investment-grade analysis of a Level 3 audit from the outset.
Installation/Implementation Notes
For contractors and engineers involved in implementing the recommendations from an ASHRAE Level 2 Energy Audit, several key considerations are paramount to ensure successful project execution and realization of anticipated energy savings:
- Detailed Planning: Before any implementation, a thorough project plan should be developed, outlining scope, schedule, budget, and responsibilities. This plan should be based on the detailed ECMs and financial analyses provided in the Level 2 audit report.
- Qualified Personnel: Ensure that all personnel involved in installation and implementation are properly trained and certified for the specific technologies and systems being modified or installed. This includes HVAC technicians, electricians, and control system specialists.
- Adherence to Specifications: Strictly follow the engineering specifications and recommendations outlined in the audit report. Any deviations should be carefully reviewed and approved by the project engineer to avoid compromising energy savings or system performance.
- Commissioning and Verification: After implementation, thorough commissioning of new or modified systems is essential. This involves testing, adjusting, and balancing (TAB) to ensure that systems operate as intended and achieve the projected energy savings. Post-implementation measurement and verification (M&V) should be conducted to track actual savings against predicted savings.
- Safety Protocols: All installation and implementation activities must adhere to relevant safety standards and regulations to protect workers and building occupants.
- Permitting and Compliance: Ensure all necessary permits are obtained and that the implemented measures comply with local, state, and national building codes and environmental regulations.
- Occupant Communication: For measures that may impact building occupants (e.g., temporary shutdowns, changes in comfort settings), clear and timely communication is vital to minimize disruption and ensure cooperation.
Maintenance and Troubleshooting
Effective maintenance and proactive troubleshooting are crucial for sustaining the energy savings achieved through a Level 2 energy audit. Regular attention to system performance can prevent energy drift and ensure long-term efficiency.
Maintenance Best Practices:
- Preventive Maintenance (PM) Schedules: Implement and strictly follow PM schedules for all HVAC equipment, lighting systems, and other energy-consuming assets. This includes routine inspections, cleaning, lubrication, and calibration.
- Filter Replacement: Regularly replace air filters in HVAC systems to maintain optimal airflow and system efficiency. Clogged filters significantly increase fan energy consumption.
- Coil Cleaning: Keep evaporator and condenser coils clean to ensure efficient heat transfer. Dirty coils reduce system capacity and increase energy use.
- Refrigerant Charge Checks: For refrigeration and AC systems, verify proper refrigerant charge annually. Incorrect charge can lead to substantial efficiency losses.
- Control System Calibration: Periodically calibrate sensors and actuators in building automation systems (BAS) to ensure accurate readings and proper system response.
- Lighting System Checks: Inspect lighting fixtures for malfunctioning lamps or ballasts and replace them promptly. Clean diffusers and reflectors to maximize light output.
- Building Envelope Integrity: Regularly inspect the building envelope for air leaks, damaged insulation, and compromised weather stripping. Seal leaks and repair damage to minimize heat gain/loss.
Common Issues and Troubleshooting:
| Issue | Potential Cause | Troubleshooting/Solution |
|---|---|---|
| Increased Energy Bills Post-ECM | Improper commissioning, system malfunction, changes in occupancy/operation, unverified savings | Re-commission systems, verify sensor calibration, review operational schedules, conduct M&V |
| HVAC System Underperformance | Dirty filters/coils, low refrigerant, faulty controls, air leaks in ducts | Clean/replace filters, clean coils, check refrigerant charge, inspect and seal ducts, calibrate controls |
| Lighting Issues (e.g., flickering, dimness) | Aging lamps/ballasts, faulty wiring, control system errors | Replace faulty components, inspect wiring, troubleshoot control system |
| Occupant Comfort Complaints | Improper temperature setpoints, poor air distribution, control system issues | Adjust setpoints, balance airflow, calibrate sensors, verify control sequences |
| Excessive Air Infiltration/Exfiltration | Damaged seals, gaps in building envelope, unsealed penetrations | Conduct air leakage test (blower door), seal gaps with caulk/weatherstripping, repair damaged components |
Standards and Codes
Adherence to relevant industry standards and codes is fundamental to conducting a credible ASHRAE Level 2 Energy Audit and implementing effective energy conservation measures. These standards provide methodologies, guidelines, and performance benchmarks.
- ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings: This is a foundational standard that provides minimum requirements for energy-efficient design of buildings. ECMs identified in a Level 2 audit should aim to meet or exceed these requirements.
- ASHRAE Standard 100: Energy Efficiency in Existing Buildings: This standard provides criteria for energy management programs in existing buildings, including guidance on conducting energy audits and implementing energy efficiency measures. It is directly relevant to Level 2 audits.
- ASHRAE Standard 189.1: Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings: While primarily for new construction and major renovations, its principles and requirements for energy performance can inform ECM recommendations in existing buildings.
- ASHRAE Guideline 14: Measurement of Energy, Demand, and Water Savings: This guideline provides methods for measuring, computing, and reporting energy, demand, and water savings from projects. It is critical for the M&V component of a Level 2 audit.
- ASHRAE Guideline 36: High-Performance Sequences of Operation for HVAC Systems: Offers advanced control sequences that can significantly improve HVAC system efficiency, often identified as ECMs in Level 2 audits.
- International Energy Conservation Code (IECC): A widely adopted model code that establishes minimum energy efficiency requirements for residential and commercial buildings. Compliance with IECC is often a legal requirement.
- Local Building Codes: Always consult and comply with local building codes and ordinances, which may have specific energy efficiency requirements or amendments to national/international codes.
- AHRI (Air-Conditioning, Heating, and Refrigeration Institute) Standards: AHRI standards provide performance rating conditions and methods for various HVACR equipment, ensuring that new or upgraded equipment meets specified efficiency levels.
- ACCA (Air Conditioning Contractors of America) Manuals: Manual J (Residential Load Calculation), Manual S (Equipment Selection), and Manual D (Duct Design) provide essential guidelines for proper HVAC system design and sizing, which are critical for optimizing energy performance.
FAQ Section
Here are some frequently asked questions regarding ASHRAE Level 2 Energy Audits:
Q1: What is the primary difference between an ASHRAE Level 1 and Level 2 Energy Audit?
A1: An ASHRAE Level 1 audit is a preliminary walk-through analysis to identify obvious energy waste and low-cost/no-cost ECMs. A Level 2 audit, on the other hand, is a more detailed energy survey and analysis that includes a thorough on-site inspection, engineering analysis, and financial evaluation of potential capital-intensive ECMs, providing more accurate savings estimates and cost-benefit analyses.
Q2: How long does a typical ASHRAE Level 2 Energy Audit take to complete?
A2: The duration of an ASHRAE Level 2 Energy Audit can vary significantly based on the size, complexity, and operational characteristics of the building. It typically involves several weeks for data collection, on-site surveys, engineering analysis, and report generation. Smaller, simpler buildings might take less time, while larger, more complex facilities could require a month or more.
Q3: What kind of financial metrics are included in a Level 2 audit report?
A3: A Level 2 audit report includes detailed financial analyses for each recommended Energy Conservation Measure (ECM). Common metrics include simple payback period, return on investment (ROI), and net present value (NPV). These metrics help building owners and managers assess the economic viability and prioritize energy efficiency investments.
Q4: Is an ASHRAE Level 2 Energy Audit a prerequisite for a Level 3 audit?
A4: While not always a strict prerequisite, a Level 2 audit often serves as a foundational step for a Level 3 audit. The detailed data, identified ECMs, and preliminary financial analyses from a Level 2 audit provide crucial information that can be further refined and expanded upon in a more intensive, investment-grade Level 3 analysis.
Q5: What are the key benefits of conducting an ASHRAE Level 2 Energy Audit?
A5: The key benefits include significant reductions in energy consumption and operational costs, improved building performance and occupant comfort, identification of both low-cost/no-cost and capital-intensive energy-saving opportunities, a clear roadmap for energy efficiency investments, and enhanced compliance with energy performance standards and certifications.