Understanding LEED® Certification: Part III

Existing Buildings: Operations & Maintenance, Energy and Atmosphere

By Jennifer Easton

August 1, 2011

Understanding LEED® Certification: Part III
Existing Buildings: Operations & Maintenance, Energy and Atmosphere

Editor's Note: This Part III is the first half of an article covering energy and atmosphere. The balance of the article will be published in the September/October issue of Green Manufacturer.

The world's energy crisis may be the single largest issue of our time. From the tangible effects of climate change to the realities of fossil fuel resource depletion, the way we generate energy is more important than ever.

Energy efficiency is one of the core principles of green building. Subsequently, they reduce energy use and greenhouse gas emissions emitted from energy production, reduce operating costs, and rely on renewable-energy sources that cause significantly less harm to the environment and communities.

Energy and Atmosphere credits in the LEED for Existing Buildings: Operations and Maintenance rating system tackle the crucial aspect of building energy use by monitoring and optimizing energy performance; by eliminating the release of chlorofluorocarbons (CFCs) that deplete the ozone layer and contribute to climate change; and by promoting the use of renewable energy to minimize acid precipitation and smog that exacerbate human health problems and climate change.

Energy and Atmosphere (EA) Prerequisite 1:
Energy Efficiency Best Management Practices – Planning, Documentation, and Opportunity Assessment (Required)

Intent: To promote continuity of information to ensure that energy-efficient operating strategies are maintained and provide a foundation for training and system analysis.

Requirements: Document the current sequence of operations for a building, and develop a plan for how it is to be operated and maintained. Create narratives describing the mechanical and electrical systems and equipment in the building, and conduct an energy audit in line with ASHRAE Level 1 walk-through assessment.

Potential Strategies: In the building operating plan, include all relevant information: Detail installed energy-consuming systems (how they operate and the environmental building requirements they must meet); identify all the building's spaces (uses and occupancy types); and create a schedule for every system.

This narrative should cover a series of base building systems, including space heating and cooling, ventilation, domestic water heating, humidification and dehumidification, and lighting. Document what operational states are desired, based on schedules and conditions (running or idle, full-load or part-load, etc.). Also, include a preventive maintenance plan for equipment listed.

Last, the energy audit must meet the guidelines of ASHRAE Level 1, walk-through analysis. It will be used to identify ways to reduce building energy use and operating costs.

EA Prerequisite 2:
Minimum Energy Efficiency Performance (Required)

Intent: To establish the minimum level of operating energy efficiency performance relative to typical buildings of similar type to reduce environmental and economic impacts associated with excessive energy use.

Requirements: Requirements for EA Prerequisite 2 vary, depending on whether or not the project is eligible for Energy Star® rating or not. Eligible projects must achieve an energy performance rating of at least 69 and use energy meters. Projects not eligible for Energy Star rating must achieve energy efficiency at least 19 percent better than the national average.

EA Prerequisite 3:
Fundamental Refrigerant Management (Required)

Intent: To reduce stratospheric ozone depletion.

Requirements: Projects must demonstrate zero usage of CFC-based refrigerants, unless not economically feasible, or have a phase-out plan in place. These exceptions must be verified by a third-party audit.

Potential Strategies: Create a plan to phase out usage within five years from the end of the project's performance period. Annual leakage of CFC-based refrigerants in the central systems should be reduced to 5 percent or less, and total leakage over the remaining life of the unit should be less than 30 percent of its refrigerant charge (by Clean Air Act standards). Small HVAC&R units, standard refrigerators, small water coolers, and cooling equipment containing less than 0.5 pound of refrigerant are exempt from EA Prerequisite 3.

When selecting replacement or conversion equipment, choose refrigerants with short environmental lifetimes, small ODP (ozone-depleting potentials), and low-GWP (global-warming potentials) values.

EA Credit 1:
Optimize Energy Efficiency Performance (1 to 18 points)

Intent: To achieve increasing levels of operating energy performance relative to typical buildings of similar type to reduce environmental and economic impacts associated with excessive energy use.

Requirements: EA Credit 1 has different requirements based on whether or not the project is eligible for Energy Star rating. If so, projects must achieve an energy performance rating of at least 71. Projects not eligible for an Energy Star rating must demonstrate energy efficiency at least 21 percent better than the national average.

Potential Strategies: Depending on Energy Star eligibility, points vary based on the rating or, for those ineligible, on the percentile level above the national median. Buildings must have dedicated energy meters, and the project's energy performance rating must be based on actual metered energy consumption for a minimum of 12 consecutive months.

To improve energy performance, reduce demand by reducing internal loads through shell and lighting improvements and setting operating schedules optimally. Harvest site energy such as daylight, solar heating, and wind energy. Increase efficiency through the site envelope, lighting, and HVAC systems, and recover waste energy through exhaust air energy recovery systems, and cogeneration.

EA Credit 2.1:
Existing Building Commissioning — Investigation and Analysis (2 points)

Intent: Through a systematic process, to develop an understanding of the operation of the building's major energy-using systems, options for optimizing energy performance, and a plan to achieve energy savings.

Requirements: The first option for this credit involves a commissioning process, while the second approach calls for an ASHRAE Level II energy audit.

Potential Strategies: The first option, building commissioning, must address all of the building's major energy-using systems and may be completed by an external commissioning agent or by members of the building operations staff. Two essential goals that should guide the commissioning process and documentation are identifying cost-effective reductions in energy consumption and improving indoor conditions for building occupants. The commissioning plan should identify the scope of the process, estimation of cost, project management tools, team members and responsibilities, as well as a timetable for completion.

To fulfill the credit's second option, conduct an energy audit that meets the requirements of ASHRAE Level II. It is recommended, but not mandatory, that project teams conduct the audit during the performance period. This type of audit must include a total of 12 key elements, including a review of existing operating and maintenance problems; a breakdown of total annual energy use; and a list of all possible modifications to equipment and operations that would save money and cost estimates.

E & A Credit 2.2:
Existing Building Commissioning – Implementation (2 points)

Intent: To implement minor improvements and identify planned capital projects to ensure that the building's major energy-using systems are repaired, operated, and maintained effectively to optimize energy performance.

Requirements: Implement no- or low-cost operations improvements, demonstrate costs and return on investment (ROI) for these improvements; provide training for management staff on sustainable building operations topics; and update the building operating plan to reflect changes.

Potential Strategies: Improvements completed for EA Credit 2.2 should be based on the findings from Credit 2.1. When calculating cost-benefit analyses, base calculations on actual observed costs as much as possible, using abbreviated time periods to extrapolate annual outcomes and actual utility rate schedules. No minimum requirement for staff training is outlined in this credit, and 24 hours per person per year is recommended.

EA Credit 2.3:
Existing Building Commissioning—Ongoing Commissioning (2 points)

Intent: To use commissioning to address changes in facility occupancy, use, maintenance, and repair. Make periodic adjustments and reviews of building operating systems and procedures essential for optimal energy efficiency and service provision.

Requirements: Implement an ongoing commissioning program, summarizing an overall commissioning cycle for the building by equipment or building system group. At least half of the work outlined in the first commissioning cycle must be completed prior to the application date for LEED 2009 for Existing Buildings: Operations & Maintenance.

Potential Strategies: This should include a detailed schedule for the completion of the overall commissioning cycle, a budget for each phase of the cycle, and a list of all building equipment relevant to the process. Also, specify procedures for responding to deviations from expected or preferred performance parameters