What is LEED? – Energy and Atmosphere

September 23, 2014

This is the fifth post in a series on the LEED green building rating system. The first post provided an Introduction to LEED, the second looked at the Sustainable Sites credit category, the third at the Location and Transportation credits, and the fourth at Water Efficiency.

LEED logo images

Energy and Atmosphere

Improving energy efficiency is one of the easiest ways to save money and improve the sustainability of a building. Therefore almost a third of the points available in LEED are found in this category.  Projects can earn these points by making the building more efficient that a code baseline building of similar size and shape, commissioning the building systems, and adding renewable power sources to the project.

Fundamental Commissioning and Verification

This is a required measure and must be completed to qualify for LEED certification.  Commissioning involves testing the equipment to verify that it is performing according to the design intent.  The commissioning agent, or person performing the testing, can be a member of the project team, but should not be directly involved in the building design.  Systems that need to be commissioned include: HVAC, electrical, plumbing, and renewable energy.  Exterior enclosures are also reviewed by the commissioning agent.

Fundamental commissioning includes: design review, development and inclusion of a commissioning plan into the construction documents, developing checklists and testing procedures, testing of the systems, maintenance of a trouble log, and reporting all findings to the building owner.

In addition, the project must develop an operations and maintenance plan designed to keep the building operating efficiently.  The plan should include: set points and schedules for the building system controls, a systems narrative, preventative maintenance plan, and an ongoing commissioning plan.

Minimum Energy Performance

This is a required measure and must be completed to qualify for LEED certification.  There are three options to meet this prerequisite.  The first involves providing a whole building energy simulation showing that the design will save at least 5% of the total energy use as compared to a code building of similar size and shape.  Projects must meet this requirement without including renewable energy sources.

The second option is to comply with the mandatory and prescriptive measures included in ASHRAE Standard 90.1-2010.  The standard provides requirements for  HVAC and service water heating requirements, including equipment efficiency, economizers, ventilation, and ducts and dampers.

Projects less than 100,000 square feet can earn this prerequisite by following the prescriptions of ASHRAE Standard 90.1-2010 Sections 1-3, which provide strategies and requirements for certain building systems.

Building-Level Energy Metering

This is a required measure and must be completed to qualify for LEED certification.  Projects must include whole building-level meters or sub-meters that can be aggregated to provide whole building use quantities for all energy consumption (natural gas, electricity, biomass, steam, propane, etc).  The project must also agree to provide this data on a monthly basis to the US Green Building Council for a five-year period.

Fundamental Refrigerant Management

This is a required measure and must be completed to qualify for LEED certification.  Projects should not use chlorofluorocarbon (CFC)-based refrigerants in new heating, ventilating, air-conditioning, and refrigeration systems.  If systems or equipment are re-used, a phase-out plan must be provided.

Enhanced Commissioning

This credit is worth 2-6 points.  Enhanced commissioning is performed in addition to the fundamental prerequisite above.  In order to receive this credit, the commissioning agent must be an independent contractor not already on the project team.  To earn 3 points