This credit requires that you demonstrate energy savings from HVAC systems and components within your project scope—only systems installed as part of the LEED-CI project, or systems within the LEED boundary. (See more detail on scope below.)
Two options, for up to ten points
There are two options for achieving this credit, either of which could earn five or ten points for your project.
- Option 1 uses a prescriptive approach. You earn five points for calculating building loads and meeting mechanical system efficiency requirements in accordance with the Advanced Buildings: Core Performance Guide (CPG), Sections 1.4, 2.9, and 3.10. You can also, separately or in addition, earn five points by demonstrating appropriate zoning and controls to promote energy efficiency.
- Option 2 is a performance approach for projects that use energy modeling to predict how much energy they’ll save. Your project has to show 15% savings (compared to the minimum performance guidelines of ASHRAE 90.1-2007) to earn five points, or a 30% savings for an additional five points. These are challenging thresholds, because you can only count savings from HVAC systems and equipment and you have to reach one of these thresholds to earn any of the points—prorating is not an option. An Exemplary Performance point via IDc1 is also available if you can demonstrate 33% energy savings.
Which way to go?
If your HVAC equipment is fairly conventional, it will likely be listed in the CPG, making Option 1 the easiest approach for five points. More unique or innovative systems may find it better to go with energy modeling.
Is your project located in a LEED-certified building? If so, investigate if the building already has an energy model that you could adapt for this credit, potentially saving cost and enabling you to earn a better score. If not, consider whether your project scope is large or complex enough to warrant using an energy model.
Watch out for hidden requirements
To achieve the first five points in Option 1 the design engineer has to demonstrate that the HVAC system in the space can maintain minimum temperature and humidity ranges that meet ASHRAE-55. This requirement makes those points tricky for projects that do not have humidity control, especially in regions with high humidity. These points also require that you have a mechanical system with efficiency requirements listed in the CPG included in your project. For example, a project with VAV boxes only will not be eligible for the credit, but a project with a split system will.
Option 2 is challenging because for a small CI project the cost of creating an energy model might outweighs the benefit of the potential energy savings achieved from using the model as a design tool. If the base-building has already developed a model, this is often more cost-effective.
It’s the scope that matters
A typical HVAC installation in an office fit-out has a minimal scope. Often the base building’s mechanical systems supply the space with heating and cooling and ventilation air. What is left to the fit-out team is the distribution system which includes diffusers, VAV boxes, and controls. In LEED Interpretation #10134, issued on 11/1/11, USGBC clarified the level of HVAC equipment that must be installed to make a LEED-CI or LEED-Retail-CI project eligible for EAc1.3, Option 1, as being one of the following:
- Air handlers with Variable Speed Controls complying with the requirements of the Core Performance Guide Section 3.10 that supply at least 60% of the total supply air volume used within the project scope.
- Mechanical equipment that complies with the prescriptive efficiency requirements of the Core Performance Guide Section 2.9, and provides at least 60% of the cooling or heating capacity for the project scope.
- The project can comply with the requirements of the credit if the project team can show that the relevant criteria have been met for all HVAC systems serving the area within the project scope, whether or not the HVAC systems are installed as part of the tenant scope of work.
Another LEED Interpretation, #10135, further clarifies project scope for this credit, noting that "'project scope' refers to all spaces within the LEED project boundary, regardless of whether or not they are included in the project's scope of work. The project can comply with the requirements of the credit as long as all spaces within the 'project scope' satisfy the requirements."
This Interpretation also notes, "Each private office must have its own active controls. Grouping of offices using a single control does not meet the intent of the requirements."