Energy Modeling (Whole Building Energy Simulations)

Energy Modeling is a powerful tool not only necessary to earn LEED certification, but more importantly, to assist the project team in accurately evaluating energy reduction strategies that maximize both energy and cost efficiency and minimize the impact on the environment. LEED rewards design teams for innovative design who pursue sustainable approaches towards building systems and usage. Energy reductions can be divided into three categories: prescriptive methods, system upgrades and improvements, and integrated whole building design. Energy reductions through innovative design can be documented and put in numbers when compared to a baseline model. the energy model must be capable of analyzing the reactions of the building’s skin and equipment to the external climate conditions and internal loads for each hour for a full year (8,760). Internal loads include heat from occupants, equipment, and lighting. External conditions include outside air temperature, solar heat gains, and infiltration. The simulation software also models the efficiency of the mechanical systems and local utility rates.

Energy Modeling Process

The energy modeling process starts with collecting building design data: construction documents, product specs, and owner's goals. The data is used to create a virtual copy of the building. We can create an accurate daily usage calculation by creating hourly usage schedules for the entire year. Finally we compare the virtual copy with a baseline version and run a report. From these reports we can determined how much the proposed building will perform to EPAct, LEED or project goals.

Design Changes and Alterations

The power of the building simulation software is the ability to make quick changes to the building design. Whether it is a project concept or an existing building, the whole building energy simulation can model the affects of any design choice. Design decisions can result in unexpected and unwanted consequences. Energy modeling can replicate the building down to its building materials and air flow patterns so you and your clients can feel confident making final design decisions.

Study Options

Energy modeling and (Building Intergrated Modeling) BIM software are designed to guide architects, engineers, and building owners in the design and maintenance of building structures and systems. These programs can model solar collection samples, air movement, natural day lighting, and heat transfer.

Energy Modeling Software

Building information modeling covers geometry, spatial relationships, light analysis, geographic information, process and non-process loads, quantities and properties of individual building components from manufacturers. Ecohill uses all of the latest Energy modeling software, including: EnergyPlus, DOE2 eQuest, Google Sketchup, Autodesk Revit, Autodesk Green Building Studio, Autodesk Ecotect, ArchiCAD, and Wrightsoft CHVAC. The reason we are fluent in the multiple programs is because each program has it's capabilities and limitations. For general energy efficiency studies we rely on the Department Of Energy designed eQuest.

Energy Modeling Reports

All of the programs can produce a raw report of the annual energy usage in the building but still needs to be interpreted correctly. A small change can mean the difference between an incorrect input and the correct results. As mentioned above, some programs need tweaks and tricks to make the simulation run correctly. Our energy modeling reports will clearly identify the energy and cost savings above baseline, will show all inputs modeled , and will verify that all there were no warnings or errorsin the simulation.

Energy Modeling for LEED

The US Green Building Council's goal is to encourage whole building design approaches that integrate various building systems. LEED uses energy modeling quantify energy efficiencies and rewards teams for sustainable approaches

  • EA Prerequisite 2: Minimum Energy Performance: establish a minimum efficieny of 10% for new construction and 5% for major renovations.
  • EA Credit 1: Optimize Energy Performance:1 point for minimum 12% NC/8% EB improvement above baseline and a max of 19 points for 48% NC/44% EB improvement.
  • EA Credit 5: Measurement and Verification: 3 points for verifying energy consumption after a one-year period.
  • IE Q Credit 8.1: Daylight and Views—Daylight: 1 point for demonstrating daylight for 75% of all regularly occupied occupied spaces.

Energy Modeling for EPAct 2005

The Energy Policy Act of 2005 (EPAct) allows for a tax deduction of $1.80/SF for commercial buildings that can demonstrate a 50% reduction in total annual energy and power costs. The 50% reduction can be demonstrated through the use of a DOE approved simulation program, such as eQuest, EnergyPlus, and Green Buildign Studio.

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