Energy Modeling

Energy Modeling

WHAT IS Building Energy Modeling?

Building Energy Modeling (BEM) is the use of computer-based simulation software to analyze a building's energy consumption and energy-using systems. It requires an energy modeler to input data to create a mathematical model of the building which is then analyzed using equations based on thermodynamics and building science. The results of the simulation are reported for annual performance and include space cooling and heating loads, energy costs and other performance-related parameters. BEM is useful for comparing energy-efficiency options, optimizing operation, exploring retrofit opportunities, and includes whole-building simulation as well as component analysis utilizing specialized software tools.

WHAT ARE THE BENEFITS?

Building Energy Modeling (BEM) supports an Integrated Design Process and provides significant benefits to both new construction and retrofit projects. BEM helps make strategic tradeoffs between upfront project costs and annual building energy costs. It can also be used to check and inform operations for existing buildings. By comparing it with actual performance, owners can identify performance deficiencies and resolve inconsistencies to ensure everything is working correctly.

• Reduced First Costs
• Reduced Operating Costs
• Improved Occupant Satisfaction

WHAT IS THE PURPOSE?

BEM is increasingly used in building efficiency projects to improve building performance, support high-performance building design, and demonstrate performance claims. It can help achieve different modeling objectives and is categorized as modeling to compare, comply, or predict. Understanding the differences can help define the modeling scope.

• LEED certification (EAc1) Adhere to LEED Building Design + Construction (BD+C) requirements for Energy & Atmosphere, Credit 1 - Optimize Energy Performance to determine and document points achieved
• Energy code compliance Demonstrate compliance with the commercial building energy code
• C-PACE energy assessment Evaluate the impact of individual energy efficiency measures (EEMs) affecting the building design
• Utility incentives
• 179D tax deduction Under Section 179D of the US tax code, owners of commercial buildings or primary designers have the chance to claim a tax deduction for properties that are created energy-efficiently.
• Energy Star SEDI a report that provides an overview of your design metrics, including the predicted ENERGY STAR score for a building that is yet to be constructed. It is also used for Designed to Earn the ENERGY STAR applications.
• Measurement & Verification Develop a calibrated model representing the existing building to establish baseline conditions to support a Measurement & Verification approach

TYPICAL MODELING COSTS

The scope and tasks involved in energy modeling depend on the purpose of the modeling, which affects the level of effort and costs required. Other factors that influence costs include:

• The size and complexity of the project.
• The resolution of the analysis.
• Any additional modeling required.
• The performance targets.

For instance, basic modeling services that cover design assistance and LEED BD+C components can cost anywhere from $6,000 to $18,000. On average, modeling costs for projects that participate in a utility-sponsored design assistance program are around $12,000 for an average size of 100,000 sq.ft.

SIMULATION SOFTWARE

Modelers can use whole-building simulation tools at different levels. They can vary the level of input by relying more or less on the software default conditions. They can also translate more or less project information to develop model input values. Modelers can also use specialized tools to support the process and/or inform the whole-building simulation. In general, the goal is to keep the model as simple (and affordable) as possible while still maintaining sufficient accuracy to meet project objectives.

Our energy modelers prefer using eQUEST, which is widely accepted in the industry. However, we can use other software tools as needed.

• eQUEST (DOE-2.2, DOE-2.3)
• EnergyPlus (DesignBuilder, OpenStudio)
• IESVE, HAP, TRACE 700, EnergyGuage, Energy Pro

Our Process

• Project Assessment
  • Gather building plans and specifications
  • Define performance goals and requirements
  • Review applicable codes and standards
  • Establish modeling scope and deliverables
• Model Development
  • Create detailed 3D building geometry
  • Input building systems and controls
  • Define occupancy and usage patterns
  • Incorporate weather data and site conditions
• Analysis & Optimization
  • Run baseline and proposed case simulations
  • Evaluate system alternatives
  • Identify energy conservation measures
  • Perform parametric studies
  • Calculate energy cost savings
• Documentation & Reporting
  • Generate detailed simulation reports
  • Prepare compliance documentation
  • Provide energy conservation recommendations
  • Develop implementation strategies
  • Calculate ROI and payback periods