January 10, 2018 by Kellie Darbonne, LEED® AP BD+C
Are you designing a new building, going through a measurement and verification process, attempting a green building certification, demonstrating compliance with code, or retrofitting an existing building? A whole-building energy model is a valuable tool for analyzing building performance data and assisting in the decision-making process for the building envelope or its systems.
A whole-building energy model can compare mechanical systems, evaluate energy conservation strategies, optimize sizing, and improve overall system performance. Simply put, an energy model is a physics-based software simulation that calculates building energy use. Modelers build a digital building by inputting various building attributes such as: envelope construction materials, HVAC systems, interior and exterior lighting, building orientation, process loads, water heating, just to name a few. Combined with local climate conditions and the building usage profile, this data is used to estimate building thermal loads and energy use and costs, while highlighting system interactions.
During early design application, referencing previous projects or using default values can serve as the input to gauge preliminary early design assessment, building loads, or system interactions. However, if the project requirements include demonstration of code compliance or green building certification, such as LEED, complete building components and information must be incorporated into the energy model before final submission.
While there are various approaches to modeling a building’s energy use, each software is unique and carries different strengths and weaknesses. To determine the best program for your needs, take into consideration key fundamentals, such as project scopes, user friendliness, cost, program flexibility, output reports, and calculation run time.