By Joe Lewis, 3R Technical Manager I
One of the strongest tools available to the built environment is an energy model. A virtual representation of a building’s utility usage is a necessary tool to ensure that the most effective energy use reduction solutions are being implemented for the building’s budget.
In the hands of a knowledgeable professional, an energy model can provide real and meaningful feedback as design professionals make their decisions as part of an integrated process. This model can then be iteratively updated along with the design to show compliance with local energy codes or show excellence within a voluntary rating system like USGBC Leadership in Energy and Environmental Design (LEED).
Example Use Case:
An architect and an owner are at odds about how many windows to put in a new office building. More windows would make the office more attractive to potential tenants, but this also puts more load on the HVAC equipment, which raises rent.
The energy modeler is consulted. Using the virtual representation of the design building, the modeler runs several scenarios and, in conjunction with construction cost estimates, determines that energy costs can be held constant by improving the proposed window thermal and solar properties at an increase to the construction budget of 10%.
The modeler notes that based on the building’s climate zone, it uses more heating than cooling and suggests that specifying a window that favors better thermal properties than solar properties, a slightly higher number of windows can be integrated into the design.
Energy models can also assist with forensic engineering and retro/ongoing commissioning. By collecting real data from the operating building through an audit and calibrated with utility bills, a virtual representation of the building can be developed to understand the expected weight of the different end uses within the building against how they are actually being run. This data helps facility managers and owners to make a strategic plan on the best opportunities to reduce operational costs through repairs and capital improvements.
The newest generation of modeling tools is expanding the capabilities at the disposal of design teams and building owners. One such next-generation function is a more accurate capture of dynamic occupancy within a building. This will make the predictive data provided by the model robust enough to be used as a predictive model for a building management system (think smart home of the future) to more closely manage lighting, thermostats, and outdoor air rates to match the movement of occupants within the building.
As more utilities move to real-time pricing structures for all commercial accounts, an energy model will be invaluable for both design and ongoing commissioning to help determine the best demand reduction strategies that minimize the impact on occupant comfort and normal business operation.
The current and future applications of energy modeling are integral to providing actionable and meaningful decision-making information that enables the minimization of operating costs and, by extension, operational greenhouse gas emissions. Energy models provide decision makers with data on the expected impacts of potential emission reduction strategies. These, combined with an annual spend on reduction activities, can make up the technical backbone of a company’s entire carbon reduction strategy and help establish a feasible net-zero target date.
JOE LEWIS has worked as an energy modeler and energy expert for 16 years and has 6 years of mechanical design experience. During his time as an energy modeler, Joe acquired a broader understanding of greenhouse gas emissions and works with clients to create actionable sustainability goals, collect data and quantify metrics, and report progress with clear and accurate key performance indicators.