An energy model is a computer-generated representation of a building used to estimate the impact of proposed changes to the building on energy use. HPAC Engineering goes over the basics of existing-building energy modeling in its December issue.
The article tells what the comparative tool is used for and goes over modeling methods, such as project type, type of data available, and level of accuracy of resolution. According to the article, energy models can be used throughout the life of a building for comparative reasons (e.g., whether HVAC systems are operating based on designed and commissioned controls sequences of operations).
The article also covers M&V, existing building commissioning and energy models. More often than not, highly detailed whole-building-simulation modeling does not fit within the constraints of an existing-building-commissioning-project budget. In such a case, it is the project manager’s responsibility to manage the expectations of the client. It also is the project manager’s responsibility to manage the energy analyst’s time and effort to meet the needs of the project while staying on budget.