Energy Modeling for LEED

Energy Modeling for FOR LEED Certification

Energy Modeling is the computerized assessment of a building structure that looks into the energy usage, utility bills as well as the overall life cycle costs of all the a variety of energy-related activities that are going on in the building in the future. This might involve activities such as air conditioning, central heating, water heating systems, electrical uses etc. Energy modeling is also used to examine and calculate the compensation periods for different types of alternative energy solutions such as wind turbines, solar panels and other similar devices. To be able to understand energy modeling, we first need to learn how to do building simulation in computer software packages. There are certain things that need to be considered while using the energy model: The model needs to be started as early as possible to achieve the best results. Secondly, be sure that you also take into account the carbon footprint of the building and lower it too. Thirdly, break down the building into smaller spaces that can make it easier for you to manage the work. When attempting to accomplish LEED Certification, the minimum energy performance prerequisite is the most important and the hardest step. It demands that evidence of a 10% improvement in the project building be shown if said project needs to be certified. This can be done by using energy modeling. This can give us a lot of information about a building’s possibility to save energy. The energy model consists of computer simulation software that requires an input of some specific building materials and then calculates its energy usage for a year and then creates a report about the projected energy consumption of the building. This model will then tell us how efficient the building can be. The method to generate this model as well as the study of the results helps make a better design for the building. The most important characteristic of the energy model is the cautious planning that it persuades us to do in developing strong green buildings which are welcome additions to the built environment.

In all new buildings, LEED Energy Modeling is an integral part of the certification process. The main reason for this is the use of ASHRAE 90.1 in the certification process. They are used in the U.S. to evaluate conformity with building codes with regard to the energy efficiency of buildings. The evaluation of energy efficiency using building simulation is a core element. The interesting thing about the ASHRAE 90.1 that all the energy costs of the building are recognized from the heating demand on the auxiliary power for fans up to the power usage of the computer. The flexibility of the simulation building control schemes, user behavior, and prevailing climate is often mapped very accurately.

The LEED Energy Modeling is simulated dynamically over the course of a year. A key output in LEED Energy simulation is the resolution of the energy costs of the building for an average year. Compliance with the minimum requirement is established in LEED from the comparison of the energy costs to those of the reference building. Depending on the how far the simulated energy consumption is lower than the reference building, up to 19 points can be awarded. With a maximum number of 110 points, almost 20 % of the total possible score is awarded based on the energy performance in LEED certification. As the core of the LEED certification, the results of LEED energy simulation are also the basis for setting the required percentage of renewable energy on the property or the necessary volume of green electricity to be purchased.

The LEED Energy Modeling of the building in operation has a special role in LEED certification. Through EAc5 Measurement & Verification, utilizing a simulation-based “Monitoring and Controlling Process” (M & V process) is awarded maximum 3 points relating to operating. The LEED energy simulation used in accordance with ASHRAE 90.1 in the planning stage is adjusted based on a minimum of one year’s data from the building in operation. By comparing the simulated consumption data together with the data recorded from the building, shortcomings in operation can be recognized. The search for potential savings is considerably simplified by the LEED Energy modeling. Another advantage is that control strategies can be tested in the LEED Energy model first before they are programmed into the actual system.Data on daylight availability can also be generated by the building simulation in addition to 2 other methods. Simulation involves less effort in large complex buildings.

The latest version of LEEDv4 was released in November 2013. This integrates the following changes:

LEED Energy simulation is based on the most recent version of ASHRAE 90.1 (2010 instead of 2007). However, this brings only marginal changes, the score for the energy simulation drops to a maximum of 18.
M & V will not be anymore part of LEED NC, but will be more focused on design.
Daylighting is a more important parameter with an up to 3 points instead of 1 point.

Altay Gursel