We hear a lot about Global Warming and the need to save energy. Energy prices are rising and we are told to conserve. But, how does one determine how much energy their house, or apartment, or small business is using? How does one understand what changes need to be made in the pursuit of having more energy efficient and affordable housing?
This is where energy modeling comes in. An energy model is a digital representation of all the items and equipment in a structure that use or lose energy. Energy models are generated to determine compliance to energy codes, to understand if a structure meets the goals of a program, and to evaluate whether energy improvements are financially feasible and a good investment. An energy model is created by a person entering data into a computer program which then compares the data to a reference energy model, and provides the results. However, energy modeling is much, much more than data entry. The ability to generate an accurate energy model is one of the most difficult and critical responsibilities of any energy professional.
You have likely heard the saying, “garbage in, garbage out”, meaning that if a system is populated with bad data, the system will produce bad results. This is very true in this case. The person generating the energy model really needs to understand not only what data must be gathered to enter in the tool, but also whether that data makes sense. If incorrect or bad data are input, the results will still be generated, but they will be incorrect, or at least very misleading. Decisions made using the resulting information could be very bad decisions.
The modeler must know construction math and building science as well as obtain a working knowledge of where the model data comes from and why it is important. An understanding of what data are gathered in the field, what to expect from that field data gathering, and how to turn that data into modeling information and enter it into the Modeling tools is also required. This is why it is important that energy models be developed by certified energy modelers. One such organization is RESNET, the Residential Energy Systems Network, which oversees the quality assurance of HERS (Home Energy Rating System) energy models. RESNET now requires this certification for anyone generating an energy model for a HERS Rating.
You can learn more about this certification training for HERS Modelers at EnergySmart Institute.
