Energy-modeling is the virtual or computerized simulation of a building or complex that focuses on energy consumption, utility bills and life cycle costs of various energy related items such as air conditioning, lights and hot water. It is also used to evaluate the payback of green energy solutions like solar panels and photovoltaics, wind turbines and high efficiency appliances. To understand energy modeling, it's important to understand building simulation:
Building simulation is the process of using a computer to build a virtual replica of a building. In layman's terms, the building is built from its component parts on a computer and a simulation is performed by taking that building through the weather conditions of an entire year. In a way, building simulation is a way to quantitatively predict the future and thus has considerable value. Building simulation is commonly divided into two categories: Load Design, and Energy-Analysis. The common phrase for building simulation when energy is involved is Energy-modeling.
Load Design is used to determine:
Air conditioning loads (the amount of cooling/heating energy needed by a space/system/building)
Volumetric air flow requirements (the amount of air needed to cool/heat a space)
Equipment capacities (since equipment may condition multiple spaces)
Hydronic Plant capacities (worst case simultaneous load)
Similarities and differences between equipment options for heating and cooling a space
Energy-Analysis or Energy-modeling is used to:
Predict the monthly energy consumption and bills
Predict the annual energy cost
Annual CO2 emmissions
Compare and contrast different efficiency options
Determine life cycle payback on various options
Who benefits from Energy-modeling?
Engineers (No more giant spreadsheets!)
Manufacturers (Quantitatively prove that your product saves money in X amount of time.)
Building Owners (Get the most bang for your buck up fron!t)
Building Tenants (lowered monthly bills!)
The Environment (one can determine the options to use the least energy and have the least emissions)
and MANY MORE BENEFITS!
How do I make a building simulation or energy-model?
In order to simulate a building on a computer, the appropriate software is needed. There are literally hundreds of options. We here at energy-models.com use eQUEST and TRACE 700.
Either software package can be learned in a short period of time, but it takes years to become a master (just like anything else worthwhile).
What do I need before I get started with Energy Modeling?
Building location and geometry
Building materials (walls, windows, u-values, shading coefficients)
General operation of the building
All interior load values (Lighting, plug loads, occupant numbers and activity level).
System types (is it constant volume or VAV? DX coils or chilled water?)
- If you don't know the system type, you can use a model to decide what's best!
You need to be smart...
Which software is best?
This is not for us to say! We don't want to get a bunch of hate mail. Each package has its pros and cons. Some packages have very good functionality but poor interface, while others have brilliant interfaces and limited functionality. It really depends on what you are doing.
eQUEST is probably the quickest option and is also free. Keep in mind that it focuses almost solely on energy and that load design in eQUEST should be limited to the experts. Check out this video that shows how awesome eQUEST is!
TRACE 700 is a great option if you need to do Load Design + Energy. Tell your boss to suck it up and buy it for you. It comes with free support.
Alternatively, if you are only interested in Load Design, you could go with TRACE 700 Load Design (it costs much less and you still get unlimited support).
Energy-Models.com is a site for energy modelers, building simulators, architects, and engineers who want learn the basics, to advanced concepts of energy modeling. We've got online training courses and tutorials for eQUEST, Trane TRACE 700, OpenStudio, and LEED for energy modeling. All our energy modeling courses are video based. What better way to learn energy modeling software than screen-casts of exactly how things are done?