Overview Existing Buildings New Construction Renewable Energy Program Support Commissioning

Energy Modeling

Service

Energy modeling assists building owners and designers to optimize building design to achieve energy and carbon reduction. The information provided by accurate energy modeling assists decision makers with pursuing investments that have the greatest impact on a building’s energy use.

kW Engineering has extensive experience with whole-building energy modeling for both retrofit and new construction projects.

Modeling Tools

Our preferred simulation tool is the DOE-2* calculation engine. We also use the eQUEST and Energy Pro DOE-2 front end graphical user interfaces. We are proficient with the raw DOE-2 building design language (BDL) programming format as well. For complex refrigeration systems we use the eQUEST Refrigeration simulation environment.

Applicability

During the initial project scope, we determine if whole building simulation modeling is correct for a client’s project. Whole building simulations are generally utilized for large, complex, comprehensive projects.

The key to successful whole building simulation is experience and know-how. At kW Engineering, we possess both.

Approach

Accurate modeling requires model calibration. Calibration involves comparison of the model results to the existing buildings’ historical utility bills. When the model results agree with historical building energy use patterns, we know that we’ve developed a model that will accurately predict proposed energy efficiency measures. For new construction projects, we calibrate model results to standard benchmark data for specific building types.

Quality Control

While these models are the most powerful tools available in the industry, they rely on a large number of inputs and parameters to describe the existing building, occupants, systems, and controls. If used improperly, hourly models can produce results that differ greatly from reality. For this reason all hourly simulation projects undergo a thorough quality control (QC) review before the results are released to the client. We perform peer QC using an engineer other than the one who completed the analysis to ensure objectivity. The reviewer relies on a checklist with a comprehensive list of factors to review and consider. The use of this process makes our approach thorough, systematic, and consistent.

Energy Savings

Once we establish baseline energy use, we use the building model to investigate proposed energy efficiency options, including lighting upgrades and controls, HVAC retrofits, HVAC controls, and envelope upgrades.

We determine the cost effectiveness of proposed energy efficiency measures by using annual energy cost savings provided by the model and estimated project costs.

*DOE-2 is a building-energy-simulation modeling tool that calculates energy use and peak demand on an hourly basis. Building parameters such as envelope construction, equipment performance, and occupancy schedules are input by the user. Climate conditions, including drybulb temperature, solar radiation, and wind speed are contained in weather files specific for the project.