Continuous Commissioning - The Use of Energy Simulations during Building Operation

Christoph Reinhart and Holly Samuelson Wasilowski

In order to reach Harvard’s reduced green house gas emission targets for 2016, the university routinely asks its design teams to generate energy models for new construction or retrofitting projects over five million dollar. To guide this process, the Office for Sustainability has produced a set of ‘energy modeling guidelines’. The objective of this research project is to gather scientific evidence to support the rewriting of the guidelines so that the resulting energy models can in the future also be used for building commissioning and operation. This project, which is being supported by the Harvard Real Estate Academic Initiative, consists of the following activities:


Part I - Gund Hall Case Study (completed)

Gund Hall, home of the Graduate School of Design, is currently in the pre-design phase of a multi-year renovation. During the fall 2008 semester the project team prepared a DesignBuilder/EnergyPlus energy model of Gund Hall as part of a GSD research seminar.

Photo of Gund Hall
DesignBuilder model of Gund Hall (left-click to download)

The simulation predictions generated by the model were compared to historic measured energy data for Gund Hall for heating, cooling and electricity use and the results were presented at the Building Simulation 2009 Conference in Glasgow in July 2009 (full paper).


Part II -Industry Consultation (ongoing)

During the summer and fall 2009 the project team administered an online survey on the use of building energy models during design, construction and operation. The survey explored the role that the electronic building model, particularly the energy model, current plays and potentially could play in the future throughout the lifetime of a building. 310 building owners, architects and energy modelersparticipated in the survey. Their responses reveal a need for legal clarification regarding model ownership with the majority of energy modelers and owners believing that they ‘own’ the energy models.

Selected Survey Result

The survey results further suggest that - once the ownership issue has been resolved – a sizable portion of the energy simulation community is prepared to expand the usage of their models from the design phase into the construction and operation phases. The full results will be available for download from this website by the end of June 2010 (study abstract).


Part III - Gund Hall Case Study Revisited (ongoing)

The initial comparison of the measured and simulated data for Gund Hall (Part I) revealed that the chilled water meter for Gund Hall reported unexpectedly high cooling loads for the building. It was determined that the meter might be faulty and it was replaced in March 2009. The following eleven months of metered data showed substantially lower cooling loads for the building than in the past. This data is currently being further analyzed (listen to Podcast).