March 2013

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Building Information Modeling (BIM) and Energy Efficiency Analysis

An industry consortium called buildingSMART is actively working on addressing this issue. It has published an open standard called COBie.

Igor Starkov
EcoDomus, Inc.

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This online magazine is called “Automated Buildings”. Without automation, buildings can’t be properly managed – we all know that. But is automation enough for improving building performance? Thousands of sensors are deployed in a typical new building; sophisticated servers are used to manage data collected by those sensors; even integration of disparate systems is no longer a problem – with open standards like BACnet, oBIX and OPC it all can be implemented.

At the same time we’ve seen several buildings from top facility owners that have sophisticated Building Automation Systems (BAS) where facility managers are not looking at the trend logs, or do not keep trend logs longer than a few days not allowing them to track the long term performance of assets. Quite often facility maintenance personnel don’t even use the BAS saying “it’s up to energy manager to optimize it, we’re not BAS experts”. There are a few reasons facility managers do not use available automation to its fullest capabilities.

We believe that the biggest reason a facility is not managed properly is lack of information on how a facility should be optimally run. This information is usually created during the design phase, later (supposed to be) updated by contractors who install actual equipment.

Unfortunately, facility managers and BAS engineers are not closely cooperating with those who deliver buildings: architects, engineers, and contractors, and as a result information about how the building is supposed to be run at optimal capacity is either lost or wasn’t recorded in the first place.

An industry consortium called buildingSMART is actively working on addressing this issue. It has published an open standard called COBie (Construction Operations Building information exchange) which is a vendor-neutral data format that is designed to store information as it becomes available during design, construction and commissioning. A COBie dataset can be represented in different file formats, such as IFC, IFCxml, and Excel.

COBie has been around for a few years and it has been adopted by leading owners such as the Department of Veterans Affairs, University of Southern California, Texas A&M University, Kaiser Permanente. It is required by the United Kingdom government on all projects. Our company, EcoDomus, recognized the value of COBie early and was the first certified COBie middleware.

Without COBie, information about building assets (components): how they are connected and grouped into systems; where these assets/components are located; what the min/max air flow parameters are for a particular type of VAV box; etc. is probably going to be either difficult to find PDFs, or even worse – a binder collecting dust in a basement.

The biggest value COBie provides is not the ability to upload a dataset of collected information into compliant facility management software. It is the ability to perform quality control activities on the information collected in BIM. And by BIM we mean not only 3D files produced by authoring applications like Autodesk Revit or Graphisoft ArchiCAD, but the whole dataset of files and corresponding documents produced during design and construction.

Another reason for facility managers not using the BAS to its full capacity is the complexity of information received from the BAS. Older systems used non-intuitive navigation, available only on a stand-alone computer in the basement, with cryptic nomenclature that had to be deciphered by those who weren’t used to it.

Compare it to the following video, showing how a Building Information Model (BIM is used for both “Model” and “Modeling”) integrated with a BAS and a Computerized Maintenance Management System (CMMS) which can be used within the EcoDomus software to analyze energy performance for a couple of assets, review work orders for those assets, and navigate in 3D reducing a need to visit that location.

[THE VIDEO] BIM integrated with CMMS and

EcoDomus’ recent project for the Federal Aviation Administration (Lifecycle BIM proof-of-concept) reviewed the workflows related to a typical service request (i.e. “cold call”) and compared existing means and methods with a fully automated and integrated approach (BIM+BAS+GIS+CMMS) and the findings revealed that a 5.5-hour long service call can be reduced to 30 minutes if necessary automation is implemented.

Obviously, what you’ve seen in the video is not possible if data is not properly collected, validated and delivered using workflows like COBie.

Also, BIM can be quite schematic and additional enhancements provided by 3D graphics, recommended by other companies on this website, is also recommended. The difference between the generic 3D graphics and BIM though is very significant. In BIM we deal with the parametric, scalable, intelligent data vs. rendered images not having any intelligence.

Beyond the generic implementation of BIM and COBie as provided in the video, there are industry efforts to improve the ways facilities are managed by comparing a simulated energy model with actual facility consumption data received from sensors and meters.

The Leadership in Energy and Environmental Design (LEED) certification, introduced in 2000 has rapidly grown in popularity and demand. Information about hundreds of green commercial building projects may be found on the internet, many with impressive claims about their projected energy consumption. But obtaining actual energy consumption data for green commercial buildings is difficult. American Physical Society’s white paper (Energy Future: Think Efficiency, 2008) reported that “…121 [analyzed] LEED buildings consume more total energy per square foot (either site or primary) than the average for the entire commercial building stock”.

Energy efficiency is but one of many criteria for LEED.  Building certification and credits for energy efficiency are awarded based on design simulations, not measured building energy performance. There has been little work on validating whether projections of performance correspond to actual building performance.

[an error occurred while processing this directive] EcoDomus addressed this challenge by introducing the first commercial off-the-shelf (COTS) solution that allows comparing predicted energy performance (BIM energy modeling) with actual performance using sensors and meters managed by Building Automation Systems.

EcoDomus EM (“Energy Management”) is a software module working within the EcoDomus PM & EcoDomus FM applications that allows continuous flow of data between BIM/COBie and the Department of Energy EnergyPlus energy simulation program for BIM energy analysis. The EcoDomus EM users will be able to not only compare simulated energy consumption with actual energy consumption for the whole facility, but also identify zones and components that are deviating from the norm and therefore requiring a more detailed review by maintenance team.

The prevalent method currently is to compare energy performance on a building or system levels, which is problematic because compensation errors often mask the performance problems (for example, an oversized pump may compensate for error caused by an undersized fan). Current methods do not combine spatial and thermal perspectives and do not consider the relationships between components of a building’s energy systems.

Traditional commissioning tests the functioning of a HVAC component; however, correctly operating HVAC components do not ensure efficient operation on the system and building levels. Also, the increasing complexity of HVAC systems increases the difficulty of testing the proper functionality of HVAC systems. This is a one-time event rather than an ongoing process for continuously controlling the performance of buildings, which leads to a decrease in performance after the one-time improvement.

Typical building operation is based on feedback from occupants allowing building operators to address energy efficiency issues on the basis of complaints. The building operators will usually adjust local set points instead of troubleshooting the problem and resolving it. The advantage of EcoDomus EM’s approach is that performance assessors (i.e. energy auditors or facility engineers) can identify more problems with less effort per problem.

Coupling an easy-to-use, visual 3D/2D interface provided by BIM, with an integrated BAS/CMMS/GIS solution may be the stepping stone allowing regular facility managers to embrace building automation completely.


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