@techreport {58905, title = {COMFEN {\textendash} Early Design Tool for Commercial Facades and Fenestration Systems}, year = {2014}, month = {03/2014}, abstract = {

California leads the nation in building energy efficiency standards and is a leader in the United States for legislation to reduce greenhouse gas emissions. Achieving these goals in practice requires that design teams and owners have access to technologies, systems and decision support tools that support their design work. This California Energy Commission funded work on the COMFEN software tool, which gives building practitioners, such as architects and engineers, the ability to assess the energy consequences of building design decisions, is thus a key enabling element that supports the AEC community in achieving ever more stringent performance requirements. COMFEN can provide needed building design guidance to not achieve the shorter term code goals but supports more aggressive achievement of the net-zero energy performance and peak load reduction required for all new buildings by 2030 as well as supporting deep retrofit of existing building stock.

Achieving a net-zero energy building cannot be done solely by improving the efficiency of the engineering systems (HVAC, lighting, equipment). It also requires consideration of the essential nature of the building starting early in the design process, including factors such as architectural form, massing, orientation and enclosure. Making informed decisions about the fundamental character of a building requires continuous assessment of the effects of the complex interaction of these factors on the resulting performance of the building as the design evolves. The complexity of these interactions necessitates the use of modeling and simulation tools to dynamically analyze the effects of the relationships. Decisions about the building fundamentals are often made in the earliest stages of design, before a complete {\textquoteright}building{\textquoteright} exists to model so that a focus on representative spaces in the building allows earlier guidance for the decision making.

COMFEN, an early-design energy modeling tool developed by LBNL, is designed specifically to make informed decisions about building fundamentals by considering the design of the building envelope, orientation and massing on building performance. It supports exploratory work early in the process by architects but is also useful for engineers and consultants later in the design process. It also supports innovation broadly as it allows teams to model new technologies and systems that are becoming available but have not yet reached mainstream status.

COMFEN focuses on the concept of a "space" or "room" and uses the EnergyPlus and Radiance{\texttrademark} engines and a simple, graphic user interface to allow the user to explore the effects of changing key early-design input variables for the fa{\c c}ade, internal loads, lighting controls and HVAC system on energy consumption, peak energy demand, and thermal and visual comfort. COMFEN also provides the ability to import glazing systems that have been developed in Window7, utilizing the International Glazing DataBase (IGDB) for glass choices. Comparative results are rapidly presented in a variety of graphic and tabular formats to help users move toward optimal fa{\c c}ade and fenestration design choices.

While the underlying simulation engines were developed over time as part of DOE{\textquoteright}s national windows and daylighting program, the specific design features of COMFEN were evolved over a several year period by consulting with a series of largely California-based architectural and engineering firms who provided important guidance and feedback on desirable features and then on functionality once the features were implemented.

COMFEN is available at no charge on the LBNL website.

}, author = {Stephen E. Selkowitz and Robert J. Hitchcock and Robin Mitchell and Maurya McClintock and Kevin Settlemyre} } @techreport {1458, title = {High Performance Building Facade Solutions: PIER Final Project Report}, year = {2009}, month = {12/2009}, abstract = {

Building fa{\c c}ades directly influence heating and cooling loads and indirectly influence lighting loads when daylighting is considered, and are therefore a major determinant of annual energy use and peak electric demand. fa{\c c}ades also significantly influence occupant comfort and satisfaction, making the design optimization challenge more complex than many other building systems.

This work focused on addressing significant near-term opportunities to reduce energy use in California commercial building stock by a) targeting voluntary, design-based opportunities derived from the use of better design guidelines and tools, and b) developing and de ploying more efficient glazings, shading systems, daylighting systems, fa{\c c}ade systems and integrated controls.

This two-year project, supported by the California Energy Commission PIER program and the US Department of Energy, initiated a collaborative effort between The Lawrence Berkeley National Laboratory (LBNL) and major stakeholders in the fa{\c c}ades industry to develop, evaluate, and accelerate market deployment of emerging, high-performance, integrated fa{\c c}ade solutions. The LBNL Windows Testbed Facility acted as the primary cata lyst and mediator on both sides of the building industry supply-user business transaction by a) aiding component suppliers to create and optimize cost effective, integrated systems that work, and b) demonstrating and verifying to the owner, designer, and specifier community that these integrated systems reliably deliver required energy performance. An industry consortium was initiated amongst approximately seventy disparate stakeholders, who unlike the HVAC or lighting industry, has no single representative, multi-disciplinary body or organized means of communicating and collaborating. The consortium provided guidance on the project and more importantly, began to mutually work out and agree on the goals, criteria, and pathways needed to attain the ambitious net zero energy goals defined by California and the US.

A collaborative test, monitoring, and reporting protocol was also formulated via the Windows Testbed Facility in collaboration with industry partners, transitioning industry to focus on the import ance of expecting measured performance to consistently achieve design performance expectations. The facility enables accurate quantification of energy use, peak demand, and occupant comfort impacts of synergistic fa{\c c}ade-lighting-HVAC systems on an apples-to-apples comparative basis and its data can be used to verify results from simulations.

Emerging interior and exterior shading technologies were investigated as potential near-term, low-cost solutions with potential broad applicability in both new and retrofit construction. Commercially-available and prototype technologies were developed, tested, and evaluated. Full-scale, monitored field tests were conducted over solstice-to-solstice periods to thoroughly evaluate the technologies, uncover potential risks associated with an unknown, and quantify performance benefits. Exterior shading systems were found to yield net zero energy levels of performance in a sunny climate and significant reductions in summer peak demand. Automated interior shading systems were found to yield significant daylighting and comfort-related benefits.

In support of an integrated design process, a PC-based commercial fenestration (COMFEN) software package, based on EnergyPlus, was developed that enables architects and engineers to x quickly assess and compare the performance of innovative fa{\c c}ade technologies in the early sketch or schematic design phase. This tool is publicly available for free and will continue to improve in terms of features and accuracy. Other work was conducted to develop simulation tools to model the performance of any arbitrary complex fenestration system such as common Venetian blinds, fabric roller shades as well as more exotic innovative fa{\c c}ade systems such as optical louver systems.

The principle mode of technology transfer was to address the key market barriers associated with lack of information and facile simulation tools for early decisionmaking. The third party data generated by the field tests and simulation data provided by the COMFEN tool enables utilities to now move forward toward incentivizing these technologies in the marketplace.

}, author = {Eleanor S. Lee and Stephen E. Selkowitz and Dennis L. DiBartolomeo and Joseph H. Klems and Robert D. Clear and Kyle S. Konis and Robert J. Hitchcock and Mehry Yazdanian and Robin Mitchell and Maria Konstantoglou} } @conference {11697, title = {DElight2 Daylighting Analysis in Energy Plus: Integration and Preliminary User Results}, booktitle = {Building Simulation 2005}, year = {2005}, month = {08/2005}, address = {Montreal, Canada}, abstract = {

DElight is a simulation engine for daylight and electric lighting system analysis in buildings. DElight calculates interior illuminance levels from daylight, and the subsequent contribution required from electric lighting to meet a desired interior illuminance. DElight has been specifically designed to integrate with building thermal simulation tools. This paper updates the DElight capability set, the status of integration into the simulation tool EnergyPlus, and describes a sample analysis of a simple model from the user perspective.

}, author = {William L. Carroll and Robert J. Hitchcock} } @conference {11534, title = {Advancing Lighting and Daylighting Simulation: The Transition from Analysis to Design Aid Tools}, booktitle = {International Building Performance Simulation Association Fourth International Conference}, year = {1995}, month = {08/1995}, address = {Madison, WI}, abstract = {

This paper explores three significant software development requirements for making the transition from standalone lighting simulation/analysis tools to simulation-based design aid tools. These requirements include specialized lighting simulation engines, facilitated methods for creating detailed simulatable building descriptions, and automated techniques for providing lighting design guidance. Initial computer implementations meant to address each of these requirements are discussed to further elaborate these requirements and to illustrate work-in-progress toward fulfilling them.

}, author = {Robert J. Hitchcock} }