@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} } @conference {1174, title = {COMFEN 3.0: Evolution of an Early Design Tool for Commercial Fa{\c c}ades and Fenestration Systems}, booktitle = {Building Enclosure Sustainability Symposium (BESS), April 29-30, 2011}, year = {2011}, month = {03/2011}, address = {Pomona, CA}, abstract = {

Achieving a net-zero energy building cannot be done solely by improving the efficiency of the engineering systems. It also requires consideration of the essential nature of the building including factors such as architectural form, massing, orientation and enclosure. Making informed decisions about the fundamental character of a building requires assessment of the effects of the complex interaction of these factors on the resulting performance of the building. The complexity of these interactions necessitates the use of modeling and simulation tools to dynamically analyze the effects of the relationships, yet decisions about the building fundamentals are often made in the earliest stages of design, before a {\textquoteright}building{\textquoteright} exists to model.

To address these issues, Lawrence Berkeley National Laboratory (LBNL) has developed an early-design energy modeling tool (COMFEN) specifically to help make informed decisions about building fa{\c c}ade fundamentals by considering the design of the building envelope, orientation and massing on building performance. 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 on energy consumption, peak energy demand, and thermal and visual comfort. 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 COMFEN 1.0 utilized an Excel{\texttrademark}{\textendash}based user interface, COMFEN 3.0 has been reworked to include a simple, more intuitive, yet powerful Graphic User Interface (GUI), a broader range of libraries for associated system and component choices and deliver a wider range of graphic outputs and options.

This paper (and presentation) outlines the objectives in developing and further refining COMFEN, the mechanics of the program, and plans for future development.\ 

}, author = {Stephen E. Selkowitz and Robin Mitchell and Maurya McClintock and Daniel McQuillen and Andrew McNeil and Mehry Yazdanian} } @conference {11515, title = {Active Load Management with Advanced Window Wall Systems: Research and Industry Perspectives}, booktitle = {ACEEE 2002 Summer Study on Energy Efficiency in Buildings: Teaming for Efficency}, year = {2002}, month = {08/2002}, address = {Pacific Grove, CA}, abstract = {

Advanced window wall systems have the potential to provide demand response by reducing peak electric loads by 20-30\% in many commercial buildings through the active control of motorized shading systems, switchable window coatings, operable windows, and ventilated double-skin facade systems. These window strategies involve balancing daylighting and solar heat gains, heat rejection through ventilation, and night-time natural ventilation to achieve space-conditioning and lighting energy use reductions without the negative impacts on occupants associated with other demand responsive (DR) strategies.

This paper explores conceptually how advanced window systems fit into the context of active load management programs, which cause customers to directly experience the time-varying costs of their consumption decisions. Technological options are suggested. We present pragmatic criteria that building owners use to determine whether to deploy such strategies. A utility{\textquoteright}s perspective is given. Industry also provides their perspectives on where the technology is today and what needs to happen to implement such strategies more broadly in the US.

While there is significant potential for these advanced window concepts, widespread deployment is unlikely to occur with business-as-usual practice. Technologically, integrated window-lighting-HVAC products are underdeveloped. Implementation is hindered by fragmented labor practices, non-standard communication protocols, and lack of technical expertise. Design tools and information products that quantify energy performance, occupant impacts, reliability, and other pragmatic concerns are not available. Interest within the building industry in sustainability, energy-efficiency, and increased occupant amenity, comfort, and productivity will be the driving factors for these advanced facades in the near term {\textemdash} at least until the dust settles on the deregulated electricity market.

}, author = {Eleanor S. Lee and Stephen E. Selkowitz and Mark S. Levi and Steven L. Blanc and Erin McConahey and Maurya McClintock and Pekka Hakkarainen and Neil L. Sbar and Michael P. Myser} }