Whole-building integration is very similar to the process used in the production of automobiles. Every part is designed and manufactured to work together to optimize car performance. Whole-building integration works the same way, only it creates high-performance buildings. The process begins with computer simulated design to analyze building components and systems and then it integrates them so that the overall building performance is optimized. Example systems and components that are designed to work well together are building orientation, heating and cooling systems, insulation, lighting, and windows. A systems integration approach enables advanced technologies to function more efficiently while still meeting the challenging reliability and cost requirements for buildings. Used in retrofit application, these technologies provide one of the best opportunities to increase energy efficiency in existing buildings.
System integration uses an integrated building design process, which is a collaborative, integrated planning and design process that uses a "project team" rather than one person (i.e., architect) to make decisions in all stages of a project's planning and delivery, starting with design. Whole-building integrated design establishes performance goals right from the start for siting, energy, water, materials, and indoor environmental quality along with other comprehensive design goals. It ensures incorporation of these goals throughout the design and lifecycle of the building. It also considers all stages of the building's life-cycle in the design stage, including site selection, construction, maintenance, and demolition. An essential technology for whole-building integration is computer simulation software for making energy analysis comparisons. For more information, see Energy Analysis and Tools.
A gap exists between real world energy performance and implementation, and simulation and analysis. This area of NREL research helps to achieve a 50% energy reduction in the retail sector of commercial buildings by analysis of existing retail building design to identify energy saving opportunities. The retail sector replicates stores by creating a set of prototype building design plans. Once building features are in the plans, they are replicated by builders until the plans change. NREL's objective is to get aggressive energy saving features into prototype plans. NREL researchers investigate and document energy saving areas of building operation and maintenance. NREL is currently working to improve prototype plans for major national retailers. Changing the plans is important because replication will occur based on these plans.
NREL also monitors retail stores to study how to reduce the energy impact of these, as well as other stores. Many lessons learned can be shared across the entire commercial sector. The information gained from these projects will help drive future building design strategies.
For small and medium-sized commercial buildings, energy saving building design packages or guidelines are the most cost-effective and quickest way for building owners to achieve net-zero energy buildings. NREL is developing cost-effective design technology packages using highly efficient component technologies, integrated controls, improved construction practices, streamlined commissioning, and maintenance and operating procedures that will make new and existing commercial buildings durable, healthy and safe for occupants. These design guides will reduce energy use for new small commercial buildings by 30% relative to conventional practice using EnergyPlus as an analysis tool. NREL is working on design packages for several small and medium building types: retail, warehouses, schools, and offices.
For completion of the design guidelines, NREL works closely with the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), the organization that sets the standards for building design and efficiency within the commercial building industry. NREL worked with ASHRAE on the publication of an Advanced Energy Design Guide for Small Retail Buildings in 2006. NREL continues to work with ASHRAE to establish a working group for the next design guide and will support the creation of future design guides.
NREL has developed critical R&D capabilities for advancing IAQ sensing and air cleaning science. We are leveraging our understanding of sustainable building science, high-efficiency HVAC, and sorbent chemistry to target research on the most energy-intensive portion of the 9 Quads of energy America consumes for heating and cooling each year. For more information, see Indoor Air Quality.
Building Controls are critical for the energy efficiency of buildings because they enable building equipment to operate at peak energy efficiency. Current generations of building controls are very primitive when compared to controls in other industries. As buildings become low-energy, the importance of controls and fault diagnostics becomes more important.
NREL investigates building control systems and algorithms that strive for robust, whole-building operation and good coordination between subsystems. We use control strategies that can be evaluated within an EnergyPlus framework. We work closely with other professionals engaged in controls work to ensure that their subsystems interact well with the entire building and that they can be modeled in the EnergyPlus framework.
Currently, NREL is leading the implementation of energy management system (EMS) style controls into the EnergyPlus core engine. This project will exercise new EnergyPlus modeling capabilities to analyze the controls and algorithms within and between the various technology option sets. Once complete, the new EMS controls within EnergyPlus can be used as a forward building model (the basis for feed-forward controls), whereas the controls area has primarily focused on inverse building models. Forward modeling may offer advantages over inverse modeling in the areas of FDD and predictive control because the models don't require learning periods and can quickly adjust to known changes in the building and as-yet-not-encountered weather conditions.
NREL designed the demand-limiting controls at the Zion National Park Visitor Center, and more generally worked on several projects in lighting controls, natural ventilation controls, HVAC controls, and thermal storage controls. We also commissioned most of our case study buildings. For more information, see "Lessons Learned from Case Studies of Six High-Performance Buildings." (PDF 3.8 MB) Download Adobe Reader.
We provide technical assistance for the production of various design guidelines. Links to a few recently published guidelines are listed below.
To achieve greater energy savings, a list of prescriptive measures is not effective. For these advanced energy savings goals, NREL is focusing on the creation of highly flexible "technology option sets" that can be combined in various ways to reach anywhere from 50% to 70% energy savings. A technology option set is an integrated group of building envelope, equipment, and control system technologies that each influence the energy performance of the other, so when combined, they act as one system. They include whole-building energy management control systems. These technology option sets are complex groups of systems that will require the expertise of several national laboratories and universities and manufacturers to fully develop.
NREL will work with DOE on the development of these technology option sets through a four-step process: 1) determining the priority technology focus areas, 2) developing selected technology to the point where its ready for full-scale building testing, 3) installing a prototype technology option set on an actual building for full-scale testing and assessment of installed performance and cost; and 4) develop the systems engineered design procedures and large-scale testing for the tested technology option set. Step 4 will require a partnership with an architectural and engineering firm that is part of DOE's commercial building integration team.
In the short-term, NREL will evaluate various technology option sets to achieve an aggressive energy savings target. Evaluation of the technology option sets will include the development of an analysis framework based on EnergyPlus for commercial building integration performers to use when characterizing and developing technology option sets. This energy analysis tool allows researchers to do a large amounts of calculations with supercomputers that tells them how a building will respond to energy consumption for various building design and technology option sets, including cost! At this time, the building optimization software is primarily for use by researchers. However, NREL plans to eventually provide a user interface for public use. For more information, see "Automated Multivariate Optimization Tool for Energy Analysis." (PDF 1.1 MB) Download Adobe Reader. When fully developed, this analysis framework will be used by NREL to provide analysis results to DOE on technology option sets.
NREL will also examine a technology option set on architectural form and its impact on cooling, heating, and daylighting building subsystems. NREL will produce a research plan based on analysis results. For additional information on tools used by NREL for building optimization, see Energy Analysis and Tools.