This case study describes the National Renewable Energy Laboratory's (NREL) data center as a showcase of energy efficiency. Most of what NREL has done can be replicated by clients; however, two design approaches are climate-dependent: near-full reliance on outside air for cooling, and photovoltaic arrays for power.
Advanced Search
Your search resulted in 16 resourcesSort by
An energy-efficient data center includes targets for its power usage effectiveness (<1.2) and energy resource efficiency (< 0.9). It should be designed with hot isle–cold isle separation, use free cooling (economizer) and evaporative cooling when available, minimize fan energy, and use the most energy-efficient equipment possible.
Few third-party guidance documents or tools are available for evaluating thermal energy storage (TES) integrated with packaged air conditioning (AC), as this type of TES is relatively new compared to TES integrated with chillers or hot water systems. To address this gap, researchers at the National Renewable Energy Laboratory conducted a project to improve the ability of potential technology adopters to evaluate TES technologies. Major project outcomes included: development of an evaluation framework to describe key metrics, methodologies, and issues to consider when assessing the performance of TES systems integrated with packaged AC; application of multiple concepts from the evaluation framework to analyze performance data from four demonstration sites; and production of a new simulation capability that enables modeling of TES integrated with packaged AC in EnergyPlus. This report includes the evaluation framework and analysis results from the project.
A case study of the overview, process, and results of the re-tuning that was conducted in a building in Arlington, Virginia by Vornado Realty Trust in October 2012. Re-tuning provided the facilities management team with the ability to identify and understand building scheduling opportunities that drove significant, low-cost energy savings. Five measures were conducted, many of which pertained to the HVAC system.
Tower Companies, a DC based owner of large multi-tenant buildings and Better Buildings Challenge partner, engaged in an aggressive program to take measured data from their buildings and turn it into real energy savings. This case study, completed by Tower in partnership with the National Resources Defense Council (NRDC) describes outcomes at three properties. The case study was highlighted on a Better Buildings Webinar on February 5, 2014.
Case study describing how adidas implemented a best practice of a planned replacement program for its rooftop units (RTUs), which resulted in significant cost and energy savings. The case study outlines the planning process, implementation, results, and the future plans of their RTU replacement program.
Cooling loads must be dramatically reduced when designing net-zero energy buildings or other highly efficient facilities. Advances in this area have focused primarily on reducing a building’s sensible cooling loads by improving the envelope, integrating properly sized daylighting systems, adding exterior solar shading devices, and reducing internal heat gains. As sensible loads decrease, however, latent loads remain relatively constant, and thus become a greater fraction of the overall cooling requirement in highly efficient building designs, particularly in humid climates. This shift toward latent cooling is a challenge for heating, ventilation, and air-conditioning (HVAC) systems. Traditional systems typically dehumidify by first overcooling air below the dew-point temperature and then reheating it to an appropriate supply temperature, which requires an excessive amount of energy. Another dehumidification strategy incorporates solid desiccant rotors that remove water from air more efficiently; however, these systems are large and increase fan energy consumption due to the increased airside pressure drop of solid desiccant rotors. A third dehumidification strategy involves high flow liquid desiccant systems. These systems require a high maintenance separator to protect the air distribution system from corrosive desiccant droplet carryover and so are more commonly used in industrial applications and rarely in commercial buildings. Both solid desiccant systems and most high-flow liquid desiccant systems (if not internally cooled) add sensible energy which must later be removed to the air stream during dehumidification, through the release of sensible heat during the sorption process.