Improving building energy efficiency: case study

The main purpose of this study was to conduct a study for improving energy efficiency of an important building in Rome, the Headquarters of the Italian State Monopoly. The study was conducted by comparing conventional analysis tools with innovative ones, in order to evaluate the possible solutions, both structural and plant, aimed at the use of renewable sources and at energy saving. After making a thermo graphic survey, the first and useful step for a good energy audit, conduct building energy was simulated, at first in steady state by the use of a software widely used at the professional level, then in transient state by the use of TRNSYS, a finite difference method software which is able to simulate more accurately conduct building energy. The next step was to propose possible redevelopment of a structural and energy plant that promotes the building energy rating higher, finding the right balance between the energetic and economic aspect. Among the interventions plant, two possible workarounds have been proposed and designed in detail: - installation of a photovoltaic system; - installation of a solar cooling system. Both solutions lead to a reduction of electricity consumption with a significant impact in economic and environmental term

Measures to enforce mandatory civil building energy efficiency codes in China

Mandatory civil building energy efficiency codes strictly govern the energy consumption of new buildings in China. As the promotion of building energy efficiency in China has increased in recent years, compliance with mandatory civil building energy efficiency codes has also improved, increasing from less than 10% in 2000 to nearly 100% in 2012, a remarkable achievement. However, because the promotion of energy efficiency strategies in China has followed a unique pattern, some researchers doubt these statistics. In response to these doubts, this paper summarises and analyses the framework of measures implemented by the Chinese government to enforce mandatory building energy efficiency codes. First, the development and implementation of China's mandatory civil building energy efficiency code system is summarised. Second, the building supervision and inspection systems used to assess energy efficiency are introduced and analysed in detail in order to provide a framework for the development of energy policies in other countries. Third, the assessment and reporting processes used to determine compliance rates are reviewed. Finally, the improvement of compliance rates and its impact on building energy savings in China are discussed. Along with the increase in compliance rates in the construction stage from 71% in 2007 to 100% in 2012, the energy savings of new buildings per increased floor area per year increased from 20.4 kWh/m2 to 28.4 kWh/m2. The supervision and inspection systems reported in this paper are the keys to enforcing building energy efficiency codes

Public engagement: Building energy futures

It is important to include the public in the processes by which decisions on societal trajectories are made. A study shows that interactive scenario-building tools can engage people in the holistic complexities of energy transitions, but these tools must be designed and used with care because elicited preferences can be influenced by contextual factors

Visualizing urban microclimate and quantifying its impact on building energy use in San Francisco

Weather data at nearby airports are usually used in building energy simulation to estimate energy use in buildings or evaluate building design or retrofit options. However, due to urbanization and geography characteristics, local weather conditions can differ significantly from those at airports. This study presents the visualization of 10-year hourly weather data measured at 27 sites in San Francisco, aiming to provide insights into the urban microclimate and urban heat island effect in San Francisco and how they evolve during the recent decade. The 10-year weather data are used in building energy simulations to investigate its influence on energy use and electrical peak demand, which informs the city's policy making on building energy efficiency and resilience. The visualization feature is implemented in CityBES, an open web-based data and computing platform for urban building energy research

Design Margins: Impact on Building Energy Performance

This paper examines the addition of design margins for building services energy infrastructure during the design process. It argues that care must be taken when applying margins; ensuring cumulative effects do not undermine the ability of systems to be energy efficient. An example of a hospital Trust is provided showing the addition of design margins impacting the energy efficiency of services provided. Tensions are found between delivery of flexibility, adaptability and other change parameters and the need for the system to be bounded, so as to encourage effectiveness

Benchmark-based, Whole-Building Energy Performance Targets for UC Buildings

Benchmark-based, whole building energy performance targets are becoming the best practice method for designing energy efficient and zero net energy buildings. There are several advantages to energy performance targets, including a static baseline (to allow for comparison of buildings over time), the ability to capture energy use and efficiency for all building energy loads (not just the loads regulated by code), and the ability to carry design targets through to operations. UC Merced has been using whole-building energy performance targets since its founding and has had great success in delivering buildings with very energy efficient designs that perform to those design targets in their ongoing operations. In addition, benchmarks available for UC campuses provide targets that address peak demand. For these reasons, the UC campuses are encouraged to adopt whole-building energy performance targets in their building design process, to help maintain UC’s leadership in energy efficiency

Contrasting the capabilities of building energy performance simulation programs

For the past 50 years, a wide variety of building energy simulation programs have been developed, enhanced and are in use throughout the building energy community. This paper is an overview of a report, which provides up-to-date comparison of the features and capabilities of twenty major building energy simulation programs. The comparison is based on information provided by the program developers in the following categories: general modeling features; zone loads; building envelope and daylighting and solar; infiltration, ventilation and multizone airflow; renewable energy systems; electrical systems and equipment; HVAC systems; HVAC equipment; environmental emissions; economic evaluation; climate data availability, results reporting; validation; and user interface, links to other programs, and availability

Simulation-assisted control in building energy management systems

Technological advances in real-time data collection, data transfer and ever-increasing computational power are bringing simulation-assisted control and on-line fault detection and diagnosis (FDD) closer to reality than was imagined when building energy management systems (BEMSs) were introduced in the 1970s. This paper describes the development and testing of a prototype simulation-assisted controller, in which a detailed simulation program is embedded in real-time control decision making. Results from an experiment in a full-scale environmental test facility demonstrate the feasibility of predictive control using a physically-based thermal simulation program

China's building stock estimation and energy intensity analysis

Reliable and objective data regarding building stock is essential for predicting and analyzing energy demand and carbon emission. However, China's building stock data is lacking. This study proposes a set of China building floor space estimation method (CBFSM) based on the improved building stock turnover model. Then it measures China's building stocks by vintage and type from 2000 to 2015, as well as building energy intensity (national level and provincial level) and energy-efficient buildings. Results showed that total building stocks increased significantly, rising from 35.2 billion m2 in 2000 to 63.6 billion m2 in 2015, with the average growth rate 4.0%. The deviations were well below 10% by comparing with China Population Census, which validated the reliability of CBFSM and the results. As for energy intensity, urban dwellings and rural dwellings showed relatively stable and increasing trend respectively. The commercial building energy intensity saw a downward trend during “12th Five Year Plan” period. This indicated the effectiveness of building energy efficiency work for commercial buildings since 2005.38.6 billion m2 residential dwellings and 5.7 billion m2 commercial buildings still need to be retrofitted in future. CBFSM can overcome shortages in previous studies. It can also provide Chinese government with technical support and data evidence to promote the building energy efficiency work