Charles Berryman

Adaptive photovoltaic system

This paper discussed a new photovoltaic (PV) system topology that uses PV energy in efficient way in order to improve system power output during different operating conditions. The proposed topology provides flexible connection between PV modules to achieve different configurations of PV array. A new switching matrix has been developed to achieve the required configurations. Preliminary simulations provide promising results for an adaptive PV array. Comparison between traditional PV system configurations and adaptive configuration is considered. A significant improvement in power curves is achieved by the proposed topology.

An AHP-weighted aggregated data quality indicator (AWADQI) approach for estimating embodied energy of building materials

PurposeAggregated data quality indicator (ADQI) method has been used to estimate probability distributions of the input data in a life cycle assessment (LCA) to compensate for insufficient data in a statistical analysis. In a traditional ADQI, a multicriteria evaluation process, the impacts of various quality indicators under investigation are often equally weighted or unweighted despite the fact that some of them may weight more than the others on contributing to the overall data uncertainty. An unweighted ADQI (UWADQI) approach, though simple, may lead to incorrect conclusions. This paper aims to develop a weighted ADQI to overcome the deficiency of the unweighted ADQI to make it more reliable for LCA uncertainty analysis.MethodTo improve the UWADQI approach, an analytical hierarchy process (AHP) is introduced in this research for estimating weighting factors in the ADQI aggregation process. An AHP’s pairwise comparison function is used to determine the weighting of each data quality indicator. Three common building materials of concrete, steel, and glass were chosen to validate the presented method.Results and discussionUsing the published results from the statistical method as the benchmarks, it was found that the proposed AHP-weighted ADQI (AWADQI) method lead to better estimated probabilistic values of embodied energy intensity than the traditional UWADQI approach for the three building materials.Conclusions and recommendationsIn conclusion, using AHP to incorporate weighing factors into an ADQI process can improve the uncertainty estimate of embodied energy of building materials, and consequently, the method can improve the reliability of a building LCA.

Comparative Study of Activity-Based Construction Labor Productivity in the United States and China

This research compares construction labor productivity (CLP) of the United States with its Chinese counterpart at the activity level to evaluate productivity differences between the two countries from an operational perspective. Supplementing other comparative construction studies measuring productivity by output value per person, this research examined CLP—measured by physical quantity installed per labor hour—based upon published national average productivity data. Sampled activities included earthwork, concrete, masonry, structural steel, waterproofing, and interior finishes. Paired comparisons (United States–China) of these selected activities were then analyzed and evaluated. The source of the U.S. labor productivity data was RSMeans Building Construction Cost Data, which was cross validated by data from the Walker’s Building Estimator’s Reference Book. The source of Chinese labor productivity data was mainly the Beijing construction quota, which was cross validated by Chinese quotas from several oth...

Real Time Power Monitoring & integration with BIM

A Real Time Power Monitoring (RTPM) System is proposed in which end-use detailed energy consumption data is provided for each load level. The data will be integrated with a BIM (Building Information Modeling) Model to create a Realtime on-line electronic BIM Model. This paper describes the RTPM system and the process leading to its creation. The basic components of the proposed system were designed and tested using a prototype board.

Economic Input-Output Life Cycle Assessment of Water Reuse Strategies in Residential Buildings

1.0 Introduction The growth of cities is putting great strains on existing freshwater supplies in many areas, including the United States (Kloss, 2008). The United States Green Building Council (USGBC) has stated that buildings consume roughly 39% of all electricity and approximately 10% of all potable water (USGBC, 2008). The growing need for freshwater has lead to an increase in water reuse applications. However, some water reuse strategies actually result in an increase in energy usage and other environmental impacts. The objective of this study is to determine the environmental sustainability of three water reuse designs through economic input-output life cycle assessments (EIO-LCA). The water reuse designs include a simple greywater reuse system for subsurface landscape irrigation; an indoor greywater reuse system for toilet flushing and laundry washing; and a hybrid greywater and rainwater reuse system for landscape irrigation, toilet flushing, and laundry washing.