Radu Zmeureanu

Using a pattern recognition approach to disaggregate the total electricity consumption in a house into the major end-uses

Abstract The method presented in this paper shows a promising potential for application in residential buildings. The results prove that the whole-house electricity consumption can be disaggregated into its major end-uses, using a pattern recognition approach and only one sensor installed on the main electric entrance of the house. It also required a one-time submetering of the target appliances during the training period, of about a week, to find the electric characteristics of appliances. The results are provided in terms of daily load profiles, energy consumption and energy contribution of selected appliances. The proposed method was tested with monitored data from 3 weeks: (i) the training period of 1 week in October, (ii) the near-to-date testing period of 1 week in November and (iii) the far-to-date testing period of 1 week in January. For instance, the difference between monitored and estimated contribution is, for the month of October 1996, as follows: (i) 13 kW h or

Nonintrusive load disaggregation computer program to estimate the energy consumption of major end uses in residential buildings

0.85 for the DHW heater and (ii) 6 kW h or

Floor shape optimization for green building design

0.36 for the refrigerator. The overall difference for both appliances does not exceed

An object-oriented framework for simulation-based green building design optimization with genetic algorithms

1.25 for the month of October, for a total electricity bill of 912 kW h and

Development of an energy rating system for existing houses

60.60, which appears to be acceptable for every homeowner. The errors in evaluating the daily energy consumption is between −10.5% and 15.9% for both the DWH heater and the refrigerator.

Thermal performance of a hollow core concrete floor system for passive cooling

This paper presents a new computer program for nonintrusive disaggregation of the total electricity consumption of a house into the major end uses. The computer program has two modes: (1) sampling and (2) evaluation. In the sampling mode, the operating characteristics (of each end use are determined from data collected over a period of several days using at least one current sensor per appliance. In the evaluation mode, only the main electric entrance of the house is monitored, and the electric signal is analyzed to disaggregate the total energy consumption. The errors in estimating the energy shares of three major end uses (water heater, baseboard heater and refrigerator) are less than 10% for most evaluation scenarios. 7 2000 Elsevier Science Ltd. All rights reserved.

Correlation based models for the simulation of energy performance of screw chillers

Shape is an important consideration in green building design due to its significant impact on energy performance and construction costs. This paper presents a methodology to optimize building shapes in plan using the genetic algorithm. The building footprint is represented by a multi-sided polygon. Different geometrical representations for a polygon are considered and evaluated in terms of their potential problems such as epistasis, which occurs when one gene pair masks or modifies the expression of other gene pairs, and encoding isomorphism, which occurs when chromosomes with different binary strings map to the same solution in the design space. Two alternative representations are compared in terms of their impact on computational effectiveness and efficiency. An optimization model is established considering the shape-related variables and several other envelope-related design variables such as window ratios and overhangs. Life-cycle cost and life-cycle environmental impact are the two objective functions used to evaluate the performance of a green building design. A case study is presented where the shape of a typical floor of an office building defined by a pentagon is optimized with a multiobjective genetic algorithm. � 2006 Elsevier Ltd. All rights reserved.

Assessment of the energy savings due to the building retrofit

Simulation-based optimization can assist green building design by overcoming the drawbacks of trial-and-error with simulation alone. This paper presents an object-oriented framework that addresses many particular characteristics of green building design optimization problems such as hierarchical variables and the coupling with simulation programs. The framework facilitates the reuse of code and can be easily adapted to solve other similar optimization problems. Variable types supported include continuous variables, discrete variables, and structured variables, which act as switches to control a number of sub-level variables. The framework implements genetic algorithms to solve (1) unconstrained and constrained single objective optimization problems, and (2) unconstrained multi-objective optimization problems. The application of this framework is demonstrated through a case study which uses a multi-objective genetic algorithm to explore the trade-off relationship between life-cycle cost and life-cycle environmental impacts for a green building design.

Thermally acceptable temperature drifts can reduce the energy consumption for cooling in office buildings

This paper presents the development of a new energy rating system for existing houses, combining the information from utility bills with on-site measurements and computer simulation. The proposed system was tested on a sample of 45 houses in Montreal, with the following main objectives: (i) to evaluate the quality of results given by the system (e.g., energy performance of houses, thermal resistance of exterior envelope, air infiltration rate), and (ii) to evaluate the methods of measurement and simulation (e.g., time required on site to collect data, time for computer simulation, accuracy of measurements and simulation).

A methodology for identifying the influence of design variations on building energy performance

Abstract A preliminary technical study of the thermal performance of a hollow core concrete floor system for passive cooling is presented. Numerical techniques have been used to solve the one- and two-dimensional models of the transient heat transfer through the building components. Computer simulations for a warm and sunny day in Montreal show that, during occupancy, the hollow core floor system provides thermal comfort without mechanical cooling.