James Lutz

The effect of efficiency standards on water use and water-heating energy use in the U.S.: A detailed end-use treatment

We analyze U.S. residential water use and water-heater energy use and apply this analysis to investigate water and energy savings associated with U.S. equipment efficiency standards currently in force.

Simulating a Nationally Representative Housing Sample Using EnergyPlus

LBNL # Simulating a Nationally Representative Housing Sample Using EnergyPlus Asa S. Hopkins, Alex Lekov, James Lutz, and Gregory Rosenquist Energy Analysis Department Lawrence Berkeley National Laboratory Berkeley, CA 94720 Lixing Gu Florida Solar Energy Center March 2011 This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Building Technology, State, and Community Programs, of the U.S. Department of Energy under Contract No. DE- AC02-05CH11231.

Variability in energy factor test results for residential electric water heaters

Recent modifications to the minimum energy efficiency requirements for residential water heaters have spurred an investigation into the variability in testing high-efficiency electric water heaters. While initial interlaboratory comparisons showed excellent agreement between test results from different labs, subsequent interlaboratory comparisons show differences between measured energy factors of up to 0.040. To determine the source of these differences, analyses of various parts of the test procedure are performed. For one case studied, the uncertainty in test results can be as high as +0.028 if instrument accuracies reach the minimum level allowed in the test procedure. Other areas of the test procedure where variability is introduced are the optional use of pre-draws, the location of the lower tank temperature-measuring device, the use of insulation on tank fittings, and the use of a warm-up period before the simulated-use test commences. The implications of these issues on test results are discussed.

Advanced technologies for residential appliance and lighting market transformation

Abstract This article describes an assessment of options for and barriers to improved efficiency in four key energy consuming residential products: refrigerator/freezers, clothes washers, electric water heaters, and lighting equipment. National energy savings were calculated using the Lawrence Berkeley National Laboratorys (LBNL) Residential Energy Model, which projects the number of households and appliance saturations over time. Energy savings are shown for the period 1998 to 2015. The analysis shows that significant energy savings beyond those achieved through existing efficiency standards are possible. In the face of market and other barriers, however, realizing the technical potentials described in this paper will require an active policy approach to market transformation. Since this article was completed, LBNL has commenced a new set of analyses of energy savings potential in refrigerator/freezers and clothes washers. These and subsequent analyses may enhance technical information given here, furthering an understanding of energy efficiency potential in the residential and commercial sectors.

Measurement of airflow in residential furnaces

In order to have a standard for furnaces that includes electricity consumption or for the efficiency of furnace blowers to be determined, it is necessary to determine the airflow of a furnace or furnace blower. This study focused on airflow testing, in order to determine if an existing test method for measuring blower airflow could be used to measure the airflow of a furnace, under conditions seen in actual installations and to collect data and insights into the operating characteristics of various types of furnace blowers, to use in the analysis of the electricity consumption of furnaces. Results of the measured airflow on furnaces with three types of blower and motor combinations are presented in the report. These included: (1) a forward-curved blower wheel with a typical permanent split capacitor (PSC) motor, (2) a forward-curved blower wheel with an electronically-commutated motor (ECM), and (3) a prototype blower, consisting of a backward-inclined blower wheel matched to an ECM motor prototype, which is being developed as an energy-saving alternative to conventional furnace blowers. The testing provided data on power consumption, static and total pressure, and blower speed.

Determining benefits and costs of improved water heater efficiencies

Economic impacts on individual consumers from possible revisions to US residential water heater energy-efficiency standards are examined using a life-cycle cost (LCC) analysis. LCC is the consumers cost of purchasing and installing a water heater and operating it over its lifetime. This approach makes it possible to evaluate the economic impacts on individual consumers from the revised standards. The methodology allows an examination of groups of the population which benefit or lose from suggested efficiency standards. The results show that the economic benefits to consumers are significant. At the efficiency level examined in this paper, 35% of households with electric water heaters experience LCC savings, with an average savings of

Research and Development Roadmap for Water Heating Technologies

106, while 4% show LCC losses, with an average loss of

Documentation of Calculation Methodology, Input data, and Infrastructure for the Home Energy Saver Web Site

40 compared to a pre-standard LCC average of

Dampers for Natural Draft Heaters: Technical Report

2565. The remainder of the population (61%) are largely unaffected.

Water and Waste Water Tariffs for New Residential Construction inCalifornia

Although water heating is an important energy end-use in residential and commercial buildings, efficiency improvements in recent years have been relatively modest. However, significant advancements related to higher efficiency equipment, as well as improved distribution systems, are now viable. DOE support for water heating research, development and demonstration (RD&D) could provide the impetus for commercialization of these advancements.