Jim Lutz

TYPICAL HOT WATER DRAW PATTERNS BASED ON FIELD DATA

TYPICAL HOT WATER DRAW PATTERNS BASED ON FIELD DATA Jim Lutz and Moya Melody Energy Analysis and Environmental Impacts Department Environmental Energy Technologies Division Lawrence Berkeley National Laboratory Berkeley, CA 94720 November, 2012 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. This work was sponsored by the Northwest Energy Efficiency Alliance under Contract No. NN620.

Laboratory Evaluation of Residential Furnace BlowerPerformance

A testing program was undertaken at Lawrence Berkeley National Laboratory and an electric utility (Pacific Gas and Electric Co.) to compare the performance of furnace blowers. This laboratory testing program was undertaken to support potential changes to California Building Standards regarding in-field furnace blower energy use. This technical support includes identifying suitable performance metrics and target performance levels for use in standards. Five different combinations of blowers and residential furnaces were tested for air moving performance. Three different types of blower and motor combinations were tested in two different furnace cabinets. The blowers were standard forward--curved impellors and a prototype impeller with reverse-inclined blades. The motors were two 6-pole permanent split capacitor (PSC) single-phase induction motors, a brushless permanent magnet (BPM) motor and a prototype BPM designed for use with a prototype reverse-inclined impellor. The laboratory testing operated each blower and furnace combination over a range of air flows and pressure differences to determine air flow performance, power consumption and efficiency. Additional tests varied the clearance between the blower housing and the furnace cabinet, and the routing of air flow into the blower cabinet.

Simulation Models for Improved Water Heating Systems

Simulation Models for Improved Water Heating Systems Jim Lutz, Peter Grant, and Margarita Kloss Energy Analysis and Environmental Impacts Department Environmental Energy Technologies Division Lawrence Berkeley National Laboratory Berkeley, CA 94720 December 2013 This work was sponsored by the California Energy Commission, Public Interest Energy Research (PIER) Program, under the National Lab Buildings Energy Efficiency Research Projects Contract No. 500-10-052. 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.

Our Environment in Hot Water: Comparing Water Heaters, A Life Cycle Approach Comparing Tank and Tankless Water Heaters in California

Residential water heating is a large source of energy use in California homes. This project took a life cycle approach to comparing tank and tankless water heaters in Northern and Southern California. Information about the life cycle phases was calculated using the European Union�s Methodology study for EcoDesign of Energy-using Products (MEEUP) and the National Renewable Energy Laboratory�s Life Cycle Inventory (NREL LCI) database. In a unit-to-unit comparison, it was found that tankless water heaters would lessen impacts of water heating by reducing annual energy use by 2800 MJ/year (16% compared to tank), and reducing global warming emissions by 175 kg CO2 eqv./year (18% reduction). Overall, the production and combustion of natural gas in the use phase had the largest impact. Total waste, VOCs, PAHs, particulate matter, and heavy-metals-to-air categories were also affected relatively strongly by manufacturing processes. It was estimated that tankless water heater users would have to use 10 more gallons of hot water a day (an increased usage of approximately 20%) to have the same impact as tank water heaters. The project results suggest that if a higher percentage of Californians used tankless water heaters, environmental impacts caused by water heating would be smaller.

Feasibility of Using Measurements of Internal Components ofTankless Water Heaters for Field Monitoring of Energy and Water Use

The objective of this study was to determine if it was feasible to collect information regarding energy use and hot water delivery from tankless gas water heaters using the sensors and controls built into the water heaters. This could then be used to determine the water heater efficiency ? the ratio of energy out (hot water delivered) to energy in (energy in the gas) in actual residential installations. The goal was to be as unobtrusive as possible, and to avoid invalidating warranties or exposing researchers to liability issues. If feasible this approach would reduce the costs of instrumentation. This paper describes the limited field and laboratory investigations to determine if using the sensors and controls built into tankless water heaters is feasible for field monitoring. It was more complicated to use the existing gas flow, water and temperature sensors than was anticipated. To get the signals from the existing sensors and controls is difficult and may involve making changes that would invalidate manufacturer warrantees. The procedures and methods for using signals from the existing gas valves, water flow meters and temperature sensors will vary by model. To be able to monitor different models and brands would require detailed information about each model and brand. Based on these findings, we believe that for field monitoring projects it would be easier, quicker and safer to connect external meters to measure the same parameters rather than using the sensors and controls built into tankless water heaters.

Development of the household sample for furnace and boilerlife-cycle cost analysis

Residential household space heating energy use comprises close to half of all residential energy consumption. Currently, average space heating use by household is 43.9 Mbtu for a year. An average, however, does not reflect regional variation in heating practices, energy costs, or fuel type. Indeed, a national average does not capture regional or consumer group cost impacts from changing efficiency levels of heating equipment. The US Department of Energy sets energy standards for residential appliances in, what is called, a rulemaking process. The residential furnace and boiler efficiency rulemaking process investigates the costs and benefits of possible updates to the current minimum efficiency regulations. Lawrence Berkeley National Laboratory (LBNL) selected the sample used in the residential furnace and boiler efficiency rulemaking from publically available data representing United States residences. The sample represents 107 million households in the country. The data sample provides the household energy consumption and energy price inputs to the life-cycle cost analysis segment of the furnace and boiler rulemaking. This paper describes the choice of criteria to select the sample of houses used in the rulemaking process. The process of data extraction is detailed in the appendices and is easily duplicated. The life-cycle cost is calculated in two ways with a household marginal energy price and a national average energy price. The LCC results show that using an national average energy price produces higher LCC savings but does not reflect regional differences in energy price.

The LBNL Water Heater Retail Price Database

Lawrence Berkeley National Laboratory developed the LBNL Water Heater Price Database to compile and organize information used in the revision of U.S. energy efficiency standards for water heaters. The Database contains all major components that contribute to the consumer cost of water heaters, including basic retail prices, sales taxes, installation costs, and any associated fees. In addition, the Database provides manufacturing data on the features and design characteristics of more than 1100 different water heater models. Data contained in the Database was collected over a two-year period from 1997 to 1999.