Compared with standard portable generators, CO emissions from the prototype machines were reduced by 90 percent or more, depending on the specific hardware used and operating conditions.
According to the Centers for Disease Control (CDC), unintentional CO poisoning claims more than 400 lives a year. More than 20,000 people visit the emergency room and more than 4,000 are hospitalized due to exposure to toxic levels of the colorless, odorless gas. Fatality is highest among people 65 and older.
Many of these deaths and illnesses stem from unsafe use of portable generators, often in the aftermath of devastating storms and other causes of electric power outages. For the years 2005 to 2008, the CPSC reports that an estimated 37 to 47 percent of non-fire-related consumer product-related CO poisoning deaths were associated with generators.
The tests performed by NIST compared two commercially available gasoline-powered generators against two similar machines that UA retrofitted with closed-loop electronic fuel injection and a small catalyst. Tests were conducted at NIST's manufactured test home, with the generator operating in the attached garage so as to simulate some common scenarios that often result in deaths or injuries.
In one series of comparisons, generators operated three or more hours in the garage with the garage bay door open and the entry to the house closed. For the stock generator tested, CO levels in the garage peaked at 1,500 parts per million (ppm,which are equivalent to microliters per liter) and inside the house ranged between 150 and 200 ppm.
Clinical symptoms of CO poisoning, including headaches, nausea, and disordered thinking, begin appearing at exposure levels of 100 ppm after at least 90 minutes exposure. During the NIST tests, emissions from the prototype generators ranged from 20 to 30 ppm in the open garage and from 5 to 10 ppm in the house.
CPSC staff conducted health effects modeling using NIST's test results, as part of CPSC's technology demonstration program of the prototype generator, to show that its engine's reduced CO emission rate is expected to result in fewer deaths by significantly delaying the onset and rate of progression of CO poisoning symptoms compared to the stock generator.
On the basis of results of findings from NIST's two earlier studies,** the CDC advises to never run a generator less than 20 feet from an open window, door, or vent where exhaust can vent into an enclosed area. Steven Emmerich, the lead NIST researcher, reminds that generators should always be operated outdoors, far from open windows. "Tragically, fatalities and injuries occur every year," he says. "We hope our research in support of CPSC's efforts to develop and demonstrate a low CO emission generator using existing emission control technology will contribute to practical safety improvements that will help to reduce this toll."
Annual sales of portable generators have been increasing in the United States and around the world, largely as insurance in the event of power failures. By 2014, U.S. sales of home generator units are predicted to reach $1.2 billion, according to a 2010 report by SBI Energy. The consultancy predicts that worldwide sales will grow to almost 13 million units in 2014.
In their study, NIST researchers also validated the use of their CONTAM*** computer model for studying the performance of prototype generators under a wider range of conditions than those tested. Results of simulations carried out with this publicly available software for studying building airflow and indoor air quality were checked against measurements of CO levels in actual tests. The predicted results were in good agreement with the CO measurements.* S.J. Emmerich, A.K. Persily, and L. Wang, Modeling and Measuring the Effects of Portable Gasoline Powered Generator Exhaust on Indoor Carbon Monoxide Level, NIST Technical Note 1781, Feb. 2013. http://www.nist.gov/manuscript-publication-search.cfm?pub_id=912197
Mark Bello | EurekAlert!
Despite government claims, orangutan populations have not increased. Call for better monitoring
06.11.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Increasing frequency of ocean storms could alter kelp forest ecosystems
30.10.2018 | University of Virginia
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
14.11.2018 | Materials Sciences
14.11.2018 | Health and Medicine
14.11.2018 | Life Sciences