Researchers at the National Institute of Standards and Technology (NIST) spent 75 days on the job carrying out some very important homeworkmeasurements in a "typical dwelling" of the release, distribution and fate of particles almost as tiny as the diameter of a single DNA molecule. Particles ranging in size from 100 nanometers down to 2.5 nanometers that were emitted by gas and electric stoves, hair dryers, power tools and candles were tracked and analyzed.*
Monitoring such tiny particles was made possible by NIST advances in measurement capabilities. Measurements were carried out in weeks of experiments at a 340-square-meter (1,500-square-feet) test house on the NIST campus in Gaithersburg, Md. The researchers used the data to develop a model for predicting changes in the size and distribution of so-called ultrafine particles (technically, particles smaller than 100 nanometers) discharged by tools, appliances and other sources.
The measurements and model will further efforts to explain the dynamics of ultrafine particles, an area of growing interest among environmental and health researchers. They also will advance work to develop accurate and reliable methods for determining how changes in heating and cooling systems, often done to reduce energy consumption, will affect indoor environments.
"If we can understand and predict the dynamics of these extremely small indoor air contaminants, designers and equipment manufacturers can avoid potential negative impacts on the environment inside homes and buildings and may even devise ways to improve conditions and save energy at the same time," explains NIST engineer Andrew Persily.
Utrafine particles are produced naturallyby forest fires and volcanoes, for exampleas well as by internal combustion engines, power plants and many other human-made sources. Although ever present in outdoor and indoor environments, ultrafine particles have eluded detection, and are not subject to federal
|Contact: Mark Bello|
National Institute of Standards and Technology (NIST)