Indoor ultrafine particles of outdoor origin: importance of window opening area and fan operation condition.

Published

February 5, 2013

Author(s)

Dong H. Rim, Lance L. Wallace, Andrew K. Persily

Abstract

Airborne ultrafine particles (UFP) have been associated with human mortality and morbidity. Human exposure to ambient UFP occurs indoors due to entry of UFP into buildings. This study investigates UFP entry as a function of building operating conditions such as central fan operation and window position. Indoor and outdoor UFP concentrations along with air change rates were continuously measured in a full-scale test building. Estimates of infiltration factor, penetration coefficient and deposition rate have been made for a range of particle sizes from 4 nm to 100 nm. The results show that UFP infiltration factor varies with particle diameter, window position, air change rate, and central fan operation. UFP entry into the building increases as air change rate and particle size increase. Larger window openings lead to higher infiltration factors due to larger extent of particle penetration into the building. Comparing the fan operation mode (on vs. off), infiltration factors were lower with fan-off condition than fan-on condition, which was likely caused by additional particle deposition loss to the furnace filter and duct surfaces.

Citation

Environmental Science and Technology

Pub Type

Journals

Download Paper

Local Download

Keywords

ultrafine particles, infiltration factor, indoor-outdoor relationship, penetration, deposition, building operating condition

Citation

Rim, D. , Wallace, L. and Persily, A. (2013), Indoor ultrafine particles of outdoor origin: importance of window opening area and fan operation condition., Environmental Science and Technology, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=912360 (Accessed January 19, 2025)