Document Type

Article

Publication Date

8-30-2018

Publication Title

Building and Environment

ISSN

1873-684X

Volume

114

DOI

https://doi.org/10.1016/j.buildenv.2018.08.044

Abstract

Low-energy home design is becoming more common in new and retrofitted homes, and energy-efficient designs often sell at a premium [1]. Efficiency measures, like tightening the building envelope saves energy, but can impact the indoor air quality (IAQ). We monitored the IAQ of nine tightly constructed homes, one tightly constructed public library, and one conventionally constructed home, and performed a repeatable cooking activity to observe the impact of the fine particulate matter (PM2.5) emissions. We compared PM2.5 concentrations from the cooking activity while operating the mechanical ventilation systems at default rates (~0.1-0.3 h-1) and in a temporary boost mode (~0.3-0.8 h-1). We also measured the concentrations of total volatile organic compounds (TVOCs), formaldehyde, radon, and bedroom carbon dioxide (CO2) levels. Results show that PM2.5 concentrations are generally low indoors, but cooking drastically increases concentrations, which are slow to decay. No significant difference was found between operating the ventilators at standard rates and utilizing the temporary boost. Completely-mixed flow reactor models of select homes show that installing and using a directly-exhausting range hood can reduce peak PM2.5 concentrations by 75% or more. Current ventilation practices in these buildings may not be adequate for these common activities. Formaldehyde was above the California Office of Environmental Health Hazard Assessment (OEHHA) chronic limit of 9 µg/m3 in all tight buildings with a median concentration of 30 µg/m3. CO2 levels in bedrooms exceeded 1000 ppm in six homes, indicating that bedroom ventilation practices are not consistent nor adequate.

Comments

This is a post-print version of an article published in Building and Environment. The publisher's version can be found here.

Available for download on Sunday, August 30, 2020

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