Title: A longitudinal study of ventilation rates in California office buildings and self-reported occupant outcomes including respiratory illness absence

Abstract

Limited evidence has associated lower ventilation rates (VRs) in offices with higher illness-related absence rates. We studied spaces in office buildings, selected without knowledge of their VRs, in three California climate zones. In each study space, real-time logging sensors measured carbon dioxide and thermal parameters for one year. Web-based surveys every three months collected data on occupants’ health outcomes. Using multivariate models, relationships were assessed between CO₂ concentrations, or VRs estimated from CO₂, and adverse occupant outcomes including respiratory infections and illness absences. For all outcomes, positive associations were hypothesized with higher CO₂ levels (and negative associations with higher VRs). Low survey response limited sample size and study power. In the 16 study spaces, CO₂ concentrations were uniformly low over the year, and most estimated VRs ranged from twice to nine times the California office minimum VR standard (7 L/s or 15 cfm per person). Primary CO₂ and VR metrics had no statistically significant relationships with occupant outcomes. Within the observed range of uniformly low CO₂ and high VRs (mostly 16–42 L/s per person), little variation in contaminant concentrations would be expected, which would explain lack of relationships with occupant outcomes. These high VRs resulted partly from frequently used energy-savingmore » “economizer” cycles in moderate California climates, but VRs at other times also substantially exceeded required VRs. These findings suggest, consistent with theory, that within a higher VR range, increased VRs do not reduce respiratory illness. Further studies are needed to better characterize such relationships.« less

Authors:

Mendell, Mark J. ^[1]; Eliseeva, Ekaterina A. ^[1]; Spears, Michael ^[1]; Chan, Wanyu R. ^[1]; Cohn, Sebastian ^[1]; Sullivan, Douglas P. ^[1]; Fisk, William J. ^[1]

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+ Show Author Affiliations

1. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Publication Date:

Sat May 09 00:00:00 EDT 2015

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE; California Energy Commission (United States)

OSTI Identifier:

1512243

Alternate Identifier(s):

OSTI ID: 1253408

Grant/Contract Number:  

AC02-05CH11231; 500-09-049

Resource Type:

Accepted Manuscript

Journal Name:

Building and Environment

Additional Journal Information:

Journal Volume: 92; Journal ID: ISSN 0360-1323

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

60 APPLIED LIFE SCIENCES; ventilation rate; indoor air quality; illness absence; respiratory illness