Evidence map›Paper›PMID 25399878›Full record

ArticleIndoor air2015

Estimation of bias with the single-zone assumption in measurement of residential air exchange using the perfluorocarbon tracer gas method.

K Van Ryswyk, L Wallace, D Fugler, M MacNeill, M È Héroux, M D Gibson, J R Guernsey, W Kindzierski, A J Wheeler

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Indoor air, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

K Van RyswykAir Health Science Division, Health Canada, Ottawa, ON, Canada.
L WallaceConsultant, Santa Rosa, CA, USA.
D FuglerConsultant, Ottawa, ON, Canada.
M MacNeillAir Health Science Division, Health Canada, Ottawa, ON, Canada.
M È HérouxAir Health Science Division, Health Canada, Ottawa, ON, Canada.
M D GibsonDepartment of Process Engineering and Applied Science, Dalhousie University, Halifax, NS, Canada.
J R GuernseyCommunity Health and Epidemiology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada.
W KindzierskiSchool of Public Health, University of Alberta, Edmonton, AB, Canada.
A J WheelerAir Health Science Division, Health Canada, Ottawa, ON, Canada.

Funding

World Health Organization 001
6 · The paper itself

Abstract

unlabelledResidential air exchange rates (AERs) are vital in understanding the temporal and spatial drivers of indoor air quality (IAQ). Several methods to quantify AERs have been used in IAQ research, often with the assumption that the home is a single, well-mixed air zone. Since 2005, Health Canada has conducted IAQ studies across Canada in which AERs were measured using the perfluorocarbon tracer (PFT) gas method. Emitters and detectors of a single PFT gas were placed on the main floor to estimate a single-zone AER (AER(1z)). In three of these studies, a second set of emitters and detectors were deployed in the basement or second floor in approximately 10% of homes for a two-zone AER estimate (AER(2z)). In total, 287 daily pairs of AER(2z) and AER(1z) estimates were made from 35 homes across three cities. In 87% of the cases, AER(2z) was higher than AER(1z). Overall, the AER(1z) estimates underestimated AER(2z) by approximately 16% (IQR: 5-32%). This underestimate occurred in all cities and seasons and varied in magnitude seasonally, between homes, and daily, indicating that when measuring residential air exchange using a single PFT gas, the assumption of a single well-mixed air zone very likely results in an under prediction of the AER. PRACTICAL IMPLICATIONS: The results of this study suggest that the long-standing assumption that a home represents a single well-mixed air zone may result in a substantial negative bias in air exchange estimates. Indoor air quality professionals should take this finding into consideration when developing study designs or making decisions related to the recommendation and installation of residential ventilation systems.

Indexed as

Air MovementsAir Pollution, IndoorBiasCanadaFluorocarbonsHousingHumansVentilationFluorocarbonsAir exchangeIndoor airMass balance equationPerfluorocarbonResidentialTracer gas

Identifiers

PMID25399878
PMCPMC4674977

What OpenQuestion holds

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LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.