Evidence map›Paper›PMID 37725631›Full record

ArticlePLOS global public health2023

The impact of heating, ventilation, and air conditioning design features on the transmission of viruses, including the 2019 novel coronavirus: A systematic review of filtration.

Gail M Thornton, Brian A Fleck, Emily Kroeker, Dhyey Dandnayak, Natalie Fleck, Lexuan Zhong, Lisa Hartling

Abstract read
In one paragraph

Article in PLOS global public health, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed, 1 pooled it
–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

2 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Managing infectious aerosols to counter engineered pandemics: Current recommendations and future research.Risk analysis : an official publication of the Society for Risk Analysis · 2025
    Guideline
  2. 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

7 authors.

Gail M ThorntonDepartment of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada.ORCID https://orcid.org/0000-0001-8569-300X
Brian A FleckDepartment of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada.ORCID https://orcid.org/0000-0002-2747-3719
Emily KroekerDepartment of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada.
Dhyey DandnayakDepartment of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada.ORCID https://orcid.org/0000-0002-8779-2682
Natalie FleckDepartment of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada.
Lexuan ZhongDepartment of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada.ORCID https://orcid.org/0000-0001-5211-8826
Lisa HartlingDepartment of Pediatrics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Canada.ORCID https://orcid.org/0000-0001-8341-3991

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Historically, viruses have demonstrated airborne transmission. Emerging evidence suggests the novel coronavirus (SARS-CoV-2) that causes COVID-19 also spreads by airborne transmission. This is more likely in indoor environments, particularly with poor ventilation. In the context of airborne transmission, a vital mitigation strategy for the built environment is heating, ventilation, and air conditioning (HVAC) systems. HVAC features could modify virus transmission potential. A systematic review was conducted to identify and synthesize research examining the effectiveness of filters within HVAC systems in reducing virus transmission. A comprehensive search of OVID MEDLINE, Compendex, and Web of Science Core was conducted to January 2021. Two authors were involved in study selection, data extraction, and risk of bias assessments. Study characteristics and results were displayed in evidence tables and findings were synthesized narratively. Twenty-three relevant studies showed that: filtration was associated with decreased transmission; filters removed viruses from the air; increasing filter efficiency (efficiency of particle removal) was associated with decreased transmission, decreased infection risk, and increased viral filtration efficiency (efficiency of virus removal); increasing filter efficiency above MERV 13 was associated with limited benefit in further reduction of virus concentration and infection risk; and filters with the same efficiency rating from different companies showed variable performance. Adapting HVAC systems to mitigate virus transmission requires a multi-factorial approach and filtration is one factor offering demonstrated potential for decreased transmission. For filtration to be effective, proper installation is required. Of note, similarly rated filters from different companies may offer different virus reduction results. While increasing filtration efficiency (i.e., increasing MERV rating or moving from MERV to HEPA) is associated with virus mitigation, there are diminishing returns for filters rated MERV 13 or higher. Although costs increase with filtration efficiency, they are lower than the cost of ventilation options with the equivalent reduction in transmission. Systematic review registration: PROSPERO 2020 CRD42020193968.

Identifiers

PMID37725631
PMCPMC10508630

What OpenQuestion holds

Textmetadata
LicenceCC BY
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.