ASHRAE Journal - July 2021 - 14

TECHNICAL FEATURE
Analysis of Spread of
Airborne Contaminants
And Risk Of Infection
BY KISHOR KHANKARI, PH.D., FELLOW ASHRAE
As businesses are poised to reopen amid the COVID-19 pandemic, people are looking
for comprehensive guidance for proper ventilation of indoor spaces. Computational
fl uid dynamics (CFD) was used to study the impact of the HVAC layout (location
and number of supply diffusers and return grilles) on indoor airfl ow patterns and
the resulting risk of infection. The results indicate an HVAC layout with distributed
supply and distributed return can form an aerodynamic containment (airfl ow envelope)
that can help reduce the spread of airborne contaminants and reduce the risk
of infection without increasing the supply airfl ow rates. CFD analyses, if performed
properly with adequate expertise, can help professionals understand complex airfl ow
patterns and the fl ow path of airborne contaminants.
Airfl ow, Ventilation and CFD
Air can carry small droplets and particles containing
the SARS-CoV-2 virus that causes COVID-19 over a long
distance. Depending on the local airfl ow patterns, some
of these respiratory droplets can travel much farther
than 6 ft (1.8 m).1 Often good ventilation is recommended,
along with social distancing and face-covering
measures to control the spread of the SARS-CoV-2
virus.2
Good ventilation is commonly referred to and understood
as an increased supply of clean air or increased
air change rates per hour (ach, h-1) for enclosed spaces.2
However, simply increasing the supply of clean air
may not be suffi cient to achieve good ventilation.2,3
Increased supply airfl ow rates can help in the dilution
of airborne contaminants and reduce the overall
concentration levels. However, the increased supply
airfl ow rate may not necessarily ensure the acceptable
concentration levels everywhere in the occupied zone.
High concentration, especially in the breathing zone,
can pose a potentially higher risk of infection.4 Airfl ow
patterns and resulting distribution of clean air in indoor
Kishor Khankari, Ph.D., is the president at AnSight LLC in Ann Arbor, Mich.
This peer-reviewed article does not represent offi cial ASHRAE guidance. For more information on ASHRAE resources on COVID-19, visit ashrae.org/COVID19.
14
ASHRAE JOURNAL ashrae.org J U LY 2 0 2 1
http://www.ashrae.org/COVID19 http://www.ashrae.org

ASHRAE Journal - July 2021

Table of Contents for the Digital Edition of ASHRAE Journal - July 2021

Contents
ASHRAE Journal - July 2021 - Intro
ASHRAE Journal - July 2021 - Cover1
ASHRAE Journal - July 2021 - Cover2
ASHRAE Journal - July 2021 - 1
ASHRAE Journal - July 2021 - Contents
ASHRAE Journal - July 2021 - 3
ASHRAE Journal - July 2021 - 4
ASHRAE Journal - July 2021 - 5
ASHRAE Journal - July 2021 - 6
ASHRAE Journal - July 2021 - 7
ASHRAE Journal - July 2021 - 8
ASHRAE Journal - July 2021 - 9
ASHRAE Journal - July 2021 - 10
ASHRAE Journal - July 2021 - 11
ASHRAE Journal - July 2021 - 12
ASHRAE Journal - July 2021 - 13
ASHRAE Journal - July 2021 - 14
ASHRAE Journal - July 2021 - 15
ASHRAE Journal - July 2021 - 16
ASHRAE Journal - July 2021 - 17
ASHRAE Journal - July 2021 - 18
ASHRAE Journal - July 2021 - 19
ASHRAE Journal - July 2021 - 20
ASHRAE Journal - July 2021 - 21
ASHRAE Journal - July 2021 - 22
ASHRAE Journal - July 2021 - 23
ASHRAE Journal - July 2021 - 24
ASHRAE Journal - July 2021 - 25
ASHRAE Journal - July 2021 - 26
ASHRAE Journal - July 2021 - 27
ASHRAE Journal - July 2021 - 28
ASHRAE Journal - July 2021 - 29
ASHRAE Journal - July 2021 - 30
ASHRAE Journal - July 2021 - 31
ASHRAE Journal - July 2021 - 32
ASHRAE Journal - July 2021 - 33
ASHRAE Journal - July 2021 - 34
ASHRAE Journal - July 2021 - 35
ASHRAE Journal - July 2021 - 36
ASHRAE Journal - July 2021 - 37
ASHRAE Journal - July 2021 - 38
ASHRAE Journal - July 2021 - 39
ASHRAE Journal - July 2021 - 40
ASHRAE Journal - July 2021 - 41
ASHRAE Journal - July 2021 - 42
ASHRAE Journal - July 2021 - 43
ASHRAE Journal - July 2021 - 44
ASHRAE Journal - July 2021 - 45
ASHRAE Journal - July 2021 - 46
ASHRAE Journal - July 2021 - 47
ASHRAE Journal - July 2021 - 48
ASHRAE Journal - July 2021 - 49
ASHRAE Journal - July 2021 - 50
ASHRAE Journal - July 2021 - 51
ASHRAE Journal - July 2021 - 52
ASHRAE Journal - July 2021 - 53
ASHRAE Journal - July 2021 - 54
ASHRAE Journal - July 2021 - 55
ASHRAE Journal - July 2021 - 56
ASHRAE Journal - July 2021 - 57
ASHRAE Journal - July 2021 - 58
ASHRAE Journal - July 2021 - 59
ASHRAE Journal - July 2021 - 60
ASHRAE Journal - July 2021 - 61
ASHRAE Journal - July 2021 - 62
ASHRAE Journal - July 2021 - 63
ASHRAE Journal - July 2021 - 64
ASHRAE Journal - July 2021 - 65
ASHRAE Journal - July 2021 - 66
ASHRAE Journal - July 2021 - 67
ASHRAE Journal - July 2021 - 68
ASHRAE Journal - July 2021 - 69
ASHRAE Journal - July 2021 - 70
ASHRAE Journal - July 2021 - 71
ASHRAE Journal - July 2021 - 72
ASHRAE Journal - July 2021 - 73
ASHRAE Journal - July 2021 - 74
ASHRAE Journal - July 2021 - 75
ASHRAE Journal - July 2021 - 76
ASHRAE Journal - July 2021 - 77
ASHRAE Journal - July 2021 - 78
ASHRAE Journal - July 2021 - 79
ASHRAE Journal - July 2021 - 80
ASHRAE Journal - July 2021 - 81
ASHRAE Journal - July 2021 - 82
ASHRAE Journal - July 2021 - 83
ASHRAE Journal - July 2021 - 84
ASHRAE Journal - July 2021 - 85
ASHRAE Journal - July 2021 - 86
ASHRAE Journal - July 2021 - 87
ASHRAE Journal - July 2021 - 88
ASHRAE Journal - July 2021 - 89
ASHRAE Journal - July 2021 - 90
ASHRAE Journal - July 2021 - 91
ASHRAE Journal - July 2021 - 92
ASHRAE Journal - July 2021 - 93
ASHRAE Journal - July 2021 - 94
ASHRAE Journal - July 2021 - 95
ASHRAE Journal - July 2021 - 96
ASHRAE Journal - July 2021 - 97
ASHRAE Journal - July 2021 - 98
ASHRAE Journal - July 2021 - 99
ASHRAE Journal - July 2021 - 100
ASHRAE Journal - July 2021 - 101
ASHRAE Journal - July 2021 - 102
ASHRAE Journal - July 2021 - 103
ASHRAE Journal - July 2021 - 104
ASHRAE Journal - July 2021 - 105
ASHRAE Journal - July 2021 - 106
ASHRAE Journal - July 2021 - 107
ASHRAE Journal - July 2021 - 108
ASHRAE Journal - July 2021 - 109
ASHRAE Journal - July 2021 - 110
ASHRAE Journal - July 2021 - 111
ASHRAE Journal - July 2021 - 112
ASHRAE Journal - July 2021 - Cover3
ASHRAE Journal - July 2021 - Cover4
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XCODFR
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QSLFGO
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ILKVNM
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2021
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OPDJKD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_VJKSRY
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SDHUTC
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JPPKRR
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SDLTTH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_CKLLES
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SLDOX
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_HJETUK
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OLUHGE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2020october
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2020october_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ZERDGH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QVMNEO
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RTPOKE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_BBATRE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_STUBMW
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TPEMPE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JNMKDS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_FBTTPA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WQMMNE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TVBRYN
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_showguide2020
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_KTUZMA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ABEDGD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201910
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201909
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2019septmeber_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2019september
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201908
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201907
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201906
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201905
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201904
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2019april
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201903
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2019march
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201902
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201901
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_showguide2019
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018december
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2018fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2018fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018october
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2018
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201810
https://www.nxtbook.com/nxtbooks/ashrae/ashraeinsights_201806
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201805
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201804
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201803
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201712
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201711
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201710
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2017fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2017fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201709
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201705
https://www.nxtbook.com/nxtbooks/ashrae/ashrae_meetinginsert_201610
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2016fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2016fall
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acrexindia
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2015summer_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2015summer
https://www.nxtbook.com/nxtbooks/amca/2014summer2
https://www.nxtbook.com/nxtbooks/amca/2014summer
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acma_2014summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201311
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201309
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acmasupp_2013fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201305
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201303
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2013winter
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201211
https://www.nxtbook.com/nxtbooks/ashrae/achr_expo_mexico2012
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201209
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201208_v3
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201208_v2
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2012summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201205
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201203
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2012winter
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201111_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201109_v2
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2011summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201105
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201103
https://www.nxtbookmedia.com