ASHRAE Journal - September 2019 - 73

COLUMN PRODUCTIVITY-ASHRAE

evidence of CO2 not affecting performance. The results
of one additional study,22 suggest a possible effect of
increased CO2. The mechanism by which increased CO2
concentrations may affect cognitive performance was
not clearly identified in any of the studies. A possible
explanation is provided by another study,25 albeit one
that increased CO2 levels by restricting ventilation rate
per person, hence concentrations of other bioeffluents
increased when the CO2 levels were higher. In this study,
as subjects were exposed to levels of CO2 increasing from
approximately 400 to 3,000 ppm their forced expiratory
volume in 1 second and forced vital capacity decreased.
Using models and prior published data, with exposure
to higher levels of CO2, the authors predicted increases
in arterial CO2 partial pressure and corresponding
increases in the bicarbonate content of the blood with a
reduction in blood pH. The increased blood bicarbonate
and reduction in blood pH was suggested as the explanation for a change in brain functioning when occupants are exposed to higher levels of CO2.
Two papers15,19 hypothesized that the level of stress

associated with the cognitive performance test might
explain the discrepancies among findings. Higher CO2
levels were associated with diminished performance
primarily from studies with very demanding, likely
stressful, tests of performance. In support of their
hypothesis, they found a tendency for subjects to have
higher salivary α-amylase concentrations, suggesting
higher mental stress, when CO2 concentrations were
increased. Further support for this hypothesis comes
from findings that pilots' performance in flight simulations was reduced when their heart rate variability
indicated a high level of stress.21 Also, two studies12,15
report some increases in blood pressure with exposure
to higher CO2 levels, suggesting higher levels of stress.
The authors of two papers hypothesized that the discrepancies among research findings when subjects took
stressful cognitive performance tests was a consequence
of the different types of subjects. In one paper,20 the
authors suggested that the astronaut-like operations
personnel and submariners might have been better able
to compensate for effects of elevated CO2 due to their

How AJ Manufacturing Helps
Make Clean Rooms Clean
Primary HVAC systems provide conditioned air to a clean
room's plenum space, and variable flow exhaust systems
maintain the correct room pressure. But it's the stainless
steel air distribution products from AJ Manufacturing
that help make and keep clean rooms clean, including:

Criti-Clean Ultra FFU
Our Criti-Clean Ultra laminar flow HEPA filter diffusers provide
filtered air in a laminar flow over work areas, meeting air quality
and room change requirements - including those needed to
meet new USP 800 needs in pharmacies. They also eliminate
leak paths, allowing IEST 34 Certification. Plus, Criti-Clean
Ultra's low plenum height (just 13.7") and available integrated
lighting make retrofitting into existing ceiling spaces easier.
Hinged Filter Grilles
Use our filter grilles as low wall returns to maximize laminar
flow in clean room spaces and allow pre-filtering without
additional ceiling penetrations to extend HEPA/ULPA filter life.

Criti-Clean Ultra
* Up to 1200 CFM
* Energy-efficient
* Quiet operation

Hinged Filter Grille

Need to meet USP 800 pharmacy
requirements? Scan code to
learn more or contact us today!

816-231-5522
ajmfg.com

S E P T E M B E R 2 0 19

ashrae.org

ASHRAE JOURNAL

73


http://www.ajmfg.com http://www.ashrae.org

ASHRAE Journal - September 2019

Table of Contents for the Digital Edition of ASHRAE Journal - September 2019

Contents
ASHRAE Journal - September 2019 - Intro
ASHRAE Journal - September 2019 - Cover1
ASHRAE Journal - September 2019 - Cover2
ASHRAE Journal - September 2019 - 1
ASHRAE Journal - September 2019 - Contents
ASHRAE Journal - September 2019 - 3
ASHRAE Journal - September 2019 - 4
ASHRAE Journal - September 2019 - 5
ASHRAE Journal - September 2019 - 6
ASHRAE Journal - September 2019 - 7
ASHRAE Journal - September 2019 - 8
ASHRAE Journal - September 2019 - 9
ASHRAE Journal - September 2019 - 10
ASHRAE Journal - September 2019 - 11
ASHRAE Journal - September 2019 - 12
ASHRAE Journal - September 2019 - 13
ASHRAE Journal - September 2019 - 14
ASHRAE Journal - September 2019 - 15
ASHRAE Journal - September 2019 - 16
ASHRAE Journal - September 2019 - 17
ASHRAE Journal - September 2019 - 18
ASHRAE Journal - September 2019 - 19
ASHRAE Journal - September 2019 - 20
ASHRAE Journal - September 2019 - 21
ASHRAE Journal - September 2019 - 22
ASHRAE Journal - September 2019 - 23
ASHRAE Journal - September 2019 - 24
ASHRAE Journal - September 2019 - 25
ASHRAE Journal - September 2019 - 26
ASHRAE Journal - September 2019 - 27
ASHRAE Journal - September 2019 - 28
ASHRAE Journal - September 2019 - 29
ASHRAE Journal - September 2019 - 30
ASHRAE Journal - September 2019 - 31
ASHRAE Journal - September 2019 - 32
ASHRAE Journal - September 2019 - 33
ASHRAE Journal - September 2019 - 34
ASHRAE Journal - September 2019 - 35
ASHRAE Journal - September 2019 - 36
ASHRAE Journal - September 2019 - 37
ASHRAE Journal - September 2019 - 38
ASHRAE Journal - September 2019 - 39
ASHRAE Journal - September 2019 - 40
ASHRAE Journal - September 2019 - 41
ASHRAE Journal - September 2019 - 42
ASHRAE Journal - September 2019 - 43
ASHRAE Journal - September 2019 - 44
ASHRAE Journal - September 2019 - 45
ASHRAE Journal - September 2019 - 46
ASHRAE Journal - September 2019 - 47
ASHRAE Journal - September 2019 - 48
ASHRAE Journal - September 2019 - 49
ASHRAE Journal - September 2019 - 50
ASHRAE Journal - September 2019 - 51
ASHRAE Journal - September 2019 - 52
ASHRAE Journal - September 2019 - 53
ASHRAE Journal - September 2019 - 54
ASHRAE Journal - September 2019 - 55
ASHRAE Journal - September 2019 - 56
ASHRAE Journal - September 2019 - 57
ASHRAE Journal - September 2019 - 58
ASHRAE Journal - September 2019 - 59
ASHRAE Journal - September 2019 - 60
ASHRAE Journal - September 2019 - 61
ASHRAE Journal - September 2019 - 62
ASHRAE Journal - September 2019 - 63
ASHRAE Journal - September 2019 - 64
ASHRAE Journal - September 2019 - 65
ASHRAE Journal - September 2019 - 66
ASHRAE Journal - September 2019 - 67
ASHRAE Journal - September 2019 - 68
ASHRAE Journal - September 2019 - 69
ASHRAE Journal - September 2019 - 70
ASHRAE Journal - September 2019 - 71
ASHRAE Journal - September 2019 - 72
ASHRAE Journal - September 2019 - 73
ASHRAE Journal - September 2019 - 74
ASHRAE Journal - September 2019 - 75
ASHRAE Journal - September 2019 - 76
ASHRAE Journal - September 2019 - 77
ASHRAE Journal - September 2019 - 78
ASHRAE Journal - September 2019 - 79
ASHRAE Journal - September 2019 - 80
ASHRAE Journal - September 2019 - 81
ASHRAE Journal - September 2019 - 82
ASHRAE Journal - September 2019 - 83
ASHRAE Journal - September 2019 - 84
ASHRAE Journal - September 2019 - 85
ASHRAE Journal - September 2019 - 86
ASHRAE Journal - September 2019 - 87
ASHRAE Journal - September 2019 - 88
ASHRAE Journal - September 2019 - Cover3
ASHRAE Journal - September 2019 - Cover4
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