ASHRAE Journal - March 2021 - 57

TECHNICAL FEATURE

(2011, 2015 and 2017) using archetype
models for small, medium and large
office buildings, schools and multiunit residential buildings (MURBs).
Simulations were performed using
the U.S. Department of Energy's
EnergyPlus V9.1 in different Canadian
climate zones; Victoria, Windsor,
Ottawa, Edmonton and Whitehorse,
which represent NECB Climate Zones 4
through 8, respectively.

TABLE 1 Differences in EPD and equivalent full-load hours, ASHRAE Standard 90.1-2016 and NECB 2017.
BUILDING TYPE

Office
School
Multiunit
Residential
Buildings

Background
Review of Plug Load Assumptions in Energy Codes and Standards
In different energy codes and standards, default
schedules and EPD values for plug loads are provided
based on building type. These values are used to represent plug loads in building simulations for demonstrating compliance with these codes and standards. A recent
review by O'Brien, et al.,3 which reviewed energy codes
in 23 regions across the world, indicated that specified
EPD values varied by nearly a factor of six between different countries (0.24 W/ft2 to 1.49 W/ft2 [2.6 W/m2 to
16 W/m2]). The review suggested the variation in plug
load schedules was not as considerable as EPD values,
yet some differences were observed, particularly with
regard to estimates of nighttime plug load use.
Within the Canadian context, although schedules
and EPD values are relatively similar in both NECB and
ASHRAE Standard 90.1, Table 1 summarizes the main
differences for office buildings, schools and MURBs.
Equivalent full-load hours per year for plug loads were
calculated based on the plug load schedules specified in
each case for weekdays and weekends.
Little information could be found regarding the
development of EPDs and related schedules in the
NECB. A review of the different versions of NECB also
showed that plug load schedules have not changed
since 1997-the year in which Canada's first building
energy code was published. However, previous ASHRAE
research projects reported on the development of EPDs
and related schedules for office buildings for ASHRAE
Standard 90.1. In particular, ASHRAE Research Project
RP-10934 presented the development process of hourly
plug load density profiles for weekdays and weekends
for office buildings. The data analyzed in that project
consisted of hourly monitored lighting and receptacle

METRIC

ASHRAE STANDARD 90.1

NECB 2017

Equipment Power Densities

0.75 W/ft2

0.7 W/ft2

Equivalent Full-Load Hours

2,899 h/yr

3,697 h/yr

Equipment Power Densities

W/ft2

0.46 W/ft2

Equivalent Full-Load Hours

2,725 h/yr

3,193 h/yr

Equipment Power Densities

0.5

W/ft2

0.46 W/ft2

Equivalent Full-Load Hours

5,715 h/yr

3,713 h/yr

0.5

loads in 46 office buildings around the United States,
which were used to derive plug load schedules.
Abushakra, et al.,5 surveyed available data sets of
monitored commercial end use electricity data, which
were used as part of ASHRAE RP-10934 and indicated
that data used in ASHRAE RP-1093 were collected in the
1980s and early 1990s. Although building occupancy
patterns have significantly changed since then (e.g., due
to new societal trends such as teleworking, co-working,
and other flexible work arrangements), assumptions
regarding plug loads have not reflected these changes.
More recent ASHRAE projects (e.g., ASHRAE RP-1482,
ASHRAE RP-17426) aimed to revise EPD values with
newer values to reflect developments in equipment
power management capabilities. However, analysis of
different versions of ASHRAE Standard 90.1 and its user
manuals shows that only EPD values have changed over
the years; plug load schedules have not.

Review of Previous Studies on Plug Load Use in Existing Buildings
As indicated above, energy codes and standards specify
EPD and schedules for plug loads based on building
type. However, previous studies showed these values
and their use profiles widely varied between existing
buildings, even those of the same type. Studies that
focused on analyzing plug loads in existing buildings
are discussed in this section, and a summary of their
reported EPDs is provided in Table 2.
Several studies focused on analyzing plug load use
in office buildings and highlighted wide discrepancies
in EPD and daily use patterns. For example, Bennet,
et al.,7 indicated electricity use varied widely between
32 tenants of office towers in eastern Ontario and
that plug load use was lower than ASHRAE design values during occupied hours. Harris and Higgins8 also
reported a wide range of EPD and related schedules
based on data from 17 office buildings in the United
States, which were categorized into high (1.6 W/ft2
MARCH 2021

ashrae.org

ASHRAE JOURNAL

57


http://www.ashrae.org

ASHRAE Journal - March 2021

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

Contents
ASHRAE Journal - March 2021 - Intro
ASHRAE Journal - March 2021 - Cover1
ASHRAE Journal - March 2021 - Cover2
ASHRAE Journal - March 2021 - 1
ASHRAE Journal - March 2021 - Contents
ASHRAE Journal - March 2021 - 3
ASHRAE Journal - March 2021 - 4
ASHRAE Journal - March 2021 - 5
ASHRAE Journal - March 2021 - 6
ASHRAE Journal - March 2021 - 7
ASHRAE Journal - March 2021 - 8
ASHRAE Journal - March 2021 - 9
ASHRAE Journal - March 2021 - 10
ASHRAE Journal - March 2021 - 11
ASHRAE Journal - March 2021 - 12
ASHRAE Journal - March 2021 - 13
ASHRAE Journal - March 2021 - 14
ASHRAE Journal - March 2021 - 15
ASHRAE Journal - March 2021 - 16
ASHRAE Journal - March 2021 - 17
ASHRAE Journal - March 2021 - 18
ASHRAE Journal - March 2021 - 19
ASHRAE Journal - March 2021 - 20
ASHRAE Journal - March 2021 - 21
ASHRAE Journal - March 2021 - 22
ASHRAE Journal - March 2021 - 23
ASHRAE Journal - March 2021 - 24
ASHRAE Journal - March 2021 - 25
ASHRAE Journal - March 2021 - 26
ASHRAE Journal - March 2021 - 27
ASHRAE Journal - March 2021 - 28
ASHRAE Journal - March 2021 - 29
ASHRAE Journal - March 2021 - 30
ASHRAE Journal - March 2021 - 31
ASHRAE Journal - March 2021 - 32
ASHRAE Journal - March 2021 - 33
ASHRAE Journal - March 2021 - 34
ASHRAE Journal - March 2021 - 35
ASHRAE Journal - March 2021 - 36
ASHRAE Journal - March 2021 - 37
ASHRAE Journal - March 2021 - 38
ASHRAE Journal - March 2021 - 39
ASHRAE Journal - March 2021 - 40
ASHRAE Journal - March 2021 - 41
ASHRAE Journal - March 2021 - 42
ASHRAE Journal - March 2021 - 43
ASHRAE Journal - March 2021 - 44
ASHRAE Journal - March 2021 - 45
ASHRAE Journal - March 2021 - 46
ASHRAE Journal - March 2021 - 47
ASHRAE Journal - March 2021 - 48
ASHRAE Journal - March 2021 - 49
ASHRAE Journal - March 2021 - 50
ASHRAE Journal - March 2021 - 51
ASHRAE Journal - March 2021 - 52
ASHRAE Journal - March 2021 - 53
ASHRAE Journal - March 2021 - 54
ASHRAE Journal - March 2021 - 55
ASHRAE Journal - March 2021 - 56
ASHRAE Journal - March 2021 - 57
ASHRAE Journal - March 2021 - 58
ASHRAE Journal - March 2021 - 59
ASHRAE Journal - March 2021 - 60
ASHRAE Journal - March 2021 - 61
ASHRAE Journal - March 2021 - 62
ASHRAE Journal - March 2021 - 63
ASHRAE Journal - March 2021 - 64
ASHRAE Journal - March 2021 - 65
ASHRAE Journal - March 2021 - 66
ASHRAE Journal - March 2021 - 67
ASHRAE Journal - March 2021 - 68
ASHRAE Journal - March 2021 - 69
ASHRAE Journal - March 2021 - 70
ASHRAE Journal - March 2021 - 71
ASHRAE Journal - March 2021 - 72
ASHRAE Journal - March 2021 - 73
ASHRAE Journal - March 2021 - 74
ASHRAE Journal - March 2021 - 75
ASHRAE Journal - March 2021 - 76
ASHRAE Journal - March 2021 - 77
ASHRAE Journal - March 2021 - 78
ASHRAE Journal - March 2021 - 79
ASHRAE Journal - March 2021 - 80
ASHRAE Journal - March 2021 - 81
ASHRAE Journal - March 2021 - 82
ASHRAE Journal - March 2021 - 83
ASHRAE Journal - March 2021 - 84
ASHRAE Journal - March 2021 - 85
ASHRAE Journal - March 2021 - 86
ASHRAE Journal - March 2021 - 87
ASHRAE Journal - March 2021 - 88
ASHRAE Journal - March 2021 - 89
ASHRAE Journal - March 2021 - 90
ASHRAE Journal - March 2021 - 91
ASHRAE Journal - March 2021 - 92
ASHRAE Journal - March 2021 - 93
ASHRAE Journal - March 2021 - 94
ASHRAE Journal - March 2021 - 95
ASHRAE Journal - March 2021 - 96
ASHRAE Journal - March 2021 - 97
ASHRAE Journal - March 2021 - 98
ASHRAE Journal - March 2021 - 99
ASHRAE Journal - March 2021 - 100
ASHRAE Journal - March 2021 - 101
ASHRAE Journal - March 2021 - 102
ASHRAE Journal - March 2021 - 103
ASHRAE Journal - March 2021 - 104
ASHRAE Journal - March 2021 - Cover3
ASHRAE Journal - March 2021 - Cover4
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