ASHRAE Journal - November 2019 - 76

COLUMN IEQ APPLICATIONS
Jeffrey Siegel

Residential Filtration
BY JEFFREY SIEGEL, PH.D., MEMBER ASHRAE

Residential filtration has always been the neglected sibling when compared to
commercial filtration. Filter standards are usually based around commercial uses and
HVAC systems. However, residential filters experience very different conditions than
commercial filters. Some of these differences include lower average flow rates, system
operation (thermostatic cycling vs. continuous), and a much higher fraction of recirculating systems rather than systems with mechanical outdoor air ventilation.
There are also some fundamental differences in context: commercial filters are largely changed according
to a contract by a professional on a fixed schedule rather
than by a homeowner who likely changes the filter when
they remember and may select a filter based on factors
other than performance.
Residential systems are often smaller and they are
much less standardized, which can lead to important
differences for filtration. Although there have been
many studies of residential filtration, most are relatively
short-term and only some have characterized the buildings and systems. As a result, the filtration community
lacks long-term data to make recommendations to
homeowners about filters.
When we embarked on the fieldwork for ASHRAE
Research Project RP-1649: Indoor Air Quality and Energy
Implications of Filters in Residential Buildings, I anticipated
that we would find that higher efficiency filters performed better than low efficiency filters and I also
anticipated some variation in performance for the same
filter in different homes. To a certain extent, this is
what we found, but the story that emerged was almost
entirely one of variation. The same filter performed very
differently in different homes and in some cases, high
efficiency and lower efficiency filters performed surprisingly similarly in the same home. The project thus
76

ASHRAE JOURNAL

ashrae.org

N O V E M B E R 2 0 19

became largely about exploring this variation and trying
to understand what it means for filtration use and filter
standards in residences.

Methods
The project monitoring subcommittee selected four
filters: a MERV 8 uncharged filter and MERV 8, 11, and 14
electret filters (hereafter called MERV 8E, 11E, and 14E),
all in a 1 in. thickness. We found 20 homes in Toronto
that were willing to tolerate frequent visits and continuous monitoring of their HVAC systems and particle concentrations in their living room for one year. The homes
were mostly single-family residences in central Toronto,
two were units in high-rise condominiums and one was
a unit in a large home converted into smaller apartments. All had forced-air systems, all but one without
mechanical ventilation (outdoor air), and all provided
both heating and cooling. We installed each filter for
three months in a random order in each home to allow
us to compare the performance of different filters across
the study without seasonal or other biases.
The measurements for the project included both
short-term measures of filter efficiency, effectiveness,
airflow, and filter pressure drop at the beginning,
Jeffrey Siegel is a professor in the Department of Civil and Mineral Engineering at the
University of Toronto.



ASHRAE Journal - November 2019

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

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