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Energy and Buildings 36 (2004) 995–1001
Sensory pollution loads in six office buildings and a department storeP. Wargocki∗, P.O. Fanger, P. Krupicz, A. Szczecinski
International Centre for Indoor Environment and Energy, Technical University of Denmark, Building 402, DK-2800 Kongens Lyngby, Denmark
Abstract
Sensory pollution loads were measured in six non-smoking office buildings with mechanical ventilation without recirculation, and ina non-smoking department store with an air-conditioning system and recirculation. Untrained panels assessed the air quality on normalweekdays with occupants in the buildings, and in the case of office buildings, also on weekends without occupants present. On bothoccasions the ventilation system was in operation as on a normal working day. Outdoor airflow rate, air temperature, relative humidity andconcentration of carbon dioxide were measured. The sensory pollution load from the building (without occupants) was found in offices tobe 0.11± 0.09 olf/m2 floor, which agrees well with the load recommended for low-polluting buildings in CEN CR 1752. This load is onlyhalf of the sensory pollution load found in previous investigations in offices and assembly halls where smoking was allowed. The loadfrom building and merchandise in the department store was 0.15 olf/m2 floor. A table is provided listing the mean sensory pollution load ofthe buildings measured in the present and in previous studies carried out in the period from 1988 to 2001 in different types of buildings inEurope. The table covers 120 buildings including offices and assembly halls (with and without previous smoking), schools, kindergartensand a department store.© 2004 Elsevier B.V. All rights reserved.
Keywords:Sensory pollution load; Perceived air quality; Office building; Department store; Sensory measurements with untrained panel; Field study
1. Introduction
The ventilation required to obtain a certain desired per-ceived indoor air quality can be calculated when the sensorypollution loads from people and their activities and fromthe building (building materials, furnishing, ventilation sys-tem) are known[1]. The load from people can be estimatedfrom the human occupancy in the building. The load fromthe building can be estimated by classifying buildings as be-longing to a certain class, each class having a certain levelof sensory pollution load from the building. Such an ap-proach has been used in CEN CR 1752[2], where buildingsare classified as low-polluting or non-low-polluting with thesensory pollution load from the building being, respectively,0.1 olf/m2 floor and 0.2 olf/m2 floor. The total sensory pol-lution load is then calculated by adding the loads from peo-ple and building. A similar approach is used in ASHRAEStandard 62-2001, Addendum 62n[3], which adds the ven-tilation required to handle people and building.
Field studies in Europe during the last 15 years[4–9] havequantified the sensory pollution loads in more than one hun-dred buildings (Table 1). The sensory pollution loads were
∗ Corresponding author. Tel.:+45-4525-4011; fax:+45-4593-2166.E-mail address:[email protected] (P. Wargocki).URL: http://www.ie.dtu.dk.
calculated in these studies using measured outdoor airflowrates, and the perceived air quality. The measurements werecarried out on normal working days to quantify pollutionloads from building plus people, and in some cases also inthe same buildings during a weekend when the premiseswere unoccupied, with the ventilation system in normal op-eration in order to quantify the sensory pollution load fromthe building. Many of these studies were carried out in the1980s and early 1990s in buildings where smoking was stillallowed and the sensory pollution load from the building istherefore expected to be higher than in non-smoking build-ings. Taking into account that office buildings today are usu-ally smoke-free, it was felt essential to measure the sensorypollution load from the building in the non-smoking build-ings. It was furthermore decided to include a smoke-freedepartment store, since the merchandise could be expectedto increase the sensory pollution load.
In some of the earlier studies, the sensory assessments ofthe perceived air quality were performed by an untrainedpanel (as specified in Appendix B of ASHRAE Standard62-2001[3]). During a period in the early 1990s it was com-mon to use a trained panel (as specified by Bluyssen et al.[10]). It was later shown that the trained panels in most casessignificantly overestimated the actual levels of perceived airquality in the buildings and the corresponding percentagesof persons dissatisfied with the indoor air quality[11,12].
0378-7788/$ – see front matter © 2004 Elsevier B.V. All rights reserved.doi:10.1016/j.enbuild.2004.06.006
996 P. Wargocki et al. / Energy and Buildings 36 (2004) 995–1001
Tabl
e1
Ave
rage
sens
ory
pollu
tion
load
sm
easu
red
prev
ious
lyin
diffe
rent
Eur
opea
nbu
ildin
gs
Bui
ldin
gLo
catio
nN
umbe
rS
mok
ing
Sen
sory
Sen
sory
pollu
tion
load
(olf/
m2
floor
)R
efer
ence
type
ofbu
ildin
gsal
low
edin
the
pane
l(n
umbe
rof
Bui
ldin
g+pe
ople
,P
eopl
ec ,B
uild
ing,
(spa
ces)
build
ing
subj
ects
)a
mea
n±
S.D
.[m
in.–
max
.]m
ean±
S.D
.[m
in.–
max
.]m
ean±
S.D
.[m
in.–
max
.]
Offi
ceD
K13
(15)
Yes
Unt
rain
ed(5
4)0.
56±0.
45[0
.08–
1.54
](0.
08
±0
.03)
([0
.01
–0
.13])
0.37
±0.
30[0
.08–
0.95
][4
]O
ffice
DK
9(5
7)Y
esT
rain
ed(1
1)0.
09±0.
03[0
.05–
0.16
]b(0
.05
±0
.02)
([0
.03
–0
.09])
(0.0
4)d
[5]
Offi
ceN
L,D
K,
UK
,G
R,
F,C
H,
FIN
,N
,D
56(2
34)
Yes
Tra
ined
(12–
15)
0.34±
0.37
[0.0
1–2.
02]b
(0.0
9±
0.0
9)([
0–
0.5
8])(0
.25)
d[6
]
Offi
ceD
14(6
17)
Yes
Tra
ined
(5–1
1)0.
11±0.
06[0
.04–
0.26
]b(0
.09)
(0.0
2)d
[7]
Ass
embl
yha
llD
K5
(5)
Yes
Unt
rain
ed(5
4)0.
49±0.
51[0
.1–1
.36]b
(0.1
1±
0.0
9)([
0.0
2–
0.2
1])0.
60±
0.54
[0.0
9–1.
32]
[4]
Sch
ool
DK
6(2
–9pe
rbu
ildin
g)N
oT
rain
ed(6
)0.
13±0.
11[0
.03–
0.28
]b(0
.18
±0
.08)
([0
.05
–0
.45])
0.06
±0.
04[0
.02–
0.12
]b[8
]K
inde
rgar
ten
DK
10(1
0)N
oT
rain
ed(1
3)0.
18±0.
20[0
.01–
0.58
]b(0
.28
±0
.13)
([0
.08
–0
.51])
0.06
±0.
06[0
–0.1
7]b[9
]
NL;
The
Net
herla
nds,
DK
;D
enm
ark,
UK
;U
nite
dK
ingd
om,
GR
;G
reec
e,F
;F
ranc
e,C
H;
Sw
itzer
land
,F
IN;
Fin
land
,N
;N
orw
ay,
D;
Ger
man
y.To
dist
ingu
ish
estim
ated
sens
ory
pollu
tion
load
sfr
omth
ose
mea
sure
d,th
eyar
eita
licis
edan
dpu
tin
brac
kets
.a
Unt
rain
ed:
assp
ecifi
edin[3
];tr
aine
d:as
spec
ified
in[10
].b
The
sens
ory
pollu
tion
load
s,w
hich
wer
eco
rrec
ted
usin
gth
etr
ansf
erfu
nctio
nbe
twee
npe
rcei
ved
air
qual
ityju
dged
bya
trai
ned
pane
lan
dby
anun
trai
ned
pane
l[11]
;se
nsor
ypo
llutio
nlo
ads,
mea
n±S
.D.
[min
.–m
ax.]
(olf/
m2
floor
),re
port
edin
orig
inal
stud
ies
wer
eas
follo
ws:
0.36±
0.09
[0.2
0–0.
50]
from
build
ing+
peop
lein
[5];
0.64
±0.
82[0
.03–
5.03
]fr
ombu
ildin
g+pe
ople
in[6
];0.
29±
0.15
[0.0
4–0.
53]
from
build
ing+
peop
lein
[7];
0.31
±0.
18[0
.12–
0.54
]fr
ombu
ildin
gan
d0.
51±0.
28[0
.19–
0.81
]fr
ombu
ildin
g+pe
ople
in[8
];an
d0.
39±
0.20
[0.2
–0.7
4]fr
ombu
ildin
gan
d0.
63±0.
41[0
.06–
1.16
]fr
ombu
ildin
g+pe
ople
in[9
].cE
stim
ated
usin
gth
em
easu
red
CO
2co
ncen
trat
ion
abov
eou
tdoo
rs,
the
outd
oor
airfl
owra
te,
and
the
prod
uctio
nra
teof
CO
2pe
rpe
rson
assu
med
inth
est
udie
s[4
–9]
from
whi
chth
eda
taw
ere
obta
ined
.d
The
sens
ory
pollu
tion
load
from
the
build
ing
appr
oxim
ated
bysu
btra
ctin
gth
ees
timat
edse
nsor
ypo
llutio
nlo
adfr
ompe
ople
from
the
sens
ory
pollu
tion
load
from
build
ing
plus
peop
le,
assu
min
gth
atth
ese
nsor
ypo
llutio
nlo
ads
can
bead
ded[1
,13]
.
This method is therefore not used anymore for field mea-surements. To convert the sensory ratings of perceived airquality made by trained panels to untrained panel ratings,a transfer function was established[11]. This function wasused to correct the sensory pollution loads measured in pre-vious studies using trained panels[5–9] (Table 1).
The aim of the present study was to supplement the pre-viously collected data on the sensory pollution load fromthe building by the sensory pollution loads measured by anuntrained panel in non-smoking office buildings and in anon-smoking department store.
2. Methods
2.1. Measurements in office buildings
A sensory panel of untrained subjects assessed the airquality in six mechanically ventilated office buildings with-out recirculation and humidity control located in Denmark.They were selected as a subset of 20 buildings chosen foranother project among 120 office buildings where the fa-cility management agreed to conduct the study. The build-ings were on average 42 years old and three of them wererenovated for 2–5 years prior to the study; the ventilationfilters were on average 8.5 months old (Table 2). In eachbuilding the measurements were made in six non-smokingsmall- or medium-sized (but no open-plan) offices with mix-ing ventilation. Sensory measurements in the buildings weremade twice: on working days during normal operation ofthe building with occupants present and on weekends with-out occupants in the building but with the ventilation sys-tem in operation as on a usual working day. Temperature,relative humidity, outdoor airflow rate and carbon dioxide(CO2) concentration were measured, along with sensorymeasurements. The ventilation rate was measured using thetracer gas decay method; to ascertain good mixing, smallfans were running inside the offices for the entire measur-ing day and the measurements were taken at two samplingpoints.
Forty-three subjects assessed the air quality using the con-tinuous acceptability scale (Fig. 1) [14]. In order to cre-ate the proper context for assessments, the acceptabilityscale was preceded with the following sentence: “Imaginethat during your daily work you are exposed to this air.How do you assess the air quality?”. The subjects were allstudents aged 19–33 years (mean± S.D. = 22.7 ± 3.0);12 were females and 14 were smokers, smoking on aver-age 5.4 cigarettes/day. Prior to sensory measurements, theytook olfactory tests in which they ranked 10, 80, 320 and1280 ppm (v/v) ofn-butanol with increasing odour intensityand matched with references 640 ppm (v/v) ofn-butanol,2-butoxyethanol, 2-butanone and a “blank” with no chemi-cal compound[15,16]; 80% passed the ranking test withouterrors and the matching test with a maximum of two errors.Subjects were paid for taking part in the measurements.
P. Wargocki et al. / Energy and Buildings 36 (2004) 995–1001 997
Table 2General characteristics of the buildings in which the present measurements took place
Specification Office buildings Department
#1 #2 #3 #4 #5 #6 store
Location Suburbs Suburbs Suburbs City City City CitySector Private Private Private Public Private Public PrivateAge of the building (years) 32 40 30 100 11 41 0.2Time since last renovation (years) 2 40 5 5 11 41 N.A.Ventilation system CAV CAV CAV CAV VAV CAV CAVTime since last change of filters (months) 6 4 12 9 12 8 2Average area of spaces/locations tested (m2) 23.2 40.4 38.1 17.6 28 18 2400Space height (m) 2.6 2.8 2.6 3.7 2.7 2.7 N.A.Total number of persons in spaces testeda 5 12 9 7 5 6 ∼500Fleecy materials on floors Yes/no No No Yes/no Yes/no Yes/no Yes/no
CAV; constant air volume, VAV; variable air volume.a The average number of office workers or customers and personnel in the department store (excluding sensory panel and group leaders) estimated
by counting persons present in the offices or on all floors of the department store several times during sensory measurements.
The measurements were made on 6 days at the turn of Oc-tober/November 2001, each day in parallel in two buildings.Sensory measurements were made always in the afternoon,between ca. 13:30 and 15:30, while the temperature, relativehumidity, CO2 and outdoor airflow rate were measured con-tinuously for the whole day. The subjects were transportedto the buildings in air-conditioned buses. Upon arrival, theyfirst assessed the air quality outdoors, and then the evalua-tions of six offices were carried out in groups of two to threesubjects. The assessments were made immediately upon en-tering the offices to reflect initial judgment of the air qual-ity when entering a space, as it is perceived by visitors, tocomply with the requirements set out in CEN CR 1752[2]and in ASHRAE Standard 62-2001, Appendix B[3]. Priorto and during measurements, the doors to the offices and thewindows were kept closed. In between assessments, sub-jects stayed for at least 1.5 min in a well-ventilated spacelocated close to the spaces where the sensory evaluations
Fig. 1. Acceptability scale used to assess the perceived air quality inthe buildings[14]; the subjects were instructed to pay attention to thedichotomy between acceptable and not acceptable.
took place so as to minimize to maximum 1–2 min the timespent in the corridor immediately prior to the sensory eval-uations and the effect of adaptation to indoor air pollution[17]. During sensory assessments, there were maximum 20subjects in the building.
2.2. Measurements in the department store
A sensory panel of untrained subjects assessed the airquality in a non-smoking department store located in a largecity in Germany (Table 2). The merchandise sold in this storeis of a relatively high quality and includes garments andleather (but no shoes) for children and adults. The assess-ments were made in 16 representative locations, distributedevenly on the seven open-plan floors in the building, eachhaving 2400 m2, and were also made outdoors. There was acentral HVAC system in the building with air-conditioningand recirculation. The total designed airflow was 6.3 L/(s m2
floor), of which 3.3 L/(s m2 floor) was outdoor air at out-door temperatures in the range from 0◦C to 26◦C, or oth-erwise 1.7 L/(s m2 floor). Ventilation filters were 2 monthsold (Table 2). Sensory measurements were made once on anormal working day during normal operation of the buildingwith merchandise, personnel and customers present. Mea-surements of temperature, relative humidity and outdoor air-flow rate were made along with the sensory measurements.The ventilation rate was calculated using the pressure dif-ferential signal from the VAV control units installed on thesupply and return duct on each floor of the building, and themain duct supplying outdoor air and exhausting the air fromthe building to control volumetric flow. During the sensorymeasurements, the HVAC system was set to operate in CAVmode so as to keep the outdoor airflow rate constant.
Forty-four subjects assessed the air quality using the con-tinuous acceptability scale (Fig. 1) [14]. In order to create theproper context for assessments, the scale was preceded withthe following sentence: “Imagine that during shopping inthe department store you would be exposed to this air. Howdo you assess the air quality?”. The subjects were mainly
998 P. Wargocki et al. / Energy and Buildings 36 (2004) 995–1001
students aged 20–35 years (mean± S.D.= 23.8± 3.5); 29were females and 9 were smokers, smoking on average 10.2cigarettes/day. The subjects were paid for participation inthe measurements.
The measurements were made on one afternoon in June2001 between 16:00 and 19:00. Prior to the measuring pro-cedure, subjects assembled in a tent in front of the build-ing, where they received instructions and were divided intosix groups of six to eight persons. The sensory evaluationswere performed by the individual subjects in each group inthe predefined order. The designated group leader led sub-jects to the location where the sensory measurements weremade. The order of assessments was balanced across all sixgroups. The assessments were made at one measuring lo-cation at a time, immediately upon arrival, to reflect initialjudgment of the air quality as it is perceived by visitors, tocomply with the requirements set out in CEN CR 1752[2]and in ASHRAE Standard 62-2001, Appendix B[3]. It tooksubjects max. 2–3 min to arrive at the measuring location,so as to minimize the effect of adaptation to indoor air pol-lution [17]. In between measurements, the subjects stayedfor at least 2 min outdoors to refresh their senses.
2.3. Analysis of the measuring data
The ratings of acceptability of air quality made by the sub-jects were used to calculate the percentage dissatisfied withthe air quality and the perceived air quality in decipol sepa-rately for each office (in the case of office buildings) and foreach floor (in the case of the department store)[1,14]. Themeasurements of perceived air quality and outdoor airflowrate were then used to calculate the sensory pollution loadfrom the building and the building plus people as the equiv-alent number of standard persons (olfs) that would causethe same percentage dissatisfied with the indoor air qualityas the pollution caused by the actual building with occu-pants absent and present, respectively[1]. Sensory pollutionloads from people were estimated in office buildings usingthe measured outdoor airflow rates and CO2 concentrationabove outdoors, assuming that a person produces 19 L ofCO2/h [2]. In the department store, the sensory pollutionload from people was estimated using the number of peoplepresent in the building during sensory measurements andassuming that each person produces 1 olf. The means andstandard deviations (S.D.) for the whole buildings were cal-culated using measuring data collected in different locationswithin each building. For the sensory pollution loads themeasuring standard errors (S.E.) were estimated by the to-tal differential method, using standard error of acceptabilityratings and the errors of measuring ventilation rates.
3. Results
Indoor climate parameters, perceived air quality and sen-sory pollution loads in the buildings are shown inTable 3.
Fig. 2. Percentage dissatisfied with the air quality as a function of theoutdoor airflow rate in the office buildings and in the department storeinvestigated in the present study.
The percentage dissatisfied with the indoor air quality is re-lated to the outdoor airflow rate inFig. 2. Due to measuringuncertainties and procedural problems, the data obtained inoffice buildings #3 and #4 without occupants could not beused. In office building #6, due to security reasons, the mea-surements were possible only on the working day with oc-cupants present in the building. During measurements, theoutdoor temperature and relative humidity ranges were, re-spectively, 5–13◦C and 50–100% in the case of office build-ings and 19◦C and 60% in the case of the department store.The outdoor concentration of CO2 was on average 370 ppm.Indoor temperatures and relative humidities, as well as out-door airflow rates, did not generally differ much betweenmeasurements made in the buildings with and without oc-cupants. In office building #5, having a VAV system, the airchange rate was slightly lower with occupants in the build-ing. The percentage dissatisfied with the indoor air qualitywas quite moderate compared to many field studies but re-flects the fact that the outdoor airflow rates were high andthe pollution sources were relatively moderate; outdoor airquality caused on average 1% to be dissatisfied.
The mean sensory pollution load from the building (in-cluding HVAC system) in the office buildings was 0.11±0.09 olf/m2 floor with a substantial variation between build-ings, and in the department store it was 0.15 olf/m2 floor(Table 4). Although the sensory pollution loads were differ-ent from building to building, increased outdoor airflow ratedecreased the percentage dissatisfied (Fig. 2), which agreeswell with previous studies[18,19].
4. Discussion
Table 4lists the mean sensory pollution load of the build-ing measured in the present and in previous studies in 120different types of buildings in Europe including offices andassembly halls (with and without previous smoking) schools,kindergartens and a department store. The mean measured
P.W
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Table 3Indoor climate parameters, perceived air quality and sensory pollution loads in the buildings investigated in the present study
Building Occupants Temperature(◦C)
Relativehumidity(%)
Carbon dioxide(includingoutdoors)(ppm)
Outdoor airflow rate Perceived air quality Sensory pollution load
h−1 L/(s m2 floor) Acceptability Decipol Peopleolf/m2 floor
Building People+ building
Officebuildings
#1 Absent 20.8± 0.8 54± 3 367± 2 3.71± 1.03 2.68± 0.74 0.617± 0.110 0.23± 0.08 − 0.04 ± 0.01 −
Present 21.6± 0.6 46± 2 446± 57 3.94± 1.32 2.85± 0.96 0.458± 0.161 0.56± 0.42 (0.04 ± 0.03)a − 0.15 ± 0.05 (0.08)d
#2 Absent 22.8± 0.9 47± 3 388± 14 1.42± 1.06 1.10± 0.82 0.171± 0.237 3.54± 3.38 − 0.27 ± 0.08 −Present 23.9± 1.9 41± 4 633± 233 2.19± 1.17 1.71± 0.91 0.150± 0.152 2.99± 2.68 (0.10 ± 0.14)a − 0.37 ± 0.13 (0.37)d
#3 Absent – – – – – – – − (0.03)c −Present 21.9± 1.1 31± 2 573± 113 2.01± 0.32 1.43± 0.23 0.400± 0.095 0.61± 0.23 (0.05 ± 0.02)a − 0.08 ± 0.02
#4 Absent – – – – – − – − (0.10)c −Present 23.0± 1.0 28± 2 522± 67 2.41± 0.79 2.44± 0.80 0.379± 0.151 0.79± 0.52 (0.04 ± 0.02)a − 0.14 ± 0.06
#5 Absent 20.9± 0.8 27± 1 363± 7 5.30± 1.16 3.97±0.87 0.575± 0.084 0.27± 0.12 – 0.08 ± 0.02 −Present 22.7± 0.8 25± 1 421± 63 4.18± 1.41 3.14± 1.05 0.575± 0.125 0.31± 0.26 (0.04 ± 0.06)a − 0.14 ± 0.06 (0.12)d
#6 Absent Not measured – (0.11)c −Present 23.3± 1.2 26± 2 475± 68 2.99± 0.25 2.24± 0.19 0.350± 0.084 0.79± 0.31 (0.05 ± 0.03)a 0.16 ± 0.06
Department store Absent Not measured – (0.15)c −– Present 21.3± 0.7 50± 2 Not measured − 3.47 0.423± 0.093 0.55± 0.23 (0.04)b − 0.19±0.05
The values are mean± S.D.; in the case of the measured sensory pollution loads, the values are mean± S.E.To distinguish estimated sensory pollution loads from those measured, they are italicised and put in brackets.
a Estimated in office buildings with occupants present using the measured outdoor airflow rates and CO2 concentration above outdoors assuming that a person produces 19 L of CO2/h [2]; similarvalues were obtained when the loads were estimated using the number of people present in offices during sensory measurements (Table 2) and assuming that each person produces 1 olf.
b Estimated using the number of people present, assuming that each person produces 1 olf.c Estimated in office buildings with occupants absent by subtracting the estimated sensory pollution load from people from the sensory pollution load from building plus people, assuming that the
sensory pollution loads can be added[1,13].d Estimated in office buildings with occupants present by adding measured sensory pollution loads from the building and predicted sensory pollution loads from people, assuming that the sensory
pollution loads can be added[1,13].
1000 P. Wargocki et al. / Energy and Buildings 36 (2004) 995–1001
Table 4Sensory pollution loads from buildings measured in previous studies[4–9]and in the present investigation
Building type Number ofbuildings
Sensory pollutionload (olf/m2 floor)
Previous and present studies
Offices & assembly halls(smoking allowed)
97 0.23± 0.06
Offices (no smoking) 6 0.11± 0.09Schools 6 0.06± 0.04Kindergartens 10 0.06± 0.06Department store 1 0.15
CEN CR 1752Low-polluting building 0.1Non-low-polluting building 0.2
For comparison, the loads specified by CEN CR 1752[2] for low-pollutingand non-low-polluting buildings are provided.
sensory pollution loads from the building (including HVACsystem) in non-smoking offices, schools and kindergartensare close to or below 0.1 olf/m2 floor, a value that is recom-mended for low-polluting buildings in CEN CR 1752[2].The sensory pollution load of the building in a departmentstore is higher than for non-smoking offices, most likely be-cause of the merchandise. The sensory pollution load canobviously change with type of merchandise, e.g., in the de-partment store investigated in this experiment, the sensorypollution load was elevated in the departments selling leathergoods. More information on the sensory pollution loads indepartment stores is required because the data presented inthis paper are from only one building. The sensory pollu-tion load of the building in offices and assembly halls wheresmoking was allowed is twice the load in non-smoking of-fices, and is also higher than 0.2 olf/m2 floor, a value that isrecommended for non-low-polluting buildings in CEN CR1752[2]. An obvious explanation is that environmental to-bacco smoke is sorbed on building surfaces and later des-orbs from them. This process results in an increased sensorypollution load from the building and was shown in the studyin which the sensory pollution load from previous smokingwas measured in bars, restaurants, cafeterias and auditoria[20]. The same process probably occurred in previously in-vestigated offices and assembly halls where smoking tookplace, although the smoking was much lower than in bars.
Building materials and furnishing[21], the HVAC systemincluding the dust collected in the particle ventilation filters[22,23], and office equipment including personal computers[24,25]are the pollution sources contributing to the sensorypollution load from building. With a typical floor area in anoffice of 15 m2 per person, the sensory pollution load fromthe building in a low-polluting building with a building loadof 0.1 olf/m2 floor is 1.5 olf per person. This is 60% of thetotal sensory pollution load from the building plus peopleand thus is still quite substantial. To save energy and/or im-prove indoor air quality, it would be obvious to decreasefurther the sensory pollution load from the building. Con-
sidering the range of sensory pollution loads from buildingmeasured in 120 buildings summarized inTable 4, it seemsquite realistic to achieve a building load below 0.04 olf/m2
floor, a value used to define the ventilation rate needed tohandle a building in Addendum 62n of ASHRAE Standard62–2001[3]. In order to achieve sensory pollution loadsfrom a building that are lower than those recommended forlow-polluting buildings in CEN CR 1752[2], it is suggestedto apply much stricter criteria for screening of building ma-terials by using sensory methods, to change ventilation par-ticle filters frequently and/or to apply new technologies forfiltering particles, and to use low-polluting personal com-puters with flat-type screens[26].
Previous studies have shown that the total sensory pol-lution load in a space can be fairly well approximated byadding sensory pollution loads from individual sources ofpollution [13]. In the present study, the total sensory pollu-tion load from building plus people predicted by the additionof sensory pollution loads from building and from peoplein three buildings in which measurements were performed,both when occupants were present and absent (buildings #1,#2 and #5), were slightly lower than the total sensory pollu-tion loads measured in the buildings with occupants present(Table 3). A possible reason could be the pollution load frompersonal computers, which were turned off in the buildingswithout occupants and in operation when occupants werepresent. Their sensory pollution strength was not accountedfor when the pollution loads were predicted by addition, butaccording to recent studies it can have the same magnitudeas the sensory strength of people[24,25].
5. Conclusions
Present and previous data on sensory pollution loads froma building have been summarized for four different types ofbuilding. The data are based on measurements in more than120 buildings.
The sensory pollution load from the building in the sixoffice buildings investigated where smoking did not occurwas 0.11± 0.09 olf/m2 floor. This agrees well with the loadrecommended for low-polluting buildings in CEN CR 1752[2] and is only half of the load found in previous studies inoffices and assembly halls where smoking was allowed. Inthe non-smoking department store investigated, the sensorypollution load from the building was 0.15 olf/m2 floor. It wasmeasured for the first time in this type of building and wascaused mainly by the merchandise.
It is recommended to reduce further the sensory pollutionload from the building in order to save energy and improveindoor air quality.
Acknowledgements
This work has been supported by the Danish TechnicalResearch Council (STVF) as part of the research programme
P. Wargocki et al. / Energy and Buildings 36 (2004) 995–1001 1001
of the International Centre for Indoor Environment and En-ergy established at the Technical University of Denmark forthe period 1998–2007. Measurements in Germany were par-tially supported by Hochtief Building. Thanks are due to JanPejtersen from the National Institute of Occupational Health,Denmark for help during selection of the office buildingsand to Gerd Hebenstreit from Hochtief Building, Germanyfor assistance in sensory measurements in the departmentstore.
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