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Climamed 2017 – Mediterranean Conference of HVAC; Historical buildings retrofit in the
Climamed 2017 – Mediterranean
Mediterranean Conference
area, 12-13 of
MayHVAC;
2017, Historical buildings retrofit in the
Matera, Italy
Mediterranean area, 12-13 May 2017, Matera, Italy
Assessment of the indoor environmental conditions of a baroque
Assessment The of15ththe indoor Symposium
International environmental on District conditions of a baroque
Heating and Cooling
library in Portugal
library in Portugal
Assessing the feasibility of using the heat demand-outdoor
Luísa Dias Pereiraa*, Adélio Rodrigues Gasparaa, José Joaquim Costaaa
a*

temperature function
Luísa Dias Pereira
a for aRodrigues
, Adélio long-term Gaspar district heat demand
, José Joaquim Costa forecast
ADAI, LAETA, Department of Mechanical Engineering, University of Coimbra, 3030-789 Coimbra, Portugal
a
ADAI, LAETA, Department of Mechanical Engineering, University of Coimbra, 3030-789 Coimbra, Portugal
I. Andrića,b,c*, A. Pinaa, P. Ferrãoa, J. Fournierb., B. Lacarrièrec, O. Le Correc
Abstract
a
AbstractIN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
b
This paper presents Veolia Recherche
the preliminary results of&theInnovation,
study of291theAvenue
indoorDreyfous Daniel, 78520
environmental Limay,inFrance
conditions a Baroque building of a XVIII
c
century
This library,
paper Département
located
presents Systèmes
in the heights
the preliminary Énergétiques
results et Environnement
of theofhistoric
the studycentre - IMT
of indoor
of the Atlantique,
the University 4 rue Alfred
of Coimbra
environmental Kastler,
(UC),
conditions 44300
which
in Nantes,
was
a Baroque France of727
established
building years
a XVIII
ago. Since
century theselocated
library, conditions
in theplay a veryofimportant
heights the historic role in theofconservation
centre the University of of
theCoimbra
books and the wood
(UC), which bookshelves,
was established experimental
727 years
surveys
ago. Since based
theseonconditions
permanentplay measurements of the role
a very important hygrothermal air conditions
in the conservation and
of the of particulate
books matter
and the wood concentrations
bookshelves, are being
experimental
carried
surveysout since
based onearly October
permanent 2016. Some early
measurements of theresults of this short
hygrothermal term studyand
air conditions are of
presented andmatter
particulate discussed.
concentrations are being
Abstract
carried out since early October 2016. Some early results of this short term study are presented and discussed.
© 2017 The Authors. Published by Elsevier Ltd.
© 2017 The
District
Peer-review Authors.
heating
under Published
networks
responsibility byofElsevier
are commonly Ltd. committee
addressed
the scientific in theofliterature as one2017
the Climamed of the most effectiveConference
– Mediterranean solutions for decreasing the
of HVAC;
© 2017 The Authors. Published by Elsevier Ltd.
Peer-review
greenhouse under
gas responsibility
emissions from of
thethe scientific
building committee
sector. These of the Climamed
systems require 2017investments
high – Mediterranean
which Conference
are returned ofthrough
HVAC; the heat
Historical
Peer-review buildings retrofit in theofMediterranean
under responsibility area.
the scientific area
committee of the Climamed 2017 – Mediterranean Conference of HVAC;
Historical
sales. Due buildings
to the retrofit
changed in the Mediterranean
Historical buildings retrofit inclimate conditions area.
the Mediterranean and building renovation policies, heat demand in the future could decrease,
prolonging
Keywords: the investment
Microclimate; return period.
Conservation; Indoor Air Quality, Particulate Matter, Heritage buildings.
The main scope of this paper
Keywords: Microclimate; Conservation; is to assess
Indoor the
Air feasibility of usingMatter,
Quality, Particulate the heat demand
Heritage – outdoor temperature function for heat demand
buildings.
forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665
1.buildings
Introductionthat vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district
renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were
1. Introduction
compared with results from a dynamic heat demand model, previously developed and validated by the authors.
As stated in [1], ‘contaminants levels must be maintained at low concentrations for human health and to
The results showed that when only weather change is considered, the margin of error could be acceptable for some applications
guarantee
As stated [1], ‘contaminants
theincorrect preservation oflevels worksmust be and
of art maintained
cultural at low concentrations
heritage’. for human
Besides the building
(the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation
itselfhealth
– the and
XVIII to
guarantee
century the
Baroque correct
library preservation
of the of
University worksof of art
Coimbra and–, cultural
the books heritage’.
kept insideBesides
are alsothe building
part
scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). of this itself –
heritage, the XVIII
and due
century
to
Theitsvalue Baroque
organic library of theincreased
characteristics,
of slope coefficient University
these are on of Coimbra
vulnerable
average –, the
the range
booksofkept
to hygrothermal
within inside
variations
3.8% are
up toand8%also
per part
contaminants.of this
decade, heritage,
thatAt the same
corresponds andtime,
todue
the
to
the its organic
deposition characteristics,
of dust, e.g. in these
the are
shelves vulnerable
and to
painted hygrothermal
woods, resultsvariations
in a and
negative contaminants.
visual
decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and effect, At
such the
as same
the time,
loss of
the deposition
brightness
renovation andof"opacity"
scenarios dust, e.g.ofin colours,
considered). the
Onshelves
the due
otherand
to painted
their
hand, woods,
accumulation
function results
intercept andin cementation
a negative
increased visual effect,
in works
for 7.8-12.7% per ofsuch
decade as the[3],
art(depending
[2], loss
on of
also
the
brightness and "opacity"
coupled scenarios). The valuesof colours,
suggesteddue couldtobetheir
usedaccumulation
to modify the and cementation
function parametersinforworks of art considered,
the scenarios [2], [3], also and
improve the accuracy of heat demand estimations.

©* Corresponding author.Published
2017 The Authors. Tel.: +351 by
239790732;
Elsevier fax:
Ltd.+351 239790771.
* E-mail address:
Corresponding
Peer-review under luisa.pereira@uc.pt
author. Tel.: +351 239790732;
responsibility fax: +351
of the Scientific 239790771.
Committee of The 15th International Symposium on District Heating and
E-mail address: luisa.pereira@uc.pt
Cooling.
1876-6102 © 2017 The Authors. Published by Elsevier Ltd.
Peer-review
1876-6102
Keywords:©Heatunder responsibility
2017demand;
The Authors. of the scientific
Published
Forecast; Climate committee
bychange
Elsevier Ltd. of the Climamed 2017 – Mediterranean Conference of HVAC; Historical buildings
retrofit in theunder
Peer-review Mediterranean area.of the scientific committee of the Climamed 2017 – Mediterranean Conference of HVAC; Historical buildings
responsibility
retrofit in the Mediterranean area.

1876-6102 © 2017 The Authors. Published by Elsevier Ltd.

Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling.
1876-6102 © 2017 The Authors. Published by Elsevier Ltd.
Peer-review under responsibility of the scientific committee of the Climamed 2017 – Mediterranean Conference of HVAC; Historical
buildings retrofit in the Mediterranean area
10.1016/j.egypro.2017.09.385
258 Luísa Dias Pereira et al. / Energy Procedia 133 (2017) 257–267
2 Author name / Energy Procedia 00 (2017) 000–000

contributing to deterioration processes [2], [4], [5].

The first studies dedicated to the indoor environmental conditions of this Baroque library were conducted at the
end of last century, at a time when it was still used as a traditional library, though with a small number of users (by
this time, the university community was already served by the General Library, built in the 1960s).
In 2013, the buildings of ‘University of Coimbra – Alta and Sofia’ were declared a World Heritage Site by
UNESCO [6], turning the Baroque Library into part of an important tourist circuit in Portugal. Currently, it closes
only 5 days a year, receiving up to 60 visitors every 20 minutes - over 400,000 tourists in 2015, becoming the third
most visited monument in Portugal. Similarly to other contemporary libraries, such as the Old Library of the Trinity
College in Dublin (Scotland) [7], the Baroque Library in Coimbra is daily open for visits: 7h/day in winter and
11h/day in summer time.
In face of this new reality, the Rectorate of the University has been very concerned about the heritage
preservation and started a research project focused on the accurate characterization of the indoor environmental
conditions within the Baroque library and on the assessment of risk situations, both for heritage and health issues.
Since the indoor conditions play a very important role in the conservation of the books and the wood
bookshelves, experimental surveys based on permanent measurements of the hygrothermal air conditions and of
particulate matter concentrations are being carried out since early October 2016, in order: (i) to assess the current
indoor environmental conditions (IEC) of the library; (ii) to investigate whether the risky IEC are mainly caused or
not by the increased occupancy / visiting rate; (iii) to propose mitigating interventions and alternative strategies.
The measuring campaign included the monitoring of the following parameters: indoor air temperature (Ta, ºC),
relative humidity (RH, %), carbon dioxide concentration values (CO2, ppm) and particulate matter (PM, µg/m3).
These were registered every ten minutes during the entire monitoring period, during day and night time.
Indoor/outdoor relations were established and collected data were compared with different guidelines – national and
international standards. Some early results of this short term study are presented and discussed.

2. Method and object of study

The case study is located in the heights of the historic centre of the University of Coimbra (UC), at the southwest
end of the university courtyard, 120 m above the sea level, as shown in Fig. 1, a). In terms of climatological data, the
average monthly rainfall (AMR) varies between 10.9 mm in July and 126.2 mm in December, the rainiest month.
Additionally, the average monthly mean (AMM) temperature values vary between 10.4ºC in December and 20.4º in
August, the hottest month [8]. The Baroque Library was built between 1717 and 1725, and the decoration works
lasted for another three years [9], [10]. The library is composed of ‘three floors: the Noble floor, richly decorated
space, the most emblematic face of the House of the Library; Intermediate Floor, workplace and acted as the guard
house; the Academic Prison, which worked here from 1773 until 1834’[11].
The library is exclusively naturally ventilated. Some of the external walls are more than 2.0 m thickness and
internally, the Noble floor walls are integrally covered by wood shelves. Herein are comprised circa 40,000
volumes [11]. The Intermediate floor has always been the deposit of the Library; nowadays it is open to the public
and it also hosts small exhibitions.
It is daily open to visitors: (a) winter (31/10/2016 to 1/3/2017): 9h00 − 13h00 & 14h00 −17h00; summer (16/3 to
30/10/2016): 9h00 − 20h00.

2.1. The monitoring campaigns

Between October and December 2016, several parameters were monitored, namely: indoor air temperature
(Ta, ºC), relative humidity (RH, %), carbon dioxide concentration values (CO2, ppm) and particulate matter
(PM, µg/m3). Table 1 presents a list of the equipment used during the monitoring campaigns: October and
November/December 2016, as well as the interval between records. During the first monitoring campaign the
Library was open to public according to the summer schedule (9h00 − 20h00) and during the second campaign visits
were possible according to winter time (9h00 − 13h00 & 14h00 −17h00).
 Luísa Dias Pereira et al. / Energy Procedia 133 (2017) 257–267 259
Author name / Energy Procedia 00 (2017) 000–000 3

2.2. The available guidelines and recommendations

In terms of particulate matter, the authors have been following the criteria presented by Pinheiro et al (2014) –
one of most recent studies on the concentration and distribution of particulate matter (PM) in Portuguese archives.
These authors recall the studies Nazaroff (2004) or Ryhl-Svendsen (2006), alerting to the hazard properties of PM,
namely showing that the inadequate exposure to PM can lead to health problems as well as to the degradation of
material and artistic objects.
Particle matter exposure values are suggested by several entities: (i) EPA (US Environmental Protection
Agency); (ii) WHO [15]; (iii) US National Bureau of Standards (1983) in Blades et al. (2000); (iv) or ASHRAE
2015. Of all these values, the recommended maximum value of PM10 for Museums by the US National Bureau of
Standards – 75 μg/m3 is highlighted, a value in accordance with category C defined in Table 2.

Table 1. List of the equipment used in the monitoring campaigns.

Parameter Equipment Monitoring period (1), (2) Monitoring interval

Particles Lighthouse 3016 IAQ 4 Oct – 19 Oct Every 10 min - six records/hour, covering the 3
(PM, µg/m ) 3
11 Nov – 30 Nov hourly visits (group entry of tourists every 20 min)

Temperature PS32 SENSOTRON 4 Oct – 19 Oct Every 10 min

(T, ºC)

Relative Humidity (HR, HOBO MX1102 Data Logger 6 Oct – 19 Oct Every 60 sec
%)
7 Nov – 16 Dec Every 5 min

Cabon dioxide HT 2000 data logger 11 Oct – 17 Oct Every 5 min

(CO2, ppm) (intermediate floor) 7 Nov – 23 Nov
28 Nov – 16 Dec

Notes: (1) Oct = October; Nov = November; Dec = December: min = minutes; sec = seconds. (2) The values presented ahead in the Results
section, correspond to a daily average < 24h: the average of the totality of the records since the equipment turned on (early in the morning)
until the moment it turned off, due to battery exhaustion (typically between 00h30 and 01h30).

a) b)

Fig. 1. a) Location of the Library [Google Maps (2016)]; b) external view of the Library East façade.
260 Luísa Dias Pereira et al. / Energy Procedia 133 (2017) 257–267
4 Author name / Energy Procedia 00 (2017) 000–000

Table 2. Rating IAQ categories for the conservation of indoor environment, proposed in [18] and [1],
defined by the average concentration values of PM10 and PM2.5.
Type Conservation categories and concentration intervals (µg/m3)

A B C D

PM 2.5 <1 1−5 5 – 10 > 10

PM 10 < 10 10 – 30 30 – 75 > 75

CO2 concentration levels were assessed according to the national legislation, which currently defines a threshold
limit for CO2 in the indoor air equal to 2250 mg/m3 (1250 ppm), average concentration value during the various
occupancy periods.
Relating air temperature and relative humidity, several norms and international recommendations have been
published since 1999, on methodologies of analysis and intervals of tolerance in the context of the preservation of
archives and / or artistic and cultural assets. At European level, the Italian standards stand out: i) UNI 10829:1999,
“Beni di Interesse Storico Artistico. Condizioni Ambientali di Conservazione. Misurazione ed Analisi”; ii) UNI
10969:2002, “Beni culturali - Principi generali per la scelta e il controllo del microclima per la conservazione dei
beni culturali in ambienti interni”, iii) UNI 15757:2010 “Conservazione dei beni culturali - Specifiche concernenti
la temperatura e l’umidità relativa per limitare i danni meccanici causati dal clima ai materiali organici
igroscopici.
In the latest, which replaced a previous standard, a significant step was taken in the face of optimum conservation
conditions. Parallel to these, the climatic history of the spaces where the works are located must always be taken
into account, that is, the mean values of the microclimatic parameters become as important as the analysis of their
fluctuations around the mean value. In other words, this standard has proposed that the acceptable microclimatic
variability and the risk limit for an artefact, whose fragility is controlled by hygroscopicity, depends on its climatic
history, during which an adaptation to "normal variability" has been developed. It is also noticeable that this
standard has been translated into English and assumed at European level as UNI EN 17757 of November 2010.
More recently, it was published ISO 11799: 2015 Information and documentation - Document storage requirements
for archive and library materials, mainly dedicated to the storage of long-term materials in repositories and
libraries.
Given its current use, the Baroque library under study has a significant human occupancy (due to regular visits by
tourists), for which it can be framed into the typology of museum space, where acceptable values of indoor air
temperature and relative humidity are greater than those recommended for the restrict conservation of books. In
[19], the author presented a significant table summarizing the latest normative guidelines on the hygrothermal
conditions of the indoor environment in museums. Notwithstanding the differences between the various normative
documents, it can be concluded that more important than the T or RH indoor air reference ranges, it is the amplitude
and frequency of their variations. Evaluating the set of recommendations, and considering the current use of the
Library, the authors considered the following values as reference in the analysis of the monitoring of its interior
environment:
• Annual average values:
Air temperature (T): 15 ºC − 25 ºC;
Relative Humidity (RH): 50 % − 60 %;
†
• Acceptable values for short-term fluctuations :
± 5 ºC; ± 10 % RH (ASHRAE (2015) Class B) ‡.

†
In this context, a ‘short period’ may be one to two weeks.
‡
According to ASHRAE 2015, Class B corresponds to ‘a very small risk for most artifacts, paintings, photographs and books; No risk to
many artifacts and to most books’ and ‘Classes B and C are useful and feasible for many medium and small institutions, and are the best that can
be done in most historic buildings’.
 Luísa Dias Pereira et al. / Energy Procedia 133 (2017) 257–267 261
Author name / Energy Procedia 00 (2017) 000–000 5

3. Results and data analysis

Since during both monitoring campaigns CO2 levels were always within the recommended values, it is herein
stated beforehand that no special attention was driven towards this parameter in the current paper.

3.1. Particulate matter

Particles were only monitored on the Noble floor. Fig. 2 presents the time evolution of the daily mean PM10
concentrations in the indoor air, resulting of the monitoring campaign carried out between 4 and 18 October 2016.
Black and grey solid lines refer to daily averages during the period of visits and to the total measurement period,
respectively. The dashed grey curve, accumulated precipitation (mm), evidences the direct effect of rainfall on the
sharp decrease in the concentration of particles within the Library, although mean values remain high, in category D
(> 75 µg / m3, Table 2).

Accumulated Precipitation (mm)

PM10 (µg/m^3) | visits period (9h-20h)
PM10 (µg/m^3) | daily
PM10 | Reference value
700 20
18
Mass concentration of particles (μg/m3)

600

Accumulated precipitation (mm)

16
500 14
12
400
10
300
8

200 6
4
100
2
0 0

Fig. 2. Time evolution of the daily mean values of mass concentration of particles (μg/m3) on the Noble floor, between 4 &18
October 2016. The maximum reference value, according to the national regulations in force for IAQ in buildings, is represented
by the red line (reference value: 50 μg/m3, added a 100% tolerance).

Overall, the daily PM10 average concentration during the visiting period is about 50% higher than the daily
average entire measurement period – this aspect gains greater highlight in dry weather days. A summary of all the
measured particle concentration values during both monitoring campaigns, both PM10 and PM2.5, is given in Table 3.
Fig. 3 shows the distribution of the totality of the recorded values of PM10 and PM2.5, distributed over the
conservation categories presented in Table 2. During the first monitoring campaign, for both PM classes, there was a
predominance of category D, the one presenting the highest risk of degradation. During the second monitoring
campaign, these values slightly improved, but they were still far from a ‘safe’ preservation target: more than 50% of
the values fell into category C and D.
262 Luísa Dias Pereira et al. / Energy Procedia 133 (2017) 257–267
6 Author name / Energy Procedia 00 (2017) 000–000

Table 3. Summary table of all registered PM values (µg/m3).

Period PM Minimum value Maximum value Average + St Dev

4 - 18 October PM 10 19.01 (visit period ) 1 1234.77 (visit period) 5 11.76 ± 5.68

2
3.39 (daily) 1234.77 (daily) 5

PM 2.5 3.64 (visit period) 3 44.42 (visit period) 6 228.76 ± 239.00

4 6
0.85 (daily) 44.42 (daily)
7
11 - 30 November PM 10 6.70 (visit period ) 856.98 (visit period) 11 8.08 ± 5.45
8 11
0.88 (daily) 856.98 (daily)
9
PM 2.5 1.34 (visit period) 35.47 (visit period) 12 54.50 ± 61.01
10 12
0.25 (daily) 35.47 (daily)
Notes – values recorded at:1 18h40m, 16/10/2016; 2 01h12m, 12/10/2016; 3 17h05m, 13/10/2016; 4 01h32m,
12/10/2016; 5 15h58m, 07/10/2016; 6 12h05m, 08/10/2016; 7 14h23m, 27/11/2016; 8 02h14m, 25/11/2016; 9 11h32m,
25/11/2016; 10 08h00m, 25/11/2016; 11 14h23m, 27/11/2016; 12 16h10m, 17/11/2016.

a) b)
70,0% 4-18 Oct 70,0% 4-8 Oct
11-30 Nov 11-30 Nov
60,0% 60,0%

50,0% 50,0%

40,0% 40,0%

30,0% 30,0%

20,0% 20,0%

10,0% 10,0%

0,0% 0,0%
< 10 10 - 30 30 - 75 > 75 <1 1-5 5 - 10 > 10

Fig. 3. Distribution of all record values of PM10 and PM2.5 according to the concentration ranges defining the conservation
categories A, B, C and D, as indicated in Table 2. a) PM 10; b) PM 2.5.

Briefly, from the analysis of all recorded data, several inferences were drawn: (i) the particles of largest
dimension (between 2.5 and 10 μm) were predominant, as it is typical of atmospheric dust (> 5 μm); (ii) the
concentration of particles was much higher during the period of visits, when the maximum values were registered.
The entrance/presence of the particles is mainly due to the transport of dust adhering to the visitors' shoes, more than
a result of the frequent openings of the main door for access or exit of tourists; (iii) these factors are intensified by
the type of lining material of the courtyard, a sand of calcareous nature, which, as a result of the dozens of tourists
waiting for their visit, is an abundant source of dust; (iv) in the absence of a significant change in the number of
visitors on 11, 12 and 13 October, the marked drop in PM values was exclusively due to the occurrence of rainfall,
with the consequent reduction of the concentration of PM (both outdoors and indoors). Fig. 2 shows the immediate
rise in PM10 concentration in October 14th, when there was no precipitation.
In the literature on the subject, values of the I/O (indoor/outdoor) ratio are frequently lower than 1 (or just
slightly above 1) for the different physicochemical pollutants. When I/O<1, it means that the concentrations of
pollutants are higher in the exterior, which is more easily verified in museums located in demarcated urban
environments. Nevertheless, the I/O ratio values obtained from the PM10 measurements were much higher than 1,
which clearly means that the suspended particles are due to action within this space.
 Luísa Dias Pereira et al. / Energy Procedia 133 (2017) 257–267 263
Author name / Energy Procedia 00 (2017) 000–000 7

3.2. Indoor air temperature and relative humidity on the Noble floor

Concerning the indoor air temperature (T, ºC) and relative humidity (RH, %), data from the HOBO equipment
were chosen. These values were recorded every minute, over 24h-periods, allowing the diurnal variation assessment
of the hygrothermal behaviour of the building. Since this equipment was placed in the Library only on the 6th
October, the analysis of the first period is focused between 7-18 October. Fig. 4 shows the simultaneous
representation of T and RH inside and outside the Library. It was verified that the variation of the RH was almost
symmetric of T, this relation is stronger in the parameters registered indoors. This relationship of practically inverse
variation of the RH with the T, suggests that the absolute humidity on the noble floor has varied little during this
measurement period.

Ta (ºC) Temp Ext (ºC)

HR (%) HR Ext (%)
31 100

90

27 80

70

23 60

50

19 40

30

15 20

10

11 0

Fig. 4. Time evolution of air temperature (T) and relative humidity (RH) inside the Library Noble floor between 6 and 19
§
October 2016 .

From data presented in Fig. 4, complemented with the totality of the collected data, the following may be
highlighted: (i) since the case-study is not provided of any HVAC system, it was observed that the building naturally
responded to the external temperature variations, in a relatively smooth and typical way of a building with relatively
high thermal inertia; (ii) within the 1st monitoring period, daily temperature fluctuations were lower than 3.5 ºC
(excepting on October 7, when it reached 4ºC); (iii) during the 2nd monitoring campaign, only in 10% of the days the
daily fluctuation was above 4ºC, but always below 5.6 ºC; (iv) concerning relative humidity (RH, %), the situation
showed to be more concerning. On the one hand, during the 12-day period in October, the mean value oscillated
between 55% and 65% (only on October 18 this figure was higher), which could be stated to be acceptable.
However, the minimum RH value was 51% and the maximum value was 70%. In summary, there was a variation of
almost 20% of RH in a short period of time, being within the limit of the value considered acceptable for
fluctuations of RH (±10%). During the 2nd monitoring, though RH daily fluctuation was not very high (always
<11%), it reached absolute values higher than 65% during 67% of the days.

§
The meteorological data were obtained from the nearest stations, installed in the Laboratory of Industrial Aerodynamics (LIA) and in the
Department of Mechanical Engineering of the Faculty of Sciences and Technology of the University, namely: ADAI@LAI:
https://www.wunderground.com/personal-weather-station/dashboard?ID=ICOIMBRA14#history; and, ADAI@DEM.UC:
https://www.wunderground.com/personal-weather-station/dashboard?ID=ICOIMBRA27
264 Luísa Dias Pereira et al. / Energy Procedia 133 (2017) 257–267
8 Author name / Energy Procedia 00 (2017) 000–000

3.3. Indoor air temperature and relative humidity on the Intermediate floor

Table 4 shows a summary of the recorded data and in Fig. A.1 (Annex) the time evolution of the recorded values
in the intermediate floor with those obtained in the noble floor (NF) are compared during the second monitoring
campaign.
The following observations stand out: (i) relating the hygrothermal behaviour of the intermediate floor of the
library it was found that the temperature in this floor is less dependent on the external conditions than those
registered on the noble floor (Fig. A.1); (ii) the temperatures recorded on the intermediate floor were always higher
(3 to 4ºC, on average) than those on the upper floor; (iii) in turn, RH values were more similar on both floors during
the 1st monitoring campaign. In Nov-Dec, RH fluctuations were lower on this floor; (iv) generally, the T recorded on
the intermediate floor presented a greater concern factor than the RH, not for the amplitude of the fluctuations
recorded, but for its higher absolute recorded values – the average value was 24.5 ºC during the 7-day period in
October and, 21,6 ºC in Nov-December; (v) except for October 14th, daily RH fluctuations recorded on the
intermediate floor during the 1st period were lower than 9%, and in Nov-December, only in 9% of the days, daily
variation was slightly higher than 10%, which can be considered as acceptable.

Table 4. Summary table of all registered values on the intermediate floor.

Period Parameter Minimum Average value Maximum External

value (average + St dev) value (min – average - max)

4 - 18 Oct T (ºC) 23.2 24.5 ± 0.5 25.3 11.5 – 16.7 – 22.6

RH (%) 51.8 58.8 ± 2.9 64.8 51 – 84 – 96

7 Nov - 16 Dec T (ºC) 18.7 21.6 ± 1.1 23.9 2.3 – 12.7 – 20.4
(except 24-278 Nov & 6-8 Dec)
RH (%) 44.0 57.2 ± 3.4 64.6 47 – 81 – 98

In summary, the preliminary analysis unveils relatively acceptable hygrothermal conditions within the Baroque
Library. However, it should be noted that this measurements: (i) refer to a relatively short period of time, (ii) a
single sampling point on each floor and (iii) mild and relatively stable climatic conditions. For a comprehensive
assessment of the hygrothermal conditions on the indoor environment of the library, a comprehensive monitoring,
both in terms of time and in sufficient number of sampling points, is mandatory. Therefore, on December 16th 2016,
a new monitoring campaign was initialized, comprehending 12 measurement points in the Noble floor and some
other on the intermediate one.

4. Conclusions and outlook

From the preliminary assessment of the environmental conditions in the Baroque Library of the University of
Coimbra, based on the measurement campaigns carried out during the months of October, November and December
2016, it can be stated that:
1) Among all the monitored parameters, the very high concentration of suspended particles (PM) recorded in
the Noble floor represents the highest risk for the book collection and the remaining heritage site;
2) The consistently high levels of PM concentration, especially during the visits’ period, can also compromise
the health of users, especially for the Library personnel, who remain in this space for an extended period of time
(workday);
3) From the comparison of recorded values during day and night periods, it was observed that the high PM
values were mainly due to: (i) the high number of visitors, (ii) the high dust load - generated and adhered to
footwear, as visitors walk through the sanded courtyard, carrying the sand indoors, and (iii) the frequent main door
 Luísa Dias Pereira et al. / Energy Procedia 133 (2017) 257–267 265
Author name / Energy Procedia 00 (2017) 000–000 9

opening exposing the indoor environment directly to the outside. This finding was in accordance to the studies of
[21] and [22];
4) Although in an informal way, the excessive amount of dust perceived by the visitors, associated to the high
number of tourists diminishes the aesthetic experience that the space promotes;
5) Although the recorded values of indoor air temperature (T) and relative humidity (RH) were not elevated
during the studied monitoring period, this deserves further attention, given that the current conservation standards
that point at the historical temporal analysis of these parameters – A permanent evaluation is therefore required;
6) At the same time, the interdependence of T and HR in the Noble and intermediate floors, as shown in
Fig. A.1, raises questions regarding the hygrothermal conditions of the interior environment in severe climatic
conditions.
In view of the obtained results and the observations set out above, a list of possible measures to resolve some of
the issues identified in this first study can be pointed: (i) protection of the architectural and exhibition heritage
through the protection of visitors' footwear (a practice that is recommended in [23], and is applied in several
museums/exhibition spaces); (ii) limitation of the number of visitors; (iii) protection of dust deposition over books
through application of dust falls between shelves [24]; (iv) changing the main access to the public.
In summary, the conclusions obtained from this preliminary analysis, point at the existence of relatively
acceptable hygrothermal conditions within the Baroque Library. However, it is noted that these are based on
measurements taken in a limited period of time, at a single sampling site on each floor of the Library and during
non–extreme climatic conditions, for which further investigations are forthcoming.

Acknowledgements

This work was supported by the University of Coimbra under project grant BJUC-AHT – “Avaliação
Higrotérmica do Ambiente Interior na Biblioteca Joanina da Universidade de Coimbra”.

Appendix A.
 10
266
Temp Ext (ºC) T interm floor (ºC) T noble floor (ºC) HR Ext (%) HR interm floor (%) HR noble floor (%)
30 100

90

25

80

70

20

60

15 50

40

10

30

20

5
Author name / Energy Procedia 00 (2017) 000–000

10
Luísa Dias Pereira et al. / Energy Procedia 133 (2017) 257–267

0 0

Fig.A.1. Variations of air temperature (Temp) and relative humidity (RH) on the intermediate floor of the Library, between November 7 and December 16, 2016: comparison with
the environmental conditions and measurements on the Noble floor during the same period.
 Luísa Dias Pereira et al. / Energy Procedia 133 (2017) 257–267 267
Author name / Energy Procedia 00 (2017) 000–000 11

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