Testing a Method to Assess the Thermal Sensation and Preference

Testing a Method to Assess the Thermal

Sensation and Preference of Children in

Kindergartens

Natalia Giraldo Vásquez Univ. of San Buenaventura, Medellín

[email protected]

Ricardo Forgiarini Rupp Univ. of San Buenaventura, Medellín

Lucas Arango Díaz

Univ. of San Buenaventura, Medellín

Ader García Cardona

National University of Colombia David Montoya Arenas

Univ. of San Buenaventura, Medellín

ABSTRACT HEADING

This paper presents the results of a method to obtain the subjective response of children regarding their

thermal environment in naturally ventilated kindergarten classrooms. The study was conducted in two

kindergartens located in the city of Medellín, Colombia (latitude 6.25°N, longitude 75.5°W and altitudes

of 1610m and 1715m above sea level). The research involved the application of thermal comfort

questionnaires in children aged between 4 and 5 years old through a tool called “Lottery” and simultaneous

measurement of the indoor thermal environment (air temperature, globe temperature, relative humidity

and air velocity). Outdoor climate was also measured for at least 7 days before the application of the

questionnaires. The questionnaire was developed together with a cognitive psychologist and the school

teachers and was previously tested in a third school. The tool used (lottery) was designed based on scales

to assess the thermal sensation and preference: ASHRAE 55 and McIntyre, respectively. Each child was

individually assessed within the classroom during October/November 2013. Cognitive development

evaluations and psycho-emotional surveys were also performed to obtain the intellectual coefficient of

each child. Most of children seemed to understand the questions. Through this study it was possible a

better understanding of children’s thermal sensation and preference in the tropical climate.

INTRODUCTION

In Medellín city, recent government politics have encouraged the development of public education

policies and physical infrastructures. The “Buen Comienzo” program of the Municipality of Medellín

seeks to improve the care of children in early childhood (0 to 5 years old). One of the criteria from this

program refers to the quality of the spaces and based on such criteria, several infrastructures have been

designed and constructed in different parts of the city. The role of architects was center on the design of

physical spaces that enable the development of various educational activities, considering the

characteristics of the thermal, lighting and acoustic environment due to the influence on cognitive

development and behavior of the occupants.

In thermal comfort area the existing researches and international standards to assess indoor

environments only consider adults and healthy people. In the case of children, the differences in their

30th INTERNATIONAL PLEA CONFERENCE16-18 December 2014, CEPT University, Ahmedabad

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metabolism, body surface area, type of clothing and preferences should be considered when assessing

perception and acceptability of the thermal environment (Parsons, 2003; Mishra & Ramgopal, 2013). The

international standards ISO 9920 (2007) and ASHRAE 55 (2013) provide data for adult clothing. Al-

Rashidi et al. (2012) studied three methods to calculate the clothing insulation and body surface area of

children between 6 and 17 years old. Due to the fact that the study was conducted in Kuwait, cultural

aspects were determinant in the definition of the type of clothing, especially to girls.

In the last decades, several studies in which the target populations were students have been performed

(Kwok, 1998; Kwok & Chun, 2003; Wong & Khoo, 2003; Hwang et al., 2006; Al-Rashidi et al., 2009).

In other studies, thermal sensation and preference were assessed in schools, adjusting the ASHRAE 55

(Liaison et al., 2010) and McIntyre scales (Haddad et al., 2012; De Giuli, Da Pos, & De Carli, 2012;

d’Ambrosio Alfano, Ianniello, & Palella, 2013; Corgnati, Ansaldi, & Filippi, 2009), respectively.

Haddad et al. (2012) tested three techniques to get the thermal preference and acceptability of children

between 11 and 12 years old. The authors submitted their questionnaire model to a previous review,

conducted by psychologists, whom examined the simplicity and structure of the questionnaire. As this

research was conducted with children with reading and writing skills developed, the researchers were also

able to test the three different scales of response assessed by Laerhoven et al. (2004): Likert, Visual

Analogue Scale and Numerical and Visual Analogue Scale - the three scales were based on the 7-point

scale of ASHRAE 55 (2013).

Conceição et al. (2012) presented the application of a model of adaptive comfort in naturally

ventilated preschool classrooms. Even though the authors mention the application of thermal comfort

questionnaire (based on ASHRAE 55), they do not make any considerations on the method used for

interviewing children between 3 and 5 years old or if children have the ability to decide when to open or

close a window, for example.

The research conducted by Fabbri (2013) with children in preschool age deals with a method to assess

the subjective preference and acceptability of the thermal environment, and compares these results with

the calculated PMV and PPD. Results indicated, according to the author, the understanding of the tool and

the questions by children. Furthermore, the author suggested paying more attention to the psychological

component.

OBJECTIVE

The aim of this study was to test a method to obtain the evaluation of thermal environment of children,

between 4 and 5 years old.

METHOD

This study assessed the thermal sensation and preference of children between 4 and 5 years old in

their classrooms. Environmental data were obtained by measurements of air temperature, globe

temperature, relative humidity and air velocity. Thermal evaluations were obtained through the application

of a questionnaire adapted to the characteristics of the target population and the climate of the city.

Place of study

Medellín city is located in the tropical zone (latitude 6.25°N, longitude 75.5°W) of the Andes

Mountains, with altitudes between 1550m and 2000m above sea level. According to Köppen-Geiger

climate classification the city has an Equatorial Climate (Kottek et al., 2006).

30th INTERNATIONAL PLEA CONFERENCE 16-18 December 2014, CEPT University, Ahmedabad

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Figure 1 shows the mean monthly outdoor air temperature, relative humidity and rainfall for Medellín

(IDEAM, 2014). Temperature conditions are stable throughout the year while the relative humidity varies

according to rainfall. This climatic feature influenced the design of the questionnaire.

Figure 1: (a) Averages of temperature vs. Relative humidity. Medelíin City.

(b) Averages of temperature vs. Rainfall. Medellín City

According to García (2011) until the year 2011, from the 184 kindergartens existing in the city, 60

were built following the considerations of the Colombian Technical Standard 4595 for Educational

Institutions (NTC 4595, 1999). For this study there were selected two classrooms from two kindergartens

that attend NTC 4595: "Brisas de Robledo" (1715m above sea level) built before the standard reviewed in

1999 and "12 de Octubre" (1610m above sea level) built in 2010. Figure shows the general characteristics

of the evaluated classrooms. "Brisas de Robledo" classroom has a square floor plan, uniform ceiling and

brick walls. "12 de Octubre" classroom has an irregular plan, variations in ceiling heights and walls with

foil insulation.

Figure 2: Classrooms where children were assessed and location of sensors.

Psychological assessment of children

In order to apply the test in children with appropriate cognitive and emotional level, it was conducted

a previously interview with the teachers of each classroom. The interview allowed identifying the children

between 4 and 5 years old who could participate actively in the research (playing the lottery).

The Weschler Intelligence WIPPSI III for preschoolers was applied in all children of the two classes

allowing to determine their intellectual capacity and to verify that the pre-selected children did not have

any kind of cognitive dysfunction. The results of this test indicated that, although some children have

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lower intellectual coefficient than others, they all were within the normal range for the age (IQ between

85 -115).

Afterwards it was constructed a scale of observation of the behavior to appraise children participating

in the test. BASC-2 (Behavior Assessment System for Children) test was applied to the parents and

teachers to compare the observation of behavior –from each child- in different environments in order to

validate the data obtained from observation. BASC-2 system enables assessment from three points -self,

teacher, and parent- to help ensure a balanced evaluation (Reynolds, Cecil and Kamphaus, 2014). The

standardization of this instrument was carried out in Medellín by the Group of Neuropsychology and

Conduct and Neuroscience Group of University of San Buenaventura, Neurological Institute of Antioquia

and University of Georgia. The methodology and results of the psychological and cognitive assessment

will be the aim of another paper.

Designing and application of tests

According to Borgers and de Leeuw (2000) and Borgers, Hox, & Sikkel (2003) it is possible to apply

questionnaires in 4 years old children, although it is not an easy task. The development of the questionnaire

should help on the first two parts of the formulation of a question: the understanding of it and the recovery

of the relevant information. These can be achieved by using words of children's language and game

activities. According to that, the design of the instrument included two important issues: the methodology

needed to address questions to the children and the characteristics of the local climate. The survey

questions were formulated based on ASHRAE 55 and 3 points McIntyre scales. For the climatic conditions

of Medellín, the ASHRAE 7-point scale was reduced to 3 points in order to facilitate understanding by

children. Table 1 shows the questions and the alternatives of answers.

The first question (Q1) allowed us to verify whether children understood the images and their

symbolic content, concerning the conditions of the day. The second question (Q2) asked children about

their feeling with the thermal conditions at the moment in the classroom –thermal sensation-. The

questions three (Q3) and four (Q4) were used to obtain the thermal evaluation. Question 3 (Q3) asked

children about their feeling with the thermal conditions answered in Q2 and Q4 was used as control to Q2

(if the child answers the room was hot then he/she should answer to wear fewer clothes). The fifth question

(Q5) helped to identify the thermal preference.

The use of a lottery as a tool to apply the questionnaire was defined with the assistance of

psychologists. This game allowed children to interact with the instrument and allowed us to vary how to

play (in this case, children would cover only the image corresponding to the chosen answer for each

question). The images used in the lottery should be clear, known by children and easy to associate with

the answers. Furthermore, it was avoided to use colors related to the sex of children, for example. The use

of male and female icons on issues relating to the evaluation and thermal preference was recommended.

It was created one lottery for girls and another one for boys. Figure 3 shows the graphical features of the

game. The selected children played the lottery individually inside the classroom with the help of a

researcher of the team. Before starting, the researcher presented for each child the rules of the game.

The response images to each question were arranged in columns. When the game-questionnaire

started the lottery was completely covered and only when a question was made the pictures of response

were uncovered. Each child should find the twin image (representing the choice) and cover it on the board.

The pictures were arranged randomly in each column of the board to avoid children related pictures on the

previous issue with the images of the following question. Each child took approximately 5 minutes to

complete the game.


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Figure 3: Lottery

In order to verify if children will understand the questions, the images and how to play the lottery, a

pre-test was performed in a third space. Adjustments in the form of the images and how to ask the questions

were realized accordingly.

Experimental protocol

Indoor measurements of the four main environmental variables (air temperature, globe temperature,

air velocity, relative humidity) were performed in the mornings on days October 30, 2013 in Brisas de

Robledo kindergarten and November 06, 2013 in 12 de Octubre kindergarten. Figure 2 shows the location

of the sensors in classrooms. Outdoor climate (air temperature and relative humidity) was also measured

for at least 7 days before the application of the questionnaires.

Simultaneously with the measurements, the thermal comfort questionnaires (lottery) were applied.

The clothing insulation (clo) was obtained through ASHRAE 55 (2013) tables and considered the

children’s clothing during the lottery. Children were performing reading/drawing activities, before and

after the lottery.

RESULTS

Table shows the responses obtained through the lottery applied in children in each classroom, in

percentage. Table summarizes the general characteristics of the sample and the climate during the period

of fieldwork.

Regarding the thermal perception in the morning (Q1), 80% of children perceived a “sunny morning”

and only 20% a “cloudy with sun” morning. The thermal perception of the classrooms (Q2) was perceived

by 45% of children as “hot”, by 30% as “not hot neither cold” and by 25% as “cold”.

Considering all children (Q3), when the classroom was “cold”, 10% of the kids were “sad” with this

condition and 15% were “happy”. 20% of children were “sad” and 10% were “happy”, when the classroom

was perceived “not hot neither cold”. Children who perceive the classroom “hot” said that they felt “sad”

(15%) and “happy” (30%).

15% of all children would wear “jersey and pants” when the classroom was “cold”, 5% would wear

“T-shirt and pants” and just 5% would wear “sleeveless shirt and skirt/shorts”. When the classrooms were

perceived “not hot neither cold” 25% of children would wear “jersey and pants”, 10% would use “T-shirt

and pants” and 10% would wear “sleeveless shirt and skirt /shorts”. When the classrooms were perceived

“hot” by children, 10% of them would wear “jersey and pants”, 10% would wear “T-shirt and pants” and

25% would wear “sleeveless shirt and skirt/shorts”.


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Table 1: Children’s answer to each question of the lottery.

Kindergarten classroom

1. THERMAL PERCEPTION 12 de Octubre Brisas de Robledo

Q1: How do you think is the morning today?

a. The day is cloudy -1 0% 0%

b. The day is cloudy with sun 0 0% 40%

c. The day is sunny 1 100% 60%

Q2: How do you think is the classroom in this morning?

a. The classroom is cold -1 20% 30%

b. The classroom is not hot neither cold 0 30% 30%

c. The classroom is hot 1 50% 40%

2. THERMAL EVALUATION 12 de Octubre Brisas de Robledo

Q3: When the classroom is ______, How do you feel? Q2 (-1) Q2 (0) Q2 (1) Q2 (-1) Q2 (0) Q2 (1)

a. Sad, gloomy -1 10% 10% 20% 10% 30% 10%

b. Joyful, happy 1 10% 20% 30% 20% 0% 30%

Q4: When the classroom is ____, What clothes would you wear? Q2 (-1) Q2 (0) Q2 (1) Q2 (-1) Q2 (0) Q2 (1)

a. Jersey and pants -1 10% 10% 0% 20% 10% 20%

b. T-shirt and pants 0 0% 10% 20% 10% 10% 0%

c. Sleeveless shirt and skirt/ shorts 1 10% 10% 30% 0% 10% 20%

3. THERMAL PREFERENCE 12 de Octubre Brisas de Robledo

Q5: At this moment,would you like to feel ____?

a. Cooler -1 0% 10%

b. No change 0 60% 30%

c. Warmer 1 40% 60%

Table 2: Characteristics of the sample and the climate during the period of fieldwork. Kindergarten classroom 12 de Octubre Brisas de Robledo

Gender

Boys 40% 40%

Girls 60% 60%

Age

4 years 20% 40%

5 years 80% 60%

Mean Clo 0.50 0.56

Mean Met 1.0 1.0

Monthly mean outdoor air temperature (ºC) 21.2 21.1

Mean daily outdoor air temperature - 7 days ago (ºC) 20.2 21.4

Mean indoor operative temperature (ºC) 24.8 24.6

Mean indoor relative humidity (%) 56.2 59.9

Mean indoor air velocity (m/s) 0.28 0.19

In the evaluation of the thermal preference (Q5) of the total number of children assessed, 5% said

they would like to feel cooler at that time, 45% said they were satisfied (no change) with the current

conditions and 50% would like to be warmer.

The mean votes of thermal sensation (Q2) and the mean votes of preference (Q5) was (a) 0.1 and 0.5

for Brisas de Robledo and (b) 0.3 and 0.4 for 12 de Octubre, respectively. These results suggested that

children, at the moment of the application of the lottery, feels slightly warm environment but prefer to feel

that way or warmer.

Comparing the actual mean votes with PMV/PPD and adaptive model of thermal comfort

The PMVc (calculated Predicted Mean Vote) (ISO 7730, 2005) for Brisas de Robledo was -0.61 with

a PPD (Predicted Percentage of Dissatisfied) of 18.27%. For 12 de Octubre the PMVc was -0.87 and the

PPD was 22.01%. In both classrooms the PMVc resulted in a slightly cooler environment whereas the

actual sensation presented a neutral/slightly warm one. Maybe such difference could be caused by the

adoption of adult’s metabolism. If we consider that 1.0 met for adults is equal to 1.2 met for children

(Fabbri, 2013) the new calculated PMV are -0.08 for Brisas de Robledo and -0.28 for 12 de Octubre, more


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closer to the actual values and indicating thermal comfort if we considered a range of PMV from -0.5 to

0.5.

Applying the data into the adaptive model of thermal comfort (ASHRAE 55, 2013) we obtained 90%

acceptability ranges of 21.8 to 26.8ºC for Brisas de Robledo and 21.9 to 26.9ºC for 12 de Octubre when

using the mean monthly outdoor air temperature; the ranges varied very little when the running mean

temperature (7 days ago with α=0.9 – ASHRAE 55, 2013) was used instead the mean monthly temperature.

This way, the measured data (mean indoor operative temperature of 24.6ºC for Brisas de Robledo and

24.8ºC for 12 de Octubre) was within the ranges for thermal comfort in both kindergartens.

CONCLUSIONS

This study allowed us to test a method for evaluating the thermal sensation and preference of children

of pre-school age in the city of Medellín, Colombia. Due to the age and development process of children,

psychologists and pedagogues were essential in formulating questions, defining the questionnaire

methodology (lottery) and selecting images to be used. However, the fact that the lottery was conducted

by a stranger person to children and untrained in pedagogy for preschool may have generated some sort

of impact on the formulation of the questions and therefore the answers. In a future study, the lottery could

be applied by children’s teacher, minimizing the errors generated by this situation. It was also confirmed

the importance of making a brief introduction to try to understand how children perceive the concept of

temperature and climate.

The results obtained using the lottery were considered positive from the methodological point of view

since the children were familiar with this type of game and understand how it should be played. The

purpose of Q1 was to identify whether children related the hot with sun and cold with rain/clouds, for

example. This association was confirmed in the answers and it is a typical characteristic of the climate of

Medellín. Questions 2 and 5 seemed to be understood by children. Analyzing Q3, it seems that the question

was not formulated properly or it was not clear to the children, because, they said they always want to be

happy. The selection of clothes (Q4) is a topic that children associate more with the weather. However, it

was not clear whether the children actually selected the type of clothes they would like to use or simply

selected the type of clothing they prefer (some children choose to wear more clothes even feeling hot, as

others selected to wear less clothes even feeling cold).

The results presented herein suggested that children feels slightly warm environment and prefer to

feel that way or warmer.

The method should be adjusted regarding the factors that led to some kind of influence on the answers

or that did not generate the expected/desired response. Finally, it is important to consider in the design of

tools and questionnaires the characteristics of the local climate, as well as cultural factors. These factors

influence the construction of knowledge and understanding of the environment, especially in the first years

of life.

ACKNOWLEDGMENTS

The authors would like to thank the University of San Buenaventura for the financial support for

carrying out this work, the Buen Comienzo program for allowed the visits to kindergartens and

implementation of surveys of children. The authors would like to thank specially the teachers and

community mothers for the help in the fieldwork.


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Documents

Testing a Method to Assess the Thermal Sensation and Preference