The Validation Modelling of Air Movement to Measure Thermal

Comfort in Building Model

Augi Sekatia

, Erni Setyowati

and Gagoek Hardiman

Doctoral Program of Architecture and Urbanism, Universitas Diponegoro,Semarang, Indonesia

Department of Architecture, Faculty of Engineering, Universitas Diponegoro, Semarang, Indonesia

Keywords: Thermal comfort, Hot wire Anemometer, Instruments, Validation.

Abstract: Discussing about passive cooling buildings cannot be separated from discussing thermal comfort, especially

in tropical climates. Natural Ventilation is one of an answer to the energy conservation issues. NV can also

help to achieve thermal comfort in a building. This study examines how air velocity affects indoor thermal

comfort in a building model with dimensions 2.5 m x 2.5 m that uses natural ventilation. The research was

conducted by taking 100 indoor air velocity (m/s) data and temperature (°C) from the two hot-wire

anemometer (KRISBOW KW0600653 and LUTRON AM-4234SD) instruments with an interval of 5

minutes for each data. The data statistically analyzed by using linear regression modelling of SPSS 24 version

software. The 100 data obtained, for indoor air velocity readings, the two brands have correlation of 75%,

while for temperature readings is 92.6%. The building didn’t achieve the thermal comfort because of

ventilations location. The purpose of this research is to prove that without natural ventilation especially the

air velocity, thermal comfort can’t be achieved by using LUTRON AM-4234SD hot-wire anemometer and

want to validate the reading values to KRISBOW KW0600653 or vice versa more easily with the equations

found in this paper.

1 INTRODUCTION

Nowadays, buildings with an energy-saving concept

is a primary consideration. This concept follows the

Green Architecture and Sustainable Design concepts.

Zhang et al (Zhang & Lin., 2020) stated that

architecture and its construction play a big role in

environmental damage and increased carbon dioxide

emissions. Therefore, the architecture field should

attempt to achieve thermal comfort in buildings by

calculating energy usage and the Green concept. To

improve understanding of thermal comfort in rooms,

one should calculate the thermal comfort standard and

consider the ventilation model of thermal comfort and

thermal adaptation from psychology, physiology, and

behavior of users (Xia, et al., 2020). The new

challenge for designers and architectural researchers

is to create flexible built environments according to

the Energy Efficiency concept (Lau, et al.,

2020).Natural ventilation is a method to achieve

thermal comfort in a room without using much

energy. It is proven in previous studies that air

velocity in a room can reduce the standard effective

temperature so that thermal comfort in the room can

be achieved (Sekati, et al., 2018)(Sekatia, et al.,

2019).

The air velocity measurement in a room should be

conducted using a measuring instrument of hot wire

anemometer. Hot wire anemometer is an essential

instrument for measuring laminar, transition, and

turbulent flows because of its accurate signal

interpretation and simplicity of use. This

measurement technique is an indirect method with an

output of tension signals. Therefore, calibration is a

critical way to measure speed effectively and

accurately (Ozahi, et al., 2010). Hot wire anemometer

also has an advantage of small probe sizes and

frequency responses that enable speed fluctuation in

a detectable high frequency (Benjamin & Roberts,

2001). Hence, for air velocity measurement in a room

with substantially small airflow, a hot wire

anemometer is required compared to traditional

anemometers that can only be used outside of the

room.

Hot wire anemometer’s brands are massive in the

market. The most used brands are KRISBOW

KW0600653 and LUTRON AM-4234SD. Both

brands have the same resolution. Therefore, this study

Sekatia, A., Setyowati, E. and Hardiman, G.

The Validation Modelling of Air Movement to Measure Thermal Comfort in Building Model.

DOI: 10.5220/0010790900003317

In Proceedings of the 2nd International Conference on Science, Technology, and Environment (ICoSTE 2020) - Green Technology and Science to Face a New Century, pages 25-30

ISBN: 978-989-758-545-6

aimed to validate both instruments, in which one

instrument, i.e., KRISBOW KW0600653 had been

calibrated and acquired a calibration certificate from

the KAN (National Accreditation Committee). The

validation was carried out in a model building with a

size of 2.5m x 2.5m in Semarang City. The study

results are two equation models to validate both

instruments and measure thermal conditions in the

model building.

2 RESEARCH METHOD

2.1 Climate Condition

Semarang City is geographically located at 109° 35‘

– 110° 50‘ East Longitude and 6° 50’ – 7° 10’ South

Latitude with an area of 373.70 km2. According to

the geographic site, it is affected by monsoons'

tropical climate with two kinds of weather, i.e., dry

weather from April – September and rainy weather

from October – March with an average annual

humidity of 77% (Pemerintah Kota Semarang, 2015).

Figure 1: Semarang Average Precipitation and Temperature

1960 – 2018 (Hikersbay, 2020)

Figure 1 shows that the average temperature of

Semarang City ranged from 30°C to 33.2°C. It was

caused by the geographic condition of Semarang

City, in which most of the areas are lowlands and

beaches. Rainfall in Semarang City was rather high,

ranging from 80 mm to 180 mm. The annual rainfall

rate of Semarang City was 1528 mm. January,

February, and March were months with the highest

rainfall.

Table 1: Specifications of measurement instruments

Instrum

Manu

facture

Para

mete

Reso

lution

Range

Accu

racy

Hot

wire

Anemo

meter

(KW06

00653)

KRISBO

China

Air

velocity

0.01 m/s

0.1 -

25.0 m/s

± 5% ±

0.1m/s

Air

temperat

ure

0.1°C 0 – 50°C ± 1.0°C

Hot

wire

Anemo

meter

(AM-

4234S

LUTRO

N, China

Air

velocity

0.01 m/s

0.2 -

35.0 m/s

± 5% ±

0.1m/s

Air

temperat

ure

0.1°C 0 – 50°C ± 0.8°C

The resolutions of the KRISBOW hot wire

anemometer (KW0600653) in measuring air velocity

and temperature are 0.01 m/s and 0.1°C. It is the same

with the LUTRON hot wire anemometer (AM-

4234SD) (see Table 1).With the same resolution, both

instruments' validation is necessary to be discovered

to ease researchers in reading the measurement result.

Data were analyzed statistically using the linear

regression software of SPSS version 24 to find the

validation equation model between the KRISBOW

hot wire anemometer (KW0600653) and LUTRON

hot wire anemometer (AM-4234SD). The model

building's thermal condition was analyzed using

Szokolay’s standard (Szokolay, 2001) and the

standard SNI 03-6572-2001 (SNI, 2010).

2.2 Data Collection and Measurements

In obtaining a reading validation of measurement

results, 100 data were obtained on a model building

with a size of 2.5m x 2.5m with two different

variables, i.e., air velocity and temperature. Each data

was taken with a 5-minute interval. Data were taken

using two hot wire anemometer instruments with

different brands, i.e., KRISBOW KW0600653 and

LUTRON AM-4234SD (see Figure 2 and 3) at the

same time and same height of 1.1m from the floor

(Brager & De Dear, 1998). The ventilation height on

the model building was constructed on 1.6m from the

floor.

ICoSTE 2020 - the International Conference on Science, Technology, and Environment (ICoSTE)

Figure 2: KRISBOW KW0600653

Figure 3: LUTRON AM-4234SD

The KRISBOW KW0600653 hot wire anemometer

had been calibrated and acquired a calibration

certificate no. S. 19 012 115 SNI ISO/IEC-17025-

2008 from the KAN (National Accreditation

Committee). KAN is a national institution in the

research instrument accreditation and calibration

field.

3 RESULTS

3.1 Air Velocity (M/S)

The form should be completed and signed by one

author on behalf of all the other authors. Air velocity

highly affects the standard effective temperature

(SET) reduction (Sekatia, et al., 2018). Szokolay

(Szokolay, 2001) stated that the air velocity comfort

zone in tropical climate ranged between 0.2 m/s – 0.8

m/s. From the measurement conducted on the model

building, obtained the average air velocity from both

hot wire anemometers ranging between 0.028 m/s to

0.032 m/s. Therefore, the model building's air

velocity didn’t meet the comfort zone standard in

tropical climate because it was under 0.2 m/s. It was

possible because there was ventilation on top of the

building shaded by the model building’s eaves.

Figure 4: Air Velocity measurement between KRISBOW

KW0600653 and LUTRON AM-4234SD

From Figure 4, it is discovered that both instruments

only had a slight difference in air velocity reading.

LUTRON AM-4234SD tended to read more

sensitively and higher than KRISBOW KW0600653.

Nevertheless, KRISBOW KW0600653 often read the

air velocity higher than LUTRON AM-4234. Hence,

from the data obtained, a statistic test using linear

regression was carried out to validate both

instruments into an equation so that the

LUTRONAM-4234SD’s reading result could be

represented into the KRISBOW KW0600653’s

reading result where this instrument had been

calibrated.

3.2 Validation and Regression Model of

Air Velocity between KRISBOW

KW 0600653 and LUTRON

AM-4234SD

The first regression model shows the air velocity

reading correlation of both hot wire anemometers,

i.e., KRISBOW KW0600653 and LUTRON AM-

4234SD.

Table 2: Model Summary Regression 1

Model R R

uar

Adjusted

Square

Std. Error o

the

Estimat

1 .750a .562 .558 .01165

a. Predictors: (Constant), LUTRON VEL

In Table 2, R is the correlation coefficient. It can be

interpreted that the correlation coefficient of air

velocity on KRISBOW and LUTRON hot air

The Validation Modelling of Air Movement to Measure Thermal Comfort in Building Model

anemometers was 0.750, meaning that the

relationship between air velocity reading of

KRISBOW and LUTRON hot wire anemometers was

75%. R square is called the Determination

Coefficient. From Table 1, it is discovered that the R

square value was 0.562, meaning that 56.2% of the

variations occurred on KRISBOW KW 0600653’s air

velocity reading was caused by LUTRON AM-

4234SD’s air velocity reading, while the rest was

unexplainable.

Table 3: Regression Model 1

Model Sum o

Square

df Mean

Square

F Sig.

Regressio

.017 1 .017 125.837 .000b

Residual .013 98 .000

Total .030 99

a. Dependent Variable: KRISBOW VEL

. Predictors: (Constant), LUTRON VEL

Model Unstandardized

Coefficients

Standar

dized

Coeffi

cients

t Sig.

B Std.

Erro

Beta

(Const

ant)

.007 .002 2.996 .003

LUTR

VEL

.682 .061 .750 11.218 .000

a. Dependent Variable: KRISBOW VEL

In Table 3.a., it is discovered that the probability or

Sig value was 0.00, where Sig value <0.05 means that

the regression model is accepted. Table 3.b. shows a

constant of 0.007 with air velocity reading coefficient

of hot wire anemometer LUTRON of 0.682. From

this regression result, obtained an equation to validate

the air velocity reading of KRISBOW KW0600653

against LUTRON AM-4234SD as follows:

𝐾𝑅𝐼𝑆𝐵𝑂𝑊 𝑉𝐸𝐿  0.007  0.682 𝐿𝑈𝑇𝑅𝑂𝑁 𝑉𝐸𝐿 (1)

Where KRISBOW Vel is the air velocity reading in

hot wire anemometer KRISBOW KW 0600653 (m/s),

and LUTRON Vel is the air velocity reading inhot

wire anemometer LUTRON AM-4234SD (m/s). The

equation above eased air velocity reading in hot wire

anemometer LUTRON Am-4234SD to obtain a

validated value in KRISBOW KW 0600653, which

had been calibrated.

3.3 Air Temperature (°C)

The temperature shown in hot wire anemometers

should not be used to measure thermal comfort in a

room. Thermal comfort can be determined using the

standard effective temperature. SET is an imaginary

environment temperature in 50% RH, <0.1 m / s (20

fpm) in the average air velocity, where the total heat

loss from imaginary occupant skin with an activity

rate of 1.0 met and clothing rate of 0.6 clo, equals with

the actual environment wearing the actual clothes and

conducting the actual activity [14]. However, in

Indonesia, SNI 03-6572-2001 regulates the air

temperature declared as comfortable in a room,

ranging between 25.8°C to 27.1°C[12]. From the

measurement conducted on the model building,

obtained an average air temperature ranging between

27.54°C to 28.2°C. It was influenced by the small

amount of air velocity entering the model building;

thus, the air temperature did not meet the comfort

zone according to SNI 03-6572-2001.

Figure 4. Air temperature measurement between

KRISBOW KW0600653 and LUTRON AM-4234SD

It can be seen in Figure 4 that the air temperature

reading in the model building only had a slight

difference, ranging from 0.1°C to 0.7°C. Again,

LUTRON AM-4234SD had a higher reading

tendency than KRISBOW KW0600653. It proves the

possibility of LUTRON AM-4234SD having higher

sensitivity. The authors conducted a linear regression

statistic test to validate and formulate an equation for

both instruments from obtained data.

3.4 Validation and Regression Model of

Air Temperature between

KRISBOW KW 0600653 and

LUTRON AM-4234SD

The second regression model shows the air

temperature reading correlation of both hot wire

anemometers, i.e., KRISBOW KW0600653 and

LUTRON AM-4234SD

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Table 4. Model Summary Regression 2

Model Summary Regression 2

Model R R Square

Adjusted

Square

Std. Erro

of the

Estimate

1 .926a .858 .856 .08727

a. Predictors: (Constant), LUTRON TEMP

In Table 4, it can be interpreted that the correlation

coefficient of air temperature on KRISBOW and

LUTRON hot air anemometers was 0.926, meaning

that the relationship between air temperature reading

of KRISBOW and LUTRON hot wire anemometers

was 92.6%. From Table 4, it is discovered that the R

square (determination coefficient) value was 0.858,

meaning that 85.8% of the variations occurred on

KRISBOW KW 0600653’s air temperature reading

was caused by LUTRON AM-4234SD’s air

temperature reading.

Table 5. Regression Model 2

Model Sum

Squar

df Mean

Square

F Sig.

Regressi

4.502 1 4.502 591.128.000b

Residua

.746 98 .008

Total 5.248 99

a. Dependent Variable: KRISBOW TEMP

. Predictors: (Constant), LUTHRON TEMP

Model Unstandardized

Coefficients

Standardi

zed

Coefficie

nts

t Sig.

B Std.

Erro

Beta

(Consta

nt)

6.123 .881 6.

.000

LUTHR

TEMP

.759 .031 .926 2

.000

a. Dependent Variable: KRISBOW TEMP

In Table 5.a., it is discovered that the Sig value

was 0.00, where Sig value <0.05 means that the

regression model is accepted. Table 5.b. shows the

constant of 6.123 with air temperature reading

coefficient of hot wire anemometer LUTRONAM-

4234SD of 0.759. From this regression result,

obtained an equation to validate the air temperature

reading of KRISBOW KW0600653 against

LUTRON AM-4234SD as follows:

𝐾𝑅𝐼𝑆𝐵𝑂𝑊𝑇𝐸𝑀𝑃  6.123 

0.759 𝐿𝑈𝑇𝑅𝑂𝑁𝑇𝐸𝑀𝑃 (2)

Where KRISBOW Temp is the air temperature

reading in hot wire anemometer KRISBOW KW

0600653 (°C), and LUTRON Temp is the air

temperature reading in hot wire anemometer

LUTRON AM-4234SD (°C). With the equation

above, air temperature validation in hot wire

anemometer LUTRON Am-4234SD against

KRISBOW KW 0600653 would be easier.

4 CONCLUSIONS

The measurement and analysis data above, it can be

concluded that the model building’s thermal

condition was not in the comfort zone of tropical

climate; hence, not achieving thermal comfort in the

building. It was caused by the open natural ventilation

height. This fault caused small airflow, which could

not reduce the air temperature in the model building.

Air velocity and temperature reading validations on

hot wire anemometer LUTRON AM-4234SD against

KRISBOW KW0600653 from two regression models

resulted in two equations, i.e.,

(1) 𝐾𝑅𝐼𝑆𝐵𝑂𝑊𝑉𝐸𝐿  0.007 

0.682 𝐿𝑈𝑇𝑅𝑂𝑁𝑉𝐸𝐿,

(2) 𝐾𝑅𝐼𝑆𝐵𝑂𝑊𝑇𝐸𝑀𝑃  6.123 

.759 𝐿𝑈𝑇𝑅𝑂𝑁𝑇𝐸𝑀𝑃 .

Both equations eased the measurement using hot wire

anemometer LUTRON AM-4234SD and validate the

reading result intohot wire anemometer KRISBOW

KW0600653 calibrated by the KAN. This research

can help researchers to make validation of the same

instrument without have to calibrate all the

instruments again to the calibration committee. The

researchers can follow this research method to

validate their instruments as well.

The Validation Modelling of Air Movement to Measure Thermal Comfort in Building Model

ACKNOWLEDGEMENTS

The authors express gratitude to the Indonesian

Ministry of Education and Culture for the Doctoral

Research grant number 225-23/UN7.6.1/PP/2020

(DIKTI). The authors also thank all staff of the

Architecture Department of Universitas Diponegoro

who helped this study implementation.

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