International Journal of Mechanical Engineering and Technology (IJMET)
Volume 10, Issue 03, March 2019, pp. 466–472, Article ID: IJMET_10_03_048
Available online at http://www.iaeme.com/ijmet/issues.asp?JType=IJMET&VType=10&IType=3
ISSN Print: 0976-6340 and ISSN Online: 0976-6359
© IAEME Publication
Scopus Indexed
IMPROVING DORMITORY THERMAL
COMFORTABILITY BY PUTTING UP
VERTICAL HYDROPONICS VEGETABLE
GARDEN IN SURABAYA INDONESIA
Eddy Imam Santoso
Architecture Department Faculty of Engineering Merdeka University Surabaya, Indonesia
Tisa Angelia
Architecture Department Faculty of Engineering Merdeka University Surabaya, Indonesia
Yeni Ika Pratiwi
Agrotecnology Department Faculty of Agriculture Merdeka University Surabaya, Indonesia
ABSTRACT
The research examined dormitory thermal comfort after it was treated with
vertically hydroponics vegetable garden on the West side (the side faces the sun) of
the building. The garden was structured vertically at 60 degrees slope by using loose
system which enabled all vegetables to be directly illuminated by the sun.
Measurement of thermal comfort of the building was carried out by opening all
openings (doors and windows) in a dormitory in Rungkut Menanggal Harapan
Surabaya. Objective research involved dry air temperature, relative humidity, wind
speed and sun radiation before and after garden installation, while subjective
research involved questions about thermal environment perception. The research
result revealed that during dry season air temperature in the rooms decreased 0,8 ○C,
while CO2 level went down 2.56 ppm and O2 level went up 0.6 %. Thermal comfort or
neutral temperature after the hydroponics installation was above ASHRAE standard
comfort zone which is 55. Subjectively it was revealed that the tenants experienced
higher thermal comfort compared to PMV (Predicted Mean Votes) prediction..
Key words: hydroponics vegetables, Neutral temperature, comfort perception.
Cite this Article: Eddy Imam Santoso, Tisa Angelia, Yeni Ika Pratiwi, Improving
Dormitory Thermal Comfortability by Putting Up Vertical Hydroponics Vegetable
Garden in Surabaya Indonesia, International Journal of Mechanical Engineering and
Technology 10(3), 2019, pp. 466–472.
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Eddy Imam Santoso, Tisa Angelia, Yeni Ika Pratiwi
1. INTRODUCTION
People’s interest in thermal comfort of a building has driven many researchers to do thermal
studies on various buildings. There are a lot of studies about the various ways to evaluate
thermal comfort to find out whether thermal surrounding is suitable for comfortable life. This
is very reasonable because people in general spend more than 90% of their time inside a
room, and because of this they need fresh air in their respective room[1].
People do various efforts to make their work place comfortable, one of which is by
creating artificial air manipulator system in the form of air conditioning (AC) or fan
installation, while others choose natural airing system or cross ventilation system in their
building designs. Using fans, the average temperatures derived from direct and indirect
investigation respectively are 28.2 and 27.2ºC. (Cheng,M., ad all. 2008). The problem of
room comfort is solved by investigating the overall air speed in the room[2].
There are some important variables in obtaining thermal comfort in a room. Some
researchers like Szokolay [3], Fanger [4], Humphreys & Nicol [5], [6] and Hougton & Yaglou
[7] stated that climate variables such as air temperature, air speed, relative humidity and
radiation temperature helped define hopes of thermal comfort [8]. Based on a research by
Santoso[9], putting up sun light shield from plants either vertically or horizontally in a
building will reduce air temperature in its rooms to about 1.5 to 2oC[10][9].
Buildings in humid tropical area are difficult to comply with ASHRAE 55 standard of
comfort zone. This is due to weak variables of thermal comfort such as air temperature,
relative humidity, sun light radiation and air speed in a room. To achieve ideal thermal
comfort one has to control or do adaptive measure such as put up good ventilation system,
arrange wind circulation mechanically, put up curtains on buildings hit directly by sun lights,
and even design and make sun lights shadings to minimize radiation heat[11][12][9].
2. METHOD
Data was collected during hot season from 2 – 7 September 2017 in a dormitory in Rungkut
Menanggal Harapan, Kelurahan Rungkut Menanggal, Kecamatan Gunung Anyar Kota
Surabaya. Dormitory dimension: length 400 m, wide 300 m, ceiling height in average 3.20 m
(Picture 1). Room volume: 38.40 m3 and floor dimension: 12.00 m2 (Picture 2). The
dormitory was part of a house located on the third floor, while the room used as this research
object was a room with openings facing West complete with a balcony (Picture 3)
The East border of the room stuck to the neighboring wall, the West side was an open
space or yard, the North boundary with the neighboring house and the South boundary with
the village road. The dormitory room was divided by two blocks or big walls (the East and
South side) and two blocks or walls with eindow openings / ventilation (West and South side).
The West opening was a two-leaves of glass louver boards window which could be opened or
closed, 80 cm high from the floor. Its opening dimension was 1.44 m2, 1.20 m wide and 1.20
m long. The West balcony was connected with an aluminium plated plywood door of 0.80 x
2,00 m. The South opening was 1 plain glass ventilation which can be open/close of 0.16 m2,
and 1 plywood door of 1.60 m2 which wasn’t hit by direct sun light because it connected the
other room. The floor was made of multi-plywood covered with carpet and the ceiling was
covered with GRC plate. The roof was made of concrete tiles.
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Improving Dormitory Thermal Comfortability by Putting Up Vertical Hydroponics Vegetable Garden in
Surabaya Indonesia
The room housed 2 college students.
1.00
2.00
1.50
3.00
1.50
2.00
1.00
3.00
1,50
3.00
Kitchen
Dorm
2.50
WH
Dining room
1.50
Drying Spot
Dorm
2.25
Dorm
Sitting
room
Dorm
Terrac
e
2nd Floor
Atap lt
Roof
275
Carport
1st Floor
Roof
2nd FLOOR MAP
Jl. Rungkut Menanggal
Harapan
2.00
1
Guest
room
3RD FLOOR MAP
: researched room
1ST FLOOR MAP
: Vertical garden
NORTH
Figure1 Research Object Map (Dormitory room)
Source : Research result
Figure 3 West side
Figure 2 dorm room (interior)
Source: Research result
Source: Research result
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15.00
Garage
1.50
Sitting
room
Eddy Imam Santoso, Tisa Angelia, Yeni Ika Pratiwi
3. RESULT AND DISCUSSION
The result of thermal comfort in a room using air as parameter can be seen in Picture 5 and
Table 1.
39
AIR TEMPERATURE
37
35
33
31
29
27
25
08.00
09.00
10.00
11.00
12.00
13.00
14.00
15.00
16.00
TIME
RESEARCH
SUHU
PENELITIAN
TEMPERATURE
INITIAL
TEMPERATURE
SUHU
AWAL
Figure 5 In door average air temperature Graph in the Room Asrama
Table 1. Result of humidity, air speed and light intensity measurement as well as average ambient of
CO2 & O2 on Dorm in door research
---------------------------------------------------------------------------------------------------Research
Time Humidity Radiation Air Speed CO2 ambient O2 ambient
%
W/m2
m/det
ppm
%
---------------------------------------------------------------------------------------------------Initial
Morning 64
133
0,00
22,2
20,4
Noon
50
475
0,00
13,2
18,2
Late noon 41
186
0,00
12,3
20,5
-------------------------------------------------------------------------------------Average
52
264
0,00
15,90
19,7
---------------------------------------------------------------------------------------------------Result
Morning 67
38
0,00
17,00
20,8
Noon
56
66
0,00
10,70
19,9
Late noon 49
81
0,00
12,33
20,1
------------------------------------------------------------------------------------Average
57
62
0,00
13,34
20,3
In picture 5, indoor air temperature in dry season declined insignificantly after a
hydroponics vegetable garden was put up vertically on the West side of the building. Before
the vertical garden was put up, research result revealed that the average air temperature was
33.3ºC. After the garden was put up, average temperature changed into 32.5ºC, decreased
about 0.8ºC. The air temperature decline was influenced by low sun radiation due to the
vegetable garden at the front of the building (sun radiation before the putting up of the garden
was 264 W/m2, after that it became 62 W/m2)
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Improving Dormitory Thermal Comfortability by Putting Up Vertical Hydroponics Vegetable Garden in
Surabaya Indonesia
Air quality was also improving although insignificant. Photosynthesis process of the
vertical vegetable garden on the West side of the building had caused CO2 attachment in the
ambient air decreased about 2.56 ppm, while O2 release of the vertical vegetable garden
increased about 0.6 %. (Table 1)
Initial Wet Bulb Temperature
Result Wet Bulb Temperature
Figure 6 Field measurement result analysis using Psychometry Chart
Based on analysis result using Psychometry Chart of average dry air temperature (Picture
6) and average air humidity (Table 1), wet air temperature during dry season was 24.5ºC.
Later, this wet air temperature data obtained from analysis result will be used to determine
efective temperature or neutral temperature or thermal comfort of the dorm room.
Dorm Effective Temperature
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Eddy Imam Santoso, Tisa Angelia, Yeni Ika Pratiwi
Figure 7 Thermal Comfort Analysis (ET) based on field dry temperature measurement and wet
temperature analysis result using Effective Temperature Diagram
Analysis result using Effective Temperature Diagram of average dry air temperature data
and analysys result of wet air temperature using Psychometry Diagram (Picture 6) was
ignored due to low air speed in the meeting room (Amirudin, Saleh, 1972). Thus neutral air
temperature or Effective Temperature (ET) or thermal comfort during dry season was 27.7 ºC
(ET), (Picture 7).
ASHRAE 55-1992 Standard recommends that to obtain the comfort zone in dry season,
the thermal comfort temperature should be between 23oC – 25.5oC with relative humidity
between 20 % - 60 % (ASHRAE.1992). Research result revealed that the dorm room was not
in the comfort zone during daily activities.
Initial studies carried out in some humid hot areas (around South East Asia) on houses
revealed that the produced neutral temperature was higher than those recommended by
ASHRAE standard, which is 55. All studies on naturally ventilated buildings revealed that
comfort temperature was higher, between 2.2 – 3.7oC above recommended. Dorm studies on
dwellings in Surabaya revealed that Effective Temperature was 27.4oC, in Jakarta 26.7oC, in
Banjarmasin 27.8oC, in Malaysia 28.3oC, in Singapore 28.9oC. (Santoso, 2015).
To be accepted 90%, suggested thermal comfort was Nt (Neutral temperature) ± 2.5 ET
(Efective Temperature), while to be accepted 80%, suggested thermal comfort was Nt ± 3.5
ET. (Auliciems, A.1981). To be accepted 80 % and 90 % on every condition, check Table 2.
Table 2 Measurement results of air parameter and thermal comfort on Dorm building
Location
Indoor
Neutral temperature /Effective
Temperature (ET)
ET 90 % accepted
80 % accepted
ETSK SB RH Angin ºC
2.5
ET+2.5 ET-3.5 ET+3.5
ºC
ºC
% m/det
ºC
ºC
ºC
ºC
32.5 24.5 57
0
27.7 25.2
30.2
23.2
31.2
Thermal Comfort Parameter
Initial Data
Research result
Temp RH
ºC
%
33.3 52
Wind
m/det
0
Thermal comfort evaluation in the dorm room was based on the dorm users through
questionnaires about initial conditions and after the garden was put on. Each room was
occupied by 2 (two) males aged 20 - 25.
Analysis of average sound prediction data (PMV) based on ASHRAE 55 scale was carried
out based on subjective measurement when doing everyday activities from 09.00 to 15.00.
PMV index (Predicted Mean Vote) by Finger (1972) was used in calculation and analysis.
Numerical PMV index explanation was as follows: colder (-3), cold (-2), quite cold (-1),
neutral (0), quite warm (+1), warm (+2), hot (+3). By using analysis from InfoGap and
Microsoft Excel, field micro weather index calculation revealed average sound prediction
(PMV) between (-1) and (+1), while based on ISO 773-94 comfort span to be considered
comfortable was when PMV was between -1 and +1. Nevertheless, all respondents tended to
say that the air temperature was about +1 (quite warm).
Study result from physical parameter on vertical hydroponics vegetable garden revealed
that all respondents stated that the air temperature was still acceptable. This is due to air
temperature lowering and air movement in the room albeit a little (all windows were open).
In this condition, respondents could still feel comfort in the room, so that subjective
assessment revealed that thermal comfort was still within the respondents tolerance limit,
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Improving Dormitory Thermal Comfortability by Putting Up Vertical Hydroponics Vegetable Garden in
Surabaya Indonesia
although the condition was still below ASHRAE 55-1992 thermal comfort zone/requirement
limit.
The research result also revealed that the international thermal standard, that is ASHRAE
55, was still hard to be implemented in Indonesia especially in Surabaya by relying solely on
natural ventilation system. Thermal comfort temperature range based on research result under
maximum condition showed that ET (Effective Temperature) = 27.3ºC, while ASHRAE 55
standard stipulates 26ºC maximum, similar to the previous research result ( Santosa, 1988 and
Karyono, TH, 1994). In some places in Indonesia with its hot-humid climate, Effective
Temperature is 27.4ºC and 28.2ºC.
4. CONCLUSIONS
PMV condition during daily activities with vertical hidroponics vegetable garden put on the building
was +1 (quite warm); neutral temperature was 27.7ºC. Dorm room thermal comfort did not match the
ASHRAE 55-92 standard.
Under neutral temperature of 27.7ºC, the tenants could still accept the heat of the room
albeit below ASHRAE comfort zone limit. This means that the ASHRAE 55 standard is not in
full effect in the dorm room equipped with vertical hydroponics vegetable garden under
humid tropical climate in the research site. This research is a sample of various comfort level
under Indonesian climate, which shows that Indonesians can adapt to higher temperature
around them.
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