High-rise campus building cooling energy share using floor area of spaces

High-rise campus had varying energy characteristics on each floor, impacting cooling energy consumption. Understanding the cooling energy needs based on space characteristics plays a role in designing strategies to reduce energy consumption. It is essential to identify the cooling energy consumption for each floor function within high-rise campus buildings. The study conducted an analysis of high-rise campus characteristics by identifying and categorizing spaces based on their energy consumption zones. Spatial data was processed using mapping, and cluster correspondence analysis was employed to understand spatial relationships within high-rise campus buildings and their energy consumption. This research was carried out using Energy plus as an energy simulation based on a high-rise campus building model in the Jakarta sub urban region on a hot humid tropic. Campus building could be divided into four types of floors, as general, office, classroom and laboratory. The highest cooling energy was the laboratory.


Introduction
The rapid development of technology provokes educational buildings to require quite large amounts of energy.Initially, electrical energy was only required for lighting in schools; nowadays, air conditioning consumes the majority of the electricity, particularly in colleges and universities.The necessity for campus development in major cities demand the construction of high-rise campuses, resulting in changes in the characteristics of school space.Higher education institutions consist of a number of faculties that provide scientific and/or professional education in a number of specific scientific disciplines, and the campus is the main building environment of the tertiary institution (university, academy) where all teaching and learning and administrative activities take place.In high-rise campus, a building with vertically stacked rooms, the energy characteristics for each floor function will varies.This also affects energy consumption.
Energy efficient building is a critical approach to sustainable building.The fundamental goal of sustainable building energy efficiency is to significantly reduce a building's carbon footprint and energy consumption.Sustainable building energy efficiency not only benefits the environment but also promoting a more sustainable and resilient future for our communities and the planet as a whole.Energy conservation on campus has the opportunity to reduce energy consumption by 6-30%.[1] In order to provide energy conservation strategies for a high-rise campus that meet the requirements, it is necessary identifying the energy consumption for each floor function.
As a general rule, campus buildings differ from other buildings such as office building in that they were not usually occupied by the same individuals for the majority of the time, sitting in the same place for long periods of time five days a week, different room operational schedules and varied facilities.Campus buildings as learning facilities consist of classrooms, libraries, laboratories / studios / workshops / production units, sports areas, art rooms, student activity unit rooms, college leadership rooms, lecturer rooms, administrative rooms and public facilities.The lecture room is a facility where face-to-face learning activities such as lectures, discussions, seminars, and tutorials take place.Varied spatial purposes need varied amounts of space and ventilation, which has been an influence on energy usage.[2][3] Located in the tropical region, Indonesia has a humid tropical climate with an average air temperature of 27 o C and a maximum daytime temperature of 35 o C, [4] buildings should design to cool the room.Air conditioning equipment consumes the most energy in any commercial building, accounting for more than 62% of total energy consumption, followed by lights and sockets, lifts and escalators, and other electrical equipment.[5] The cooling energy estimates in this study were not intended for energy audits, it was illustrated building design situations for cooling energy use.Understanding space characteristics based on cooling energy plays a role in understanding building design strategies to reduce energy consumption.

Method
The study was carried out to identify and classify spaces based on zones related to cooling energy share.Case study taken on a high-rise campus on Indonesia.Alam Sutera campus was located in a peri-urban area which consists of tall buildings and low buildings in between.Ten floors were studied, the layout was represented by the first, second, third, and fourth levels in Figure 1.Cooling energy was simulated on Energy Plus for ten representative floors with building element specification model on Table 1.Based on the role of educational facilities and space in tall structures, spaces were identified.Cluster correspondence analysis found spatial relationships regarding floor types and cooling energy share on a high-rise campus in hot humid, Indonesia.

Result and Discussion
The floor plan arrangement varies each floor.The first floor had a lobby and library, the second floor had media centre rooms such as the TV room, the third and fourth floors had lecturer and admissions rooms, and the fifth floor and above had classrooms.Classrooms were planned for floors 6-10 of the tower and laboratory rooms for levels 10.Space allocation on each floor is shown in the distribution graph in Figure 2. In public space floor had characteristic of it was dominated by 40% Hall and Lobby lift and 20% Administration.Others consist of School type and Laboratories.At low level, the floors were intended for space public areas, media laboratories and lecturer rooms.Approximately 70% of the area was dedicated to lecturer room, classroom and media rooms according to the intended floor type.At middle level, the floors were dedicated for classroom and laboratories.Its dominated around 50 -55 % for lecture-related space (classrooms / laboratories), 30% for corridor, toilet and core, and the rest was balcony.Above podium levels, provided 10 -15% area for balcony space.At high level, the floors were functioned for digital laboratories.The school type floors allowed space for 12 % core, and 18 -20% circulation.In this building, 30 -34 % was allocated for transition space (20% corridors and 10 -15% for balconies) and services 17 % (13,5% core and 3,5% toilet).Space types of campus show in figure 2.

Figure 2. Distribution of room function
This classification resulted in eight different data on cooling energy consumption and floor were depending on the purpose of space on each floor were included in this study.The simulation results were used to compute the building cooling energy per story.Annual electrical energy consumption data based on monthly electrical energy usage is used to calculate cooling energy consumption.The function of each level's determined the floor type, cooling energy usage were examined in this study.The building cooling energy per story was calculated based on the simulation findings.To determine cooling energy consumption, annual electrical energy consumption data based on monthly electrical energy usage was employed.Monthly cooling energy average was 170.269 kWh / month.October was the highest energy consumption, while February was the lowest.
The lowest cooling energy was located on the third, seventh, and first floors.The cooling energy share was depicted in Figure 3.The third floor primarily serves as a lecturer's room / lecture administration office.On the seventh floor, approximately 55% of the space was devoted to classrooms.The first floor was designated for public activities.The highest cooling energy was found on the second floor, followed by the fourth floor and the eighth floor.A second floor consists of 60% laboratories and television rooms, a fourth floor consists of 50% lecturer/lecture administration rooms, and an eighth floor consists of 50% classrooms.The identical activities on the dominating floor of the lecturer's room have varied cooling energy, and building variables were also evaluated in both situations.Despite the low cooling energy of the seventh floor, the same room function on the seventh floor had a high cooling energy.Building envelopes played a significant role in this process.
Each floor consists of a combination of several space functions with a certain dominant percentage, and each floor had a different cooling energy consumption.Based on this, a grouping analysis was carried out based on space function and energy consumption variables using hierarchical clustering to produce building floor types with EUI cooling based on floor function.As a result of hierarchical clustering, eight types of space are divided into four groups, namely general type floors, laboratories, offices, and classrooms.The public type floors, which account for 47% of the area dedicated for public activities, have an IEU cooling capacity of around 184 kWh/m 2 .The laboratory floor has 61% of the space allocated to laboratories with IEU cooling of approximately 289 kWh/m 2 , the office floor has 55% of the space allocated to offices with IEU cooling of 135 -253 kWh/m 2 , and the classroom type floor has 45% of the space allocated to classes with IEU cooling of 178 -234 kWh/m 2 .(fig.4)   According to the building envelope information on table 1 indicates that the class had two types of Building envelope materials, specifically precast concrete massif walls and transparent curtain walls.It can also be seen in figure 1, which represents the floor plan layout, that the layout is different on each

Figure 3 .
Figure 3. Cooling energy share associated with spaces and floor types

Figure 4 .
Figure 4. Hierarchy clustering dendogram show a distance of 2.59 with a number of clusters of four, and 1.769 with a number of clusters of 5

Table 1 .
Building dataRooms were classified based on their primary use, taking into account space type in school / university facility and high-rise structures.Table2shows the building types and room types on this campus.Hall, Gallery, Student services, Lab TV, Lab Video, Lecturer room, Lounge, Faculty room, Class, Large Class, Lab computer, Corridor, Toilet and Marketing are the functions of room in campus buildings.Panel room, AHU room, Emergency stair, Lift, Lobby Lift, Balcony are types of space in high-rise buildings.This classification resulted in eight different sorts of space: (1) public, (2) office, (3) laboratory, (4) classroom, (5) service, (6) circulation (7) open space and (8) Office.

Table 2 .
Building type and space type

Table 3 .
Cooling energy of floor type