Checking and calculation of the air conditioning system for remax plaza project

Trang 1 GRADUATION PROJECTMAJOR: THERMAL ENGINEERING TECHNOLOGYHo Chi Minh City, July 2023CHECKING AND CALCULATION OF THE AIR CONDITIONING SYSTEM FOR REMAX PLAZA PROJECTINSTRUCTOR: HOANG

GRADUATION PROJECT MAJOR: THERMAL ENGINEERING TECHNOLOGY

Ho Chi Minh City, July 2023

CHECKING AND CALCULATION OF THE AIR

CONDITIONING SYSTEM FOR REMAX PLAZA PROJECT

INSTRUCTOR: HOANG AN QUOC, Assoc Prof Dr STUDENT: DO QUOC HUY

LE PHAM VIET TRUONG

TA NHI KHANG

S K L 0 1 1 6 4 9

TECHNOLOGY AND EDUCATION

FACULTY FOR HIGH QUALITY TRAINING

CHECKING AND CALCULATION OF THE AIR CONDITIONING SYSTEM FOR

REMAX PLAZA PROJECT

ii

HO CHI MINH CITY UNIVERSITY OF

TECHNOLOGY AND EDUCATION

SOCIALIST REPUBLIC OF VIETNAM Independence - Liberty - Happiness

FACULTY FOR HIGH QUALITY TRAINING Ho Chi Minh City, Sunday, July 23 rd ,2023

MISSION OF UNDERGRADUATE THESIS

Student’s Name :

Email: 19147001@student.hcmute.edu.vn Tel: 0902820967

2 Le Pham Viet Truong ID: 19147060

Email: 19147060@student.hcmute.edu.vn Tel: 0773894818

Email 19147062@student.hcmute.edu.vn Tel: 0786847415

Major : Thermal Engineering Technology

Academic years : 2019 – 2023 Class : 19147CLA1 /19147CLA2

Topic : “ Checking and calculation of the air conditioning system for Remax Plaza

project”

1 Mission thesis

Calculating , checking the air conditioning system

Simulation 3D model of project by using the Revit 2021 solfware

2 The product of thesis

Graduation Thesis

Revit Modeling of the Air Conditioning and Ventilation System for the Project

3 Instructor : Assoc Prof Dr Hoang An Quoc

4 Date of assignment : date month year 2023

5 Task complete date : date month year 2023

(Sign, full name)

HO CHI MINH CITY UNIVERSITY OF

TECHNOLOGY AND EDUCATION

SOCIALIST REPUBLIC OF VIETNAM Independence - Liberty - Happiness

FACULTY FOR HIGH QUALITY TRAINING Ho Chi Minh City, Sunday, July 23 rd ,2023

COMMENTS FOR UNDERGRADUATE THESIS

(FOR INSTRUCTOS ONLY) Student’s Name :

2 Le Pham Viet Truong ID: 19147060

Topic : “ Checking and calculation of the air conditioning system for Remax Plaza

project”

Major : Thermal Engineering Technology

Instructor: Assoc Prof Dr Hoang An Quoc

2 Comments on the results of the undergraduate thesis

2.1 Structure and presentation of undergraduate thesis

2.2 Contents of undergraduate

iv

develop)

2.3 Results

2.4 Mistakes (if any)

3 Evaluate

Score

Score Achieved

Correct format with full form and contents of

items

10

Goals , missions and overview of topic 10

Ability to apply knowledge of Mathematics ,

science and engineering , social sciences

5

Ability to perform , analyze , synthesize and

evaluate

10

, component or process that meets a given

requirement with specified contranits actual

forcing

Ability to improve and develop 15

Ablity to use technical tools , specialized

software branch

5

3 Evaluate the applicability of the topic 10

4 Conclusion

 Allowed to do undergraduate thesis

 Do not allowed to do undergraduate thesis

Ho Chi Minh city , date month year 2023

Intructor

vi

TECHNOLOGY AND EDUCATION Independence - Liberty - Happiness

FACULTY FOR HIGH QUALITY TRAINING

COMMENTS FOR UNDERGRADUATE THESIS

(FOR REVIEWER TEACHER) Student’s Name :

2 Le Pham Viet Truong ID: 19147060

Topic : “ Checking and calculation of the air conditioning system for Remax Plaza

project”

Major: Thermal Engineering Technology

Reviewer: Trần Thanh Tình

COMMENTS

1 Structure and presentation of undergraduate thesis

Structure and presentation are proper for the undergraduate thesis (well organized

structure, nice presentation, and very nice English)

9 chapters, a conclusion section, total 110 pages

2 Contents of undergraduate thesis

(Theory, practicality and applicability of the project, research directions can continue to

develop)

Calculating heat load by using Carrier method and Trace 700 software

Building 3D models using Revit software

3 Results

Nice agreement between results of heat load calculation by Carrier method or Trace

700 software and the design cooling capacity

3D models in Revit

Format of decimal number, e.g 1.5 instead of 1,5

Correct format with full form and contents of items 10

Goals , missions and overview of topic 10

Ability to apply knowledge of Mathematics,

science and engineering , social sciences

5

Ability to perform, analyze, synthesize and

evaluate

10

The ability to design and manufracture a system,

component or process that meets a given

requirement with specified contranits actual

forcing

15

Ability to improve and develop 15

Ablity to use technical tools, specialized software

branch

5

3 Evaluate the applicability of the topic 10

viii

7 Conclusion

 Allowed to do undergraduate thesis

 Do not allowed to do undergraduate thesis

Ho Chi Minh city , date 21 month 07 year 2023

Reviewer

TECHNOLOGY AND EDUCATION Independence - Liberty - Happiness

FACULTY FOR HIGH QUALITY TRAINING Ho Chi Minh City, Sunday, July 23 rd ,2023

UNDERGRADUATE THESIS COMPLETION CONFIRMATION

Student’s Name :

2 Le Pham Viet Truong ID: 19147060

Topic : “ Checking and calculation of the air conditioning system for Remax Plaza

project”

Major : Thermal Engineering Technology

After incorporating and adjusting based on the feedback from the instructor, the

reviewer, and the members of the Defense Council, the graduation thesis has been

completed correctly according to the requirements for content and format

Chairman: Dr Le Minh Nhut

Intructor: Assoc Prof Dr Hoang An Quoc

Reviewer: Dr Tran Thanh Tinh

x

Thank you

With the assignment from the professors in the Department of Refrigeration and Air Conditioning – Faculty For High Quality Training, Ho Chi Minh City University of Technology and Education, under the guidance of Assoc Prof Dr Hoang An Quoc, our group was tasked with completing the graduation project titled "Checking and calculation of the air conditioning system for Remax Plaza project"

To successfully complete the graduation project report, "Checking and calculation of the air conditioning system for Remax Plaza project" in addition to our personal efforts

in research, applying acquired knowledge, and collecting relevant information and data, our group has always received enthusiastic support from the professors, teachers, and friends

We would like to express our gratitude to the Head of Department and the professors in the Faculty For High Quality Training, Ho Chi Minh City University of Technology and Education, for their assistance and provision of knowledge that has formed the foundation for our project In particular, we sincerely thank Assoc Prof Dr Hoang An Quoc for his dedicated guidance in completing the graduation project report

Throughout the process of completing this graduation project report, despite our efforts

to improve the topic through reference materials and exchanging ideas, we certainly cannot avoid errors Therefore, we greatly appreciate the valuable feedback and contributions from the esteemed professors to further improve our graduation project report

Our group would like to sincerely thank everyone involved for their support and guidance

Ho Chi Minh City, Sunday, July 23rd,2023

CONTENTS

CHAPTER 1: OVERVIEW OF THE PROJECT 1

1.1 Reason for choosing the topic and overview of air conditioning 1

1.2 Introduction to the project 3

1.3 Architectural features and functions of the project 7

1.4 Summary of architectural features and calculation approach 8

1.5 Choose outdoor design parameters 8

1.6 Choose indoor design parameters 8

CHAPTER 2: CALCULATING HEAT LOAD BY CARRIER METHOD 10

2.1 Conspectus 10

2.2 Calculating 10

2.2.1 Heat radiated through glass Q11 10

2.2.2 Heat transfer through ceiling(roof) Q21 15

2.2.3 Heat transfer through the wall Q22 16

2.2.4 Heat transfer through the floor Q23 21

2.2.5 Heat transfer through lights Q31 23

2.2.6 Heat transfer by machinery Q32 24

2.2.7 The sensible and latent heat by people Q4 26

2.2.8 The sensible and latent heat from the fresh air QNh and QNa 27

2.2.9 The sensible and latent heat from the leak air Q5h and Q5a 29

2.2.10 Other heat sources 30

2.2.11 Total heat load 30

2.3 Establishment of air conditioning diagram 31

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2.3.2 Identify the points on the t-d graph 32

2.3.3 Calculation of cooling capacity 37

2.3.4 Calculation of heat load using Trace 700 software 38

2.3.5 Compare results of heat load calculation by carrier method and Trace700 software 44

CHAPTER 3: CHECK THE DESIGN OPTIONS AND EQUIPMENT SELECTION 47

3.1 Check the design plan 47

3.1.1 Multi-system air conditioning system 47

3.1.2 VRV/VRF System 48

3.1.3 Water Chiller system 50

3.1.4 Analyze, compare and make the right choice 52

3.2 Check equipment selection for the project 56

3.2.1 Check equipment selection for tower block 56

3.2.2 Check equipment selection for podium block 58

CHAPTER 4: CHECK WATER-COOLED CHILLER SYSTEM 64

4.1 Calculation and check the size of water pipes 64

4.2 Calculation and check selection of pump for chilled water system 65

4.3 Calculation and check selection of pump for cooled water system 69

CHAPTER 5: CHECK SUPPLY AND FRESH AIR DUCT 71

5.1 Introduction 71

5.1.1 Overview of the air duct systems in the project 71

5.1.2 Air duct design method 71

5.1.3 Theoretical basis for calculation of duct 73

conditioned space 74

5.2.1 Check the selection of the air grille: 74

5.2.2 Check the size of ducts – air grille - selection the fan 75

CHAPTER 6: CHECK THE VENTILATION SYSTEM FOR TOILET 81

6.1 Introduction 81

6.2 Calculation and check ventilation of toilet 81

CHAPTER 7: CHECK THE VENTILATION SYSTEM FOR BASEMENT 84

7.1 Introduction of basement ventilation system 84

7.2 Theoretical basis for calculating basement ventilation 84

7.3 Calculation and check basement ventilation system for Remax Plaza project 85

7.4 Comment on the results and selection fan of the project 88

CHAPTER 8: CHECK STAIRWELL PRESSURIZATION SYSTEM 90

8.1 Introduction of stairwell pressurization system 90

8.1.1 Overview 90

8.1.2 Anti-smoke protection mechanism of stairwell pressurization system 90

8.2 Calculation and check the stairwell pressurization system for Remax Plaza project 90

8.2.1 Theoretical basis/applicable standards: 90

8.2.2 Check Calculations 91

CHAPTER 9: BUILDING 3D MODELS FOR CONSTRUCTIONS 97

9.1 Introduction to BIM industry and Revit 2021 software 97

9.2 Instructions on how to use the software 99

9.3 Building a model of air conditioning system for shopping centers and apartments by Revit 102

xiv

9.3.2 Some pictures of the model of the shopping mall and the apartment 106

CONCLUSION 109 REFERENCES 110

LIST OF FIGURE

Figure 1 1: Wind tower of the Persians 1

Figure 1 2: Cross section of the Persian wind tower 2

Figure 1 3: Perspective of Remax Plaza 4

Figure 1 4: Typical floor plan for the first floor 5

Figure 1 5: Typical floor plan of 5th floor (Apartment) 6

Figure 2 1: Diagram of single-stage air conditioning 32

Figure 2 2: Single-stage diagram with sensible heat factor, bypass factor 32

Figure 2 3: Determine the points on the t-d graph of the first floor 35

Figure 2 4: Entering weather parameters 39

Figure 2 5: Creating templates 39

Figure 2 6: Entering the construction parameter of template 40

Figure 2 7: Entering the Thermostat parameter of Template 40

Figure 2 8: Enter the parameter of the function to calculate the load 41

Figure 2 9: : Entering Partition parameters 41

Figure 2 10: Creating system 42

Figure 2 11: Assigning rooms to each system 43

Figure 2 12: Running the software 43

Figure 2 13: The first floor heat load result 44

Figure 3 1: Description of the Multi system 48

Figure 3 2: Description of VRV IV Daikin system 49

Figure 3 3: Characterization of VRV IV system 50

Figure 3 4: Simple diagram of the working principle of Water Chiller 51

Figure 3 5: Chiller efficiency varies with percentage of load 59

xvi

Figure 3 7: Carrier's Chiller Catalog 61

Figure 3 8: Carrier's FCU Catalog 63

Figure 4 1: Water velocity varies with pipe size - document [13] 65

Figure 4 2: Schematic diagram of chilled water pipe in basement 1 66

Figure 4 3: Check fluid velocity in pipe and pressure loss with Pipe Flow Wizard Software 67

Figure 5 1: Duct Checker software and Ashrae Duct Fitting Database 73

Figure 5 2: Image of louver, single grille and ceiling diffuser 74

Figure 5 3: Calculation by Ductcheker 75

Figure 5 4: Checking wind speed of fresh air Louver with Ductcheker 78

Figure 6 1: Excerpt from Table 6.5 documents [12] 81

Figure 6 2: Calculate velocity at the air grille with Ductchecker 82

Figure 6 3: Toilet ventilation system at basement B1 83

Figure 7 1: Excerpt from Appendix G – document [4] 84

Figure 7 2: Fresh air flow – document [14] 87

Figure 8 1: Stairway of Remax Plaza 91

Figure 9 1: Revit 2021 software interface 97

Figure 9 2: The project is implemented using Revit 2021 software 99

Figure 9 3: Software interface 99

Figure 9 4: “Ribbon” toolbar 100

Figure 9 5: Device information is displayed on the “Properties” window 100

Figure 9 6: The “Project Browser” window 101

Figure 9 7: Set the piping details for the drawing in the “Systems” section 102

Figure 9 8: Link architecture file to Revit software 103

toolbar 104

Figure 9 10: Systems are viewed in 2D and 3D 104

Figure 9 11: “Interference Check” dialog box for collision checking 105

Figure 9 12: 2D drawing of the basement B1 to third floor 106

Figure 9 13: 3D drawing of the basement B1 106

Figure 9 14: 2D drawing of the Apartment area in 4th floor 107

Figure 9 15: 3D drawing of the the Apartment area in 4th floor 107

Figure 9 16: 3D model of Cooling Tower 108

Figure 9 17: Water-Cooled Screw Chiller 3D model of the technical floor 108

xviii

Table 2 1: The largest amount of solar radiation RTmax và RK 13

Table 2 2: Radiant heat through glass in each direction 14

Table 2 3: Total radiant heat through glass of each area 15

Table 2 4: Heat transfer through roofs of apartments 16

Table 2 5: Heat transfer coefficient through the wall 17

Table 2 6: Heat transfer through the wall Q22t 18

Table 2 7: Heat transfer through the door Q22c 19

Table 2 8: Heat transfer through glass Q22k 20

Table 2 9: Total heat transfer through the wall Q22 21

Table 2 10: Heat transfer through the floor Q23 22

Table 2 11: Heat released by lights Q31 23

Table 2 12: Heat released by the equipment of podium block 25

Table 2 13: Heat released by the equipment of tower block 26

Table 2 14: Sensible and latent heat by people 27

Table 2 15: The sensible and latent heat from the fresh air QN 28

Table 2 16: The sensible and latent heat from the leak air of podium block Q5 29

Table 2 17: Total heat load of podium block 30

Table 2 18: Total heat load of tower block 31

Table 2 19: Sensible and latent heat from fresh air, total sensible and latent heat of room 36

Table 2 20: Bypass factor, GSHF, RSHF, ESHF 36

Table 2 21: Parameters of points on the t-d graph of the first floor 36

Table 2 22: Calculation of cooling capacity for podium block 38

Table 2 23: Compare the results of calculating the heat load for base block 44

Table 3 1: Capacity of indoor and outdoor units of tower block by design 57

Table 3 2: Total designed FCU cooling capacity 62

Table 3 3: Number of FCUs selected 63

Table 4 1: Water flow through each floor 66

Table 4 2: Checking water pipe size in basement B1 67

Table 4 3: Dimensions, velocity, and pressure drop of chilled water pipe 69

Table 4 4: Dimensions, velocity, and pressure drop of cooled water pipe 70

Table 5 1: Common design methods of air duct 71

Table 5 2: Checking the pressure loss of supply air duct for the first floor 76

Table 5 3: Checking the pressure loss of fresh air duct for the first floor 79

Table 5 4: Checking the pressure head of fresh air fan No.2 80

Table 5 5: Checking the pressure head of fresh air fan No.1 80

Table 6 1: Checking the pressure loss of exhaust air duct for toilet at basement B1 82

Table 7 1: Checking the pressure loss of exhaust air duct for basement B1 86

Table 7 2: Checking the pressure head of exhaust air fan for basement B1 87

Table 8 1: Checking the pressure head of fresh air fan for stairs N2 95

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HVAC – Heating, Ventilation, and Air Conditioning

ASHRAE – American Society of Heating, Refrigerating, and Air-Conditioning Engineers

VRV – Variable Refrigerant Volume

VRF – Variable Refrigerant Flow

AHU – Air Handling Unit

FCU – Fan Coil Unit

RSHF – Room Sensible Heat Factor

GSHF – Grand Sensible Heat Factor

ESHF – Effective Sensible Heat Factor

BF – Bypass Factor

VCD – Volume Control Damper

FD – Fire Damper

CHAPTER 1: OVERVIEW OF THE PROJECT 1.1 Reason for choosing the topic and overview of air conditioning

Since ancient times, humans have known how to create the most suitable air conditions for themselves In winter, they warm up the surroundings, and in summer, they cool them down

Ancient Egyptians had the knowledge to construct cooling models for their own comfort The simplest model they created involved hanging wet cloths on windows and then spraying water on them The purpose of this model was to allow the wind to pass through, carrying the moisture into the room, thus humidifying and cooling the air inside This method helped the ancient Egyptians alleviate the heat from the desert where they lived

Another cooling method used by ancient Romans was to surround the walls of their houses with a system of water pipes When the water circulated, it would cool down the house Cooling with water was also applied by the medieval Persians Their system consisted of wind towers and large water reservoirs that helped cool the air inside the house

These ancient techniques demonstrate the resourcefulness and ingenuity of our ancestors in finding ways to create comfortable living conditions They provide valuable insights into the early development of air conditioning systems and serve as a foundationfor the advancements

In modern times, when it comes to air conditioning, the credit must be given to the significant contributions of American engineer Willis H Carrier He played a pivotal role in the development of the air conditioning industry, not only in the United States but also worldwide

Willis Carrier's air conditioning system was initially used in a printing plant This system helped control the temperature and maintain humidity within the plant

Today, with industrialization and the modernization of countries, there has been

a surge in construction projects The field of air conditioning has also made remarkable progress and has become increasingly familiar in daily life and production activities The air conditioning industry aims to create a favorable environment for human activities and establish suitable conditions for manufacturing, processing, and preserving machinery and equipment Thus, air conditioning plays a crucial role and holds significant importance in various sectors, from the economy to engineering It is considered a criterion for evaluating the quality of social life, and the air conditioning industry has a powerful impact on the development of most sectors, both domestically and internationally

Figure 1 2: Cross section of the Persian wind tower

The advancements in air conditioning technology have greatly enhanced comfort, productivity, and efficiency in various fields Moreover, it has contributed to the well-being and quality of life for individuals, making it an integral part of modern society

In summary, the evolution of air conditioning, spearheaded by the achievements

of pioneers like Willis Carrier, has revolutionized various industries and had a profound impact on society as a whole Its importance and significance in creating favorable living and working conditions cannot be overstated

With the popularity of the air conditioning industry and the knowledge acquired

at Ho Chi Minh City University of Technical Education, I have made the decision to select a topic related to air conditioning for my graduation thesis

1.2 Introduction to the project

Investor's Name: Nhật Quang Construction Investment Joint Stock Company Project Name: Goldland Bình Tây Plaza (Remax Plaza)

Project Development Company: Thanh Nien Media Corporation Joint Stock Company in collaboration with Saigon Remax Limited Liability Company

Design Company: Thai Thinh Real Estate Investment Joint Stock Company Project Address: 116-117-118 Bãi Sậy Street, Ward 01, District 06, Ho Chi Minh City (10°44'51.6"N 106°38'59.3"E)

The Remax Plaza apartment complex began construction in 2008 under the

names Richland and Goldland Bình Tây To date, more than 6 years have passed since the project started The project has a scale of a 28-story building, comprising 192 mid-range apartments with sizes ranging from 80 to over 100 square meters, depending on whether they are 2-bedroom or 3-bedroom units

The building's amenities, including a nursery, spa, cafe, fountain, 5-star standard swimming pool, and supermarket, are located on the commercial floors spanning four levels

Remax Plaza has great potential for future development The real estate market in the

western part of Ho Chi Minh City is experiencing significant changes with the emergence of numerous high-end apartment projects Additionally, land prices in District 6 are increasing rapidly, and infrastructure is gradually being improved The advantages of the western area of the city also include central projects such as the Children's Hospital, high-tech medical facilities, and large commercial centers The Remax Plaza apartment project will also address the housing needs of young workers

in the area

Figure 1 3: Perspective of Remax Plaza

Here are a few typical floor plans of the Remax Plaza project

The architectural features will be detailed in the attached drawings in the thesis 02-03-04-05-06)

(01-Figure 1 4: Typical floor plan for the first floor

Figure 1 5: Typical floor plan of 5th floor (Apartment)

1.3 Architectural features and functions of the project

Basement 2, located entirely underground, covers an area of 2816m2 The majority of this space is dedicated to parking, serving as the designated parking area for the building

Basement 1, situated below ground level, spans a total area of over 2600m2 The majority of this floor is dedicated to retail space, housing a supermarket The remaining area is allocated for parking and other auxiliary functions

Floor 1 is predominantly enclosed with glass, covering an area of 1500m2 The entire floor is designated as a commercial area, providing space for various retail and business establishments

Floors 2 and 3 are predominantly enclosed with glass, spanning a total area of 1563m2 The entirety of these floors is designated as a commercial area, providing space for various retail and business establishments

The technical floor, covering an area of 1560m2, serves as the location for equipment and other functions such as offices and a nursery

Floor 4 consists of 8 high-end apartments, namely A3, B4, C1, and D1, with a total area of 1174m2

Floors 5 to 23 feature 8 mid-range apartments divided into 8 types: A, B, C, D, A-M, B-M, C-M, and D-M, with a total area of 963m2

Floor 24 comprises 8 high-end apartments divided into 8 types: A1, C, B1, D, A1-M, C-M, B1-M, and D-M, with a total area of 963m2

Floor 25 consists of 8 high-end apartments divided into 8 types: A2, C, B2, D, A2-M, C-M, D-M, and B2-M, with a total area yet to be specified 963m2

Floor 26 features 6 high-end apartments divided into 6 types: B3, E-M, G, G-M,

E, and B3-M The total area is not specified 963m2

Floor 27 consists of 6 high-end apartments divided into 6 types: B3, E1-M, G1, G1-M, E1, and B3-M The total area is not specified 963m2

Floor 28 features 4 high-end apartments divided into 4 types: H, I-M, I, and

H-M The total area is not specified 963m2

Roof Floor

1.4 Summary of architectural features and calculation approach

Features of Remax Plaza project:

 Podium Block: The lower three floors and a portion of Basement 1 serve as commercial spaces

 Tower Block: From the 5th floor onwards, the building consists of rental apartments Floors 5 to 23 are mid-range apartments, while the remaining floors are high-end apartments, each with distinct architectural features

For convenience and to reduce the complexity of the verification calculations, we will exclude the high-end apartments from the analysis Therefore, floors 4 to 28 will be considered to consist of only 8 types of mid-range apartments (A, B, C, D, A-M, B-M, C-M, D-M)

In this thesis, the term "podium block" will refer to the commercial floors, while the term "tower block" will be used to describe the residential apartment floors

1.5 Choose outdoor design parameters

Taking data from table 1.9 [1] or document [8], choose outdoor design parameters for the month with the hottest average temperature of the year in Ho Chi Minh City (April) Temperature 𝑡𝑁 = 34.6oC

1.6 Choose indoor design parameters

Refer to Appendix A [4], look up the calculated parameters of the indoor air used to design air conditioners to ensure thermal comfort Because the design object is a commercial center and an apartment, the state of light or medium labor should be selected, then:

Indoor air temperature 𝑡𝑇 = 250C

CHAPTER 2: CALCULATING HEAT LOAD BY CARRIER METHOD 2.1 Conspectus

The problem of calculating the heat load here is understood as determining the amount

of excess heat that the refrigeration system needs to remove in the conditioned spaces Chosing the Carrier method to calculate the heat load

The general heat balance equation: 𝑄𝑡 = 𝑄ℎ + 𝑄𝑎, 𝑊

𝑄𝑡: total excess heat, W

𝑄ℎ, 𝑄𝑎: are the total sensible heat and the total latent heat, respectively, given off

in the room and brought into the room by outdoor air, W

Development 𝑄𝑡:

𝑄𝑡 = 𝑄11+ 𝑄21+ 𝑄22+ 𝑄23+ 𝑄31+ 𝑄32+ 𝑄𝑁 + 𝑄4+ 𝑄5, W

𝑄11: radiant heat through glass, W

𝑄21: heat transfer through ceiling, W

𝑄22: heat transfer through the wall, W

𝑄23: heat transfer through the floor, W

𝑄31: heat released by the lights, W

𝑄32: heat released by machines, W

𝑄𝑁: sensible and latent heat from fresh air, W

𝑄4: sensible and latent heat by people, W

𝑄5: sensible and latent heat from leak air, W

2.2 Calculating

During the calculation process, the methods and data will be sourced from Vietnamese references If any values or standards are not clearly stated in Vietnamese references,

we will refer to international standards for guidance

2.2.1 Heat radiated through glass Q 11

Method 4.1 [1]: 𝑄11 = 𝑛𝑡 × 𝑄11′

 𝑛𝑡: instantaneous effect factor

Value 𝑛𝑡< 1 tThe percentage of solar radiation heat that passes through the building envelope (including walls, ceilings, and floors) and enters the conditioned space can be expressed as follows

Value 0 < (1 − 𝑛𝑡) < 1 The percentage of solar radiation heat absorbed by the building envelope can be expressed as

𝑛𝑡 = 𝑓(𝑔𝑠), where is the average density, kg/m2 of the floor of the entire structure covering the wall, ceiling and floor Then:

F is the surface area of the window with the steel frame, m2

𝑅𝑇 is the heat radiated by the sun through the glass door into the room, W/m2

𝜀𝑐 is the influence coefficient of height above sea level, and:

𝜀𝑐 = 1 + 𝐻

1000× 0.023

 Take 𝜺𝒄 = 1 for all floors

 𝜀𝑑𝑠 is the coefficient that takes into account the effect of the difference between the dew point temperature of the outdoor air of the building and the dew point temperature of the air above sea level of 20

𝜀𝑑𝑠 = 1 −(𝑡𝑑𝑠− 20)

10 × 0.13 = 1 −

28.7 − 20

10 × 0.13 = 0.8869

 𝜀𝑚𝑚 is the influence coefficient of clouds, when the sky is not cloudy, and 𝜀𝑚𝑚

= 1 and when it's cloudy 𝜀𝑚𝑚 = 0 Choose 𝜺𝒎𝒎 = 1

 𝜀𝑘ℎ is the frame influence factor, for metal frames, taking: 𝜺𝒌𝒉 = 1.17

 𝜀𝑚 is the glazing coefficient, which depends on the color and type of glass Look

up table 4.3 [1], with flat clear glass, 6mm thick can be checked 𝜺𝒎= 0.94

 𝜀𝑟 is the solar coefficient taking into account the effect of the base glass when there is a curtain inside the glass Look up table 4.4 [1] room without curtains,

choose 𝜺𝒓 = 1

 𝑅𝐾 is the solar radiant heat entering the room other than the basic glass

Rewrite the formula 4.2 [1] as follows:

𝑄11′ = 𝐹 × 𝑅𝐾 × 𝜀𝑐 × 𝜀𝑑𝑠 × 𝜀𝑚𝑚 × 𝜀𝑘ℎ × 𝜀𝑚× 𝜀𝑟 =>𝑄11′ = 0.975 × 𝐹 × 𝑅𝐾, W

 𝑅𝐾 (W/m2) is the solar radiation reaching the outer surface of the 6mm thick flat glass under consideration

 𝑅𝐾 in case of glass with curtain (for apartment floors)

𝑅𝐾 = [0.4𝛼𝑘 + 𝜏𝑘] × 𝑅𝑇

0.88 = [0.40 × 15 + 0.77] ×

𝑅𝑇0.88 = 0.9432𝑅𝑇Choose a light-colored curtain for the apartment, then:

 𝛼𝑚: Absorption coefficient of the curtain

 𝜌𝑚: Reflectance of the curtain

 𝜏𝑚: The penetration coefficient of the curtain

𝑅𝑇 is the solar radiation through the glass to the inside of the conditioned space corresponding to the case of basic glazed windows Look up table 4.3 [1], latitude 100

North, April, value 𝑅𝑇 varies by hour of the day, select the values R Tmax corresponding

to each time frame and the radial directions subject to solar radiation

Table 2 1: The largest amount of solar radiation R Tmax và R K

Glass without curtain (𝑅𝐾 = 0.9432𝑅𝑇𝑚𝑎𝑥)

R k

(W/m2)

RTmax(W/m2)

R k

(W/m2)

RTmax(W/m2)

R k

(W/m2)

Determine the instantaneous effect factor 𝜂𝑡

To determine the instantaneous action factor, we must determine the total mass of the surfaces that make up the harmonic space calculated on 1m2, then look up table 4.6 [1] Choose the instant factor at the time frame with the highest instantaneous factor

Choose wall materials with volume 360 kg/m2, ceiling and floor have volume 410 kg/m2

𝑔𝑠 =𝐺

′+ 0.5𝐺′′

𝐹𝑠 kg/m

2 sàn With:

 G’ – Mass of wall with outer surface exposed to solar radiation and of floor above ground, kg

 G’’ - Mass of walls with outside faces not exposed to solar radiation and of floors not above the ground, kg

 Fs– floor area, m2

Table 2 2: Radiant heat through glass in each direction

Floor Name Fk Direction nt

Q11

(W) (m2)

70.2 NW 0.71 22127.2 77.22 NE 0.68 23305.4 97.5 SW 0.77 35465.4 77.22 SE 0.75 27359.1

2F-3F Mall

54.6 NW 0.71 17210.1 69.3 NE 0.68 20920.6 73.5 SW 0.77 26735.5 69.3 SE 0.75 24553

TF

Classroom 38.95 NW 0.71 12277.1

29.52 NE 0.68 8905.6 Office 50.43 SW 0.77 18343.8

4F-28F

A

12.42 SW 0.77 1817.2 8.28 SE 0.75 1180

Table 2 3: Total radiant heat through glass of each area

2.2.2 Heat transfer through ceiling(roof) Q 21

Heat transfer through roof 𝑸𝟐𝟏 calculated according to the formula

Choose concrete floor 150mm thick, cement mortar layer above 25mm

Select heat transfer coefficient 𝑘 = 1.67 (𝑊/𝑚2𝐾), table 4.15[1]

Assume the apartments do not operate simultaneously, so heat flows through the roof

𝑸𝟐𝟏 will be charged for all apartments

Table 2 4: Heat transfer through roofs of apartments

2.2.3 Heat transfer through the wall Q 22

Heat transfer through the wall will be in:

𝑄22 = ∑𝑄2𝑖 = 𝑘𝑖 × 𝐹𝑖 × ∆𝑡 = 𝑄22𝑡 + 𝑄22𝑐+ 𝑄22𝑘, 𝑊

In there:

- 𝑄2𝑖: Heat transfer through walls, doors (wood, aluminum), windows (glass)…

- 𝑘𝑖: Corresponding heat transfer coefficient of wall, door, glass, 𝑊/𝑚2𝐾

- 𝐹𝑖: Area of corresponding wall, door, glass, 𝑚2

1 Heat transfer through the wall 𝑸𝟐𝟐𝒕

𝑄22𝑡 = 𝑘22𝑡 × 𝐹22𝑡 × ∆𝑡(𝑊)

In there :

t : Temperature difference inside and outside the house, K

When the wall is exposed to the outdoor air : t = tN – tT

When the outside of the wall is in contact with the air-conditioned space: t = 0

𝐹22𝑡: Wall area, m 2

𝑘22𝑡: Heat transfer coefficient through the wall, W/m 2 , K

 𝛼𝑁: Heat dissipation coefficient outside the wall,

 When the wall is in direct contact with the outside air: 𝛼𝑁 = 20 𝑊/𝑚2𝐾

 When the wall is in indirect contact with the outside air: 𝛼𝑁 = 10 𝑊/

𝑚2𝐾

 The coefficient of heat dissipation inside the house:

𝛼𝑇 = 10 𝑊/𝑚2𝐾

 𝛿𝑖: Thickness of the ith material layer of the wall structure, m,

 𝜆𝑖: Thermal conductivity coefficient of material layer i of the wall structure, W/mK,

Remax Plaza building, there are 2 basic types of walls used:

Inner wall 100mm (70mm brick and 30mm mortar)

Outer wall 200 (170mm brick and 30mm mortar)

Look up table 4,11[1],we get the thermal conductivity coefficients of the wall and mortar materials,

Cement on the inside 0.015 0.93

Inner wall 100mm

3.14 W/m 2 K

Cement on the outside 0.015 0.93

Cement on the inside 0.015 0.93

Table 2 6: Heat transfer through the wall Q 22t

Floor Name Souter wall

 t : Temperature difference inside and outside the house, K

 tT = 25oC room temperature,

 tN = 34.6oC nhiệt độ bên ngoài phòng,

 𝐹22𝑐: Door area, 𝑚2

 𝑘22𝑐: Heat transfer coefficient through the door, 𝑊/𝑚2𝐾

The Remax Plaza project needs to calculate the heat transfer through the doors at the following locations:

 1st floor, 2nd floor, 3rd floor, 4th floor: Doors adjacent to elevators, doors

 Floors 5 to 28: the doors of each apartment

Select the door parameter according to [4,2], document [1]

Heat transfer coefficient 𝐾 = 2.01 𝑊/(𝑚2𝐾) (Thick wooden door 50mm)

Table 2 7: Heat transfer through the door Q 22c

of door Size

Door area (m2)