This document summarizes the design of an HVAC system for a commercial building in Aurangabad, India. It includes calculating the building's heat load based on factors like climate conditions, building materials and occupancy usage. A hybrid VRF system is selected that uses both refrigerant and water pipes for efficiency. Indoor air quality is improved through measures like air purifiers, outdoor air treatment and indoor plants. The system aims to achieve IGBC silver certification for benefits like energy efficiency and cost savings. It incorporates innovations like a heat recovery system, solar panels and an electric vehicle charging station.

1. Design of HVAC system for a commercial building.
Jayesh Mahajan1
, Prathamesh Brid1
, Shefali Suryakant
More1
, Vikas Patil1
,
1 Student, Department of Mechanical Engineering,
Saraswati College of Engineering,
Navi Mumbai, Maharashtra, India
Sunil Jankar 2
2 Head Of Department, Department of Mechanical Engineering,
Saraswati College of Engineering,
Navi Mumbai, Maharashtra, India
Abstract---HVAC & R system stands for Heating Ventilation Air
Conditioning and Refrigeration. These systems are particularly
used in commercial offices, residential buildings, schools, hotels,
etc. The main aim of the project is to design an energy efficient and
cost efficient HVAC system for a given layout of a commercial
building. This project particularly deals with the heat load
calculation, selection of materials, selection of systems taking into
consideration of various factors like-Structure of Building, Glass
Material, Path of Sun, Climate and Atmospheric Condition of the
Given Area and Requirement of the Customer. The project will
follow all the HVAC safety standards provided by the ISHRAE
(Indian Society of Refrigeration and Air Conditioning) and the
norms regarding human comfort and also considering
environmental aspects. The outcome of the project will be a plan
of complete HVAC&R systems of the layout of the commercial
building with consideration of all aspects including the latest
technologies in HVAC industries.
Keywords---HVAC, Chillers, Fresh Air, CPVC Pipe, ISHRAE
Data Book, Human Comforts Charts HVAC System, Life Safety,
CFM, AHU, HVRF, etc.
Author for correspondence (email):
jayeshmahajan138@gmail.com
I. INTRODUCTION
HVAC (Heating Ventilation and Air Conditioning)
systems means; the processing of air in an indoor environment
to maintain Humidity, Temperature, Air Quality (CO2 level,
dust particles), ventilation, and Air motion called Air
conditioning. Temperature can be controlled not only by
heating but also by cooling the air and Humidity is controlled
by removing or adding the moisture from air. With the help of
filtration, we can prevent the entry of dust particles, which
supplies clean air, and ventilation is achieved by supplying
required fresh outside air. We can reduce the noise levels in our
Air-conditioned area by acoustic layers or sound attenuators.
[8]
All of this process can be achieved by different HVAC
systems available in market, which have different variations.
Even though the goal of all systems is common to provide better
comfort, HVAC systems differ a lot according to the
requirement of client/project, applications and design
conditions. [4] Therefore, it is very difficult to select the right
type of HVAC system for our design. HVAC design engineers
must consider various factors while selecting the equipment like
heat gain from different objects inside the air-conditioned area,
location, special requirement of the system, space availability,
Load variations, operating conditions, Energy efficiency, and
total expenditure, etc. HVAC systems are classified as Air-
Cooled Chiller System, HVRF system, Water-Cooled Chiller
System, VRF System, and DX System.
Problem Statement:
COVID-19 is having devastating impacts on our society.
The same condition goes for our project. The client has invested
a huge amount of money into this project. But Architect has
backed out due to the COVID-19 situation, it is now our duty to
design HVAC & R system and take this project ahead. The main
problem with the designing of today’s HVAC system is the
availability of different refrigeration system has made it more
complex than it was earlier. We have to provide system which
is flexible in different climates conditions to provide better
comfort in the space.
Objectives:
 To design the optimum HVAC system for a commercial
building with the new and upcoming improved
technology of HVAC.
 To calculate the heat load of the provided layout and
analyse the factors affecting it.
 To study different systems available and select the best
out of them.
 To ensure better indoor air quality.
 To include appropriate safety measures due to COVID-
19.
 IGBC certification

2. II. HEAT LOAD
Example:- [6]
1. Aurangabad-
Latitude: 19.87620
N,
Longitude: 75.3433o
E,
Altitude: 1864 Ft.
2. Outside design condition: Temperature: 1020
F (38.90
C).
3. Relative Humidity : 39.2%
4. Indoor design condition: 75.2F (240
C).
5. Relative Humidity : 55%
6. Selecting inside design for summer condition:
Offices: Temp: 75.20F & RH: 55%,
Meeting room: Temp: 75.20
F& RH: 55%,
Cafeteria: Temp: 78.50
F & RH: 50%.
7. Considering the overall factor for double pane glass(48
to 56% absorbing outside) as per ISHRAE standard
table: required (CFM)-9878.495
8. Total Dehumidified CFM- 83698.167
9. Solar gain through the glass in north direction- 6,157
10. Solar gain through the glass in east direction- 1,697
11. Total Solar & Transmission gain- 965.17
12. Area (sq. ft.)- 5,310.38
13. By-Pass Factor- 0.15
14. Total tonnage-18.703
15. Effective Room Total Heat- 1,74,755.62
III. SYSTEM USED
Hybrid VRF is a unique 2 way pipe heat recovery VRF
System that replaces refrigerant with water in occupied area.
Between the Hybrid Branch Circuit Controller and the outdoor
units we have refrigerant and between HBC and indoors we
have water. Hybrid VRF is an easy, flexible, and quick top
system and it can be installed using the same network and
controls as traditional variable refrigerant flow systems. With
water in the occupant area, Hybrid VRF provides comfort with
same air temperature throughout working time with no
refrigerant in occupied spaces, which helps to comply with
refrigerant legislation EN-378. In addition, it minimising the
need of leak detection. [18]
Total tonnage: 18.73 TR
Considering diversity: 20-25%
Overall tonnage: 14.047 TR
A cooling tower is a heat rejection device, which extracts waste
heat to the atmosphere through the cooling of a water stream to
a lower temperature.[2,11,12] There is a need of the water
softening plant to fulfil the required pH of water in the HVRF
system. We will recommend using CPVC pipes. Ceiling
mounted cassette compact multi-flow, Round flow with sensing
and double-flow type are popular in a commercial building.
IV. INDOOR AIR QUALITY
Air quality of inside and outside occupied area and
building structure and it relates to the health and comfort of
occupants inside the building is IAQ. [3] Understanding and
removing pollutants from indoors can help to reduce health
problems due to air quality. Air pollutants may cause health
issues and are experienced just after it or after some interval of
time.
Released gases or particles into the air from pollution
sources affect indoor air quality. Insufficient ventilation can
increase indoor pollutant levels inside the occupant area and its
exhaust can pollute outdoor too. High humidity and temperature
levels help to increase concentrations of some pollutants in the
indoor or occupied area. [1,5]
In order to improve the IAQ of our building we have:
1. Air Quality Monitor
2. Outdoor Air Treatment Unit
3. Air Purifier Unit.
4. We suggest to plant indoor plants to increase the O2
level.
5. On the 3rd
and 5th
floor, there is excess space and we can
cover it with a small garden which will increase the
productivity of the occupant.
6. The green floor also reduces the heat gain through the
roof.
Covid-19 pandemic has brought many challenges. For the same,
we have introduced certain changes in our system, which are:
1. Waterless urines and Sensor-based taps to avoid
communicable diseases and save water.
2. Air purifies gel (it purifies not only air but also disinfect
open surfaces)
3. MERV-15 filters.
4. Sanitization room outside main entrance door.
5. Automatic doors at main entrance and louver for
staircase because it is at the periphery of the commercial
building.

3. V. VALUE ENGINEERING, CERTIFICATION, AND
INNOVATION
Our commercial building has adopted the following methods
and equipment has to gain the maximum benefits:
CPVC Pipe. Silver Certified by IGBC
Heat Recovery System. Solar plant at roof top
Sewage Treatment Plant Electric charging spot
BMS Sola tube
VI. CONCLUSION
We can conclude that our building is “Silver certified by
IGBC” which have many benefits like subsidy in land tax,
Energy Efficiency, Water Saving, Cost reduction, better IAQ,
Improved System Life, User friendly controls, Improved
Cooling Efficiency last but not least Safe for Covid19 situation
which is requirement of current situations.
In addition, we are not only saving our daily expenditure
by using free light through Solatube, free water from STP, free
heat from Heat recovery system but also we are getting revenue
by accepting charging spot in basement for EV cars and two
wheelers.
REFRENCES
[1] G. Brager, Energy-Related Indoor Environmental
Quality Research, MD20899 USA, July 1, 2002.
[2] K.S.L. Prasanna, K Srinivasa Rao, “Design of Cooling
Tower”. International Journal of Scientific &
Engineering Research, 1560 (2013).
[3] Chandra Sekhar, “Space Temperature Difference,
Cooling Coil and Fan, Energy and Indoor Air Quality
Issue revisited”, Jan, 2005.
[4] J. Young, “The Future of Air Conditioning for
Buildings”, Oak Ridge Lab, July, 2016.
[5] Y.H.Liub, “Review of research on Air- Conditioning
systems and Indoor Air Quality Control For Human
Health” Vol-33, Issue-1, Jan 1, 2009.
[6] Junnaid Hussain, “Heat Load Calculation”, ISSN: 2456-
6470, Vol-3, Aug 5, 2019.
[7] Marco Masoreo, “Inspection and energy auditing of
HVAC Systems”, article-9, 2005.
[8] R. Nadira, Schick, “HVAC System fault diagnosis and
energy optimization using state – space methods and
modern control theory”, Aug 1, 1984.
[9] Sen Hunang, “Optimization of the water-cooled chiller
plant system operation”, Dec 9, 2014.
[10] W. Goetzler, “Variable refrigerant flow system”,
Apr,2007.
[11] I Swathi, K Srinivas, “Design of cooling tower”, Jun
24,2017.
[12] Mustafa Jassim, “Investigating the energy performance
of a forced draft wet cooling tower”, Vol-7 No-4, 2018.
[13] “Solatube/ Commercial Daylighting” Accessed on Nov.
14, 2020. [Online]. Available:
https://www.solatube.com/commercial
[14] “EC High Efficiency fans” Accessed on Oct. 1, 2020.
[Online]. Available:
https://continentalfan.com/product-category/ec-fans/
[15] “Terracotta Cladding, Terracotta Façade Cladding
System” Accessed on Sep. 15, 2020. [Online].
Available: https://www.terracotta-panel.com/terracotta-
cladding/
[16] “ECBC User guide – Bureau of EE” Accessed on Sep.
15, 2020. [Online]. Available:
https://beeindia.gov.in/sites/default/files/ECBC%20Use
r%20Guide%20V-0.2%20%28Public%29.pdf
[17] “Green buildings and hotels – IGBC Green New
Buildings in India” Accessed on Nov. 15, 2020.
[Online]. Available:
https://igbc.in/igbc/redirectHtml.htm?redVal=showGre
enNewBuildingsnosign
[18] “Mitsubishi HVRF system” Accessed on Sep. 21, 2020.
[Online]. Available:
https://www.buildingdesign.co.uk/pdf/mitsubishi
-cat-HVRF.pdf
[19] “Sun path” Accessed on Sep. 21, 2020. [Online].
Available:
https://www.sunearthtools.com/dp/tools/pos_su
n.php