our summer training with Zhiar Shero

1. 1
Natural Air Ventilation & Air
conditioning in Buildings
Student Name: Zhiar Shero Hussein
Rawa Abdullah Taha
Class: Third
Course Title: Summer Training
Department: Mechanic and Mechatronics
Supervisor Engineer: Ahmed Ibrahim Mahmood (MSc)
General Supervisor: For Committee of Summer Training
Of Mechanical Engineering Department
College of Engineering
Salahaddin University - Erbil
Academic Year 2020 – 2021

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TABLE OF CONTENTS
INTRODUCTION…………………………………………..................... 3
PREFACE…………………………………………………………….......4
ADVANTAGES OF NATURAL AIR VENTILATION………….……..4
WAYS WE CAN MAKE AIR VENTILATION…………………...…...5
SEVERAL AFFECT TO NATURAL AIR MOVEMENT………….......5
SEVERAL AFFECT TO NATURAL AIR MOVEMENT……………....6
WAYS TO CREATING AIR VENTILATION IN BUILDINGS………7
VENTING FAN………………………………………………………….7
AIR COOLER……………………………………………………………8
AIR CONDITION …………………………………………………....….9
SPLIT UNIT……………………………………………………….…....10
THEORY/DESIGN……………………………………………...….…..11
THE NAME PLATE ………………………………………………..….12
TYPES OF SPLIT UNIT ACCORDING TO THEIR USAGE….……..13
VRF SYSTEM……. …………………………………………………....14
RAPARIN ELECTRICAL DISTIRBUTION DIRECTORATE
BUILDING………………………………………………………..…….15
CONCLUSION…....................................................................................16

3. 3
INTRODUCTION
In the past, natural ventilation is sufficient for humans due to usual and
simple life style and the clean atmosphere of the earth in common.
Now days , due to the increasing temperature of the planet caused by
pollution of
and
gasses
2
o
C
o and
C
of
emission
global warming and
atmosphere , human beings obliged to use artificial ways for air
ventilation and air conditioning by this training course is about this issue.

4. 4
PREFACE
The amount of physiological comforts of humans depends on several
things. One of them is environment condition for example:
1. Temperature
2. Humidity
3. Air Movement
4. Sunlight
In Building designing one of the major elements is creating a natural
movement for the air inside this natural air ventilation will help to reduce
temperature, and prevent wasting mechanical energy.
Advantages of Natural Air Ventilations:
and clean air with more oxygen and less polluted
healthy
provides a
It
1.
gases.
2
CO
2. It will decrease temperatures during hot conditions to several degrees.
3. not only that but it also helps to reduce humans bodytemperature and
help us to avoid odors and sweat.

5. 5
Ways we can to make Air ventilation:
1. Creating natural ventilation through the windows on the walls. This is
to form a difference in the air's pressure to force its movement.
2. We must also consider direction of the wind and air pressure of the
location before building structures, to choosethe right orientation of the
building.
3. Mechanical ways or artificial ways.
There are several things that affect natural air movement:
1. Building's face orientation.
even through a perfect angle for wind direction and sunlight is a bit rare
and challenging , we can face the buildings in a way that we can take
most advantage of , which the wind direction must be perpendicular to
the buildings face , as shown in figure (1) :
Wind direction:
Fig. (1)

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What's more, the windows are preferred to have an angle of 45 degrees as
shown in figure (2):
Fig. (2)
Note: in all conditions we must have at least one inlet/outlet air vents to
create air ventilation.
2. Planting trees plays a huge role in changing wind direction and
providing shade for buildings, as well as clean Air.
With having trees around buildings we obtain a major decrease in
temperature inside the house. This is becauseit prevents sunlight
interring the house and also providing a cooled Air for the building.

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The artificial ways of creating ventilation and Air
Conditioning in Buildings:
After relying on using natural ways for ventilation inside buildings, we
must consider establishing artificial ways to create the same effect if the
natural method didn’t accomplish proper ventilation that the building
needs. We are currently facing a terrible disaster which is Global
Warming. Due to this disaster, we must overcome it by stepping forward
into building new methods to reduce heat inside buildings and lay out a
comfortable environment that is friendly to humans. We have come up
with several ideas that are extremely helpful, Including:
1- Venting Fan
2- Air Cooler
3- Air Conditioner
4- Split Unit
5- VRF System
Venting Fan is a small mechanical motor which circulates a fan to
ventilate air inside building by excluding the hot and polluted air out and
saving air inside buildings cold and clean.
Fig .(3) Venting Fan

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Air Cooleris an electro-mechanical machine which consists of motor
that turns a Flywheel Fan which then pushes the air forward into the
room.
Fig. (4) Air Cooler
The air, first, flows through a honey-comb filtration which is cooled by
the water that’s come with the help of a water pump. After that, the air
inside the Air Cooler gets colder than outside. Finally, it will be pushed
forward to the room. This process is continuously repeated, and the water
is always circulating inside to coolthe filters down. Therefore, this is an
efficient method to provide coolair. We may vary the specifications of
the Air Cooler according to the room’s size. What’s more, the brand of
the Air Cooler and its size play a huge role in its performance.
We have two ways to set up an Air Cooler; first, is the direct way which
is being placed on a spotoutside the windows and it gets through the
them directly.
The second is by installing a Duct to the roof from inside the house. This
way you must have the Air cooler on the rooftop and let it send air
through the duct until it reaches the rooms.
One more important thing is to be considered which is to avoid wasting
energy. This is done by insulating the entire duct and not gives room to
any energy leaks.

9. 9
Air Conditioning it's also an electro-mechanical machine which cools
air inside rooms by circulating the hot air and through an inside fan to a
very cold which resulted the cold air into the room.
Fig. (5) Air Conditioning
This machine can cause a huge difference in room Temperature; it can
create a very cold environment for summer and an extreme hot
environment for winter. It is controlled by a Remote Control and can be
set to desired temperature whenever needed. The development of this
machine has been profoundly seen throughout decades. The classical type
did consists of (a Compressor, Fan, and a control for adjustments).
It was one Unit and it had huge noise which bothered habitants inside the
building.

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Therefore, refrigeration experts evolved this technology into a better
machine and split it into two units Outdoorand indoor units that called it
Split Unit.
Fig. (6) Split Unit
This particular machine has two
parts, indoor and outdoor. With this
Split Unit system first, we get rid of
the noise. Second, it's more efficient.
And Third, is more compatible and
friendly with interior and exterior
design and it seamlessly interacts
with the decoration. This system
works on pretty much the same
principal as Air Conditioner.
However, it has separated the unit,
which includes a fan and produces
hot air, to outside, and the unit with a
cooling radiator and a fan to inside. In a split system, the compressor
condenses and circulates the refrigerant gas through the outdoor unit,
changing it from a gas to a liquid. The liquid is then forced through the
indoor evaporator coil which is called capillary tube. The indoor unit’s
fan circulates the inside air to pass across the capillary tube. The capillary
tube’s metal fins exchange the thermal energy with the air around it.
There, the refrigerant turns from liquid into vapor, removing any heat
from the surrounding air. As the heat is removed from the air, the air is
cooled and blown back into the house.
From that point, the condenser or outdoor unit then turns the refrigerant
vapor back into a liquid, removing any heat. By the time the fluid leaves
the capillary tube again, it is a cool, low-pressure gas, eventually
returning to the condenser to begin its trip all over again. This process
continues again and again until your home reaches the cooling
temperature you want, as programmed and sensed by your thermostat
setting.
The split needs to rest just like humans and for that the experts have
installed a thermostat into the indoor Unit to control the room’s
temperature. Its role will take place when the room has reached the
desired temperature. It will automatically switch of the Split to take a
break from the continuous efforts of increasing the room’s temperature.
After the room’s temperature is going up, the thermostat will then give
permission to the split to start working again and drop the surrounding
temperature. Therefore, it plays a huge role in saving energy and giving a
rest to the machine.

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THEORY / DESIGN
We choosedifferent types of Split Units according to the design of each
room or building, the dimension of the room which more clearly means
Volume. We multiply height, width and length in order to get Volume.
After that, we will divide it into a standard number which is used now
days by local designers is about 1/40 ton/ m3 and is used as a standard to
determine the British Thermal Unit/ heat capacity of a room. However,
there are other advanced engineering ways that lead us into more accurate
results, including: the type of material used for walls, having insulation,
and the wall’s capacity to loose heat. All of these will make a great asset
to finding out the perfect BTU for the room.
Ex :
If we have a room with directions (6 * 4 * 3) m (L, w, h), calculate the
split capacity for this room?
Volume of the room = 6 * 4 * 3 = 72 m3
The split unit per designing is about (1/40 ton/m3)
Split calculation = 72 m3 * 1/40 ton/m3 = 1.8 tons
≈ 2 tons
1ton = 12000 BTU
= 2 * 12000
= 24000 BTU

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The name plate:
The important document in split units is the name plate, which contain
the entire specification of the split units, such as:
- Brand
- Electrical specification
- Voltage system: 220 V, 110V
- Phases: Single phase
Three phase
-Mechanical specification
- split capacity
Ex.24000 BTU or 2 tons
- Refrigerant gasses:R22, R410
etc… as shown in figure (7).
Fig. (7)

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Types of split unit according to their usage:
A. wall mounted type, as shown in figure 8.
B. Cassette type split unit, as shown in figure 9.
C. Standing ductless split unit as shown in figure 10.
___________________________________________________________
A. Wall mounted type:
*
Fig. (8)
*B. Cassette type split unit
Fig. (9)
*C. Standing ductless split unit
Fig. (10)

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VRF systemAll these types of split units mentioned above consistof
two units which are separately installed for each room. This has several
disadvantages: first, for each indoor unit we must have an outdoorwhich
makes things complicated, and invades lots of spacethat could be utilized
for other purposes. Second, it consumes a huge amount of electrical
energy, and costs a lot of money. Finally, its unsuitable with both indoor
and outdoordecoration. Therefore, experts have developed a new
technology to overcome this issue by inventing VRF Air Conditioning
system. It’s a short form for Variable Refrigerant Flow. With this specific
type of Air Conditioning we only have one outdooras a common package
which is an assemble for all the indoor units together. You can install as
many indoor units according to the VRF's capability and capacity to cool
down a building, and save spaceand energy simultaneously. What's
more, the VRF has an adaptive and abstractdesign that suits with almost
every type of decorations. All in all, VRF is a profound technology that
has helped us overcome the problems we have had with the traditional
split units .In figure11:
Fig. (11)

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Raparin Electrical Distribution Directorate Building
In this building, the air conditioning system based on using splits units, in
the two types: wall mounted & cassette type. This building has about 40
split units:
- 32 wall mounted type starting from ( 1.5 to 2.75 tons single phase units)
-8 cassette type starting from (3.5 to 4.5 tons three phase units).

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CONCLUSION
We have gotten familiar with all types of Air Conditioning systems and
their capabilities. Their principle of work, their models, design and costs.
During our internship studies/ summer trainings we have seen several
examples of different types of Air Conditioners, inside the building we
worked at, and have studied them thoroughly in order to understand their
functionality and their capabilities to either warm or coolthe rooms
inside a building. Having to study the models in real life and in front of
our eyes, it’s fair enough to mention that we have learned a vast amount
of information about ventilation and providing a comfortable
environment for inhabitants. What’s more, we did learn to set a suitable
design for a specific room or building by considering every principal
factors that affect the temperature and air inside. All in all, we found that
summer training very helpful and we believe that it has taught us enough
to be confident to work on our own as mechanical engineers in the future.