TABLE OF CONTENT
CHAPTER 1...................................................................................... 1
SAFETY PRECAUTIONS IN REFRIGERATION AND AIR CONDITIONING
PRACTICE ......................................................................................... 1
CHAPTER 2...................................................................................... 4
TOOLS EQUIPMENT AND THEIR USES ................................................ 4
CHAPTER 3...................................................................................... 6
PIPING IN REFRIGERATION AND AIR CONDITIONING. ........................ 6
CHAPTER 4.................................................................................... 17
FOUR MAJOR COMPONENTS OF REFRIGERATION AND AIR
CONDITIONING SYSTEMS. ............................................................... 17
CHAPTER FIVE .............................................................................. 31
BRAZING TECHNIQUES .................................................................... 31
CHAPTER 6.................................................................................... 36
VACUUMING AND CHARGING OF REFRIGERANTS.............................. 36
CHAPTER 7.................................................................................... 40
LEAK DETECTION ............................................................................ 40
CHAPTER 8.................................................................................... 45
INSTALLATION AND COMMISSIONING OF AIR CONDITIONING AND
REFRIGERATING EQUIPMENT .......................................................... 45
CHAPTER 9.................................................................................... 48
SERVICING OF AIR CONDITIONERS ................................................. 48
i
, CHAPTER 1
SAFETY PRECAUTIONS IN REFRIGERATION AND AIR
CONDITIONING PRACTICE
Safety is prevention of accident, and minimizing the loss of lives
and property arising from unplanned and undesirable occurrences.
Hence safety is viewed as the cornerstone of every successful
industrial undertaking, because very activity has an acceptable way
of executing it and if they are ignored then accident is bound to
occur.
Since Air Conditioning and refrigeration personal work close to
many potential dangerous situations such as liquid, and gases
under pressure, electrical energy, heat, cold, chemicals, rotating
machinery, moving heavy objects, and so on, the job must be
completed without injury the following safety precautions must be
observed in refrigeration and Air Conditioning practice.
1. Always carry a pressured cylinder with a protective cap. If the
cylinder is too large, it should be well chained to a cart.
2. Do not apply heat to refrigerant cylinders while charging a
system. If the pressure is to be maintained from dropping, the
refrigerant cylinder should be set near warm water with a
temperature not higher than 320C.
3. Always keep your eyes and skin away from escaped liquid
refrigerant should there be leakage, stand back and look for a
valve with which to shut it off. Do not try to stop it with your
hands to avoid frost bite. Ensure that you wear approved
goggles.
4. Always shut off electrical power when installing the equipment
or plant. The electrical panel should be provided with a padlock
so that the technician carrying out the repair can personally
lock it by himself to avoid someone turning the power on.
1
,5. When carrying out test with power on, ensure that your hands
touch only the meter probes and your arms and the rest of
your body stay clear all electrical terminals and connections.
Make sure that you know the voltage on the system and be
sure that the testing instrument is well set.
6. Never you stand on a wet or damp area when carrying out
electrical test and ensure that you wear heavy safety shoes
with an insulating sole and heel.
7. Always use non-conducting ladders on all jobs.
8. Always provide or it should be provided (a fire extinguisher)
when soldering or brazing and be able to use it in case fire
occurs.
9. When soldering is to be made next to combustible materials or
finished surface, a non-combustible materials should be used to
shield the combustible materials or a fire resistant is sprayed
over the combustible materials.
10. Do not solder tubing that is sealed. Service valves must be
open before carrying out soldering on large plant.
11. To avoid frost-bite, always wear proper clothing (coat) and
water proof boots and gloves when repairs is to be carried out
in low freezing freezers.
12. When working on rotating equipment such as motors, fan,
compressors and pump, do not wear loose clothing or tie, it
can be caught by rotating machinery.
13. Always stand by the side when starting an open motor because
the coupling or belt might fly off the drive. Never attempt to
stop a motor or other mechanism by gripping the belt because
the momentum may pull your hand into the pulley and under
the belt.
14. Do not wear jewellery or a bracelet when using a grinder or
sharpen tools, use a face shield when grinding.
15. Do not try to lift heavy equipment by yourself, use a crane
when the equipment is to be installed on top of a building,
when you must lift use your leg and not your back.
2
, 16. Always work on refrigerant piping in a well-ventilated
environment so as not to inhale refrigerant vapour that is toxic
when concentration becomes too high fans may also be used
to push or pull fresh air into the working environments.
17. Always read manufacturer’s directions when using chemicals
such as the one used for cleaning condenser and evaporators.
CAUSES OF ACCIDENTS THAT MUST BE AVOIDED ARE AS
FOLLOWS;
1. When personnel’s will not know that it is important to clean up
all spilled or splash oil or grease. Invariably an emergency,
leads to rapid movement of people. It may cause trip and fall
which may cause injury to oneself, this delay in production
could be disastrous to the organization.
2. Misplacement of tools can inflict injury on personnel in the
workshop.
3. Horse play is a most dangerous practice, often resulting inn
injury or death and is strictly forbidden.
4. Use of wrong tools for a particular job is a source of accident
hence the right tools should always be used.
5. Over-confidence lead to attempting to what one does not have
knowledge about. Therefore do not operate equipment without
having knowledge of it or being instructed to operate.
3
CHAPTER 1...................................................................................... 1
SAFETY PRECAUTIONS IN REFRIGERATION AND AIR CONDITIONING
PRACTICE ......................................................................................... 1
CHAPTER 2...................................................................................... 4
TOOLS EQUIPMENT AND THEIR USES ................................................ 4
CHAPTER 3...................................................................................... 6
PIPING IN REFRIGERATION AND AIR CONDITIONING. ........................ 6
CHAPTER 4.................................................................................... 17
FOUR MAJOR COMPONENTS OF REFRIGERATION AND AIR
CONDITIONING SYSTEMS. ............................................................... 17
CHAPTER FIVE .............................................................................. 31
BRAZING TECHNIQUES .................................................................... 31
CHAPTER 6.................................................................................... 36
VACUUMING AND CHARGING OF REFRIGERANTS.............................. 36
CHAPTER 7.................................................................................... 40
LEAK DETECTION ............................................................................ 40
CHAPTER 8.................................................................................... 45
INSTALLATION AND COMMISSIONING OF AIR CONDITIONING AND
REFRIGERATING EQUIPMENT .......................................................... 45
CHAPTER 9.................................................................................... 48
SERVICING OF AIR CONDITIONERS ................................................. 48
i
, CHAPTER 1
SAFETY PRECAUTIONS IN REFRIGERATION AND AIR
CONDITIONING PRACTICE
Safety is prevention of accident, and minimizing the loss of lives
and property arising from unplanned and undesirable occurrences.
Hence safety is viewed as the cornerstone of every successful
industrial undertaking, because very activity has an acceptable way
of executing it and if they are ignored then accident is bound to
occur.
Since Air Conditioning and refrigeration personal work close to
many potential dangerous situations such as liquid, and gases
under pressure, electrical energy, heat, cold, chemicals, rotating
machinery, moving heavy objects, and so on, the job must be
completed without injury the following safety precautions must be
observed in refrigeration and Air Conditioning practice.
1. Always carry a pressured cylinder with a protective cap. If the
cylinder is too large, it should be well chained to a cart.
2. Do not apply heat to refrigerant cylinders while charging a
system. If the pressure is to be maintained from dropping, the
refrigerant cylinder should be set near warm water with a
temperature not higher than 320C.
3. Always keep your eyes and skin away from escaped liquid
refrigerant should there be leakage, stand back and look for a
valve with which to shut it off. Do not try to stop it with your
hands to avoid frost bite. Ensure that you wear approved
goggles.
4. Always shut off electrical power when installing the equipment
or plant. The electrical panel should be provided with a padlock
so that the technician carrying out the repair can personally
lock it by himself to avoid someone turning the power on.
1
,5. When carrying out test with power on, ensure that your hands
touch only the meter probes and your arms and the rest of
your body stay clear all electrical terminals and connections.
Make sure that you know the voltage on the system and be
sure that the testing instrument is well set.
6. Never you stand on a wet or damp area when carrying out
electrical test and ensure that you wear heavy safety shoes
with an insulating sole and heel.
7. Always use non-conducting ladders on all jobs.
8. Always provide or it should be provided (a fire extinguisher)
when soldering or brazing and be able to use it in case fire
occurs.
9. When soldering is to be made next to combustible materials or
finished surface, a non-combustible materials should be used to
shield the combustible materials or a fire resistant is sprayed
over the combustible materials.
10. Do not solder tubing that is sealed. Service valves must be
open before carrying out soldering on large plant.
11. To avoid frost-bite, always wear proper clothing (coat) and
water proof boots and gloves when repairs is to be carried out
in low freezing freezers.
12. When working on rotating equipment such as motors, fan,
compressors and pump, do not wear loose clothing or tie, it
can be caught by rotating machinery.
13. Always stand by the side when starting an open motor because
the coupling or belt might fly off the drive. Never attempt to
stop a motor or other mechanism by gripping the belt because
the momentum may pull your hand into the pulley and under
the belt.
14. Do not wear jewellery or a bracelet when using a grinder or
sharpen tools, use a face shield when grinding.
15. Do not try to lift heavy equipment by yourself, use a crane
when the equipment is to be installed on top of a building,
when you must lift use your leg and not your back.
2
, 16. Always work on refrigerant piping in a well-ventilated
environment so as not to inhale refrigerant vapour that is toxic
when concentration becomes too high fans may also be used
to push or pull fresh air into the working environments.
17. Always read manufacturer’s directions when using chemicals
such as the one used for cleaning condenser and evaporators.
CAUSES OF ACCIDENTS THAT MUST BE AVOIDED ARE AS
FOLLOWS;
1. When personnel’s will not know that it is important to clean up
all spilled or splash oil or grease. Invariably an emergency,
leads to rapid movement of people. It may cause trip and fall
which may cause injury to oneself, this delay in production
could be disastrous to the organization.
2. Misplacement of tools can inflict injury on personnel in the
workshop.
3. Horse play is a most dangerous practice, often resulting inn
injury or death and is strictly forbidden.
4. Use of wrong tools for a particular job is a source of accident
hence the right tools should always be used.
5. Over-confidence lead to attempting to what one does not have
knowledge about. Therefore do not operate equipment without
having knowledge of it or being instructed to operate.
3
