Arulmigu Meenakshi Amman College of Engineering
Vadamavandal-604410.
Impotant questions and answers
REFRIGERATION AND AIR CONDITIONING
Prepared by
V.Umapathy,
Prof. /Mech.
S.No. Questions and answers
Unit-I
INTRODUCTION
2 – marks question and answers
1. Define refrigeration.
The process of cooling a substance (or) the art of producing and maintaining the temperature in a
space below the atmospheric temperature is called refrigeration.
2. Define refrigerator.
Refrigerator is a device which is maintains the temperature always below the atmospheric temperature.
3. Write the classification of refrigerator.
1. Ice refrigerator-Ice is kept in the cabinet of refrigerators and this acts as the refrigerating means.
2. Air refrigerators-Air is used as working agent in these types of refrigerators.
3. Vapour refrigerators-The working agent employed in this type are vapours like ammonia,
carbondioxide, sulphur dioxid, freons, etc. The vapour refrigerators can be further classified as
A. Vapuor compression refrigerators
B.Vapour absorption refrigerators.
Vapour refrigerators are widely used in various field, vapour compression system is used usually for all
purpose of refrigeration.
4. Write some applications of refrigeration.
1.In ice manufactyring,2.Preservation of food items in houses,3.For cooling water,4.For comfort air-
, conditioning in hospitals,theatres,etc.,5.For preservation of tablets and medicines in pharmaceutical
industries,6.In chemical industries for separating and liquefying gases and vapours,7.For the preservation
of blood, tissues,etc.in medical fields.
5. What units are used to express refrigeration capacity?
The two most common units used to express refrigeration capacity are the ton of refrigeration and the watt.
In thermodynamics, one ton of refrigeration is defined as the amount of refrigeration produced by melting
one tone of ice in 24 hours.
6. Define COP (coefficient of performance).
The ratio of refrigeration effect to the work done.
7. Define refrigerant.
Refrigerant is a substance which is always in vapour state. Examples- Ammonia, carbon dioxide, sulphur
dioxide, Freon.
8. List the desirable properties of refrigerants.
1. Low boiling point, 2.Low specific heat of liquid, 3.Low specific volume, 4.Non-toxic, 5.Non-corrosive
to metal, 6.High latent heat of vapourisation, 7.Non-flammable, 8.Non-explosive and 9. Low cost and
10.Easly available in nature.
9. Define refrigeration effect.
The amount of heat removed from a space in a given period of time is called the refrigeration effect.
10. What is a GWP in a refrigerant?
The potential for a single molecule of the refrigerant to destroy the Ozone Layer. All refrigerants use R11
as a datum reference where R11 has an ODP = 1.0. The less the value of the ODP - the better the
refrigerant is for the ozone layer and the environment. 2) GWP - The GWP, or Global Warming Potential.
11. What is ODP & why is it important?
ODP value is basically a measurement of how damaging something is for the ozone layer. The lower this
measurement, the less destructive a particular refrigerant is to the ozone layer. Back in the 80’s to 90’s the
ozone was a major topic of discussion and got greater attention as the environmental movement became
more mainstream.
, 13 and 15 marks question and answers
12. Describe the refrigerating properties of ammonia for use in domestic and commercial type of
refrigerating appliances.
,
Vadamavandal-604410.
Impotant questions and answers
REFRIGERATION AND AIR CONDITIONING
Prepared by
V.Umapathy,
Prof. /Mech.
S.No. Questions and answers
Unit-I
INTRODUCTION
2 – marks question and answers
1. Define refrigeration.
The process of cooling a substance (or) the art of producing and maintaining the temperature in a
space below the atmospheric temperature is called refrigeration.
2. Define refrigerator.
Refrigerator is a device which is maintains the temperature always below the atmospheric temperature.
3. Write the classification of refrigerator.
1. Ice refrigerator-Ice is kept in the cabinet of refrigerators and this acts as the refrigerating means.
2. Air refrigerators-Air is used as working agent in these types of refrigerators.
3. Vapour refrigerators-The working agent employed in this type are vapours like ammonia,
carbondioxide, sulphur dioxid, freons, etc. The vapour refrigerators can be further classified as
A. Vapuor compression refrigerators
B.Vapour absorption refrigerators.
Vapour refrigerators are widely used in various field, vapour compression system is used usually for all
purpose of refrigeration.
4. Write some applications of refrigeration.
1.In ice manufactyring,2.Preservation of food items in houses,3.For cooling water,4.For comfort air-
, conditioning in hospitals,theatres,etc.,5.For preservation of tablets and medicines in pharmaceutical
industries,6.In chemical industries for separating and liquefying gases and vapours,7.For the preservation
of blood, tissues,etc.in medical fields.
5. What units are used to express refrigeration capacity?
The two most common units used to express refrigeration capacity are the ton of refrigeration and the watt.
In thermodynamics, one ton of refrigeration is defined as the amount of refrigeration produced by melting
one tone of ice in 24 hours.
6. Define COP (coefficient of performance).
The ratio of refrigeration effect to the work done.
7. Define refrigerant.
Refrigerant is a substance which is always in vapour state. Examples- Ammonia, carbon dioxide, sulphur
dioxide, Freon.
8. List the desirable properties of refrigerants.
1. Low boiling point, 2.Low specific heat of liquid, 3.Low specific volume, 4.Non-toxic, 5.Non-corrosive
to metal, 6.High latent heat of vapourisation, 7.Non-flammable, 8.Non-explosive and 9. Low cost and
10.Easly available in nature.
9. Define refrigeration effect.
The amount of heat removed from a space in a given period of time is called the refrigeration effect.
10. What is a GWP in a refrigerant?
The potential for a single molecule of the refrigerant to destroy the Ozone Layer. All refrigerants use R11
as a datum reference where R11 has an ODP = 1.0. The less the value of the ODP - the better the
refrigerant is for the ozone layer and the environment. 2) GWP - The GWP, or Global Warming Potential.
11. What is ODP & why is it important?
ODP value is basically a measurement of how damaging something is for the ozone layer. The lower this
measurement, the less destructive a particular refrigerant is to the ozone layer. Back in the 80’s to 90’s the
ozone was a major topic of discussion and got greater attention as the environmental movement became
more mainstream.
, 13 and 15 marks question and answers
12. Describe the refrigerating properties of ammonia for use in domestic and commercial type of
refrigerating appliances.
,
