CHANGE OF STATE

TheTheTheThe melting pointmelting pointmelting pointmelting point of a solid is the temperature at of a solid is the temperature at of a solid is the temperature at of a solid is the temperature at which which which which

changeschangeschangeschanges statestatestatestate fromfromfromfrom solidsolidsolidsolid totototo liquidliquidliquidliquid at atmospheric at atmospheric at atmospheric at atmospheric pressure. pressure. pressure. pressure. EgEgEgEg . Ice to water.. Ice to water.. Ice to water.. Ice to water.

TheTheTheThe boiling boiling boiling boiling pointpointpointpoint ....

The temperature at which changes state from liquid to gas at atmospheric The temperature at which changes state from liquid to gas at atmospheric The temperature at which changes state from liquid to gas at atmospheric The temperature at which changes state from liquid to gas at atmospheric

pressure. pressure. pressure. pressure. EgEgEgEg . . . . water water water water to to to to vapour.vapour.vapour.vapour.

Freezing Freezing Freezing Freezing pointpointpointpoint

The temperature at which changes state from The temperature at which changes state from The temperature at which changes state from The temperature at which changes state from liquid liquid liquid liquid to to to to solid solid solid solid at atmospheric at atmospheric at atmospheric at atmospheric

pressure. pressure. pressure. pressure. EgEgEgEg . . . . water water water water to to to to iceiceiceice

Condensing pointCondensing pointCondensing pointCondensing point

The temperature at which changes state from The temperature at which changes state from The temperature at which changes state from The temperature at which changes state from gas gas gas gas to to to to liquid liquid liquid liquid at atmospheric pressure. at atmospheric pressure. at atmospheric pressure. at atmospheric pressure.

EgEgEgEg . . . . vpourvpourvpourvpour to to to to waterwaterwaterwater

Melting point of ice = 32Melting point of ice = 32Melting point of ice = 32Melting point of ice = 32°°°°F (0F (0F (0F (0°°°°C) , boiling point of water = 212C) , boiling point of water = 212C) , boiling point of water = 212C) , boiling point of water = 212°°°°F (100F (100F (100F (100°°°°C) , freezing C) , freezing C) , freezing C) , freezing

point of water = 32 point of water = 32 point of water = 32 point of water = 32 °°°°F F F F (0(0(0(0°°°°C) C) C) C) , condensing point of vapour = , condensing point of vapour = , condensing point of vapour = , condensing point of vapour = 212212212212°°°°F (100F (100F (100F (100°°°°C) C) C) C)

LATENT HEAT (LH)

Latent means hide. The heat which brings about a change of state with no change in Latent means hide. The heat which brings about a change of state with no change in Latent means hide. The heat which brings about a change of state with no change in Latent means hide. The heat which brings about a change of state with no change in

temperature is called latent heat. temperature is called latent heat. temperature is called latent heat. temperature is called latent heat.

EgEgEgEg . Boiling point of water is 212. Boiling point of water is 212. Boiling point of water is 212. Boiling point of water is 212°°°°F F F F (100(100(100(100°°°°C) C) C) C) . 1 pound water reach . 1 pound water reach . 1 pound water reach . 1 pound water reach 212212212212°°°°F (100F (100F (100F (100°°°°C) C) C) C) , , , ,

then we give 970 BTU heat again water state change to vapour state at 212then we give 970 BTU heat again water state change to vapour state at 212then we give 970 BTU heat again water state change to vapour state at 212then we give 970 BTU heat again water state change to vapour state at 212°°°°F.F.F.F.

LATENT HEAT OF VAPOURISATION /CONDENSATION

The heat absorbed when a substance changesThe heat absorbed when a substance changesThe heat absorbed when a substance changesThe heat absorbed when a substance changes phasephasephasephase fromfromfromfrom liquidliquidliquidliquid totototo gasgasgasgas....

Latent heat of Latent heat of Latent heat of Latent heat of vapourisationvapourisationvapourisationvapourisation of water = 970.4 BTU/poundof water = 970.4 BTU/poundof water = 970.4 BTU/poundof water = 970.4 BTU/pound

LATENT HEAT OF MELTING /FREEZING

The heat absorbed as a substance changesThe heat absorbed as a substance changesThe heat absorbed as a substance changesThe heat absorbed as a substance changes phasephasephasephase fromfromfromfrom liquidliquidliquidliquid totototo solidsolidsolidsolid, a , a , a , a process process process process

calledcalledcalledcalled fusionfusionfusionfusion orororor solidificationsolidificationsolidificationsolidification

Latent heat of Latent heat of Latent heat of Latent heat of freezing / melting freezing / melting freezing / melting freezing / melting of water = of water = of water = of water = 144 144 144 144 BTU/poundBTU/poundBTU/poundBTU/pound

UNITS OF HEAT

In British system (FPS) BTU ( British Thermal Unit) & Metric system (CGS) CalorieIn British system (FPS) BTU ( British Thermal Unit) & Metric system (CGS) CalorieIn British system (FPS) BTU ( British Thermal Unit) & Metric system (CGS) CalorieIn British system (FPS) BTU ( British Thermal Unit) & Metric system (CGS) Calorie

What is BTU?What is BTU?What is BTU?What is BTU?

The heat required to rise One pound water to 1The heat required to rise One pound water to 1The heat required to rise One pound water to 1The heat required to rise One pound water to 1°°°°F . Temperature of 1 pound water to F . Temperature of 1 pound water to F . Temperature of 1 pound water to F . Temperature of 1 pound water to

reduce 1reduce 1reduce 1reduce 1°°°°F , we need to remove 1 BTU heat.F , we need to remove 1 BTU heat.F , we need to remove 1 BTU heat.F , we need to remove 1 BTU heat.

What is What is What is What is calorie?calorie?calorie?calorie?

The heat required to The heat required to The heat required to The heat required to rise rise rise rise One One One One gram gram gram gram water to water to water to water to 1111°°°°C.C.C.C.

1 BTU = 252 calorie1 BTU = 252 calorie1 BTU = 252 calorie1 BTU = 252 calorie

1 K 1 K 1 K 1 K calcalcalcal = 3.97 BTU= 3.97 BTU= 3.97 BTU= 3.97 BTU

UNITS OF REFRIGERATION

The amount of heat required to melt 1 ton of ice in 24 hrs. is called ton of The amount of heat required to melt 1 ton of ice in 24 hrs. is called ton of The amount of heat required to melt 1 ton of ice in 24 hrs. is called ton of The amount of heat required to melt 1 ton of ice in 24 hrs. is called ton of

refrigeration or ton. The capacity of ac and ice plant mention in ton. refrigeration or ton. The capacity of ac and ice plant mention in ton. refrigeration or ton. The capacity of ac and ice plant mention in ton. refrigeration or ton. The capacity of ac and ice plant mention in ton.

0.5,0.75,1,1.5,2 ton capacity window ac are available in the market. Capacity of 0.5,0.75,1,1.5,2 ton capacity window ac are available in the market. Capacity of 0.5,0.75,1,1.5,2 ton capacity window ac are available in the market. Capacity of 0.5,0.75,1,1.5,2 ton capacity window ac are available in the market. Capacity of

ice plant and central ac are normal 15 to 500 ton.ice plant and central ac are normal 15 to 500 ton.ice plant and central ac are normal 15 to 500 ton.ice plant and central ac are normal 15 to 500 ton.

A ac machine absorbed 12000 BTU heat per hr. is call 1 ton capacity acA ac machine absorbed 12000 BTU heat per hr. is call 1 ton capacity acA ac machine absorbed 12000 BTU heat per hr. is call 1 ton capacity acA ac machine absorbed 12000 BTU heat per hr. is call 1 ton capacity ac

1ton= 12000 BTU/hr.1ton= 12000 BTU/hr.1ton= 12000 BTU/hr.1ton= 12000 BTU/hr.

1 BTU = 252 calorie1 BTU = 252 calorie1 BTU = 252 calorie1 BTU = 252 calorie

1 ton = 3024 K calorie/hr.1 ton = 3024 K calorie/hr.1 ton = 3024 K calorie/hr.1 ton = 3024 K calorie/hr.

Heat required to melt 1 pound ice in 24 hr. = 144 BTUHeat required to melt 1 pound ice in 24 hr. = 144 BTUHeat required to melt 1 pound ice in 24 hr. = 144 BTUHeat required to melt 1 pound ice in 24 hr. = 144 BTU

Heat required to melt 1 ton ( 2000 pound) ice in 24 hr. = 288000 BTUHeat required to melt 1 ton ( 2000 pound) ice in 24 hr. = 288000 BTUHeat required to melt 1 ton ( 2000 pound) ice in 24 hr. = 288000 BTUHeat required to melt 1 ton ( 2000 pound) ice in 24 hr. = 288000 BTU

So heat required to melt 1 ton ice in 1 hr. = 288000/24 =12000 BTU/hr.So heat required to melt 1 ton ice in 1 hr. = 288000/24 =12000 BTU/hr.So heat required to melt 1 ton ice in 1 hr. = 288000/24 =12000 BTU/hr.So heat required to melt 1 ton ice in 1 hr. = 288000/24 =12000 BTU/hr.

1.1.1.1. 0000°°°°C = 5/9 (C = 5/9 (C = 5/9 (C = 5/9 (°°°°F F F F ---- 32)32)32)32)

2.2.2.2. °°°°F = 9/5 x F = 9/5 x F = 9/5 x F = 9/5 x °°°°C + 32C + 32C + 32C + 32

3.3.3.3. 1 meter = 3.281 ft.1 meter = 3.281 ft.1 meter = 3.281 ft.1 meter = 3.281 ft.

4.4.4.4. 1 ft. = 0.3038 m1 ft. = 0.3038 m1 ft. = 0.3038 m1 ft. = 0.3038 m

5.5.5.5. 1 KJ = 0.9478 BTU1 KJ = 0.9478 BTU1 KJ = 0.9478 BTU1 KJ = 0.9478 BTU

6.6.6.6. 1 kW = 1.341 1 kW = 1.341 1 kW = 1.341 1 kW = 1.341 hphphphp

7.7.7.7. 1W = 3.415 BTU/hr.1W = 3.415 BTU/hr.1W = 3.415 BTU/hr.1W = 3.415 BTU/hr.

8.8.8.8. 1 calorie/ sec = 14.286 BTU/ hr.1 calorie/ sec = 14.286 BTU/ hr.1 calorie/ sec = 14.286 BTU/ hr.1 calorie/ sec = 14.286 BTU/ hr.

9.9.9.9. 1 k Pa = 4.0186 inch of water ( in. of WG or WC)1 k Pa = 4.0186 inch of water ( in. of WG or WC)1 k Pa = 4.0186 inch of water ( in. of WG or WC)1 k Pa = 4.0186 inch of water ( in. of WG or WC)

= 0.339 ft. of H20= 0.339 ft. of H20= 0.339 ft. of H20= 0.339 ft. of H20

= 0.145 psi = 0.01 bar= 0.145 psi = 0.01 bar= 0.145 psi = 0.01 bar= 0.145 psi = 0.01 bar

10.10.10.10. 1 sq. m = 10.764 1 sq. m = 10.764 1 sq. m = 10.764 1 sq. m = 10.764 sq.ftsq.ftsq.ftsq.ft....

11.11.11.11. 1 cubic meter = 35.3146 cubic ft.1 cubic meter = 35.3146 cubic ft.1 cubic meter = 35.3146 cubic ft.1 cubic meter = 35.3146 cubic ft.

12.12.12.12. 1 m/s = 196.85 fpm1 m/s = 196.85 fpm1 m/s = 196.85 fpm1 m/s = 196.85 fpm

13131313 1 cubic meter/ sec = 2119 1 cubic meter/ sec = 2119 1 cubic meter/ sec = 2119 1 cubic meter/ sec = 2119 cfmcfmcfmcfm

14141414 1 cubic meter/ hr. = 0.5886 1 cubic meter/ hr. = 0.5886 1 cubic meter/ hr. = 0.5886 1 cubic meter/ hr. = 0.5886 cfmcfmcfmcfm

15151515 1 l/s = 2.119 1 l/s = 2.119 1 l/s = 2.119 1 l/s = 2.119 cfmcfmcfmcfm

16161616 1 l/s = 15.85 1 l/s = 15.85 1 l/s = 15.85 1 l/s = 15.85 gpmgpmgpmgpm

17171717 1 kg = 2.205 1 kg = 2.205 1 kg = 2.205 1 kg = 2.205 lblblblb (pound)(pound)(pound)(pound)

18181818 1 TR = 12000 BTU / hr.1 TR = 12000 BTU / hr.1 TR = 12000 BTU / hr.1 TR = 12000 BTU / hr.

= 3.517 kW= 3.517 kW= 3.517 kW= 3.517 kW

19 1 mm of water ( aqua) = 9.8 Pa19 1 mm of water ( aqua) = 9.8 Pa19 1 mm of water ( aqua) = 9.8 Pa19 1 mm of water ( aqua) = 9.8 Pa

20 1 in. water ( aqua) = 249 Pa20 1 in. water ( aqua) = 249 Pa20 1 in. water ( aqua) = 249 Pa20 1 in. water ( aqua) = 249 Pa

21212121 1 psi ( pound per square inch) = 0.07 bar1 psi ( pound per square inch) = 0.07 bar1 psi ( pound per square inch) = 0.07 bar1 psi ( pound per square inch) = 0.07 bar

22222222 CfmCfmCfmCfm = cubic feet per minute = cubic feet per minute = cubic feet per minute = cubic feet per minute

23232323 Fpm = feet per minute Fpm = feet per minute Fpm = feet per minute Fpm = feet per minute

24242424 GpmGpmGpmGpm = gallon per minute= gallon per minute= gallon per minute= gallon per minute

BASIC REFRIGERATION SYSTEM

DIAGRAMDIAGRAMDIAGRAMDIAGRAM

REFRIGERATION CYCLEWHAT ARE THE COMPONENTS IN A REFRIGERATOR ?WHAT ARE THE COMPONENTS IN A REFRIGERATOR ?WHAT ARE THE COMPONENTS IN A REFRIGERATOR ?WHAT ARE THE COMPONENTS IN A REFRIGERATOR ?

A.A.A.A. Evaporator Evaporator Evaporator Evaporator

B.B.B.B. CompressorCompressorCompressorCompressor

C.C.C.C. CondenserCondenserCondenserCondenser

D.D.D.D. Expansion valveExpansion valveExpansion valveExpansion valve

What happened in a refrigerator ?What happened in a refrigerator ?What happened in a refrigerator ?What happened in a refrigerator ?

It is a process of removing heat from one substance and transferring it to another It is a process of removing heat from one substance and transferring it to another It is a process of removing heat from one substance and transferring it to another It is a process of removing heat from one substance and transferring it to another

substance.substance.substance.substance.

How and where does it happen?How and where does it happen?How and where does it happen?How and where does it happen?

It happens in the evaporator . Opening the valve allows the liquid refrigerant to flow It happens in the evaporator . Opening the valve allows the liquid refrigerant to flow It happens in the evaporator . Opening the valve allows the liquid refrigerant to flow It happens in the evaporator . Opening the valve allows the liquid refrigerant to flow

in to coil. As warm air is blown over the surface of the coil , the liquid refrigerant in to coil. As warm air is blown over the surface of the coil , the liquid refrigerant in to coil. As warm air is blown over the surface of the coil , the liquid refrigerant in to coil. As warm air is blown over the surface of the coil , the liquid refrigerant

inside the coil will absorb heat from the air, causing the refrigerant to boil while the inside the coil will absorb heat from the air, causing the refrigerant to boil while the inside the coil will absorb heat from the air, causing the refrigerant to boil while the inside the coil will absorb heat from the air, causing the refrigerant to boil while the

air is cooled.air is cooled.air is cooled.air is cooled.

REFRIGERATION SYSTEM

After the liquid refrigerant passes through the coil and collect in the drum as a After the liquid refrigerant passes through the coil and collect in the drum as a After the liquid refrigerant passes through the coil and collect in the drum as a After the liquid refrigerant passes through the coil and collect in the drum as a

vapour. vapour. vapour. vapour.

For functioning continuously you need to close the cycle.For functioning continuously you need to close the cycle.For functioning continuously you need to close the cycle.For functioning continuously you need to close the cycle.

The refrigeration vapour must then be transformed back in to a liquid in order to The refrigeration vapour must then be transformed back in to a liquid in order to The refrigeration vapour must then be transformed back in to a liquid in order to The refrigeration vapour must then be transformed back in to a liquid in order to

return to the evaporator and repeat the process.return to the evaporator and repeat the process.return to the evaporator and repeat the process.return to the evaporator and repeat the process.

A compressor is used to pump the low pressure refrigerant vapour from the A compressor is used to pump the low pressure refrigerant vapour from the A compressor is used to pump the low pressure refrigerant vapour from the A compressor is used to pump the low pressure refrigerant vapour from the

evaporator and compress it to a high pressure.evaporator and compress it to a high pressure.evaporator and compress it to a high pressure.evaporator and compress it to a high pressure.

A condenser is used to cool the refrigerant using air or water as a cooling medium.A condenser is used to cool the refrigerant using air or water as a cooling medium.A condenser is used to cool the refrigerant using air or water as a cooling medium.A condenser is used to cool the refrigerant using air or water as a cooling medium.

PH DIAGRAM

DiagramDiagramDiagramDiagram

1.1.1.1. Heat is a form of energyHeat is a form of energyHeat is a form of energyHeat is a form of energy

2.2.2.2. Heat can vary in quantity and intensityHeat can vary in quantity and intensityHeat can vary in quantity and intensityHeat can vary in quantity and intensity

3.3.3.3. Heat energy can’t destroyedHeat energy can’t destroyedHeat energy can’t destroyedHeat energy can’t destroyed

4.4.4.4. Heat can be transferred from one substance to anotherHeat can be transferred from one substance to anotherHeat can be transferred from one substance to anotherHeat can be transferred from one substance to another

5.5.5.5. Heat always flows from a higher temp. substance to a lower temp. substance.Heat always flows from a higher temp. substance to a lower temp. substance.Heat always flows from a higher temp. substance to a lower temp. substance.Heat always flows from a higher temp. substance to a lower temp. substance.

6.6.6.6. Refrigeration is a method of removing heat.Refrigeration is a method of removing heat.Refrigeration is a method of removing heat.Refrigeration is a method of removing heat.

WINDOW AC

Window ac units comes in 0.5 ton, 1 ton, 1.5 ton and 2 ton . It is mostly preferred Window ac units comes in 0.5 ton, 1 ton, 1.5 ton and 2 ton . It is mostly preferred Window ac units comes in 0.5 ton, 1 ton, 1.5 ton and 2 ton . It is mostly preferred Window ac units comes in 0.5 ton, 1 ton, 1.5 ton and 2 ton . It is mostly preferred

way of cooling the residential and small offices. The unit is divided in to two way of cooling the residential and small offices. The unit is divided in to two way of cooling the residential and small offices. The unit is divided in to two way of cooling the residential and small offices. The unit is divided in to two

partitions , evaporator side and condenser side. Divided with a partition that is partitions , evaporator side and condenser side. Divided with a partition that is partitions , evaporator side and condenser side. Divided with a partition that is partitions , evaporator side and condenser side. Divided with a partition that is

insulated.insulated.insulated.insulated.

GAS CHARGING

1.1.1.1. Discharge pressure = 275 psiDischarge pressure = 275 psiDischarge pressure = 275 psiDischarge pressure = 275 psi

2.2.2.2. Suction pressure = 75 psiSuction pressure = 75 psiSuction pressure = 75 psiSuction pressure = 75 psi

Refrigerant required to charge Refrigerant required to charge Refrigerant required to charge Refrigerant required to charge

1 TR = 1.2kg of R221 TR = 1.2kg of R221 TR = 1.2kg of R221 TR = 1.2kg of R22

TR No. of strands and TR No. of strands and TR No. of strands and TR No. of strands and guageguageguageguage

1.1.1.1. 1 31 31 31 3----20202020

2.2.2.2. 1.5 71.5 71.5 71.5 7----20202020

3.3.3.3. 2 72 72 72 7----18181818

Liquid line size is smaller than gas lineLiquid line size is smaller than gas lineLiquid line size is smaller than gas lineLiquid line size is smaller than gas line

FOR VENTILATION

Open = air comes in from outOpen = air comes in from outOpen = air comes in from outOpen = air comes in from out

Close = sealed , no fresh air comes inClose = sealed , no fresh air comes inClose = sealed , no fresh air comes inClose = sealed , no fresh air comes in

StabilizerStabilizerStabilizerStabilizer

3 Minutes delay stabilizer3 Minutes delay stabilizer3 Minutes delay stabilizer3 Minutes delay stabilizer

1.1.1.1. 1 TR = 3kVA1 TR = 3kVA1 TR = 3kVA1 TR = 3kVA

2.2.2.2. 1.5 TR = 4kVA1.5 TR = 4kVA1.5 TR = 4kVA1.5 TR = 4kVA

3.3.3.3. 2.0 TR = 5kVA2.0 TR = 5kVA2.0 TR = 5kVA2.0 TR = 5kVA

WINDOW AC DIAGRAM

Diagram Diagram Diagram Diagram

Window ac should be placed at such a place where the sun is minimum. If kept in Window ac should be placed at such a place where the sun is minimum. If kept in Window ac should be placed at such a place where the sun is minimum. If kept in Window ac should be placed at such a place where the sun is minimum. If kept in

sun path give shading to (compressor ) unit.sun path give shading to (compressor ) unit.sun path give shading to (compressor ) unit.sun path give shading to (compressor ) unit.

Always above 6 ft. from ground to avoid dust collection.Always above 6 ft. from ground to avoid dust collection.Always above 6 ft. from ground to avoid dust collection.Always above 6 ft. from ground to avoid dust collection.