1. AIRCONDITIONING BASICS
AIR-CONDITIONING CAPACITY
TR or ton of refrigeration - unit of measure of all air conditioners.
Indicates a certain quantity of heat.
British thermal unit (BTU) is the quantity of heat needed to raise the temperature of 1 pound of water by 1 degree F
Calorie is the metric unit of heat quantity. It is heat needed to raise temperature of 1 gm of water by 1 deg C Cal = 1 kilo calorie (K Cal)
1TR = BTU = 3000 K Cal

2. AIR CONDITIONING IN TODAY'S CONTEXT:
In hot climate the air has to be cooled,
in cold climate the air has to be heated,
in dusty space the air has to be cleaned and
In all the above cases the air has to be properly distributed.
Here air conditioning is required mainly for human comfort.
But some times for other purposes like manufacturing goods, medicine, textiles etc the temperature and humidity control may vary. For this purpose also air conditioning is required.

4. AIR CONDITIONING PROCESS
Controlling the quality of indoor air for the benefit of Human comfort, human health and performance of equipment /process.
Human comfort is related to the control of temperature, humidity and air movement.
A process called REFRIGERATION controls the temperature and humidity.
The human health is related to the control of dust, pollutants and other contaminants. This is achieved by filtration or by dilution of air.

5. DEFINITIONS
process of treating air and simultaneously controlling temp, humidity, impurities and distribution for comfort and health of human being and/ or for the industrial process permitting the best product yield during manufacture and storage.
Process, which heats, cools, cleans and circulates air and controls its moisture content, simultaneously and on a year round basis.
Science, which deals with supplying and maintaining desirable internal atmospheric conditions irrespective of external conditions. Temperature control, humidity control, air movement & circulation, air filtering/ cleaning/ purification.

6. TEMPERATURE CONTROL Temperature most suited to majority of people
It varies in summer (20 to 23 deg C) and winter (18 to 22 deg C) due to body temperature
Office, club, lounge etc – 24.5deg C
Residence, Hotel rooms, Guest house etc – 24deg C
Shops, super markets, Cinema halls, Public places – 23.5deg C
Major operation theatre – 21deg C
Computer rooms, Laboratories etc – 22deg C

7. HUMIDITY CONTROL Amount of moisture present in air
Varies from place to place & time to time
Coastal areas are more humid
DEHUMIDIFICATION
Removal of excess moisture from the air
HUMIDIFICATION
Adding moisture to any volume

8. RELATIVE HUMIDITY
Ratio of amount of water vapour present in air to maximum amount of vapour the air can hold in a given temperature
If the temperature increases the capacity to hold moisture also increases
At 70°F, 8 grains = 100%. At 80°F, 11 grains = 100%.
To increase RH, increase actual moisture content or decrease the temperature of the air.
To decrease RH, decrease the moisture content or increase the temperature of the air.
100% indicates the saturation level

9. Human comfort – %
Pharmaceutical – %
Computer lab etc – %
Spinning & weaving – %
Low humidity - the air has very less moisture content. The air has tendency to absorb moisture from the surrounding.
High humidity – uncomfortable, reduces evaporation process through skin and in turn cooling of body. Our body maintain comfort by perspiration as in coastal weather

10. AIR MOVEMENT
Keeps the body comfortable during hot weather. Increase in air movement results in,
Increase of evaporation process as the moisture of skin evaporates faster
Increase of convection process as the warm air next to the body is carried up faster.
Increase of radiation process due to removal of heat from the surrounding surfaces
Decrease in air movement decreases evaporation, convection and radiation which, decreases heat removal process from our body, keeps the body comfortable in cold weather
Air movement is created by - fans or blowers, through ducts for even distribution

11. VENTILATION IN AC AREAS
It is supply of fresh air, its circulation and distribution
Same air cannot be re-circulated again and again. After some time some fresh air may be added for human comfort. This is done through a cowl (small opening) in AHU room.
In rooms provided with window AC system always allow some fresh air when ac is not being used.

12. DUST CONTROL DUST CONTROL IN AC AREAS
Dust enters ac areas through openings like door etc
Through occupants
Use different types of filters

13. PURITY & FILTERS: Air to be free from dust, dirt and other impurities
Clean air for breathing and human health
In food product manufacture place dirt, germs create harmful effects
Clean air needed in manufacturing processes
Clogging of dirt etc., may create serious hazards to machinery parts
To maintain purity Air filters are used.
Filters are normally located in R.A. path
Various filters effectively reduce the above hazards

14. FILTERS All air filters can be divided into five basic types.
Dry filters
Viscous impingement filters
Electronics filters
Chemical filters
Carbon filters
Submission particulate “absolute” filters

15. 1 Dry filters
They separate dust, pollen and bacteria by using fabrics of woven cotton, wool, felt, cellulose or fiber glass.
The filter is supported in wire or angle frame located in return air path.
Fiber glass media is less expensive and very widely used.
Confined to smaller systems. Sizes x 450, 500 x 500, 600 x 600, etc
Airflow required is up to 5-metre cube per second.
Permanent dry type
Efficiency 95%. Materials – fabrics processed from plastics or brush type.
Serviced by washing or by compressed air or vacuum cleaning.

16. Dry filters Dry replaceable media type
Efficiency 95%. Fabric media over metal frame
Serviced by replacing the media.
Used as main filter or as pre filter to high efficiency filters.
Throwaway type –
Efficiency up to 95%. Used in smaller plants
Panels with filter media of fabrics, plastics, glass or metal fibre over wood or metal frame.
Standard filter -
a) Metallic filter – ½”, 1”, 13/4” thick.
b) Polypropylene coir filter – ¼” thick.
These are used in simple applications of comfort A/c.
It can be used in central, packaged and window units.
Dust filteration is up to 25 to 30 microns.

17. 2 VISCOUS IMPINGEMENT FILTERS
screen or mesh in a metal frame.
Glass fibre or other fiber filter medium covered with viscous adhesive or oil film to retain dust particles.
Metal media impingement filters are washed with hot water / steam / solvent to remove dust particles. Later it is cleaned with oil solution.
Expensive Impingement filter - available in automatic roll models
Viscous impingement filter –
Efficiency 80 – 90% Used for industrial or engine air taker.
Serviced by washing and reoiling.
Automatic air filters -
Efficiency up to 90%. Used for larger systems.
Operation normally time switch controlled.
Deposited dust can be removed manually.

18. Self Cleaning Viscous Type Air Filter (Oil Wetted) For removal of coarse and abrasive dust usually used as first stage filter in industrial application. To remove fibrous dust from the main air stream. very tough and rigid Area like Cotton/ Textile/ Jute/ Mills, Steel & Cement Plants, Fertilizer Units, DG set house etc. Self cleaning in nature, easy/ low maintenance Available on various designs in multiple sizes to suit clients exact requirements .

19. 3 ELECTRONIC FILTERS
High voltage used to attract dust particles over electrically charged plates installed in the return air path.
Impingement filters as pre-filter to remove coarse dust particles & to create constant pressure across the plates.
Removes smoke & fine particles, initial cost is high.

20. Electrostatic cleaners Achieve optimum filtration level down to 0
Electrostatic cleaners Achieve optimum filtration level down to 0.1 micron. To be backed by microwave filters or pre filters Booster fan is not necessary for this

21. ELECTROSTATIC FILTER 1. Dirt Laden Air 2. Pre-Filter Screen 3
ELECTROSTATIC FILTER 1. Dirt Laden Air 2. Pre-Filter Screen 3. Electronic Filter Cell 4. Activated Carbon Filter 5. Circulating Fan 6. Clean Fresh Air

22. NASAL AIR FILTER This Indian patented product is not yet produced in India. It is available in other countries for the use of people. In India it has a large market as the dust pollution is at it's high in the Indian cities. People and Children are exposed to the pollution, dust and stink which causes severe health problems. This simple, soft, disposable, cost effective ( Rs 2/-per one day use) filter have a market of 10 million in Indian cities daily. Gives you a pleasant fragrance always when you walk through dusty smelly road sides, and while talking to others you are protected form airborne communicable diseases. I am ready to sell the patent right to the reputed company who wish to produce and market the filter in India.

23. 4 CHEMICAL FILTERS
consists of a belt with nozzles on top.
Nozzles spray solution of glycerine, germicide and odour absorbing chemicals.
Absorbs dust, dirt, bacteria,odour etc.
Solution collected in a basin at the bottom & When saturated with contaminants, cleaned by chemicals and recirculated.
Very expensive and used in hospitals etc.

24. 5 CARBON FILTERS To remove objectionable odor from the air.
Useful when outside air polluted
Useful when same air is re-circulated continuously
Carbon pack filter –
To remove odours, fumes, vapours, gasses, etc.
Carbon is activated and this filter quickly clogged with atmospheric dust.
As per the manufacturers recommendation throwaway type OR reusable type may be adopted

25. CARBON FILTER

26. ACTIVATED CARBON FILTER
Activated Carbon - Odour Absorbing Filter The simple human activated carbon filter naturally absorbs odors. After extended use, the filter's odor absorbing ability can be recharged by placing it in direct sunlight. HOW TO USE
simply peel off the double-sided adhesive tape on the back of the filter and attach to a clean surface area where there are odors, such as the underside of your trash can's lid or inside a cabinet door

27. 6 ABSOLUTE FILTERS
Pleated continuous sheet of filter of glass-asbestos medium with ply wood, metal frame. The pleats are separated by corrugated paper or aluminum foil inserts.
Used to filter airborne contaminants to protect life, to recover valuable products or in clean rooms
Hospitals - to remove bacteria, Atomic reactors - to remove radioactive dust, Food and drug plants - to provide sterile air
Dry filter as pre-filter to remove coarse dust particle for better efficiency.

28. HIGH EFFICIENCY PARTICULATE AIR (HEPA) OR ABSOLUTE FILTERS
For filtration below 5 microns. Filter particles down to 0.3 microns. Used in central A/c, package unit, etc.
Booster fans are needed for this. Microwave and metallic filters as pre-filters
Microvee filter
Dust filtration up to 5 microns.
For computer rooms, operation theatre etc
Incorporated in central, packaged units

29. HIGH EFFICIENCY PARTICULATE AIR (HEPA) OR ABSOLUTE FILTERS

30. SELECTION FACTORS for FILTERS
Flow rate of the filter.
Face velocity of filter ( air in m/s entering the effective face of filter).
Resistance i.e., difference between static pressure upstream and downstream specified for clean and dirty conditions.
Efficiency of filter
Dust holding capacity
Economy, durability and maintenance.
Fire safety.

31. LOCATION AND INSTALATION OF FILTERS
Before cooling coil to protect from dust
For high degree filtration two filters - Pre filters at down stream & regular filter before cooling coil or up stream.
Avoid fresh air intake through roof surface & from fume and odor.
Servicing accessibility for filter cleaning
A meter after filter to change or clean filter medium
All ducts should be clean before the filters are cleaned.
Air tight filter frame to prevent percolation of dust
Door and hatches giving access to live high voltage conductors of electrostatic precipitator should be equipped with locks.

32. NON CENTRAL AIR-CONDITIONING UNITS
1. Window air-conditioner (unit ac)
2. Split Air-conditioners
2a) Floor mounted
2b) Wall mounted
2c) Ceiling mounted – (exposed, hidden & cassette type)

33. WINDOW AIR CONDITIONERS
Compressor, condenser, fan, evaporator, capillary tube in a single unit
Fixed on any external wall or a window (blocks light partially)
5 deg slope to exterior is needed for easy flow of condensate water
Fixing location should serve best possible air circulation
Hermetically sealed (air tight steel shell with compressor and motor) reciprocating, scroll or rotary type compressor is used
Precaution to be taken for hot air released by condenser
Noisy and no uniform air circulation but economical
Lower level fixing helps in easy maintenance and operation
For narrow / long room - high level installation - better air circulation
Adjustable grills are provided to direct air movement
Available from 0.5 to 2 TR suitable for 5 to 20 Sqm
Larger spaces to be handled by multiple units
‘Filter clean reminder’ notice & sleep mode facility

34. WINDOW AC UNIT

35. Window Air Conditioner with Electronic Controls Ideal for large-size rooms up to 1672 square feet, delivers a 2TR cooling capacity and an energy-efficiency rating of 9.4 electronic controls - full-function remote capabilities, simple to operate, variable-speed fan, multiple air direction, energy saver and sleep modes, 24-hour on/off timer, and auto cool offer a filter-check reminder and clean-air features

36. WINDOW AC UNIT AND COOLING CYCLE For every sq m 200 btu (0
WINDOW AC UNIT AND COOLING CYCLE For every sq m 200 btu (0.6 TR) is needed as a thumb rule

37. PARTS OF WINDOW AC UNIT

38. WINDOW AC UNIT

39. WINDOW AC UNIT
Advantages-
Each room can be controlled with required humidity & temperature.
Ducts are eliminated
No plumbing work needed.
Simple, low cost & easy to install
Disadvantages-
Noisy & servicing is needed
Requires an external window
Occupies space in window
Aesthetically pleasing
Distribution not uniform

40. WORKING PRINCIPLE OF WINDOW AC
AIR CYCLE in Window AC
Evaporator with cooling coil consists of cold refrigerant
The Fan blows air in to the room through grilles
During this process the air is dehumidified to some extent and moisture is collected in tray
The used air or hot air from the room enters the unit through filter at the lower portion
This air mixes with outside air and is blown by fan through evaporator as conditioned air to room
This conditioned air is used by the occupants for comfort and the air cycle repeats

41. REFRIGERATION CYCLE in Window AC
Evaporator - cold refrigerant with low pressure
Air blows over it - cooled - refrigerant becomes hot vapor - under low pressure
Hot vapor - to compressor - pressure - hot & high pressure vapor – to condenser coil
Out side air – blow over condenser coil - absorbs heat & become hot - vapor inside coil - liquid (under high pressure)
High pressure Liquid refrigerant - capillary tube - pressure is released - becomes cold refrigerant - passed to evaporator
Evaporator - cold refrigerant - air is blown - conditioned, circulated
Evaporator - air partially dehumidified - water collected in a tray – to another tray below condenser - evaporates - cools condenser
Compressor, condenser - outer portion - cools from outside air through fan - position - to reduce the noise to interior
control panel - controls refrigerant temp - human comfort.

42. COMPARISON OF UNITARY SYSTEM WITH CENTRAL SYSTEM
Saves installation and labour
Reqd temp of each room is met
Zoning, distribution, duct eliminatd
Unit run only where A/C is needed
Failure restricted to particular rm.
Easy to A/C the spaces in phases.
Large area this works out costly
Noise/vibration cannot be elimintd
Maintenance disturbs the room.
CENTRAL SYSTEM
Installation cost is more
Uniform throughout.
Zoning, Ductwork is a must.
Runs throughout
Failures disturbs all A/C area.
A/C system - worked out - including future expansion
Economical for large areas
Remote plant rm - eliminate noise, vibration
Easy maintenance

43. SPLIT AIR-CONDITIONING UNIT
Two units - indoor unit (IDU) & outdoor unit (ODU)
IDU & ODU – linked by refrigeration tubing & electrical cables
ODU can be mounted outside the room
ODU - condenser, fan, compressor -reduce noise
IDU - evaporator and blower fan
Available up to 5TR
Many advantages over window unit
Non-availability of suitable window or external wall, noisy interior etc

45. SPLIT AIR-CONDITIONING UNIT
Multiple units to cool 2 or 3 adjacent rooms
Fits well to the interior aesthetics
occupies space for ODU
Frequent operation of doors may bring fresh air but not desirable for large spaces
Best for executive cabins, show rooms, noise less commercial spaces etc
Hermetically sealed (air tight steel shell with compressor and motor) reciprocating, scroll or rotary type compressor is used

46. SPLIT UNIT

47. SPLIT AIR-CONDITIONING UNIT
Piping between IDU & ODU
Ensure right distance between the two units, if increased the disadvantages are,
The refrigerant pressure drops and decreases cooling capacity
The lubricant oil does not return to compressor & damages the compressor. (Provide oil trap at every 3m in suction line)
Extra un-evaporated refrigerant in long tube flows back & damages the compressor
Insulation cost increases for refrigerant piping
ADVANTAGES
Elegant look, Add beauty to the interior
Reduces noise level, Easy maintenance
Electronic control – precise, sleek, accurate control, saves power

48. CONDENSATE WATER IN SPLIT UNITS
Evaporator - moisture of the air accumulates as water
Collected in a pan and drained out by gravity / pump, slope needed
MOUNTING OUTDOOR UNIT
Good air circulation - open space – good air movement - close to IDU
Support and structural care – servicing - railing, safety measures
locations - plinth protection, over sunshade, terrace, wall with supports
Care for ODU coastal regions
Avoid - condenser fan facing sea wind – reduce speed
Avoid - close to ground - sand dust clogging the condenser coils
Supports coated with anticorrosive paint
Switch, electrical components - protected from moisture

49. SPLIT AIR-CONDITIONING UNIT TYPES
Floor mounted
Wall mounted
Ceiling mounted
Exposed type
Hidden type
Cassette type

50. FLOOR MOUNTED on floor or a platform - elegant unit with grills Air throw is upwards - affect the furniture layout Occupies floor space - not very user friendly

51. FLOOR MOUNTED

52. WALL MOUNTED
Fixed above 2m over wall - Control by cord or cordless remote - Saves floor space, Ideal for congested rooms - Most widely used type

54. WALL & FLOOR MOUNTED UNIT

55. WALL & FLOOR MOUNTED UNIT

57. WALL MOUNTED UNITS

58. CEILING MOUNTED – EXPOSED
Directly fixed to the ceiling - resembles floor mounted type but in ceiling
Easy to fix - No false ceiling - Cord or cordless remote unit for control
Turbo splits are large type units (5TR) to cover large areas
CEILING MOUNTED – HIDDEN
Hidden in a box like unit or false ceiling - Additional cost - Interior looks bright and uniform - Cord or cordless remote unit for control
CEILING MOUNTED – CASSETTE
Mounted above false ceiling - Outlet grill flush with surface of false ceiling - Cord or cordless remote unit for control
Slim, occupies less space - placed directly above the required area
Multiple units - for larger spaces
A small motorized pump to drain out condensate water

59. SPLIT UNITS

60. CEILING MOUNTED UNITS

61. CEILING MOUNTED

62. The cold side, consisting of the expansion valve and the cold coil, is generally placed into a air handler. The air handler blows air through the coil and routes the air throughout the building using a series of ducts. The hot side, known as the condensing unit, lives outside the building.
A split-Ductable system air conditioner splits the hot side from the cold side of the system

63. REFRIGERATION CYCLE IN PACKAGE UNIT

64. FLOOR MOUNTED PACKAGE UNIT

65. DX SYSTEM

66. CENTRAL AC – CHILLED WATER SYSTEM AC PLANT ROOM WATER COOLED CONDENSER AHU ROOMS PLENUM / FC