Transcript
TYPES OF AIR CONDITIONING SYSTEMS
BASED ON ARRANGEMENT
CENTRAL ZONED UNITARYUNITARY-CENTRAL
PURPOSE
INDUSTRIAL COMFORT/DOMESTIC
CENTRAL SYSTEMCentral AC Systems serve several rooms, the entire system is monitored centrally
using a thermostat
The condenser, compressor, cooling a humidifying coils are located outside the area that has to be air conditioned.
Air is circulated through ducts. Central air conditioning system follow a combination of open and closed cycles of operation. Some of the air is exhausted to the atmosphere while some portion is re-used
PRIMARY AIR FILTER
SECONDARY AIR FILTER (ELECTROSTATIC/FABRIC)
PREHEATER COIL
TEMPERATURE AND HUMIDITY
CONTROL
RECIRCULATED AIR
CONDENSOR COIL
DEHUMIDIFIER
FAN
APPLICATIONS
Big factory spaces
Movie Theatres
Restaurants
Auditoriums
Homes
CENTRAL SYSTEM
ADVANTAGES
The temperature of a very large space can be regulated.
Noise is less as operating equipment is placed outside
Low investment cost when compared to individual units
The exhaust air can be re-used
Though the cost to set-up the unit, the running cost per unit of refrigeration is less
DISADVANTAGES
Very large set-up, occupies plenty of space.
Cost of components like compressors, cooling tubes, ducts are high.
UNIT SYSTEMIn this system, equipment and control mechanisms are packed into a single unit
These are generally used for room air conditioning, as attic fans and remote units
They are generally installed in or near the vicinity of the space that has to be cooled.
ATTIC FAN
UNIT SYSTEMADVANTAGES:
Cost of installation is low
Individual room temperature control is possible
Failure of a unit affects only the area that was served by that unit
It is sufficient to install units in only the rooms where cooling is essential.
HUMIDITY CONTROL
WHAT IS HUMIDITY?Humidity is the amount of water vapour in the atmosphere.
Humidity is measured using a
Psychrometer or Hygrometer
WHY CONTROL HUMIDITY?
Comfort-This is why air conditioners were introduced in the first place.
Storage and Preservation
1. To prevent corrosion
2. Mildew and Mould prevention
3. To prevent condensation
HOW IT HAPPENSThe process of humidity control can be classified as
Mechanical dehumidification
Desiccant dehumidification
MECHANICAL DE-HUMIDIFICATION
MECHANICAL DEHUMIDIFIER
DISADVANTAGES OF MECHANICAL DEHUMIDIFIERS
Very noisy operation
Economical only when used in regions where humidity and temperature are high (above 40% RH)
The compressor unit consumes a large amount of electric power
DESICCANT DEHUMIDIFIER
DESICCANT DEHUMIDIFIER
MATERIALS USED IN DESICCANT DEHUMIDIFIERSZeolites:
-Silica Gel
-Clinitilophite
-Chabazite
APPLICATIONS
PHARMACEUTICAL & BIOMEDICAL INDUSTRY
Any substance has affinity for moisture.
Moisture absorption can affect critical
parameters such as chemical concentration,
thermal expansion
Desiccant dehumidification is generally used.
APPLICATIONSINDUSTRIAL PLANTS, MILITARY AND ELECTRONICS INDUSTRY
One of the primary functions of de-
humidification is to prevent corrosion
Moisture acts as a catalyst
Moisture on PCBs and electronic
components can severely impact their
operation.
APPLICATIONSFOOD AND TEXTILE INDUSTRIES
Moisture and damp conditions are ideal
conditions for the growth of mildew and
mold
Desiccant dehumidifiers are generally
used as the temperature and humidity
in food storage units are generally low.
INDUSTRIAL DEHUMIDIFIER
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