Air Conditioning Presentation on the basics

a Presentation about the basics of A/C

1. Home Cooling
EGEE 102

2. EGEE 102 -Pisupati 2
Function of an Air
conditioner

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Humidity in air
•Relative Humidity
•A measure of of
much water is
in the air
relative to the
maximum
amount air can
hol at that
tmperature

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http://www.ae.iastate.edu/Ast473/Lectures/%285%29Psychrometric_Chart/sld024.htm

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Principle
A.Expansion Valve
B.Compressor

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Arrangement

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TYPES OF AIR
CONDITIONERS
•Room air conditioners
•Central air conditioning systems
•Heat pumps
•Evaporative coolers

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Air Conditioning

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Room air conditioner
•Room air conditioners cool rooms rather than
the entire home.
•Less expensive to operate than central units
•Their efficiency is generally lower than that of
central air conditioners.
•Can be plugged into any 15-or 20-amp, 115-
volt household circuit that is not shared with
any other major appliances

10. EGEE 102 -Pisupati 10

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Central Air conditioning
•Circulate cool air through a system of supply
and return ducts. Supply ducts and registers
(i.e., openings in the walls, floors, or ceilings
covered by grills) carry cooled air from the air
conditioner to the home.
•This cooled air becomes warmer as it
circulates through the home; then it flows
back to the central air conditioner through
return ducts and registers

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Types of Central AC
•split-system
•an outdoor metal cabinet contains
the condenser and compressor,
and an indoor cabinet contains the
evaporator
•Packaged
•the evaporator, condenser, and
compressor are all located in one
cabinet

13. EGEE 102 -Pisupati 13
Large air conditioning
systems
•Outside air is drawn in,
filtered and heated before it
passes through the main air
conditioning devices. The
colored lines in the lower
part of the diagram show the
changes of temperature and
of water vapor concentration
(not RH) as the air flows
through the system.

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Total Air Conditioning

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•Variable fresh air mixer and dust and
pollutant filtration.
•Supplementary heating with radiators in
the outer rooms and individual mini
heater and
•Humidifier in the air stream to each
room.

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Sizing Air Conditioners
•how large your home is and how many
windows it has;
•how much shade is on your home's windows,
walls, and roof;
•how much insulation is in your home's ceiling
and walls;
•how much air leaks into your home from the
outside; and
•how much heat the occupants and appliances
in your home generate

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Energy Consumption
•Air conditioners are rated by the number of
British Thermal Units (Btu) of heat they can
remove per hour. Another common rating
term for air conditioning size is the "ton,"
which is 12,000 Btu per hour.
•Room air conditioners range from 5,500 Btu
per hour to 14,000 Btu per hour.

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Energy Efficiency
•Today's best air conditioners use 30%
to 50% less energy than 1970s
•Even if your air conditioner is only 10
years old, you may save 20% to 40% of
your cooling energy costs by replacing it
with a newer, more efficient model

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Energy Efficiency
•Rating is based on how many Btu per hour
are removed for each watt of power it draws
•For room air conditioners, this efficiency
rating is the Energy Efficiency Ratio, or EER
•For central air conditioners, it is the Seasonal
Energy Efficiency Ratio, or SEER

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Room Air Conditioners
•Built after January 1, 1990, need have
an EER of 8.0 or greater
•EER of at least 9.0 if you live in a
mild climate
•EER over 10 for warmer climates

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Central AC
•National minimum standards for central
air conditioners require a SEER of
•9.7 for single-package and
•10.0 for split-systems
•Units are available with SEERs
reaching nearly 17

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Energy Saving Methods
•Locate the air conditioner in a window
or wall area near the center of the room
and on the shadiest side of the house.
•Minimize air leakage by fitting the room
air conditioner snugly into its opening
and sealing gaps with a foam weather
stripping material.

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Numerical Problem
•A EER from 5.0 to 9 saving and pay
back period