home cooling egee 102. egee 102 - pisupati2 function of an air conditioner

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Home Cooling EGEE 102

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Page 1: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

Home Cooling

EGEE 102

Page 2: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 2

Function of an Air conditioner

Page 3: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 3

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

Page 4: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 4

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

Page 5: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 5

Principle

A. Expansion ValveB. Compressor

Page 6: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 6

Arrangement

Page 7: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 7

TYPES OF AIR CONDITIONERS

• Room air conditioners • Central air conditioning

systems • Heat pumps • Evaporative coolers

Page 8: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 8

Air Conditioning

Page 9: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 9

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

Page 10: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 10

Page 11: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 11

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

Page 12: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 12

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

Page 13: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

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.

Page 14: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 14

Total Air Conditioning

Page 15: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 15

• 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.

Page 16: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 16

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

Page 17: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 17

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.

Page 18: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 18

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

Page 19: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 19

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

Page 20: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 20

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

Page 21: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 21

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

Page 22: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 22

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.

Page 23: Home Cooling EGEE 102. EGEE 102 - Pisupati2 Function of an Air conditioner

EGEE 102 - Pisupati 23

Numerical Problem

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