“ALL OR NOTHING”

A simple look at

Domestic Air-conditioning

An air conditioner (often referred to as AC or air con) is an appliance, system, or

machine designed to change the air temperature and humidity within an area typically using a refrigeration cycle but

sometimes using evaporation, commonly for comfort cooling in buildings and motor

vehicles. There may even be a heating cycle.

In 1902, the first modern electrical air-conditioning unit was invented by Willis Haviland Carrier in Buffalo, New York,

after graduating from Cornell University.

SPLIT - TYPE

1 piece WINDOW - TYPE

Squeezing gas causes it to get HOT, lowering the pressure causes it to

COOL.

***

Hot air rises - cooling air falls.

***

Hot air can hold a lot of moisture.

Cold air cannot hold as much moisture.

Squeezing a gas

causes it to get HOT

Lowering the pressure

causes it to COOL

Where should you place the two parts of a

‘SPLIT – TYPE’ air-con?

First the outside unit.

(Condenser)

The air-con will probably be used at night in a

bedroom.

Do NOT place the outside unit under the window!

Try not to place in direct mid-day sun.

Try to place on a solid wall with no window.

After all this, place as close to the inside unit

as possible. The shorter the pipe, the better the

result.

Where should you place the inside unit of a

‘SPLIT – TYPE’ air-con?There are two types of

indoor unit, WALL & FLOOR.

(Evaporator)

Hot air rises

Cooling air falls

De-Humidifying

The art of drying air

Hot air can hold a lot of moisture.

Cold air cannot hold as much moisture.

SPLIT - TYPE

If you blow hot, wet air against a cold metal box the air cannot

hold the moisture and it will fall as water.

Where does the water go?

SPLIT - TYPE

Two pipes carry gas to and from the indoor unit.

One pipe carries the water from the moist air to the outside

world

SPLIT - TYPE

If indoor unit is out of reach, a remote control is

required.

These days they can be very complex with many useful

cycles of operation.

If long periods of inactivity occur, run air-con for about 10 mins every 3 or 4

weeks. Any rubber or synthetic material will degrade over time and can cause

gas to escape.

NO GAS = NO WORK!

Later Air-conditioners use a more complex compressor control unit

Inverter Controlled Compressor Motors

This allows a variable motor speed and a variable temperature ‘cold-box’.

Much better control of temperature.

More expensive.

The first air conditioners and refrigerators employed toxic or

flammable gases, such as ammonia, methyl chloride, or

propane, that could result in fatal accidents when they leaked.

The first non-flammable, non-toxic chlorofluorocarbon gas, Freon, in 1928.

Chlorofluorocarbon (CFC) Hydrochlorofluorocarbon (HCFC)

Hydrofluorocarbon (HFC) refrigerant

DuPont

Squeezing gas causes it to get HOT, lowering the pressure causes it to

COOL.

***

Hot air rises - cooling air falls.

***

Hot air can hold a lot of moisture.

Cold air cannot hold as much moisture.

Why

“ALL OR NOTHING”

THE END

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