Split Air Conditioner working principle

SPLIT AIR CONDITIONER SYSTEM BUILDING SERVICES II (ARC313)

Presented by Hima Karthik. S 1190100870 III year V sem SPA Vijayawada

What is a Split Air Conditioner System A split air conditioner consists of an outdoor unit and an indoor unit. The outdoor unit is installed on or near the exterior wall of the room that you wish to cool. This unit houses the compressor, condenser coil and the expansion coil or capillary tubing. The indoor unit contains the cooling coil, a long blower and an air filter.

The indoor and outdoor units are connected with a set of electrical wires and tubing, generally covered using glass wool as an insulating material.

External unit

Internal unit

Tubing

Installation of a split air conditioner is much simpler because it does not require ductwork, so there’s less of a chances of losing a lot of energy due to heat exchange in the air duct system, therefore also decreases the energy expenditures.

Benefits Ductwork

• Quiet performance of a split air conditioner system • Can also opt for multi split system • Energy efficient compared to central air conditioning

Basic working of AC Both indoor and outdoor units of a split AC contains coils with continuously flowing refrigerant fluid inside them. The indoor unit contains evaporator coil whereas the outdoor unit contains condenser coil.

The fundamental principle for an AC to work is to - Keep evaporator cool (colder than the room temperature) and - Keep the condenser hot (hotter than the surroundings).

With the above conditions, the continuously flowing fluid will obviously absorb the heat from the room and eject it out to the surroundings. To achieve this objective, we need compressor and expansion valves.

STEP I The compressor increases the pressure of the refrigerant by compressing it.

The compressor handles the refrigerant in its gaseous state so that as it compresses the gas, the temperature rises along with the pressure. The temperature at the compressor outlet will be far higher than the atmospheric temperature. Therefore, if you pass this hot gas through the condenser(which acts as a heat exchanger), you can easily eject the heat. Fan in the condenser makes it easier.

During this process, the gas gets condensed to a liquid.

Low pressure hot

High pressure

STEP II Expansion valve cools the liquid refrigerant.

An expansion valve is fitted at the exit of the condenser. The purpose of the expansion valve is to restrict the refrigerant flow, thus reducing the pressure of the fluid. The valve is designed to remove pressure from the refrigerant and rapidly cool it down into a cold gas.

The valve doesn’t remove heat, only pressure, but removing the pressure has the effect of lowering the temperature of the refrigerant.

The refrigerant will be cold by the time it leaves expansion valve.

Low pressure High pressure

STEP III Cold refrigerant reaches evaporator coil The gaseous state refrigirant in a very cool state will help cool the air in the room and convert the air to a very low temperature.

Near to the evaporator coils, the air temperature will be quite low. This will lead to water condensation on the evaporator coils. That's why we need a pipe to remove this water condensate. The evaporator coil also has a blower that circulates room air with the coil.

The gas keeps flowing through the compressor, and the process keeps repeating to provide you with cool air in the room.

Main panel

Air filters Blower

Evaporator coil compressor

Condenser coil

expansion valve

Working model of a split AC

Evaporator coil, expansion valve

In simple words, the air in the room will pass through the evaporating coils, and they contain cool gas that makes the air in the room cool.

The air conditioner container blowers and they help in blowing or pushing the cool air back into the room.

The cooling cycle Starting from the compressor, going further through the condenser coil, expansion valve, evaporator coil, refrigerant comes back to the compressor, completing one cycle. This cycle repeats again and again, so that the temperature of the room reaches the temperature that you have set on the air conditioner.

Main panel

Air filters Blower

Blower Internal unit of a split AC

External unit of a split AC

4

3

1

The cooling cycle Drain pipe

2

Tubing of internal unit and drain pipe

Air Conditioner unit parts

Condenser coils

Inverter AC

fan

Compressor

Inverter air conditioner is an air conditioner with variable cooling speed.

These systems provide high-efficiency cooling performance without all the strain or cost of a standard air conditioning system. An inverter air conditioner has a compressor unit that provides a more accurate approach to cooling.

An inverter air conditioner can reach the desired temperature up to 25% faster than regular air conditioners, and can reduce power consumption by 30% to 40% compared to ordinary AC.

External unit

Internal unit

Mesh above air filters

REFERENCES • https://www.networx.com/article/split-air-conditioner-system#:~:text=A%20split%20air%20conditioner%20consists%20of %20an%20outdoor,coil%20and%20the%20expansion%20coil%20or%20capillary%20tubing .

• https://htrmechanical.com/how-does-air-conditioning-work/ • https://homeparticle.com/working-of-split-ac/ • https://www.goservicemax.com/blog/air-conditioning-service/what-does-the-expansion-valve-do-in-an-air-conditioning-s ystem/ • https://www.iamdeepa.co.in/split-ac-working/#:~:text=%20Here%20is%20How%20a%20Split%20Air%20Conditioner,be% 20again%20covert%20into%20a%20gas...%20More%20 .