Installation of the Refrigerant Tubing in Ductless Split Air Conditioners

In the previous articles of this series on installation of the ductless split AC we saw the factors to be considered for selecting the location of the indoor and outdoor units and the step-by-step installation of the indoor unit and the outdoor unit. In this article we shall see the installation of the refrigerant tubing, and electric connections.

Installation of the Refrigerant Tubing

Indoor and outdoor units connected by refrigerant
Indoor unit connections
Outdoor unit connections

Installation of the Refrigerant Tubing

Once the indoor and the outdoor units of the split air conditioner have been installed, the refrigerant tubing connecting the two units can be installed. The refrigerant tubing is the flexible copper piping that can be bent easily by bending instruments. Various connections can also be made easily at the end of the copper tubing by using flaring tool. The copper tubing are connected to the indoor and the outdoor units by flare nuts and other flaring fittings using male and female connections. The copper tubing can also be connected to each other by brazing. The refrigerant tubing comes along with the new split air conditioner, and you don’t have to purchase the new one unless the distance between the indoor and outdoor units is too long.

There are two connections between the indoor and the outdoor units. The first connection carries refrigerant at low temperature from the outdoor unit to the indoor unit and the other one carrying return refrigerant at medium temperature from the indoor unit to the outdoor unit.

The refrigerant tubing is laid over long distance and in open atmosphere, which is at very temperature. If the tubing is exposed directly to the sun, the refrigerant flowing from the outdoor unit to the indoor unit will get heated and loose all the refrigerating effect before producing the cooling effect in the indoor unit. To prevent this loss of the cooling effect, the tubing is covered with the insulation material. Similarly, the refrigerant travelling through return tubing from indoor unit to outdoor unit is also at medium temperature and may get superheated when exposed directly to the atmosphere. This can lead to the reduction in the compressor efficiency, and overall reduction in cooling effect. To avoid this, the return tubing is also covered with the insulation material so that the refrigerant enters compressor at lowest possible temperature in gaseous state.

The insulation material is also accompanied with the new split AC. The material used for insulation is foam which is in the form of the tube inside which the copper tubing can be easily fitted. To make the fitting more rigid, the insulation tape is covered with sticky tape though this may not be necessary all the times.

Connecting the Refrigerating Tubing to the Indoor Unit

Here are the steps for connecting refrigerating tubing to the indoor unit of split AC:

1) From the indoor unit of the split AC two copper tubing emerge which are passed through the hole made in the wall, these two tubing have flaring connections at their ends.

2) The distance between the indoor and outdoor unit is measured, and two copper tubing of this length are cut.

3) On one of the ends of the these two tubing flaring connections are made for connecting into the flare nut already available on the tubing emerging from the indoor unit. One can also directly connect the two newly cut tubing to the indoor unit tubing by brazing without making flare connections. One end of each of the two tubing is now connected to the indoor unit.

4) Next, extend these tubing to the outdoor unit. On the way, you can provide support to these tubing to the wall by using brackets so that they won’t keep on hanging here and there. This is to avoid the breakage of connections due to vibrations resulting in leakage of the refrigerant.

5) Before connecting the refrigerant tubing to the outdoor unit, it should be covered with the insulation material, which is usually the foam tube.

Connecting Refrigerant Tubing to the Outdoor Unit

Here are steps for connecting the refrigerant tubing to the outdoor unit:

1) Make the flare connections at the two free ends of the two tubing using flaring tool and inserting the female flare nut.

2) Connect the nuts of each of the tubing to the connector provided outside the outdoor unit and tighten the connection.

The indoor and outdoor units are now connected by the refrigerant tubing. The two units can now be connected together by the electric wiring which is finally connected to the main supply. Now the final process of gas charging and starting of the split air conditioner can be started.

Image Courtesy

1) 220V Appliances


3) Friedrich

This post is part of the series: Installation of Wall Mounted Split Air Conditioners

This is the series of articles that gives step-by-step guide for installation of split air conditioners. It explains various factors, like deciding location of the indoor and outdoor units, their installation, gas charging etc.
  1. Installation of the Split Air Conditioners: Deciding the Location of Indoor and Outdoor Units
  2. Installation of the Wall Mounted Indoor Unit
  3. Installation of the Outdoor Unit of Split Air Conditioners
  4. Installation of the Refrigerant Tubing in Split Air Conditioners
  5. Gas Charging in Split Air Conditioners