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What Is A Split System Air Conditioner?

Air conditioning systems are beneficial for a number of reasons. Not only are they great for lowering and regulating temperatures, but they also boast a number of health benefits too.

There are many different air conditioning systems to suit a variety of needs. One of the most popular types is the split system air conditioner. In this guide, we’ll explain the split system AC as well as how they work, how they are installed and how you can benefit from this type of system.

What is a split system AC?

A split system air conditioner consists of inner and outer components or units. These two parts of the system are connected by piping and electric cable, which allows the refrigerant, a cooling agent used in refrigeration products, to flow to and from each unit. The largest part of the air conditioning system, which is also the loudest, is situated outside, while the lighter and quieter unit can be placed almost anywhere inside a building.

More modern designs of split system air conditioning can be worked with a remote control as well as being fitted with a heating pump facility. This ensures the system can be used all year round for maximum comfort and optimum room temperatures. As well as this, systems now have built in timers and different controls to personalise your experience with every use.

What is a multi split system air conditioner?

Where a single split system has one indoor unit, the multi split air conditioner has multiple indoor units in different rooms. This system would be ideal for properties which need air conditioning in more than one room or area, or if you live in a house with more than one floor.

How does a split air conditioning system work?

In general, air conditioners use certain chemicals that can change their form from a gas to a liquid. This particular system works by a refrigerant being fed into the system’s compressor. The refrigerant starts off as a low pressure gas. When the gas heats up and is pressurised, it is then condensed into a liquid. The liquid then travels through condenser tubes and becomes a gas again.

When the gas loses pressure, it also releases heat and becomes cooler, thanks to the refrigerant. Then, when the gas passes back into the compressor, the process repeats itself. This is the main cycle.

Throughout this cycle, the air from a room is pulled into the air conditioning unit and travels over the evaporator coils. This cools the air and pushes it into the room through the indoor air conditioning vents. The air continues to circulate around until a specific temperature is reached. This temperature can be amended remotely by a control. When it is reached, the system shuts off to conserve energy.

How to install a split system ac unit.

The installation of a split air con system should be carried out by a professional engineer. The way to install a split system air conditioner may vary depending on its manufacturer, but here is the basic way an interior unit will be installed:

  • You’ll need to find an ideal place for your inside wall unit to sit. This place should be away from direct sunlight and heat, and somewhere where there is around 15 cm of open space around all of the sides. The wall you choose should also be able to take the weight of the system. In some cases, an additional frame can be used to provide much more support for the unit.
  • The first job is to secure the mounting plate to your chosen interior wall. Your engineer will measure the perfect height for your unit to sit and fix the plate to the wall with screws.
  • You’ll then need to create a hole above the mounting plate to fit the system’s piping through. Before this is done, the length of the piping and the distance to the outside unit needs to be considered.
  • Check the inside unit and its connections, and then connect the pipes from the inside unit to the outside unit. Your engineer will know the length and type of pipe and connect the two, as well as how to connect the drainage pipe to the base of the interior unit.
  • The indoor unit will then be connected to the mounting plate ready for the set up of the outside unit.

The outdoor unit can then be installed:

  • The outdoor unit will also need to be located in a suitable place, away from hot areas or where there is a lot of movement. It will need around 30cm of space around the outside of the unit.
  • The ground underneath the outdoor unit will need to be levelled out before it is placed in position. It’s common for a concrete slab or similar to be laid on the ground where the unit will sit, but it needs to sit high enough from the ground to prevent anything such as water from flooding or snow from entering, for example.
  • The outdoor unit can now be placed in the desired spot and the wires from the indoor unit can be connected. Your engineer will remove the cover of the outdoor unit and connect the wires correctly. When everything is secured, the cover can be replaced.

When the indoor and outdoor units of the split system AC are secured, it’s important to bleed the air from the outdoor unit. You should also secure the pipework to the wall using clamps and screws and seal up any holes. It’s important to remember that split system air conditioner installation should always be carried out by a registered professional.

The benefits of a split system air conditioner.

Opting for the split system AC can be beneficial for a number of reasons, both for residential and commercial use:

Easy to install.

Even though the process of installing a split system air conditioner is relatively straightforward, it’s important that an engineer does it for you. Once the indoor and outdoor units are set up, all that’s needed is the feeding through of pipework from one to the other and to ensure that holes are sealed and pipes are held into place.

Quiet in operation.

The noisiest parts of the air conditioner such as the fan and the condenser are conveniently placed in the outdoor unit, meaning that the quietest part of the air conditioner is indoors. This means the split system can keep your rooms cool as quietly as possible.


One of the main advantages of this system is its ability to heat different rooms with multiple cooling units. With the multi split system, you’ll be able to amend the temperatures of different rooms where you see fit thanks to the thermostat and remote control, and only cool the rooms you need to, saving money and energy in the process.

Energy efficient.

Split systems help to reduce the amount of energy used and ensure you’re not wasting power. Multi split system air conditioners have the added benefit of operating more than one indoor unit but is still one of the most energy efficient air con systems around. However, it’s important to choose the right system for your property to prevent energy wastage.

Cost effective.

The average cost of split system air conditioning systems can vary as with any large purchase. As a guide, the system and installation costs can start from around £1000 to £2000 depending on how many units you need and the installation costs. However, split systems can pay for themselves over time, especially with the energy efficiency of them saving you money on your bills each month.

The split system air conditioner can be a worthy investment.

This type of A/C system does have its benefits. With so many options combined with optimum convenience, you can easily be able to control the temperature of your home, without any stress.

Get a custom quote from BOXT for your split system air conditioner. Our engineers are ready to answer any questions you may have – talk to us today through our live chat or, alternatively, find out which air conditioning system would be perfect for your home by using our quick ‘Find An A/C System’ tool.

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