Guide written by:
Michael, Professional and passionate welder, Sheffield
More effective than a fan and more efficient and affordable than a portable air conditioner, a split model air conditioner can work to considerably lower the temperature of your home during summer heat waves and shouldn't impact your electricity bill too badly – provided you choose the right model for the room in question.
Split air conditioning systems are made up of two units: an outdoor unit and an indoor unit. The compressor, which turns warm air into cool air, is installed outdoors since it can emit noise and vibrations. The unit responsible for blowing out cool air is installed indoors. An air conditioning kit comes with several parts:
an indoor unit with a fixing bracket;
an outdoor unit with a bracket and anti-vibration mounts;
an insulated copper refrigerant line;
a condensate hose;
connection and power cables;
remote control;
PVC cable trunking (optional).
Please note that reversible air to air heat pumps (designed to produce cool air in summer and warm air in winter) can be installed using the method set out below.
Position your indoor unit
Cut chases in your walls
Install the outdoor unit
Connect the units
Test out the air conditioner
The position of your indoor unit depends largely on the length of the refrigerant line that is supplied with the air conditioning kit. You will need to position both the indoor and outdoor units with this in mind. The indoor unit must be installed at least 15cm from the ceiling and at a height of over 2 metres on any load-bearing wall. Avoid setting up your air conditioner too close to any heat sources.
The bracket designed to secure the indoor unit will often be blank allowing you to set out the holes where you want to install the unit. Use a spirit level and tape measure to mark out your anchor points in the bracket. Mark out the spot where the refrigerant line and the cables will be fed through the wall. Use a hammer drill or rotary hammer to drill holes for the wall plugs. Be sure to choose the correct fixings based on the material that makes up your wall.
To link the two units, you'll need the refrigerant line which comes supplied with a liquid refrigerant. This pipe is made up of two insulated copper tubes and is sealed at each end with a special fitting designed to stop the liquid escaping from the pipe. A condensate hose, power cables and cables designed to connect the two units complete the installation kit.
To feed the cables through your wall, pre-drill a hole using a long drill bit. Your hole needs to go right through the wall and should be drilled at a downward angle (ideally: ± 5°) working from the inside.
Then use a drill fitted with a tungsten carbide hole saw attachment in the right size to widen the hole so it's big enough to fit through the refrigerant pipe, the condensate hose and the power cables. Be careful: before drilling the wall with the hole saw, ensure the drill is no longer on hammer mode. This attachment should only be used on drilling mode.
Before you decide where to put the outdoor unit, you need to measure the length of the refrigerant pipe. Choose a clear, well-ventilated spot far away from any obstacles to ensure the compressor can do its job properly. Avoid installing the outdoor unit in a draughty area as this can cause dust to block up the unit. Think about the noise of the unit and place it somewhere where it won't bother your neighbours.
After deciding on the perfect spot, which will largely be determined by the cable lengths, you have two options:
Place the outdoor unit up high: in this case, you'll need a bracket for secure installation (this may be supplied with the kit or purchased separately).
Install the outdoor unit on the ground: in this case, you'll need to anchor the mounts to a concrete surface. It's important to ensure that the unit is not sitting on the ground in order to reduce vibrations.
In either case, you'll need to use anti-vibration mounts (or silent blocs) to absorb vibrations and reduce operating noise.
The best way to link the two units is to fit PVC cable trunking around all the connecting cables for a clean finish.
The two units will produce condensation which is drained out of the condensate hose. The hoses should be secured low down on the wall and directed towards a point where the water can easily drain away. Your drainage set-up will have to handle a maximum of 30 litres a day.
The refrigerant pipe comes with special end feed fittings which are designed to allow you to connect the pipe without losing any refrigerant fluid.
Connect the power cables to the units and plug them in to the mains.
Once the indoor unit is in place, remove the front filter and pour a little water into the condensate tray. If the water drips freely towards the drainage point, your installation has been successful.
Replace the filters.
After leaving the units to settle for a few hours, turn on the air conditioner and check for leaks using a leak detector spray.
A remote control can be used to set whatever temperatures you want. However, for your own comfort, it's best to avoid excessively low temperatures as this can be harmful to health.
It is possible to find reversible air conditioners (heat pumps) also designed to provide heat in the winter. Installation will be more or less the same for these models.
You don't need any particular skills to install an air conditioner. However, you do need to be able to perform a few DIY basics including using a drill to drill through the wall, choosing the right wall plugs, using a spirit level, taking accurate measurements using a tape measure, following instructions and connecting the unit to the power supply safely.
Approx. 4 hours
2 people
Long masonry drill bit
Tungsten carbide hole saw
A set of open-ended spanners
Allen keys
PVC cable trunking
Leak detector
Please note: this is a non-exhaustive list; Be sure to match your personal protective equipment to the job at hand.
Guide written by:
Michael, Professional and passionate welder, Sheffield
I was trained as a pipe worker and a pipe-welder and after having travelled for 35 years working around the UK, I became the head of a metal shop, then a designer and in the end the head engineer. I have designed and built a workshop where I make metal sculptures: I managed to find a piece of paradise where I can let my imagination run wild. Auctions and garage sales are no secret to me. I find unusual objects and old tools there that I collect or transform into works of art. I also like decoration, painting on canvas, and gardening. I am developing new technologies concerning tools. To share my passion and advise you in your choice of materials is a real pleasure.