We recently had a client contact us about an installation of three Fujitsu split air conditioners down the side of their house. The units had already been installed and mounted on wall brackets.

House is weatherboard.

Side of house

The distance between the house and the side fence was 940mm. The installers had told the client that that was not enough room to mount the units on the ground as the air coming from the out door unit would hit the fence and potentially cause problems with the air blowing back into the outdoor unit.

As you can see, mounting the unit higher on the wall allows the air to blow over the fence. One potential problem here is to make sure your neighbours are aware that air will be blowing over the fence and they have no objections.

Split system mounted on the weatherboard wall

Installation requirements seem to vary from unit to unit and brands. A rule of thumb would be the higher the unit in KW, the further it would need to be away from the fence. Some manuals will specify any where from 200mm to 600mm from the front of the unit to the fence. I have seen some that say 2m.

This particular model was the FUJITSU ASTG09KMCA which specifies only 200mm to be in front of the unit and 100mm behind.

 The measurements on this install where,

Back of unit from the house – 200mm

Depth of unit – 290mm

Space left in from of unit to fence -450mm


 That distance looks like it is ok.

Split system mounted on the the ground


The installers insisted that the units be mounted on the wall at a height that would allow the air to blow over the fence instead. They owners decided to go ahead with that solution but still had doubts as to wether it was going to be suitable.


When units are wall mounted onto weather board houses, they can cause some vibration. Depending on the stability and integrity of the boards themselves, this can cause quite a disturbance in noise. It’s not a loud noise, it generally comes out as a low hum/vibration that is audible especially at night when there is less ambient noise around. Two of the units were installed in bedrooms. The owners unfortunately did find this to be the case and contacted the installation company about it. They were told that it was too bad because they had authorised for the work to go ahead. They could re-install them, but at a cost.

We where contacted by the owners and asked about our thoughts and also asked to quote on de-commisioning and relocating the units for them. Based on Fujitsu’s requirements we though the install could have gone ahead with the units on the ground.

Why would the installers insist on mounting on the wall? One reason is they may not have really known exactly what distance would be ok and figured better to be safe (although not so sorry) which makes you wonder what else they don’t know. Or it could have been a sales/install mis-communication (not uncommon in bigger air conditioning companies). The sales guys tell the client one thing and the installer arrives ready to install another. Easier to talk the client into going ahead than to re-organise the install with different materials, fittings etc.

The outcome at this point is the owners have taken the AC company to tribunal to recover the cost of having the units re-located.