wall mounted air conditioner problem

[markfox]

This year (after 9 months without use) the air conditioning unit is only cooling the room very slightly although it appears to be working normally. The air filter is clean. Could this be a general maintenance / dirt problem or might the gas need topping up in the outside unit?

[happybaggy]

Sounds as if there could have been a refrigerant leak. Get the experts in! You should not attend to the refrigerant yourself because it is a serious offence to discharge refrigerant into the atmoshphere. (greenouse gasses etc.)