Have a couple of air cons at home, lived in the same place 5 years. Always get a pro cleaner in every 4-6 months but about every 2 months I give the filters a good spray with the bum gun and usually enough to remove the dusty build up on the filters. Notice last 2 times, particularly the lounge room air con (approx 18000kw), filter really blocked with black greasy <deleted> that isn't easily removed. This time the worst have had to soak it in sunlight, looked like a range hood filter. We hardly every have any windows open in the lounge room, place is swept every day. Not exposed to kitchen fumes or smoking inside etc. Can't work it out?

 

I mean if the air quality inside is that bad can only imagine what it's like outside. Is there something I am missing here or could there be another reason for it. Really effects the efficiency of the air con not to mention our power bill

You probably have a leak of the refrigerant, which contains oil... Hence the oily build up

Get your local AC guy to come round and check the pressures. Might need a re-gas but also find the leak if there is one.

It could well be a coolant leak, is the beast cooling ok and not icing up?

 

To remove the yuk, try a strong solution of washing powder rather than sunlight, I find it removes oily residue very effectively.

I put filtrete paper on my aircon filters due to the Chiang Mai air.

 

After a few weeks they are dark grey, when they were previously white.

 

Without that paper my family would have breathed in whatever is in the filtrete paper.

7 minutes ago, Crossy said:

To remove the yuk, try a strong solution of washing powder

I'll have to try and remember that for next time...my aircon compressor unit is right next to  where "the oil devil" does her 2-3 times daily cooking ..even though I built a  hood and extractor which helps, oil build up takes longer but still clogs things up eventually.

In the past I used some very caustic  "coil cleaner"  which worked wonders but  had to wear long rubber gloves and eye protection..some dripped onto kitchen tiles and stained them  and corroded some metal parts because I dint notice and wash them down quick enough !!!  ( ooh it also eats the special coatings on spectacles )

 

 

I find that dish soap and soft bristled scrub-brush works well to clean the filters.

 

If is a good practice to occasionally run the unit in "Fan" mode all day to dry it out. This will eliminate the mold growth.