You may have started using the air conditioning more due to the extremely hot and humid weather that is in Singapore. And with that, you started seeing molds growing about your room. It is probably not the AC's fault but the usage of the toilet. This is because when you take a shower, the heat gets dispersed from the water and into the air whereby it stays around in toilet until.. you open it. Hot air rises, cold air sinks, the hot air touches the cool walls and ceilings of the room and condenses creating a lovely environment for the molds to grow on. You could install an exhaust fan for the toilets and turn it on during and after your showers to allow the hot air to go out the other way and not into your room. But the molds are still there anyway, so call us, we will get rid of it for you.