Does anyone use extractor fans for toilets here？ do they work well？ are  they noisy？ any particular brands are better？

try to have natural ventilation for all toilets if possible. i think the most common brand is KDK

6 hours ago, Topline said:

Does anyone use extractor fans for toilets here？ do they work well？ are  they noisy？ any particular brands are better？

Typically can hear a slight hum - but really depends on how powerful the fan you install. The more powerful, the better it works, but noisier of course.

The installer/contractor will be able to advise what speed/size fan to install for the area/volume you need you need to vent for the bathroom. 

Do consider whether you want to link the fan to switch on when the lights are on, or whether it is linked. Meaning lights on, fans also auto switch on. Convenience versus Flexibility.

don't forget that the extractor fan should be linked to a duct which extracts the air to outside the house. else it will be useless as the air will still remain within the toilet. so you will need to drop your ceiling more or do a box up for the ducting to conceal it.

having the fan linked to lights means you need to leave the lights and fan on after you finish your business else you can extract the air. having the fan on a separate switch will give you the risk of forgetting to turn it off later on and end up wasting electricity.

Read somewhere that extractor fans dont work for humid countries and that getting a dehumidifier is better. But in SG we cannot have electric socket in toilet right？ Anyone using a dehumifier for toilets？ would like to learn how to do it.... extension cord？

Singapore’s weather is so humid so how much can you dehumidify? You may be better off just leaving the toilet door open and let it air through the room windows. 
 

in toilets, you can have shaver points installed. 13A sockets might be able to be installed if the socket is far enough from the water source. I don’t have the Singapore standards documents on electrical installations but the international one which we take reference to for most of our standards shows the zones and distance from water sources where power points can be installed. But I’m not sure if Singapore followed this particular standard or not so it is best you check with your electrician. 

Problem is that toilet has no window....

is toilet ensuite? even if if it a shared toilet within the house, you can leave the toilet door open to let it air after using.

I've lived with extractor fans in my toilets for 10+ years. After this experience, all I can say is that I resolved to only buy homes with toilets that have windows😀

Issues include: 

1. The startup noise of the fan can be noisy as the fan gets older and may wake others in the room if it's an attached toilet.

2. In my case (condo), there is a continuous air duct running from the master toilet to the common toilet and finally terminates at the kitchen yard. Sometimes, heavy cooking from the kitchen can cause smells to "backflow" from kitchen to the toilets and eventually the rooms. So be careful where your fan ducts go

3. Mold is a big issue for poorly ventilated toilets.

I have installed KDK extractor fan (commercial type) and it clears up the humidity, foul smell and circulate the air very quickly.  Maybe I am used to the noise, I find that the noise produced doesn't disturb me.  At my bathroom, I have windows in addition to extractor fan which sends air to the external area of the house.  If I turned on the extractor fan and washed the toilets, it dries up the floor very quickly too.  Extractor fan is is a really good to have feature together with a broad enough louver windows in each toilet.