We see exhaust fans as a must in bathrooms with showers or baths. Exhaust fans reduce steam and condensation which means mould won’t develop on the ceilings and walls. Mould is dangerous to health and expensive to remove!
We don’t rate the fans in most Heat/Light/Fan fittings. They just don’t seem to do the job! When these fittings are installed, we always recommend installing a separate exhaust fan as well.
Remember, exhaust fans will only be effective if there is air entering the room to replace the air that is sucked out of the room by the exhaust fan, creating circulation. So make sure a window is open even slightly, or have a carpenter shorten your door, so there is a 20mm gap between the floor tiles and the door to allow for circulation.
If you suspect your family members, house mates or tenants are not using the exhaust fan when they shower, have an electrician combine the light and fan in one switch. This way the bathroom user won’t have a choice but to use the exhaust fan!