If your bathroom ceiling is peeling and the grout on the shower tiles has turned black, the problem is not cleanliness. The problem is trapped water vapour.
For decades, the typical installation in Greek homes was a simple wall fan connected to the light switch. You walked in, turned on the light, it ran. You walked out, turned off the light, it stopped. The huge mistake: When you finish a hot shower, the bathroom is full of dense steam. By turning off the light as you leave, you also turn off the fan at exactly the moment you need it the most! The steam stays inside, condenses on cold walls, and mould has a field day.
The solution lies in "smart" exhaust fans.
This is the best value-for-money upgrade you can make. The Timer fan is connected to the light switch, but includes its own extra control board and a permanent power supply (L and N permanently connected, Switched Live from the light switch).
You walk into the bathroom and turn on the light. The fan starts. When you finish and switch the light off, the fan does not stop. It continues running for a preset period (5, 10 or 15 minutes) and then shuts off by itself! The run-on time is usually set via a small potentiometer on the unit body.
It gives you the necessary time to extract all the steam from a shower (or unpleasant odours), while you have already left and the light is off for economy. No need to remember anything - the fan does its job on its own.
A fan with a Timer costs just €40-70. Installation is simple (it replaces the old fan 1:1, provided there is a permanent power supply at the back box). It will save your bathroom from frequent repainting and tile re-grouting.
3 cables: Permanent Live (L), Neutral (N) and Switched Live (SL) from the light switch. The fan is powered permanently but only activates when it receives a signal from the switch. If your home has only 2 cables in the back box, a separate line needs to be run.
Here we move to total automation. The unit has a built-in sensor (hygrostat) that continuously measures the humidity levels in the bathroom air. You can set the threshold (e.g. at 60% humidity).
If you simply use the toilet or wash your hands, humidity does not rise significantly - the fan works as a simple Timer. But if you take a hot shower, humidity rockets to 80-90%. The unit detects this and will continue running at full speed, even if the Timer period has already elapsed.
Only when humidity drops back below the threshold (e.g. 60%). Then and only then will it stop. This means after a summer shower (lower water temperature) it will stop sooner, while after a winter steam bath it will run much longer until the space is dry.
Your bathroom remains permanently "dry" and protected, entirely automatically. No need to think about switching anything on or off. The fan takes care of everything by itself - it is the best ally against mould.
The best models combine both functions. After the light is switched off, they run the Timer. If humidity remains high, the hygrostat extends operation. This covers every scenario - from a quick hand wash to a marathon steam bath.
Even if you buy the most expensive fan, it will do absolutely nothing unless you obey one basic rule of physics: To extract air from a room, new air must enter from somewhere (Makeup Air).
The internal bathroom door must never seal against the floor. It must have a mandatory 1-2 centimetre gap at the bottom. Alternatively, fit a special plastic grille low on the door. Without this, the fan creates negative pressure and spins uselessly!
The fan goes high up (on the wall or ceiling), ideally opposite the door. This layout creates a diagonal airflow: dry air enters low through the gap, sweeps the bathroom diagonally, and the moist air is extracted high up.
Mistake 1: Fan next to the door - fresh air enters and exits immediately without cleaning the room. Mistake 2: Fan on the same wall as the window - it "short-circuits" the air. Mistake 3: Door without a gap - the fan makes noise but extracts nothing.
The fan must discharge air to the outside (not into a false ceiling or attic!). Use a Ø100 or Ø125 mm duct in a straight line or with minimal bends. Every 90° elbow reduces performance by 15-20%. At the external outlet, fit a gravity backdraft shutter to prevent cold air from blowing back.
Electricity and water are deadly enemies. You cannot install just any fan directly above the shower or bathtub (specifically in Zone 1 according to the electrical regulation).
Zone 0: Inside the bathtub/shower tray - ALL electrical appliances FORBIDDEN. Zone 1: The ceiling directly above the bathtub - only devices rated IP45+ or low-voltage 12V (SELV) are allowed. The 220V→12V transformer is hidden safely outside the shower zone.
Zone 2: The area 0.6 m around the bathtub - requires at least IP44. Outside zones: If the fan is 1+ metres from the shower, IP20-IP24 is sufficient. This is the safest and most economical position.
The ideal solution for a fan inside the shower zone: 12 Volt SELV. Even if water falls directly onto the motor, there is no risk of electrocution. The transformer is mounted in the adjacent room or in the back box behind the wall.
The Greek electrical installations regulation (ELOT HD 384, Section 701) strictly defines protection zones in rooms with baths/showers. Do not ignore these rules - your life literally depends on correct installation!
🚿 Ditch the simple, noisy fans that switch off with the light. A unit with Timer and Hygrostat costs €40-70, but it will save your bathroom from mould, eliminate black grout and keep your mirrors fog-free!
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