Overview of tips for ventilating a windowless bathroom
Appropriate ventilation is essential to ensure a pleasant and healthy climate in a bathroom. It transports moisture outside and prevents the formation of mould. Regular natural intense ventilation works best. But not every home has a bathroom with natural daylight. Many charming old dwellings have completely internal bathrooms.
What can you do if you have a windowless bathroom? Don’t worry – a few handy tips will help you ventilate even a windowless bathroom! We present various tricks in more detail below:
- Installing a fan in a bathroom with an external wall
- Installing a fan in an internal bathroom
- Draughts for air exchange
- Installing a dehumidifier
High air humidity in the bathroom – points to note
Showering and bathing increase air humidity in a bathroom. Provided the moisture can then escape quickly, this is not a problem. However, if damp air remains in the bathroom for longer periods it could cause mould to develop. Where possible, the air in a bathroom should therefore have a moisture content of 50 to 70 per cent.
Installing a fan in a bathroom with an external wall
Without doubt, the most elegant solution for air exchange in a windowless bathroom is: an electric fan. However, whether your bathroom has an external wall or is entirely internal makes a big difference. In the case of a bathroom with an external wall, it is possible to install a decentral ventilation system to extract the air directly to the outside. Installation is quick and generally not too expensive. You simply need to drill a hole through the wall to install the bathroom fan on the external wall and place the connecting shaft inside the bathroom.
When choosing ventilation for a windowless bathroom, make sure you opt for a model with heat recovery. These systems use warmth from the escaping air to heat the fresh incoming air to the correct temperature. This process consumes very little electricity and is environmentally friendly as it avoids extra heating costs. Decentral ventilation also consumes very little electricity so noticeably higher energy costs are not a consideration. The electricity costs for an entire year – depending on the model and usage intensity – are slightly over 30 euros.
Installing a fan in an internal bathroom
If your bathroom has only internal walls, you can install a central exhaust fan. This will channel air outdoors through pipes or ventilation shafts. This is another relatively practical and cost-effective solution for windowless bathrooms. However, if you choose this type of ventilation, you will need to ensure a flow of fresh air back into the bathroom. You can use, for example, louvres on the bathroom door for this. One disadvantage of this exhaust fan: It has no heat recovery function, which means extra heating costs must be factored in.
What’s more: In windowless bathrooms, the installation of a fan is prescribed by law – according to the DIN 18017 standard in the federal building code for ventilation of windowless rooms. So if you live in rented accommodation, you can discuss this with your landlord.
If you can’t or don’t wish to install a fan, try the following method: Create your own air exchange by causing draughts. Leave the bathroom door open and open windows in a neighbouring room too. But keep doors to other rooms in the house closed to ensure damp air is channelled directly to the open window. It is a good idea to use a hydrometer to check the level of air humidity in the bathroom. You will then always know when it’s time to ventilate – and when you can close the window again. Tip: A fan helps to transport air from the bathroom. Please note: On its own, passive ventilation – for example, louvres on doors – is not enough!
Installing a dehumidifier
Although a dehumidifier does not provide any air exchange, it extracts moisture from the air which improves the indoor climate. Electric dehumidifiers are the most effective. They are often installed on the wall which means they take up very little space. Some models come with an integrated hygrometer which automatically measures the moisture content in the air and switches on when this becomes too high.
One option is to purchase a chemical dehumidifier from a hardware store. However, these are not usually very efficient and can also pose a potential risk if you have young children or pets. A good alternative: Arrange little boxes or sachets filled with salt or cat litter. These substances will extract moisture from the air and they are completely harmless.
Avoiding mould in an internal bathroom
Internal bathrooms are particularly vulnerable to mould. Here are a few important points to note:
- Wipe any splashes of water from the walls after showering or bathing.
- Dry the shower, bath and taps with a towel after use.
- Pull the shower curtain out to its full length after showering to allow it to dry better.
- Do not leave any damp laundry in the bathroom.
- Dry wet towels over the radiator.
- Change all towels at least once a week.
- If you notice any mould in the bathroom, remove it immediately.
Summary: Appropriate ventilation in the bathroom
If you are planning a new bathroom, always choose a layout with a window: As well as letting in lots of light, this will also allow more effective ventilation. But we have some helpful tips if you need to ventilate a bathroom without windows. A fan or a dehumidifier and fan can be very effective. A smart ventilation concept with draughts, a fan and hygrometer will also help you to control humidity. If you remember to dry ceramics and tiles every time you shower or have a bath as well, this will also help to create a pleasant indoor climate in the bathroom even without daylight – as well as preventing mould.