Bathroom Ventilation

[leescortxr3i]

Hi. I've bought a powerful extractor fan for my bathroom for a wetroom area. I've heard stories online about needing to have an INTAKE of air somewhere in the bathroom either through an open window/trickle vent or a vent in the bathroom door (or leaving the door ajar). I had a thought and wanted to know if the method below could be an alternative. I was thinking of putting a short duct run to span the wall between the bathroom and the stairs landing area outside the door which could act as an air source to bring into the bathroom rather than having to leave the door/window open. One advantage of this would be that it would be bringing in warm air from the landing rather than cold air from outside. I've tried to illustrate it below (excuse the crude drawing! )
Cheers, Lee

 

[Murdochcat]

Shortening the door by about 6 mm does the job and don’t leave the window open in this weather, as it makes things worse

 

[foxhole]

Gap under the door does it , definitely don’t leave door or windows open .

 

[Odds]

Victorian Plumbing advises...

• Leaving windows open during and for a while after showering or taking a bath will stop condensation forming. If your bathroom doesn’t have any windows, leaving a door open will reduce the presence of excessive amounts of moisture. Keeping any damp laundry or towels out of the room will also go a long way to combat condensation.

 

[foxhole]

Victorian Plumbing advises...

• Leaving windows open during and for a while after showering or taking a bath will stop condensation forming. If your bathroom doesn’t have any windows, leaving a door open will reduce the presence of excessive amounts of moisture. Keeping any damp laundry or towels out of the room will also go a long way to combat condensation.

On a cold day will drastically increase condensation .No explanation given by the shop?

 

[Murdochcat]

Victorian Plumbing advises...

• Leaving windows open during and for a while after showering or taking a bath will stop condensation forming. If your bathroom doesn’t have any windows, leaving a door open will reduce the presence of excessive amounts of moisture. Keeping any damp laundry or towels out of the room will also go a long way to combat condensation.

That advice is not to be recommended

 

[Jurassicspark]

That advice is not to be recommended

Please can you explain why it shouldn't be recommended?

 

[pcaouolte]

The idea is to achieve a flow of air across the room, to change the moist air in the room for dryer air.

If your extractor fan is in the ceiling at one end of the bathroom the ideal air intake is at floor level at the other end of the bathroom, this will introduce warm dry air from another room into the bathroom while the fan expels the moist air.

Opening a window often provides a short path for outside air to enter the room and leave by the fan, this air misses a lot of the room and doesn't provide complete air changes, leaving a lot of the moist air in the room.

Opening the bathroom door often allows moist air to escape from the bathroom and make bedrooms damp.

The advice to open a window would be better than doing nothing if there was no extractor fan. It is difficult to see any circumstances where leaving the door open would be a good idea.

 

[Murdochcat]

Please can you explain why it shouldn't be recommended?

Because the OP on this thread has a fan and wants to make it more effective.

Leaving the window open during a shower or bath will simply add to the moisture in the room ..................

 

[leescortxr3i]

The idea is to achieve a flow of air across the room, to change the moist air in the room for dryer air.

If your extractor fan is in the ceiling at one end of the bathroom the ideal air intake is at floor level at the other end of the bathroom, this will introduce warm dry air from another room into the bathroom while the fan expels the moist air.

Opening a window often provides a short path for outside air to enter the room and leave by the fan, this air misses a lot of the room and doesn't provide complete air changes, leaving a lot of the moist air in the room.

Opening the bathroom door often allows moist air to escape from the bathroom and make bedrooms damp.

The advice to open a window would be better than doing nothing if there was no extractor fan. It is difficult to see any circumstances where leaving the door open would be a good idea.

Thank you that makes sense. Ideally I'd want an air inlet at ground level. I was thinking my idea of the second air inlet at ceiling level wouldn't be as effective, but may at least help clear the steam in the air along the ceiling. I suppose I could try putting an air inlet at the bottom of the stud wall rather than in the ceiling, but I'll try the idea of the gap under the door first as this would be the easiest.

 

[Murdochcat]

Thank you that makes sense. Ideally I'd want an air inlet at ground level. I was thinking my idea of the second air inlet at ceiling level wouldn't be as effective, but may at least help clear the steam in the air along the ceiling. I suppose I could try putting an air inlet at the bottom of the stud wall rather than in the ceiling, but I'll try the idea of the gap under the door first as this would be the easiest.

Increasing the gap under the door is the most effective and cheapest solution

Why over complicate matters ?

 

[Odds]

On a cold day will drastically increase condensation .No explanation given by the shop?

Did you read the link?

 

[foxhole]

Did you read the link?

Yes thank you .

 

[Odds]

Yes thank you .

Did you find Victoria's explanation?