Enough natural ventilation to create through-draft in cellar?

[foxhole]

Many fans which include a humidity sensor, tend to not work that well, so I would suggest a better option would be an external, decent quality one, which includes an adjustment for humidity level.

If it has an adjustment for humidity level would it not mean it has a humidity sensor or did I misunderstand your comment?

 

[MacLaverty]

Many fans which include a humidity sensor, tend to not work that well, so I would suggest a better option would be an external, decent quality one, which includes an adjustment for humidity level.

Sorry what do you mean by external extractor fan?

 

[MacLaverty]

Also, thanks all for your replies. It's hugely appreciated.

 

[Harry Bloomfield]

If it has an adjustment for humidity level would it not mean it has a humidity sensor or did I misunderstand your comment?

The fans with built-in sensors both tend not to have any adjustment, and the enclosed sensors tend to be tucked away inside the fan anyway, out of the (when the fan is off) the room air. The separate sensors can be mounted in a more representative location in the room, of the true humidity level.

 

[Harry Bloomfield]

Sorry what do you mean by external extractor fan?

Sorry, I simply meant one which extracted air to outside, to the outdoor atmosphere.

 

[MacLaverty]

Thanks again all. Bit of a random one for another room, if I use a dehumidifier in a room with an air brick will it be relatively pointless as I will just be dehumidifing the outside air and losing my dryer air back out the air brick?

 

[foxhole]

Thanks again all. Bit of a random one for another room, if I use a dehumidifier in a room with an air brick will it be relatively pointless as I will just be dehumidifing the outside air and losing my dryer air back out the air brick?

dehumidifing any room with access to outside air is pointless .

 

[Lower]

Thanks again all. Bit of a random one for another room, if I use a dehumidifier in a room with an air brick will it be relatively pointless as I will just be dehumidifing the outside air and losing my dryer air back out the air brick?

You need to think about airflow. If the room is essentially sealed (ie no other ventilation) and air brick will allow very little air movement from inside to outside. The dehumidifier only moves air around inside the room, so doesn't pull in or push any more air out of the room so you are dehumidifying only the very small amount of outside air that the airbrick lets into the room.

 

[Harry Bloomfield]

Thanks again all. Bit of a random one for another room, if I use a dehumidifier in a room with an air brick will it be relatively pointless as I will just be dehumidifing the outside air and losing my dryer air back out the air brick?

A proportion of it, yes. It mostly depends upon how leaky the room is, via other sources to feed the vent.

 

[Harry Bloomfield]

dehumidifing any room with access to outside air is pointless .

All rooms have some access to external air, they are never built airtight.

 

[foxhole]

All rooms have some access to external air, they are never built airtight.

Not directly .

 

[Harry Bloomfield]

Not directly .

Sometimes air drawn in from other rooms, sometimes from under floors.

 

[MacLaverty]

Ok great, the room is in the attic and currently has the window on a latch 24/7 to create a through draft with the air brick but it's still a tad moldy so presume when dehumidifing I need to close the window fully and then just leave the air brick as it is as otherwise the dry air will just get sucked out either the air brick or window with the through draft? Sorry I'm not very good at all this hence all the questions so I fully understand it all.

 

[Harry Bloomfield]

Ok great, the room is in the attic and currently has the window on a latch 24/7 so presume when dehumidifing I need to close the window fully and then just leave the air brick as it is? Sorry I'm not very good at all this

If the dehumidifier is in the same room (or close to it) then yes, it needs to be closed. The idea is the dehumidifier 'sucks' the moisture from the air, condensing and collecting it into a container. The drier air, will help remove moisture from the material and fabrics in the room. If the dried air can be too easily replaced with moist air, then the unit will not be as effective and cost more to run.

I use a dehumidifier and a fan, to dry clothes in our utility room, as a cheaper much alternative to a running the dryer. The rule is, when the system is on, the door is kept closed. With the door closed, and the unit turned off, I would expect lots of condensation to form on cool surfaces, if wet washing were hung in there.

 

[MacLaverty]

So I left the window on a latch for about 2 weeks whilst we were away, dehumidifier was off. Came back to a very wet smelling cellar and mold everywhere. Back to window closed and dehumidifier on but am I best sealing up the air brick as well or just leave that as it is?