In-line extractor via humidistat?

[PJF220]

I have a bathroom with a wall mounted extractor and also an in-line ceiling fan, fed through the loft. They have both failed with faulty components so one or the other, or both need fixing.

We rarely use the lights in the bathroom as during the day, the window gives plenty of light, and in the evening, the light coming through the glass over the door provides ample light. With this in mind, when showering, the fan would never come on as we don't use the light pull switch.

My investigation to fix one or both has led me to believe the in-line fan has far better flow to clear humidity than the wall mounted one. However, the in-line ones don't come with a humidistat option.

Is it a feasable option, and within regs, to power the in-line through a remote humidistat to trigger when the steam builds up the humidity, or is there a good reason in-line one's don't have this feature?

 

[RandomGrinch]

Hi,

You are right, the in-line fans are usually far more effective at ventilation, than a small wall mounted unit; especially if the vent for the in-line fan has been fitted to the ceiling in a suitable location.
For the most efficient clearing of the room, also ensure that there is an adequate source of make-up air.

There are specific humidity sensors and timers that are designed for use with in-line fans, such as:
https://www.screwfix.com/p/manrose-1361-remote-bathroom-fan-humidity-control-with-timer/44376

They are pricey though! And there have been previous comments on this forum, suggesting that by the time a humidistat is triggered, it might already be too late! (although I may disagree!)

The simplest method of controlling the fan, is just a switch; allowing you to select a ventilation boost, only when you need it.

I hope that helps

 

[Harry Bloomfield]

Opinions vary on how effective humidity switches work, much more certain to trigger are PIR's which detect the presence of a moving body in a bathroom. Our bathroom extract is fitted with both and both systems work well. Like you we have plenty of light through a window and only need the light on after dark. If you walk in the bathroom, the fan runs and continues to run for 20 minutes. If the bathroom is still moist after a bath or shower, the fan continues to run until the moisture level is reduced.

In-line systems lack any PIR or humidity stat, because wall fans can have these can be included in the unit build.

 

[Harry Bloomfield]

They are pricey though! And there have been previous comments on this forum, suggesting that by the time a humidistat is triggered, it might already be too late! (although I may disagree!)

I think why some fail to work, is because the moist air is not drawn to the stat. If the fan is triggered by PIR and the stat is mounted in the air flow, or better in the duct of an inline unit, they will be better able to sense the moisture level.

 

[foxhole]

I fitted a ceiling pir sensor to my fan, ideal if fan runs at every use .

 

[Deleted member 292770]

some clever wiring could enable you to use a wall/ceiling fan with built in humidistat that will switch your in line extractor.