Pipe thermostat for 2nd extractor

[jacko555]

I've recently had a large shower put in the bathroom.
The existing timed extractor fan comes on with the light and works fine for baths. However, the condensation is too much for it when we have multiple showers.

I read on here about using a pipe thermostat to control an extractor fan. In theory, great idea.

Thought process is a second extractor directly above the shower, controlled with a pipe thermostat on the hot feed.

E.g. https://salus-controls.com/ie/product/ct100/

I think I'd prefer this to uprating the existing fan.

Has anyone actually done this though?
Is it a silly idea?
My main concern is how long does it take a pipe full of warm water to cool? E.g, turn shower off, pipe is still full of hot water, fan stays on for a ridiculous amount of time.

What do you think?

 

[flameport]

Using a pipe thermostat is a valid option, either to switch the extractor on/off, or more useful would be a 2 speed extractor with the pipe thermostat switching it to high speed.

Installing 2 extractors into the same room is not, as the pressure difference between them will result in neither of them working properly.

 

[jacko555]

Hadn't considered the pressure difference.

Can anyone suggest a 2 speed inline extractor? Quick look on screwfix for 2 speed models use a jumper to set the speed at install time, rather than a low/high speed I can control like this

 

[flameport]

This one: https://www.screwfix.com/p/xpelair-ximx100-100mm-axial-inline-extractor-fan-240v/5465H
instructions here: https://product-portal.gdhv.com/sites/default/files/assets/Xpelair_XIMX_instructionmanual.pdf
there are others.