humidistat fan

[ban-all-sheds]

I doubt very much that anything similar could work simply by being clipped to the outside of a copper pipe.

A temperature sensor on a hot pipe will.

 

[echoes]

A temperature sensor on a hot pipe will.

That's quite a good idea. Would require electronics though.
Edit... Thinks.. Or just a simple bimetallic stat?

 

[ban-all-sheds]

No, it's just a switch which could trigger a fan.

 

[echoes]

@ban-all-sheds do you have a part in mind? I'm assuming fan is expecting a 240 V trigger, and imagining a thermocouple or thermistor stuck to the pipe. Unless it's a solved problem...

 

[JohnW2]

A temperature sensor on a hot pipe will.

True, it could do the job - but I wouldn't personally count a temperature sensor as "anything similar" to a flow sensor!

TTC had suggested that simple 'clip on' flow sensors for copper pipes existed, and I was saying that I found it hard to see how they could.

Kind Regards, John

 

[JohnW2]

Edit... Thinks.. Or just a simple bimetallic stat?

A pipe or cylinder stat could probably do it - IF you could find one which had contacts which closed with rising temperature (as well as the 'normal' one which opened with rising temp).

Kind Regards, John

 

[echoes]

A pipe or cylinder stat could probably do it - IF you could find one which had contacts which closed with rising temperature (as well as the 'normal' one which opened with rising temp).

Kind Regards, John

They are normally SPDT.

 

[JohnW2]

They are normally SPDT.

That's fine, then.

Kind Regards, John

 

[echoes]

TTC had suggested that simple 'clip on' flow sensors for copper pipes existed, and I was saying that I found it hard to see how they could.

Ultrasonic sensors exist, but for more £££s than the reed switch type.

 

[JohnW2]

Ultrasonic sensors exist, but for more £££s than the reed switch type.

Can they detect (reliably) laminar flow of totally clean water (with no bubbles or cavitation)?

Kind Regards, John

 

[echoes]

Past the limits of my knowledge there! Some only appear to work by using bubbles or filth in the water. Not my idea of a nice shower.

 

[JohnW2]

Past the limits of my knowledge there! Some only appear to work by using bubbles or filth in the water. Not my idea of a nice shower.

Beyond the limits of my knowledge, too, but that's what I was thinking. The ultrasound is not going to work on molecules, so needs something (like muck or bubbles) to look at. It's also got to get through a copper pipe.

Kind Regards, John

 

[ban-all-sheds]

True, it could do the job - but I wouldn't personally count a temperature sensor as "anything similar" to a flow sensor!

Maybe not.

But I personally would when the functional requirement is to detect the flow of water in a pipe in the context (which this is) of triggering a fan when a shower is used. If there is a hot water pipe to a mixer shower then a temperature sensor will detect when hot water starts to flow in the pipe. Seems pretty damn similar from a functional POV to me.

 

[EFLImpudence]

Just do without a fan.

 

[Taylortwocities]

TTC had suggested that simple 'clip on' flow sensors for copper pipes existed, and I was saying that I found it hard to see how they could.

I actually was asking if a clip on type did exist. And asked for advice from others. I actually said:

I believe there are others that just clip on to a pipe. But that’s plumbing and something I try and avoid. Others on here may be able to advise you better on that.