MVHR & Humidity sensing

[vfrdave]

I am not fitting boost switches for my mvhr as the wife and kids will simply not use them and was going to depend solely on the humidity sensor within the unit.  On speaking with BPC they inferred that for longer runs ie over 2m not to rely on the in-built sensor as ideally you would want boost before that.  Bathroom will be fine as it is more or less below the manifolds, en-suites are further away and I was thinking of using the room sensors but not sure if this is ideal as it will boost unnecessarily, I know others have done this.

 

The only other option I can think of is to use humidity sensors remote from the unit/manifold possibly mounted in the ceiling plenum in some way.  Would the dhc-100 that @JSHarris used be suitable for this, though the sensor looks quite big?  There is a round bit on the top of the plenum looks like it could be drilled out to take a small sensor fixed in place.

 

 

[Declan52]

For about the first month I had it drilled into the kids that before they showered to go into the utility room and hit the boost button. I reckon they done it maybe twice and then just gave up. Am in my house 3 1/2 years now and  while it's not as fast as a normal extractor fan it will still clear the room of any steam within 5 mins.

[jack]

I don't bother with boosting. Even in the coldest depths of winter with sequential hot showers, all trace of condensation is gone within an hour or so. And that's with the boost set at less than half that suggested by building regs.

[Roundtuit]

I'm hoping the in-built humidity sensor will do its job ok, but I've fitted manual boost switches.  Not sure what sort sensor I would have needed to clear the air the morning after curry night. Maybe something canary-based?

[le-cerveau]

8 hours ago, Roundtuit said:

Not sure what sort sensor I would have needed to clear the air the morning after curry night.

 

You need to connect the cistern to the extract for that.  I did it based on @JSHarris and others designs!

[SteamyTea]

https://playground.arduino.cc/Main/MQGasSensors

But you could just do it on noise.

Or sense the 'strength of grip' on the staining bars.

[vfrdave]

On 01/06/2018 at 16:28, Declan52 said:

while it's not as fast as a normal extractor fan it will still clear the room of any steam within 5 mins.

I was hoping it would be faster than a normal extract. Still think I would like some way of auto sensing humidity before it travels all the way to the built in sensor.

[PeterW]

Don’t forget you have built in ducts all the way to the rooms .... easy to thread a length of Cat5 with a DHT or similar on the end of it  from the terminal all the way back to the manifold and just terminate there in a Sonoff or a PIC based switch and you can decide the humidity setting you want to trigger at.