Temperature sensing for presence etc ...

[chris_j_hunter]

kind of an obvious one, but something that came up on UK_Selfbuild led to a thought I'd previously not really latched onto - ie: having a temperature sensor on the hot-water pipe feed to a tap & using it as a trigger for warming the towel-rail ... ie: use this not just for the towel-rail, but also as a presence-indicator !

ditto the feed to the shower & use it either as well as, or as an alternative to, the room humidity sensor for switching the extractor fan - ie: use it for presence, too !

not sure, but wonder if a temperature sensor on a gas pipe would allow Cortex to notice when gas is flowing - if so, several uses might be envisaged, hob-wise & boiler-wise, as well as presence ...

[Gumby]

I've got a QAI in the bathroom just waiting for the time to do just this ... Rapid have some neat clip on thermistors ...

[chris_j_hunter]

aye, look good ...

http://www.rapidonline.com/Electronic-Components/Sensors/Thermal-Sensors/Pipe-clip-temperature-sensors/76422

just need to find a connector to go with them !

[Viv]

Some installations have the hotwater feed to bathrooms on a circular loop and have a pump in circuit.

Cortex detecting presence starts the pump and ensures hotwater is available immediatly at the tap. The tap hot water feed also goes through the towel rail ensuring a visit to the bathroom will dry the towel also.

Viv

[chris_j_hunter]

aye, we're doing secondary circulation ... and having it switched-on by presence would be the ideal way-'round ...

running the secondary circulation through the towel rail sounds a good idea - 'though maybe only so long as the secondary circulation can be very carefully controlled ... hmmm, must think about it !

OTOH, while it'd work well for bathrooms etc, in some locations effective presence detection might need some extra help - eg: our open-plan parlour (kitchen/dining/morning-room) will have a separate sink in a corner, so people can wash their hands without getting in cook's way ... meaning people being around would not be enough to decide when to run the secondary circulation / heat the towel-rail, etc - former of which could be quite tricky, second of which maybe could be eased by using a temperature sensor on the DHW feed to the tap ... (?)

BTW, a thermistor on a pipe might be a metre or two, even ten, away from a QAI - so the cable between the two might need to be carefully arranged - not sure how, at the moment - need to do some homework !

'wonder if a digital sensor might be good / better - eg: over on UK_Selfbuild, this sort of thing has been used for sensors that have to be more remote than is ideal :

http://www.mmselectronics.co.uk/smt160-30.htm

seems complicated, and not at all sure how it would be linked into Cortex ...