Had a query for a job, and need some ideas .
Bathroom ( ensuite ) with separate shower and bath, basin and WC, customers hate fans so use cross ventilation ( Windows ) when using the shower etc, don't ask. They've opted to go for a demister pad behind the large bespoke mirror and I'm wondering what's most practical to switch it on / off as required.
First thought was off the lights, but with 4 lighting circuits and no guarantee which ones will be used and when, it's time to think a bit harder. Next thought is a thermistor which triggers a timer, located on the 22mm hot pipe as it enters the ensuite. Idea being that it turns on as DHW is drawn to either the bath or shower, not the basin, and stays on for say 30 mins after the pipe cools down. That's my favoured option right now, so question is, can I get a mains switching thermistor, and what would I need for a timer ? eg thermistor via a ( solid state for reliability ) relay triggering the timer / other?
Thoughts plaese .