Thank you.  1 Kwh has an average price of £0.25 or about £2.25 per year.  That doesn’t seem too much to fork out.

Background to my request is that I have a tenanted flat where the bathroom has been allowed to develop mould. That has been treated with “Mould stop” to little effect.

The bathroom window is left open ajar as confirmed by the letting agent but still the mould has returned. I think the problem is that there is no through draft. There is an extractor fan that comes on when the light is on plus a delay after but that has not solved the problem. I guess the tenant is resistant to leaving the bathroom door open especially in winter!

The suggestion is to install a fan with humidity control and Trickle mode for constant air movement, but I needed to show the tenant that having the fan on Trickle would not significantly be a burden on the electricity bill.

Bob