We need a new tumble dryer. The space we have for it is an outside annex, where the boiler is. So it's obviously not heated but the boiler generates a little bit of heat so it's never very very cold either. I would say it doesn't get below maybe 8-10C. Would a heat pump tumble dryer be a really bad idea? Our current condenser one that just broke down also took a lot longer in the winter, maybe up to 3 hours, and it wasn't too much of an issue...